cmd/5l etc: restore comments lost during C -> Go conversion
It appears that c2go dropped comments inside struct { ... } and enum { ... }.
Restore them.
Identified missing comments by checking for comments present
in the C code but not the Go code, made a list, and then reapplied
with some mechanical help.
Missing comment finder: http://play.golang.org/p/g6qNUAo1Y0
Change-Id: I323ab45c7ef9d51e28eab3b699eb14bee1eef66b
Reviewed-on: https://go-review.googlesource.com/6899
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/5l/asm.go b/src/cmd/5l/asm.go
index 3f9b7ad..525764e 100644
--- a/src/cmd/5l/asm.go
+++ b/src/cmd/5l/asm.go
@@ -619,7 +619,7 @@
fmt.Fprintf(&ld.Bso, "%5.2f dwarf\n", obj.Cputime())
}
- if ld.Debug['w'] == 0 {
+ if ld.Debug['w'] == 0 { // TODO(minux): enable DWARF Support
dwarfoff := uint32(ld.Rnd(int64(uint64(ld.HEADR)+ld.Segtext.Length), int64(ld.INITRND)) + ld.Rnd(int64(ld.Segdata.Filelen), int64(ld.INITRND)))
ld.Cseek(int64(dwarfoff))
diff --git a/src/cmd/5l/l.go b/src/cmd/5l/l.go
index 9eb078d..a521545 100644
--- a/src/cmd/5l/l.go
+++ b/src/cmd/5l/l.go
@@ -67,8 +67,8 @@
PtrSize = 4
IntSize = 4
RegSize = 4
- MaxAlign = 8
- FuncAlign = 4
+ MaxAlign = 8 // max data alignment
+ FuncAlign = 4 // single-instruction alignment
MINLC = 4
)
diff --git a/src/cmd/6l/asm.go b/src/cmd/6l/asm.go
index 828aafc..3617a95 100644
--- a/src/cmd/6l/asm.go
+++ b/src/cmd/6l/asm.go
@@ -134,11 +134,11 @@
r.Type = ld.R_ADDR
return
- // TODO: What is the difference between all these?
// Handle relocations found in Mach-O object files.
case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0:
+ // TODO: What is the difference between all these?
r.Type = ld.R_ADDR
if targ.Type == ld.SDYNIMPORT {
diff --git a/src/cmd/6l/l.go b/src/cmd/6l/l.go
index f698679..6b42088 100644
--- a/src/cmd/6l/l.go
+++ b/src/cmd/6l/l.go
@@ -1,37 +1,3 @@
-// Inferno utils/6l/asm.c
-// http://code.google.com/p/inferno-os/source/browse/utils/6l/asm.c
-//
-// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
-// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-// Portions Copyright © 1997-1999 Vita Nuova Limited
-// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-// Portions Copyright © 2004,2006 Bruce Ellis
-// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-// Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package main
-
-// Writing object files.
-
// Inferno utils/6l/l.h
// http://code.google.com/p/inferno-os/source/browse/utils/6l/l.h
//
@@ -62,9 +28,11 @@
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
+package main
+
const (
thechar = '6'
- MaxAlign = 32
+ MaxAlign = 32 // max data alignment
FuncAlign = 16
)
diff --git a/src/cmd/8g/reg.go b/src/cmd/8g/reg.go
index 4749855..9f2cb60 100644
--- a/src/cmd/8g/reg.go
+++ b/src/cmd/8g/reg.go
@@ -34,7 +34,7 @@
import "cmd/internal/gc"
const (
- NREGVAR = 16
+ NREGVAR = 16 /* 8 integer + 8 floating */
)
var regname = []string{
diff --git a/src/cmd/8l/l.go b/src/cmd/8l/l.go
index fbeee98..6005085 100644
--- a/src/cmd/8l/l.go
+++ b/src/cmd/8l/l.go
@@ -1,37 +1,3 @@
-// Inferno utils/8l/asm.c
-// http://code.google.com/p/inferno-os/source/browse/utils/8l/asm.c
-//
-// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
-// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-// Portions Copyright © 1997-1999 Vita Nuova Limited
-// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-// Portions Copyright © 2004,2006 Bruce Ellis
-// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-// Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package main
-
-// Writing object files.
-
// Inferno utils/8l/l.h
// http://code.google.com/p/inferno-os/source/browse/utils/8l/l.h
//
@@ -62,12 +28,14 @@
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
+package main
+
const (
thechar = '8'
PtrSize = 4
IntSize = 4
RegSize = 4
- MaxAlign = 32
+ MaxAlign = 32 // max data alignment
FuncAlign = 16
MINLC = 1
)
diff --git a/src/cmd/9g/opt.go b/src/cmd/9g/opt.go
index a029420..4a134f1 100644
--- a/src/cmd/9g/opt.go
+++ b/src/cmd/9g/opt.go
@@ -1,42 +1,12 @@
-// Derived from Inferno utils/6c/peep.c
-// http://code.google.com/p/inferno-os/source/browse/utils/6c/peep.c
-//
-// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
-// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-// Portions Copyright © 1997-1999 Vita Nuova Limited
-// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-// Portions Copyright © 2004,2006 Bruce Ellis
-// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-// Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package main
-
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+package main
+
// Many Power ISA arithmetic and logical instructions come in four
// standard variants. These bits let us map between variants.
const (
- V_CC = 1 << 0
- V_V = 1 << 1
+ V_CC = 1 << 0 // xCC (affect CR field 0 flags)
+ V_V = 1 << 1 // xV (affect SO and OV flags)
)
diff --git a/src/cmd/9g/reg.go b/src/cmd/9g/reg.go
index b1b681a..fb0c2e3 100644
--- a/src/cmd/9g/reg.go
+++ b/src/cmd/9g/reg.go
@@ -34,7 +34,7 @@
import "cmd/internal/gc"
const (
- NREGVAR = 64
+ NREGVAR = 64 /* 32 general + 32 floating */
)
var regname = []string{
diff --git a/src/cmd/9l/l.go b/src/cmd/9l/l.go
index 7ddac3f..e7dc102 100644
--- a/src/cmd/9l/l.go
+++ b/src/cmd/9l/l.go
@@ -66,7 +66,7 @@
PtrSize = 8
IntSize = 8
RegSize = 8
- MaxAlign = 32
+ MaxAlign = 32 // max data alignment
FuncAlign = 8
MINLC = 4
)
diff --git a/src/cmd/internal/gc/esc.go b/src/cmd/internal/gc/esc.go
index 169dec6..8b5430b 100644
--- a/src/cmd/internal/gc/esc.go
+++ b/src/cmd/internal/gc/esc.go
@@ -206,15 +206,27 @@
)
type EscState struct {
- theSink Node
+ // Fake node that all
+ // - return values and output variables
+ // - parameters on imported functions not marked 'safe'
+ // - assignments to global variables
+ // flow to.
+ theSink Node
+
+ // If an analyzed function is recorded to return
+ // pieces obtained via indirection from a parameter,
+ // and later there is a call f(x) to that function,
+ // we create a link funcParam <- x to record that fact.
+ // The funcParam node is handled specially in escflood.
funcParam Node
- dsts *NodeList
- loopdepth int
- pdepth int
- dstcount int
- edgecount int
- noesc *NodeList
- recursive bool
+
+ dsts *NodeList // all dst nodes
+ loopdepth int // for detecting nested loop scopes
+ pdepth int // for debug printing in recursions.
+ dstcount int // diagnostic
+ edgecount int // diagnostic
+ noesc *NodeList // list of possible non-escaping nodes, for printing
+ recursive bool // recursive function or group of mutually recursive functions.
}
var tags [16]*string
@@ -530,7 +542,10 @@
// However, without this special case b will escape, because we assign to OIND/ODOTPTR.
case OAS,
OASOP:
- if (n.Left.Op == OIND || n.Left.Op == ODOTPTR) && n.Left.Left.Op == ONAME && (n.Right.Op == OSLICE || n.Right.Op == OSLICE3 || n.Right.Op == OSLICESTR) && (n.Right.Left.Op == OIND || n.Right.Left.Op == ODOTPTR) && n.Right.Left.Left.Op == ONAME && n.Left.Left == n.Right.Left.Left { // dst is ONAME dereference // src is slice operation // slice is applied to ONAME dereference // dst and src reference the same base ONAME
+ if (n.Left.Op == OIND || n.Left.Op == ODOTPTR) && n.Left.Left.Op == ONAME && // dst is ONAME dereference
+ (n.Right.Op == OSLICE || n.Right.Op == OSLICE3 || n.Right.Op == OSLICESTR) && // src is slice operation
+ (n.Right.Left.Op == OIND || n.Right.Left.Op == ODOTPTR) && n.Right.Left.Left.Op == ONAME && // slice is applied to ONAME dereference
+ n.Left.Left == n.Right.Left.Left { // dst and src reference the same base ONAME
// Here we also assume that the statement will not contain calls,
// that is, that order will move any calls to init.
@@ -578,13 +593,12 @@
if e.loopdepth == 1 { // top level
break
}
+ // arguments leak out of scope
+ // TODO: leak to a dummy node instead
fallthrough
- // go f(x) - f and x escape
- // arguments leak out of scope
- // TODO: leak to a dummy node instead
- // fallthrough
case OPROC:
+ // go f(x) - f and x escape
escassign(e, &e.theSink, n.Left.Left)
escassign(e, &e.theSink, n.Left.Right) // ODDDARG for call
@@ -899,14 +913,15 @@
OSLICEARR,
OSLICE3ARR,
OSLICESTR:
+ // Conversions, field access, slice all preserve the input value.
escassign(e, dst, src.Left)
- // Append returns first argument.
case OAPPEND:
+ // Append returns first argument.
escassign(e, dst, src.List.N)
- // Index of array preserves input value.
case OINDEX:
+ // Index of array preserves input value.
if Isfixedarray(src.Left.Type) {
escassign(e, dst, src.Left)
}
diff --git a/src/cmd/internal/gc/go.go b/src/cmd/internal/gc/go.go
index 95c3c7c..f05ba27 100644
--- a/src/cmd/internal/gc/go.go
+++ b/src/cmd/internal/gc/go.go
@@ -32,6 +32,8 @@
)
const (
+ // These values are known by runtime.
+ // The MEMx and NOEQx values must run in parallel. See algtype.
AMEM = iota
AMEM0
AMEM8
@@ -58,9 +60,9 @@
)
const (
- Mpscale = 29
- Mpprec = 16
- Mpnorm = Mpprec - 1
+ Mpscale = 29 // safely smaller than bits in a long
+ Mpprec = 16 // Mpscale*Mpprec is max number of bits
+ Mpnorm = Mpprec - 1 // significant words in a normalized float
Mpbase = 1 << Mpscale
Mpsign = Mpbase >> 1
Mpmask = Mpbase - 1
@@ -86,42 +88,44 @@
type Val struct {
Ctype int16
U struct {
- Reg int16
- Bval int16
- Xval *Mpint
- Fval *Mpflt
- Cval *Mpcplx
- Sval string
+ Reg int16 // OREGISTER
+ Bval int16 // bool value CTBOOL
+ Xval *Mpint // int CTINT, rune CTRUNE
+ Fval *Mpflt // float CTFLT
+ Cval *Mpcplx // float CTCPLX
+ Sval string // string CTSTR
}
}
type Pkg struct {
- Name string
- Path string
+ Name string // package name
+ Path string // string literal used in import statement
Pathsym *Sym
- Prefix string
- Imported uint8
- Exported int8
- Direct int8
- Safe bool
+ Prefix string // escaped path for use in symbol table
+ Imported uint8 // export data of this package was parsed
+ Exported int8 // import line written in export data
+ Direct int8 // imported directly
+ Safe bool // whether the package is marked as safe
Syms map[string]*Sym
}
type Sym struct {
- Lexical uint16
- Flags uint8
- Sym uint8
- Link *Sym
- Uniqgen uint32
- Importdef *Pkg
- Linkname string
+ Lexical uint16
+ Flags uint8
+ Sym uint8 // huffman encoding in object file
+ Link *Sym
+ Uniqgen uint32
+ Importdef *Pkg // where imported definition was found
+ Linkname string // link name
+
+ // saved and restored by dcopy
Pkg *Pkg
- Name string
- Def *Node
- Label *Label
- Block int32
- Lastlineno int32
- Origpkg *Pkg
+ Name string // variable name
+ Def *Node // definition: ONAME OTYPE OPACK or OLITERAL
+ Label *Label // corresponding label (ephemeral)
+ Block int32 // blocknumber to catch redeclaration
+ Lastlineno int32 // last declaration for diagnostic
+ Origpkg *Pkg // original package for . import
Lsym *obj.LSym
}
@@ -130,63 +134,83 @@
Nointerface bool
Noalg uint8
Chan uint8
- Trecur uint8
+ Trecur uint8 // to detect loops
Printed uint8
- Embedded uint8
+ Embedded uint8 // TFIELD embedded type
Siggen uint8
- Funarg uint8
+ Funarg uint8 // on TSTRUCT and TFIELD
Copyany uint8
- Local uint8
+ Local uint8 // created in this file
Deferwidth uint8
- Broke uint8
- Isddd uint8
+ Broke uint8 // broken type definition.
+ Isddd uint8 // TFIELD is ... argument
Align uint8
- Haspointers uint8
- Nod *Node
- Orig *Type
- Lineno int
- Thistuple int
- Outtuple int
- Intuple int
- Outnamed uint8
- Method *Type
- Xmethod *Type
- Sym *Sym
- Vargen int32
- Nname *Node
- Argwid int64
- Type *Type
- Width int64
- Down *Type
- Outer *Type
- Note *string
- Bound int64
- Bucket *Type
- Hmap *Type
- Hiter *Type
- Map *Type
- Maplineno int32
- Embedlineno int32
- Copyto *NodeList
- Lastfn *Node
+ Haspointers uint8 // 0 unknown, 1 no, 2 yes
+
+ Nod *Node // canonical OTYPE node
+ Orig *Type // original type (type literal or predefined type)
+ Lineno int
+
+ // TFUNC
+ Thistuple int
+ Outtuple int
+ Intuple int
+ Outnamed uint8
+
+ Method *Type
+ Xmethod *Type
+
+ Sym *Sym
+ Vargen int32 // unique name for OTYPE/ONAME
+
+ Nname *Node
+ Argwid int64
+
+ // most nodes
+ Type *Type // actual type for TFIELD, element type for TARRAY, TCHAN, TMAP, TPTRxx
+ Width int64 // offset in TFIELD, width in all others
+
+ // TFIELD
+ Down *Type // next struct field, also key type in TMAP
+ Outer *Type // outer struct
+ Note *string // literal string annotation
+
+ // TARRAY
+ Bound int64 // negative is dynamic array
+
+ // TMAP
+ Bucket *Type // internal type representing a hash bucket
+ Hmap *Type // internal type representing a Hmap (map header object)
+ Hiter *Type // internal type representing hash iterator state
+ Map *Type // link from the above 3 internal types back to the map type.
+
+ Maplineno int32 // first use of TFORW as map key
+ Embedlineno int32 // first use of TFORW as embedded type
+
+ // for TFORW, where to copy the eventual value to
+ Copyto *NodeList
+
+ Lastfn *Node // for usefield
}
type Label struct {
- Used uint8
- Sym *Sym
- Def *Node
- Use *NodeList
- Link *Label
- Gotopc *obj.Prog
- Labelpc *obj.Prog
- Breakpc *obj.Prog
- Continpc *obj.Prog
+ Used uint8
+ Sym *Sym
+ Def *Node
+ Use *NodeList
+ Link *Label
+
+ // for use during gen
+ Gotopc *obj.Prog // pointer to unresolved gotos
+ Labelpc *obj.Prog // pointer to code
+ Breakpc *obj.Prog // pointer to code
+ Continpc *obj.Prog // pointer to code
}
type InitEntry struct {
- Xoffset int64
- Key *Node
- Expr *Node
+ Xoffset int64 // struct, array only
+ Key *Node // map only
+ Expr *Node // bytes of run-time computed expressions
}
type InitPlan struct {
@@ -205,14 +229,14 @@
EscNever
EscBits = 3
EscMask = (1 << EscBits) - 1
- EscContentEscapes = 1 << EscBits
+ EscContentEscapes = 1 << EscBits // value obtained by indirect of parameter escapes to some returned result
EscReturnBits = EscBits + 1
)
const (
- SymExport = 1 << 0
+ SymExport = 1 << 0 // to be exported
SymPackage = 1 << 1
- SymExported = 1 << 2
+ SymExported = 1 << 2 // already written out by export
SymUniq = 1 << 3
SymSiggen = 1 << 4
SymAsm = 1 << 5
@@ -231,6 +255,7 @@
const (
Txxx = iota
+
TINT8
TUINT8
TINT16
@@ -242,13 +267,18 @@
TINT
TUINT
TUINTPTR
+
TCOMPLEX64
TCOMPLEX128
+
TFLOAT32
TFLOAT64
+
TBOOL
+
TPTR32
TPTR64
+
TFUNC
TARRAY
T_old_DARRAY
@@ -261,17 +291,23 @@
TANY
TSTRING
TUNSAFEPTR
+
+ // pseudo-types for literals
TIDEAL
TNIL
TBLANK
+
+ // pseudo-type for frame layout
TFUNCARGS
TCHANARGS
TINTERMETH
+
NTYPE
)
const (
CTxxx = iota
+
CTINT
CTRUNE
CTFLT
@@ -282,6 +318,8 @@
)
const (
+ /* types of channel */
+ /* must match ../../pkg/nreflect/type.go:/Chandir */
Cxxx = 0
Crecv = 1 << 0
Csend = 1 << 1
@@ -290,29 +328,31 @@
// declaration context
const (
- Pxxx = iota
- PEXTERN
- PAUTO
- PPARAM
- PPARAMOUT
- PPARAMREF
- PFUNC
- PDISCARD
- PHEAP = 1 << 7
+ Pxxx = iota
+ PEXTERN // global variable
+ PAUTO // local variables
+ PPARAM // input arguments
+ PPARAMOUT // output results
+ PPARAMREF // closure variable reference
+ PFUNC // global function
+
+ PDISCARD // discard during parse of duplicate import
+
+ PHEAP = 1 << 7 // an extra bit to identify an escaped variable
)
const (
- Etop = 1 << 1
- Erv = 1 << 2
+ Etop = 1 << 1 // evaluated at statement level
+ Erv = 1 << 2 // evaluated in value context
Etype = 1 << 3
- Ecall = 1 << 4
- Efnstruct = 1 << 5
- Eiota = 1 << 6
- Easgn = 1 << 7
- Eindir = 1 << 8
- Eaddr = 1 << 9
- Eproc = 1 << 10
- Ecomplit = 1 << 11
+ Ecall = 1 << 4 // call-only expressions are ok
+ Efnstruct = 1 << 5 // multivalue function returns are ok
+ Eiota = 1 << 6 // iota is ok
+ Easgn = 1 << 7 // assigning to expression
+ Eindir = 1 << 8 // indirecting through expression
+ Eaddr = 1 << 9 // taking address of expression
+ Eproc = 1 << 10 // inside a go statement
+ Ecomplit = 1 << 11 // type in composite literal
)
const (
@@ -364,8 +404,8 @@
eofnl int
last int
peekc int
- peekc1 int
- cp string
+ peekc1 int // second peekc for ...
+ cp string // used for content when bin==nil
importsafe bool
}
@@ -383,14 +423,18 @@
* smagic and umagic
*/
type Magic struct {
- W int
- S int
- Bad int
- Sd int64
- Sm int64
- Ud uint64
- Um uint64
- Ua int
+ W int // input for both - width
+ S int // output for both - shift
+ Bad int // output for both - unexpected failure
+
+ // magic multiplier for signed literal divisors
+ Sd int64 // input - literal divisor
+ Sm int64 // output - multiplier
+
+ // magic multiplier for unsigned literal divisors
+ Ud uint64 // input - literal divisor
+ Um uint64 // output - multiplier
+ Ua int // output - adder
}
/*
@@ -670,67 +714,94 @@
var zerosize int64
type Flow struct {
- Prog *obj.Prog
- P1 *Flow
- P2 *Flow
+ Prog *obj.Prog // actual instruction
+ P1 *Flow // predecessors of this instruction: p1,
+ P2 *Flow // and then p2 linked though p2link.
P2link *Flow
- S1 *Flow
+ S1 *Flow // successors of this instruction (at most two: s1 and s2).
S2 *Flow
- Link *Flow
- Active int32
- Id int32
- Rpo int32
- Loop uint16
- Refset uint8
- Data interface{}
+ Link *Flow // next instruction in function code
+
+ Active int32 // usable by client
+
+ Id int32 // sequence number in flow graph
+ Rpo int32 // reverse post ordering
+ Loop uint16 // x5 for every loop
+ Refset uint8 // diagnostic generated
+
+ Data interface{} // for use by client
}
type Graph struct {
Start *Flow
Num int
- Rpo []*Flow
+
+ // After calling flowrpo, rpo lists the flow nodes in reverse postorder,
+ // and each non-dead Flow node f has g->rpo[f->rpo] == f.
+ Rpo []*Flow
}
/*
* interface to back end
*/
type ProgInfo struct {
- Flags uint32
- Reguse uint64
- Regset uint64
- Regindex uint64
+ Flags uint32 // the bits below
+ Reguse uint64 // registers implicitly used by this instruction
+ Regset uint64 // registers implicitly set by this instruction
+ Regindex uint64 // registers used by addressing mode
}
const (
- Pseudo = 1 << 1
- OK = 1 << 2
- SizeB = 1 << 3
- SizeW = 1 << 4
- SizeL = 1 << 5
- SizeQ = 1 << 6
- SizeF = 1 << 7
- SizeD = 1 << 8
- LeftAddr = 1 << 9
- LeftRead = 1 << 10
- LeftWrite = 1 << 11
+ // Pseudo-op, like TEXT, GLOBL, TYPE, PCDATA, FUNCDATA.
+ Pseudo = 1 << 1
+
+ // There's nothing to say about the instruction,
+ // but it's still okay to see.
+ OK = 1 << 2
+
+ // Size of right-side write, or right-side read if no write.
+ SizeB = 1 << 3
+ SizeW = 1 << 4
+ SizeL = 1 << 5
+ SizeQ = 1 << 6
+ SizeF = 1 << 7
+ SizeD = 1 << 8
+
+ // Left side (Prog.from): address taken, read, write.
+ LeftAddr = 1 << 9
+ LeftRead = 1 << 10
+ LeftWrite = 1 << 11
+
+ // Register in middle (Prog.reg); only ever read. (arm, ppc64)
RegRead = 1 << 12
CanRegRead = 1 << 13
+
+ // Right side (Prog.to): address taken, read, write.
RightAddr = 1 << 14
RightRead = 1 << 15
RightWrite = 1 << 16
- Move = 1 << 17
- Conv = 1 << 18
- Cjmp = 1 << 19
- Break = 1 << 20
- Call = 1 << 21
- Jump = 1 << 22
- Skip = 1 << 23
- SetCarry = 1 << 24
- UseCarry = 1 << 25
- KillCarry = 1 << 26
- ShiftCX = 1 << 27
- ImulAXDX = 1 << 28
- PostInc = 1 << 29
+
+ // Instruction kinds
+ Move = 1 << 17 // straight move
+ Conv = 1 << 18 // size conversion
+ Cjmp = 1 << 19 // conditional jump
+ Break = 1 << 20 // breaks control flow (no fallthrough)
+ Call = 1 << 21 // function call
+ Jump = 1 << 22 // jump
+ Skip = 1 << 23 // data instruction
+
+ // Set, use, or kill of carry bit.
+ // Kill means we never look at the carry bit after this kind of instruction.
+ SetCarry = 1 << 24
+ UseCarry = 1 << 25
+ KillCarry = 1 << 26
+
+ // Special cases for register use. (amd64, 386)
+ ShiftCX = 1 << 27 // possible shift by CX
+ ImulAXDX = 1 << 28 // possible multiply into DX:AX
+
+ // Instruction updates whichever of from/to is type D_OREG. (ppc64)
+ PostInc = 1 << 29
)
type Arch struct {
diff --git a/src/cmd/internal/gc/gsubr.go b/src/cmd/internal/gc/gsubr.go
index 48a24a6..cee5099 100644
--- a/src/cmd/internal/gc/gsubr.go
+++ b/src/cmd/internal/gc/gsubr.go
@@ -167,6 +167,7 @@
Clearp(Pc)
}
+// Fixup instructions after allocauto (formerly compactframe) has moved all autos around.
func fixautoused(p *obj.Prog) {
for lp := &p; ; {
p = *lp
@@ -258,6 +259,7 @@
return false
}
+// Sweep the prog list to mark any used nodes.
func markautoused(p *obj.Prog) {
for ; p != nil; p = p.Link {
if p.As == obj.ATYPE || p.As == obj.AVARDEF || p.As == obj.AVARKILL {
diff --git a/src/cmd/internal/gc/order.go b/src/cmd/internal/gc/order.go
index 3f16d75..f7e9d4b 100644
--- a/src/cmd/internal/gc/order.go
+++ b/src/cmd/internal/gc/order.go
@@ -41,9 +41,9 @@
// Order holds state during the ordering process.
type Order struct {
- out *NodeList
- temp *NodeList
- free *NodeList
+ out *NodeList // list of generated statements
+ temp *NodeList // head of stack of temporary variables
+ free *NodeList // free list of NodeList* structs (for use in temp)
}
// Order rewrites fn->nbody to apply the ordering constraints
diff --git a/src/cmd/internal/gc/plive.go b/src/cmd/internal/gc/plive.go
index 100b82b..97e870b 100644
--- a/src/cmd/internal/gc/plive.go
+++ b/src/cmd/internal/gc/plive.go
@@ -2,6 +2,17 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// Garbage collector liveness bitmap generation.
+
+// The command line flag -live causes this code to print debug information.
+// The levels are:
+//
+// -live (aka -live=1): print liveness lists as code warnings at safe points
+// -live=2: print an assembly listing with liveness annotations
+// -live=3: print information during each computation phase (much chattier)
+//
+// Each level includes the earlier output as well.
+
package gc
import (
@@ -34,28 +45,49 @@
// ...
// }
type BasicBlock struct {
- pred []*BasicBlock
- succ []*BasicBlock
- first *obj.Prog
- last *obj.Prog
- rpo int
- mark int
- lastbitmapindex int
- uevar Bvec
- varkill Bvec
- livein Bvec
- liveout Bvec
- avarinit Bvec
- avarinitany Bvec
- avarinitall Bvec
+ pred []*BasicBlock // predecessors; if none, probably start of CFG
+ succ []*BasicBlock // successors; if none, probably ends in return statement
+ first *obj.Prog // first instruction in block
+ last *obj.Prog // last instruction in block
+ rpo int // reverse post-order number (also index in cfg)
+ mark int // mark bit for traversals
+ lastbitmapindex int // for livenessepilogue
+
+ // Summary sets of block effects.
+
+ // Computed during livenessprologue using only the content of
+ // individual blocks:
+ //
+ // uevar: upward exposed variables (used before set in block)
+ // varkill: killed variables (set in block)
+ // avarinit: addrtaken variables set or used (proof of initialization)
+ uevar Bvec
+ varkill Bvec
+ avarinit Bvec
+
+ // Computed during livenesssolve using control flow information:
+ //
+ // livein: variables live at block entry
+ // liveout: variables live at block exit
+ // avarinitany: addrtaken variables possibly initialized at block exit
+ // (initialized in block or at exit from any predecessor block)
+ // avarinitall: addrtaken variables certainly initialized at block exit
+ // (initialized in block or at exit from all predecessor blocks)
+ livein Bvec
+ liveout Bvec
+ avarinitany Bvec
+ avarinitall Bvec
}
// A collection of global state used by liveness analysis.
type Liveness struct {
- fn *Node
- ptxt *obj.Prog
- vars []*Node
- cfg []*BasicBlock
+ fn *Node
+ ptxt *obj.Prog
+ vars []*Node
+ cfg []*BasicBlock
+
+ // An array with a bit vector for each safe point tracking live pointers
+ // in the arguments and locals area, indexed by bb.rpo.
argslivepointers []Bvec
livepointers []Bvec
}
diff --git a/src/cmd/internal/gc/popt.go b/src/cmd/internal/gc/popt.go
index c56dc8e..813f24a 100644
--- a/src/cmd/internal/gc/popt.go
+++ b/src/cmd/internal/gc/popt.go
@@ -79,16 +79,25 @@
)
type Reg struct {
- set Bits
- use1 Bits
- use2 Bits
+ set Bits // regopt variables written by this instruction.
+ use1 Bits // regopt variables read by prog->from.
+ use2 Bits // regopt variables read by prog->to.
+
+ // refahead/refbehind are the regopt variables whose current
+ // value may be used in the following/preceding instructions
+ // up to a CALL (or the value is clobbered).
refbehind Bits
refahead Bits
+
+ // calahead/calbehind are similar, but for variables in
+ // instructions that are reachable after hitting at least one
+ // CALL.
calbehind Bits
calahead Bits
- regdiff Bits
- act Bits
- regu uint64
+
+ regdiff Bits
+ act Bits
+ regu uint64 // register used bitmap
}
type Rgn struct {
@@ -639,14 +648,14 @@
type TempVar struct {
node *Node
- def *Flow
- use *Flow
- freelink *TempVar
- merge *TempVar
- start int64
- end int64
- addr uint8
- removed uint8
+ def *Flow // definition of temp var
+ use *Flow // use list, chained through Flow.data
+ freelink *TempVar // next free temp in Type.opt list
+ merge *TempVar // merge var with this one
+ start int64 // smallest Prog.pc in live range
+ end int64 // largest Prog.pc in live range
+ addr uint8 // address taken - no accurate end
+ removed uint8 // removed from program
}
type startcmp []*TempVar
diff --git a/src/cmd/internal/gc/range.go b/src/cmd/internal/gc/range.go
index 3de70ba..8dbb002 100644
--- a/src/cmd/internal/gc/range.go
+++ b/src/cmd/internal/gc/range.go
@@ -135,6 +135,13 @@
}
func walkrange(n *Node) {
+ // variable name conventions:
+ // ohv1, hv1, hv2: hidden (old) val 1, 2
+ // ha, hit: hidden aggregate, iterator
+ // hn, hp: hidden len, pointer
+ // hb: hidden bool
+ // a, v1, v2: not hidden aggregate, val 1, 2
+
t := n.Type
a := n.Right
diff --git a/src/cmd/internal/gc/syntax.go b/src/cmd/internal/gc/syntax.go
index d2b735a..7584af2 100644
--- a/src/cmd/internal/gc/syntax.go
+++ b/src/cmd/internal/gc/syntax.go
@@ -11,31 +11,34 @@
// node with Op=ONAME for a given instance of a variable x.
// The same is true for Op=OTYPE and Op=OLITERAL.
type Node struct {
- Left *Node
- Right *Node
- Ntest *Node
- Nincr *Node
- Ninit *NodeList
- Nbody *NodeList
- Nelse *NodeList
- List *NodeList
- Rlist *NodeList
+ // Tree structure.
+ // Generic recursive walks should follow these fields.
+ Left *Node
+ Right *Node
+ Ntest *Node
+ Nincr *Node
+ Ninit *NodeList
+ Nbody *NodeList
+ Nelse *NodeList
+ List *NodeList
+ Rlist *NodeList
+
Op uint8
Nointerface bool
- Ullman uint8
- Addable uint8
- Trecur uint8
- Etype uint8
- Bounded bool
- Class uint8
- Method uint8
- Embedded uint8
- Colas uint8
- Diag uint8
- Noescape bool
- Nosplit bool
- Builtin uint8
- Nowritebarrier bool
+ Ullman uint8 // sethi/ullman number
+ Addable uint8 // type of addressability - 0 is not addressable
+ Trecur uint8 // to detect loops
+ Etype uint8 // op for OASOP, etype for OTYPE, exclam for export
+ Bounded bool // bounds check unnecessary
+ Class uint8 // PPARAM, PAUTO, PEXTERN, etc
+ Method uint8 // OCALLMETH name
+ Embedded uint8 // ODCLFIELD embedded type
+ Colas uint8 // OAS resulting from :=
+ Diag uint8 // already printed error about this
+ Noescape bool // func arguments do not escape
+ Nosplit bool // func should not execute on separate stack
+ Builtin uint8 // built-in name, like len or close
+ Nowritebarrier bool // emit compiler error instead of write barrier
Walkdef uint8
Typecheck uint8
Local uint8
@@ -45,219 +48,255 @@
Isddd uint8
Readonly uint8
Implicit uint8
- Addrtaken uint8
- Assigned uint8
- Captured uint8
- Byval uint8
- Dupok uint8
- Wrapper uint8
- Reslice uint8
- Likely int8
- Hasbreak uint8
- Needzero bool
- Needctxt bool
- Esc uint
+ Addrtaken uint8 // address taken, even if not moved to heap
+ Assigned uint8 // is the variable ever assigned to
+ Captured uint8 // is the variable captured by a closure
+ Byval uint8 // is the variable captured by value or by reference
+ Dupok uint8 // duplicate definitions ok (for func)
+ Wrapper uint8 // is method wrapper (for func)
+ Reslice uint8 // this is a reslice x = x[0:y] or x = append(x, ...)
+ Likely int8 // likeliness of if statement
+ Hasbreak uint8 // has break statement
+ Needzero bool // if it contains pointers, needs to be zeroed on function entry
+ Needctxt bool // function uses context register (has closure variables)
+ Esc uint // EscXXX
Funcdepth int
- Type *Type
- Orig *Node
- Nname *Node
- Shortname *Node
- Enter *NodeList
- Exit *NodeList
- Cvars *NodeList
- Dcl *NodeList
- Inl *NodeList
- Inldcl *NodeList
- Closgen int
- Outerfunc *Node
- Val Val
- Ntype *Node
- Defn *Node
- Pack *Node
- Curfn *Node
- Paramfld *Type
- Decldepth int
- Heapaddr *Node
- Outerexpr *Node
- Stackparam *Node
- Alloc *Node
- Outer *Node
- Closure *Node
- Top int
- Inlvar *Node
- Pkg *Pkg
- Initplan *InitPlan
- Escflowsrc *NodeList
- Escretval *NodeList
- Escloopdepth int
- Sym *Sym
- InlCost int32
- Vargen int32
- Lineno int32
- Endlineno int32
- Xoffset int64
- Stkdelta int64
- Ostk int32
- Iota int32
- Walkgen uint32
- Esclevel int32
- Opt interface{}
+
+ // most nodes
+ Type *Type
+ Orig *Node // original form, for printing, and tracking copies of ONAMEs
+
+ // func
+ Nname *Node
+ Shortname *Node
+ Enter *NodeList
+ Exit *NodeList
+ Cvars *NodeList // closure params
+ Dcl *NodeList // autodcl for this func/closure
+ Inl *NodeList // copy of the body for use in inlining
+ Inldcl *NodeList // copy of dcl for use in inlining
+ Closgen int
+ Outerfunc *Node
+
+ // OLITERAL/OREGISTER
+ Val Val
+
+ // ONAME
+ Ntype *Node
+ Defn *Node // ONAME: initializing assignment; OLABEL: labeled statement
+ Pack *Node // real package for import . names
+ Curfn *Node // function for local variables
+ Paramfld *Type // TFIELD for this PPARAM; also for ODOT, curfn
+ Decldepth int // declaration loop depth, increased for every loop or label
+
+ // ONAME func param with PHEAP
+ Heapaddr *Node // temp holding heap address of param
+ Outerexpr *Node // expression copied into closure for variable
+ Stackparam *Node // OPARAM node referring to stack copy of param
+ Alloc *Node // allocation call
+
+ // ONAME closure param with PPARAMREF
+ Outer *Node // outer PPARAMREF in nested closure
+ Closure *Node // ONAME/PHEAP <-> ONAME/PPARAMREF
+ Top int // top context (Ecall, Eproc, etc)
+
+ // ONAME substitute while inlining
+ Inlvar *Node
+
+ // OPACK
+ Pkg *Pkg
+
+ // OARRAYLIT, OMAPLIT, OSTRUCTLIT.
+ Initplan *InitPlan
+
+ // Escape analysis.
+ Escflowsrc *NodeList // flow(this, src)
+ Escretval *NodeList // on OCALLxxx, list of dummy return values
+ Escloopdepth int // -1: global, 0: return variables, 1:function top level, increased inside function for every loop or label to mark scopes
+
+ Sym *Sym // various
+ InlCost int32 // unique name for OTYPE/ONAME
+ Vargen int32
+ Lineno int32
+ Endlineno int32
+ Xoffset int64
+ Stkdelta int64 // offset added by stack frame compaction phase.
+ Ostk int32
+ Iota int32
+ Walkgen uint32
+ Esclevel int32
+ Opt interface{} // for optimization passes
}
// Node ops.
const (
OXXX = iota
- ONAME
- ONONAME
- OTYPE
- OPACK
- OLITERAL
- OADD
- OSUB
- OOR
- OXOR
- OADDSTR
- OADDR
- OANDAND
- OAPPEND
- OARRAYBYTESTR
- OARRAYBYTESTRTMP
- OARRAYRUNESTR
- OSTRARRAYBYTE
- OSTRARRAYBYTETMP
- OSTRARRAYRUNE
- OAS
- OAS2
- OAS2FUNC
- OAS2RECV
- OAS2MAPR
- OAS2DOTTYPE
- OASOP
- OCALL
- OCALLFUNC
- OCALLMETH
- OCALLINTER
- OCALLPART
- OCAP
- OCLOSE
- OCLOSURE
- OCMPIFACE
- OCMPSTR
- OCOMPLIT
- OMAPLIT
- OSTRUCTLIT
- OARRAYLIT
- OPTRLIT
- OCONV
- OCONVIFACE
- OCONVNOP
- OCOPY
- ODCL
- ODCLFUNC
- ODCLFIELD
- ODCLCONST
- ODCLTYPE
- ODELETE
- ODOT
- ODOTPTR
- ODOTMETH
- ODOTINTER
- OXDOT
- ODOTTYPE
- ODOTTYPE2
- OEQ
- ONE
- OLT
- OLE
- OGE
- OGT
- OIND
- OINDEX
- OINDEXMAP
- OKEY
- OPARAM
- OLEN
- OMAKE
- OMAKECHAN
- OMAKEMAP
- OMAKESLICE
- OMUL
- ODIV
- OMOD
- OLSH
- ORSH
- OAND
- OANDNOT
- ONEW
- ONOT
- OCOM
- OPLUS
- OMINUS
- OOROR
- OPANIC
- OPRINT
- OPRINTN
- OPAREN
- OSEND
- OSLICE
- OSLICEARR
- OSLICESTR
- OSLICE3
- OSLICE3ARR
- ORECOVER
- ORECV
- ORUNESTR
- OSELRECV
- OSELRECV2
- OIOTA
- OREAL
- OIMAG
- OCOMPLEX
- OBLOCK
- OBREAK
- OCASE
- OXCASE
- OCONTINUE
- ODEFER
- OEMPTY
- OFALL
- OXFALL
- OFOR
- OGOTO
- OIF
- OLABEL
- OPROC
- ORANGE
- ORETURN
- OSELECT
- OSWITCH
- OTYPESW
- OTCHAN
- OTMAP
- OTSTRUCT
- OTINTER
- OTFUNC
- OTARRAY
- ODDD
- ODDDARG
- OINLCALL
- OEFACE
- OITAB
- OSPTR
- OCLOSUREVAR
- OCFUNC
- OCHECKNIL
- OVARKILL
- OREGISTER
- OINDREG
- OCMP
- ODEC
- OINC
- OEXTEND
- OHMUL
- OLROT
- ORROTC
- ORETJMP
+
+ // names
+ ONAME // var, const or func name
+ ONONAME // unnamed arg or return value: f(int, string) (int, error) { etc }
+ OTYPE // type name
+ OPACK // import
+ OLITERAL // literal
+
+ // expressions
+ OADD // x + y
+ OSUB // x - y
+ OOR // x | y
+ OXOR // x ^ y
+ OADDSTR // s + "foo"
+ OADDR // &x
+ OANDAND // b0 && b1
+ OAPPEND // append
+ OARRAYBYTESTR // string(bytes)
+ OARRAYBYTESTRTMP // string(bytes) ephemeral
+ OARRAYRUNESTR // string(runes)
+ OSTRARRAYBYTE // []byte(s)
+ OSTRARRAYBYTETMP // []byte(s) ephemeral
+ OSTRARRAYRUNE // []rune(s)
+ OAS // x = y or x := y
+ OAS2 // x, y, z = xx, yy, zz
+ OAS2FUNC // x, y = f()
+ OAS2RECV // x, ok = <-c
+ OAS2MAPR // x, ok = m["foo"]
+ OAS2DOTTYPE // x, ok = I.(int)
+ OASOP // x += y
+ OCALL // function call, method call or type conversion, possibly preceded by defer or go.
+ OCALLFUNC // f()
+ OCALLMETH // t.Method()
+ OCALLINTER // err.Error()
+ OCALLPART // t.Method (without ())
+ OCAP // cap
+ OCLOSE // close
+ OCLOSURE // f = func() { etc }
+ OCMPIFACE // err1 == err2
+ OCMPSTR // s1 == s2
+ OCOMPLIT // composite literal, typechecking may convert to a more specific OXXXLIT.
+ OMAPLIT // M{"foo":3, "bar":4}
+ OSTRUCTLIT // T{x:3, y:4}
+ OARRAYLIT // [2]int{3, 4}
+ OPTRLIT // &T{x:3, y:4}
+ OCONV // var i int; var u uint; i = int(u)
+ OCONVIFACE // I(t)
+ OCONVNOP // type Int int; var i int; var j Int; i = int(j)
+ OCOPY // copy
+ ODCL // var x int
+ ODCLFUNC // func f() or func (r) f()
+ ODCLFIELD // struct field, interface field, or func/method argument/return value.
+ ODCLCONST // const pi = 3.14
+ ODCLTYPE // type Int int
+ ODELETE // delete
+ ODOT // t.x
+ ODOTPTR // p.x that is implicitly (*p).x
+ ODOTMETH // t.Method
+ ODOTINTER // err.Error
+ OXDOT // t.x, typechecking may convert to a more specific ODOTXXX.
+ ODOTTYPE // e = err.(MyErr)
+ ODOTTYPE2 // e, ok = err.(MyErr)
+ OEQ // x == y
+ ONE // x != y
+ OLT // x < y
+ OLE // x <= y
+ OGE // x >= y
+ OGT // x > y
+ OIND // *p
+ OINDEX // a[i]
+ OINDEXMAP // m[s]
+ OKEY // The x:3 in t{x:3, y:4}, the 1:2 in a[1:2], the 2:20 in [3]int{2:20}, etc.
+ OPARAM // The on-stack copy of a parameter or return value that escapes.
+ OLEN // len
+ OMAKE // make, typechecking may convert to a more specific OMAKEXXX.
+ OMAKECHAN // make(chan int)
+ OMAKEMAP // make(map[string]int)
+ OMAKESLICE // make([]int, 0)
+ OMUL // *
+ ODIV // x / y
+ OMOD // x % y
+ OLSH // x << u
+ ORSH // x >> u
+ OAND // x & y
+ OANDNOT // x &^ y
+ ONEW // new
+ ONOT // !b
+ OCOM // ^x
+ OPLUS // +x
+ OMINUS // -y
+ OOROR // b1 || b2
+ OPANIC // panic
+ OPRINT // print
+ OPRINTN // println
+ OPAREN // (x)
+ OSEND // c <- x
+ OSLICE // v[1:2], typechecking may convert to a more specific OSLICEXXX.
+ OSLICEARR // a[1:2]
+ OSLICESTR // s[1:2]
+ OSLICE3 // v[1:2:3], typechecking may convert to OSLICE3ARR.
+ OSLICE3ARR // a[1:2:3]
+ ORECOVER // recover
+ ORECV // <-c
+ ORUNESTR // string(i)
+ OSELRECV // case x = <-c:
+ OSELRECV2 // case x, ok = <-c:
+ OIOTA // iota
+ OREAL // real
+ OIMAG // imag
+ OCOMPLEX // complex
+
+ // statements
+ OBLOCK // block of code
+ OBREAK // break
+ OCASE // case, after being verified by swt.c's casebody.
+ OXCASE // case, before verification.
+ OCONTINUE // continue
+ ODEFER // defer
+ OEMPTY // no-op
+ OFALL // fallthrough, after being verified by swt.c's casebody.
+ OXFALL // fallthrough, before verification.
+ OFOR // for
+ OGOTO // goto
+ OIF // if
+ OLABEL // label:
+ OPROC // go
+ ORANGE // range
+ ORETURN // return
+ OSELECT // select
+ OSWITCH // switch x
+ OTYPESW // switch err.(type)
+
+ // types
+ OTCHAN // chan int
+ OTMAP // map[string]int
+ OTSTRUCT // struct{}
+ OTINTER // interface{}
+ OTFUNC // func()
+ OTARRAY // []int, [8]int, [N]int or [...]int
+
+ // misc
+ ODDD // func f(args ...int) or f(l...) or var a = [...]int{0, 1, 2}.
+ ODDDARG // func f(args ...int), introduced by escape analysis.
+ OINLCALL // intermediary representation of an inlined call.
+ OEFACE // itable and data words of an empty-interface value.
+ OITAB // itable word of an interface value.
+ OSPTR // base pointer of a slice or string.
+ OCLOSUREVAR // variable reference at beginning of closure function
+ OCFUNC // reference to c function pointer (not go func value)
+ OCHECKNIL // emit code to ensure pointer/interface not nil
+ OVARKILL // variable is dead
+
+ // thearch-specific registers
+ OREGISTER // a register, such as AX.
+ OINDREG // offset plus indirect of a register, such as 8(SP).
+
+ // 386/amd64-specific opcodes
+ OCMP // compare: ACMP.
+ ODEC // decrement: ADEC.
+ OINC // increment: AINC.
+ OEXTEND // extend: ACWD/ACDQ/ACQO.
+ OHMUL // high mul: AMUL/AIMUL for unsigned/signed (OMUL uses AIMUL for both).
+ OLROT // left rotate: AROL.
+ ORROTC // right rotate-carry: ARCR.
+ ORETJMP // return to other function
+
OEND
)
diff --git a/src/cmd/internal/gc/typecheck.go b/src/cmd/internal/gc/typecheck.go
index 845aac6..5ae418c 100644
--- a/src/cmd/internal/gc/typecheck.go
+++ b/src/cmd/internal/gc/typecheck.go
@@ -490,7 +490,7 @@
case OIND:
ntop := Erv | Etype
- if top&Eaddr == 0 {
+ if top&Eaddr == 0 { // The *x in &*x is not an indirect.
ntop |= Eindir
}
ntop |= top & Ecomplit
diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index 842deab..a96ce07 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -2950,10 +2950,9 @@
nif.Ntest = Nod(OGT, nt, Nodintconst(0))
// instantiate growslice(Type*, []any, int) []any
- fn := syslook("growslice", 1)
-
- argtype(fn, s.Type.Type)
- argtype(fn, s.Type.Type)
+ fn := syslook("growslice", 1) // growslice(<type>, old []T, n int64) (ret []T)
+ argtype(fn, s.Type.Type) // 1 old []any
+ argtype(fn, s.Type.Type) // 2 ret []any
// s = growslice(T, s, n)
nif.Nbody = list1(Nod(OAS, s, mkcall1(fn, s.Type, &nif.Ninit, typename(s.Type), s, nt)))
@@ -3774,8 +3773,8 @@
// by a constant
w := int(nl.Type.Width * 8)
- s := 0
- pow := powtwo(nr)
+ s := 0 // 1 if nr is negative.
+ pow := powtwo(nr) // if >= 0, nr is 1<<pow
if pow >= 1000 {
// negative power of 2
s = 1
diff --git a/src/cmd/internal/ld/decodesym.go b/src/cmd/internal/ld/decodesym.go
index 74fa4b5..e960f10 100644
--- a/src/cmd/internal/ld/decodesym.go
+++ b/src/cmd/internal/ld/decodesym.go
@@ -165,7 +165,7 @@
return int64(decode_inuxi(s.P[commonsize()+Thearch.Ptrsize+2*Thearch.Intsize+i*structfieldsize()+4*Thearch.Ptrsize:], Thearch.Intsize))
}
-// InterfaceTYpe.methods.length
+// InterfaceType.methods.length
func decodetype_ifacemethodcount(s *LSym) int64 {
return int64(decode_inuxi(s.P[commonsize()+Thearch.Ptrsize:], Thearch.Intsize))
}
diff --git a/src/cmd/internal/ld/dwarf.go b/src/cmd/internal/ld/dwarf.go
index f850180..c103438 100644
--- a/src/cmd/internal/ld/dwarf.go
+++ b/src/cmd/internal/ld/dwarf.go
@@ -2,6 +2,16 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// TODO/NICETOHAVE:
+// - eliminate DW_CLS_ if not used
+// - package info in compilation units
+// - assign global variables and types to their packages
+// - gdb uses c syntax, meaning clumsy quoting is needed for go identifiers. eg
+// ptype struct '[]uint8' and qualifiers need to be quoted away
+// - lexical scoping is lost, so gdb gets confused as to which 'main.i' you mean.
+// - file:line info for variables
+// - make strings a typedef so prettyprinters can see the underlying string type
+
package ld
import (
@@ -173,10 +183,11 @@
// Go-specific type attributes.
const (
- DW_AT_go_kind = 0x2900
- DW_AT_go_key = 0x2901
- DW_AT_go_elem = 0x2902
- DW_AT_internal_location = 253
+ DW_AT_go_kind = 0x2900
+ DW_AT_go_key = 0x2901
+ DW_AT_go_elem = 0x2902
+
+ DW_AT_internal_location = 253 // params and locals; not emitted
)
// Index into the abbrevs table below.
@@ -201,7 +212,7 @@
DW_ABRV_IFACETYPE
DW_ABRV_MAPTYPE
DW_ABRV_PTRTYPE
- DW_ABRV_BARE_PTRTYPE
+ DW_ABRV_BARE_PTRTYPE // only for void*, no DW_AT_type attr to please gdb 6.
DW_ABRV_SLICETYPE
DW_ABRV_STRINGTYPE
DW_ABRV_STRUCTTYPE
@@ -632,8 +643,8 @@
type DWAttr struct {
link *DWAttr
- atr uint16
- cls uint8
+ atr uint16 // DW_AT_
+ cls uint8 // DW_CLS_
value int64
data interface{}
}
@@ -643,9 +654,11 @@
link *DWDie
child *DWDie
attr *DWAttr
- offs int64
- hash []*DWDie
- hlink *DWDie
+ // offset into .debug_info section, i.e relative to
+ // infoo. only valid after call to putdie()
+ offs int64
+ hash []*DWDie // optional index of children by name, enabled by mkindex()
+ hlink *DWDie // bucket chain in parent's index
}
/*
@@ -1871,7 +1884,7 @@
const (
CIERESERVE = 16
DATAALIGNMENTFACTOR = -4
- FAKERETURNCOLUMN = 16
+ FAKERETURNCOLUMN = 16 // TODO gdb6 doesn't like > 15?
)
func putpccfadelta(deltapc int64, cfa int64) {
diff --git a/src/cmd/internal/ld/dwarf_defs.go b/src/cmd/internal/ld/dwarf_defs.go
index 5be8389..61389d9 100644
--- a/src/cmd/internal/ld/dwarf_defs.go
+++ b/src/cmd/internal/ld/dwarf_defs.go
@@ -89,21 +89,25 @@
DW_TAG_variant_part = 0x33
DW_TAG_variable = 0x34
DW_TAG_volatile_type = 0x35
- DW_TAG_dwarf_procedure = 0x36
- DW_TAG_restrict_type = 0x37
- DW_TAG_interface_type = 0x38
- DW_TAG_namespace = 0x39
- DW_TAG_imported_module = 0x3a
- DW_TAG_unspecified_type = 0x3b
- DW_TAG_partial_unit = 0x3c
- DW_TAG_imported_unit = 0x3d
- DW_TAG_condition = 0x3f
- DW_TAG_shared_type = 0x40
- DW_TAG_type_unit = 0x41
- DW_TAG_rvalue_reference_type = 0x42
- DW_TAG_template_alias = 0x43
- DW_TAG_lo_user = 0x4080
- DW_TAG_hi_user = 0xffff
+ // Dwarf3
+ DW_TAG_dwarf_procedure = 0x36
+ DW_TAG_restrict_type = 0x37
+ DW_TAG_interface_type = 0x38
+ DW_TAG_namespace = 0x39
+ DW_TAG_imported_module = 0x3a
+ DW_TAG_unspecified_type = 0x3b
+ DW_TAG_partial_unit = 0x3c
+ DW_TAG_imported_unit = 0x3d
+ DW_TAG_condition = 0x3f
+ DW_TAG_shared_type = 0x40
+ // Dwarf4
+ DW_TAG_type_unit = 0x41
+ DW_TAG_rvalue_reference_type = 0x42
+ DW_TAG_template_alias = 0x43
+
+ // User defined
+ DW_TAG_lo_user = 0x4080
+ DW_TAG_hi_user = 0xffff
)
// Table 19
@@ -118,7 +122,7 @@
DW_CLS_BLOCK
DW_CLS_CONSTANT
DW_CLS_FLAG
- DW_CLS_PTR
+ DW_CLS_PTR // lineptr, loclistptr, macptr, rangelistptr
DW_CLS_REFERENCE
DW_CLS_ADDRLOC
DW_CLS_STRING
@@ -126,185 +130,187 @@
// Table 20
const (
- DW_AT_sibling = 0x01
- DW_AT_location = 0x02
- DW_AT_name = 0x03
- DW_AT_ordering = 0x09
- DW_AT_byte_size = 0x0b
- DW_AT_bit_offset = 0x0c
- DW_AT_bit_size = 0x0d
- DW_AT_stmt_list = 0x10
- DW_AT_low_pc = 0x11
- DW_AT_high_pc = 0x12
- DW_AT_language = 0x13
- DW_AT_discr = 0x15
- DW_AT_discr_value = 0x16
- DW_AT_visibility = 0x17
- DW_AT_import = 0x18
- DW_AT_string_length = 0x19
- DW_AT_common_reference = 0x1a
- DW_AT_comp_dir = 0x1b
- DW_AT_const_value = 0x1c
- DW_AT_containing_type = 0x1d
- DW_AT_default_value = 0x1e
- DW_AT_inline = 0x20
- DW_AT_is_optional = 0x21
- DW_AT_lower_bound = 0x22
- DW_AT_producer = 0x25
- DW_AT_prototyped = 0x27
- DW_AT_return_addr = 0x2a
- DW_AT_start_scope = 0x2c
- DW_AT_bit_stride = 0x2e
- DW_AT_upper_bound = 0x2f
- DW_AT_abstract_origin = 0x31
- DW_AT_accessibility = 0x32
- DW_AT_address_class = 0x33
- DW_AT_artificial = 0x34
- DW_AT_base_types = 0x35
- DW_AT_calling_convention = 0x36
- DW_AT_count = 0x37
- DW_AT_data_member_location = 0x38
- DW_AT_decl_column = 0x39
- DW_AT_decl_file = 0x3a
- DW_AT_decl_line = 0x3b
- DW_AT_declaration = 0x3c
- DW_AT_discr_list = 0x3d
- DW_AT_encoding = 0x3e
- DW_AT_external = 0x3f
- DW_AT_frame_base = 0x40
- DW_AT_friend = 0x41
- DW_AT_identifier_case = 0x42
- DW_AT_macro_info = 0x43
- DW_AT_namelist_item = 0x44
- DW_AT_priority = 0x45
- DW_AT_segment = 0x46
- DW_AT_specification = 0x47
- DW_AT_static_link = 0x48
- DW_AT_type = 0x49
- DW_AT_use_location = 0x4a
- DW_AT_variable_parameter = 0x4b
- DW_AT_virtuality = 0x4c
- DW_AT_vtable_elem_location = 0x4d
- DW_AT_allocated = 0x4e
- DW_AT_associated = 0x4f
- DW_AT_data_location = 0x50
- DW_AT_byte_stride = 0x51
- DW_AT_entry_pc = 0x52
- DW_AT_use_UTF8 = 0x53
- DW_AT_extension = 0x54
- DW_AT_ranges = 0x55
- DW_AT_trampoline = 0x56
- DW_AT_call_column = 0x57
- DW_AT_call_file = 0x58
- DW_AT_call_line = 0x59
- DW_AT_description = 0x5a
- DW_AT_binary_scale = 0x5b
- DW_AT_decimal_scale = 0x5c
- DW_AT_small = 0x5d
- DW_AT_decimal_sign = 0x5e
- DW_AT_digit_count = 0x5f
- DW_AT_picture_string = 0x60
- DW_AT_mutable = 0x61
- DW_AT_threads_scaled = 0x62
- DW_AT_explicit = 0x63
- DW_AT_object_pointer = 0x64
- DW_AT_endianity = 0x65
- DW_AT_elemental = 0x66
- DW_AT_pure = 0x67
- DW_AT_recursive = 0x68
- DW_AT_lo_user = 0x2000
- DW_AT_hi_user = 0x3fff
+ DW_AT_sibling = 0x01 // reference
+ DW_AT_location = 0x02 // block, loclistptr
+ DW_AT_name = 0x03 // string
+ DW_AT_ordering = 0x09 // constant
+ DW_AT_byte_size = 0x0b // block, constant, reference
+ DW_AT_bit_offset = 0x0c // block, constant, reference
+ DW_AT_bit_size = 0x0d // block, constant, reference
+ DW_AT_stmt_list = 0x10 // lineptr
+ DW_AT_low_pc = 0x11 // address
+ DW_AT_high_pc = 0x12 // address
+ DW_AT_language = 0x13 // constant
+ DW_AT_discr = 0x15 // reference
+ DW_AT_discr_value = 0x16 // constant
+ DW_AT_visibility = 0x17 // constant
+ DW_AT_import = 0x18 // reference
+ DW_AT_string_length = 0x19 // block, loclistptr
+ DW_AT_common_reference = 0x1a // reference
+ DW_AT_comp_dir = 0x1b // string
+ DW_AT_const_value = 0x1c // block, constant, string
+ DW_AT_containing_type = 0x1d // reference
+ DW_AT_default_value = 0x1e // reference
+ DW_AT_inline = 0x20 // constant
+ DW_AT_is_optional = 0x21 // flag
+ DW_AT_lower_bound = 0x22 // block, constant, reference
+ DW_AT_producer = 0x25 // string
+ DW_AT_prototyped = 0x27 // flag
+ DW_AT_return_addr = 0x2a // block, loclistptr
+ DW_AT_start_scope = 0x2c // constant
+ DW_AT_bit_stride = 0x2e // constant
+ DW_AT_upper_bound = 0x2f // block, constant, reference
+ DW_AT_abstract_origin = 0x31 // reference
+ DW_AT_accessibility = 0x32 // constant
+ DW_AT_address_class = 0x33 // constant
+ DW_AT_artificial = 0x34 // flag
+ DW_AT_base_types = 0x35 // reference
+ DW_AT_calling_convention = 0x36 // constant
+ DW_AT_count = 0x37 // block, constant, reference
+ DW_AT_data_member_location = 0x38 // block, constant, loclistptr
+ DW_AT_decl_column = 0x39 // constant
+ DW_AT_decl_file = 0x3a // constant
+ DW_AT_decl_line = 0x3b // constant
+ DW_AT_declaration = 0x3c // flag
+ DW_AT_discr_list = 0x3d // block
+ DW_AT_encoding = 0x3e // constant
+ DW_AT_external = 0x3f // flag
+ DW_AT_frame_base = 0x40 // block, loclistptr
+ DW_AT_friend = 0x41 // reference
+ DW_AT_identifier_case = 0x42 // constant
+ DW_AT_macro_info = 0x43 // macptr
+ DW_AT_namelist_item = 0x44 // block
+ DW_AT_priority = 0x45 // reference
+ DW_AT_segment = 0x46 // block, loclistptr
+ DW_AT_specification = 0x47 // reference
+ DW_AT_static_link = 0x48 // block, loclistptr
+ DW_AT_type = 0x49 // reference
+ DW_AT_use_location = 0x4a // block, loclistptr
+ DW_AT_variable_parameter = 0x4b // flag
+ DW_AT_virtuality = 0x4c // constant
+ DW_AT_vtable_elem_location = 0x4d // block, loclistptr
+ // Dwarf3
+ DW_AT_allocated = 0x4e // block, constant, reference
+ DW_AT_associated = 0x4f // block, constant, reference
+ DW_AT_data_location = 0x50 // block
+ DW_AT_byte_stride = 0x51 // block, constant, reference
+ DW_AT_entry_pc = 0x52 // address
+ DW_AT_use_UTF8 = 0x53 // flag
+ DW_AT_extension = 0x54 // reference
+ DW_AT_ranges = 0x55 // rangelistptr
+ DW_AT_trampoline = 0x56 // address, flag, reference, string
+ DW_AT_call_column = 0x57 // constant
+ DW_AT_call_file = 0x58 // constant
+ DW_AT_call_line = 0x59 // constant
+ DW_AT_description = 0x5a // string
+ DW_AT_binary_scale = 0x5b // constant
+ DW_AT_decimal_scale = 0x5c // constant
+ DW_AT_small = 0x5d // reference
+ DW_AT_decimal_sign = 0x5e // constant
+ DW_AT_digit_count = 0x5f // constant
+ DW_AT_picture_string = 0x60 // string
+ DW_AT_mutable = 0x61 // flag
+ DW_AT_threads_scaled = 0x62 // flag
+ DW_AT_explicit = 0x63 // flag
+ DW_AT_object_pointer = 0x64 // reference
+ DW_AT_endianity = 0x65 // constant
+ DW_AT_elemental = 0x66 // flag
+ DW_AT_pure = 0x67 // flag
+ DW_AT_recursive = 0x68 // flag
+
+ DW_AT_lo_user = 0x2000 // ---
+ DW_AT_hi_user = 0x3fff // ---
)
// Table 21
const (
- DW_FORM_addr = 0x01
- DW_FORM_block2 = 0x03
- DW_FORM_block4 = 0x04
- DW_FORM_data2 = 0x05
- DW_FORM_data4 = 0x06
- DW_FORM_data8 = 0x07
- DW_FORM_string = 0x08
- DW_FORM_block = 0x09
- DW_FORM_block1 = 0x0a
- DW_FORM_data1 = 0x0b
- DW_FORM_flag = 0x0c
- DW_FORM_sdata = 0x0d
- DW_FORM_strp = 0x0e
- DW_FORM_udata = 0x0f
- DW_FORM_ref_addr = 0x10
- DW_FORM_ref1 = 0x11
- DW_FORM_ref2 = 0x12
- DW_FORM_ref4 = 0x13
- DW_FORM_ref8 = 0x14
- DW_FORM_ref_udata = 0x15
- DW_FORM_indirect = 0x16
+ DW_FORM_addr = 0x01 // address
+ DW_FORM_block2 = 0x03 // block
+ DW_FORM_block4 = 0x04 // block
+ DW_FORM_data2 = 0x05 // constant
+ DW_FORM_data4 = 0x06 // constant, lineptr, loclistptr, macptr, rangelistptr
+ DW_FORM_data8 = 0x07 // constant, lineptr, loclistptr, macptr, rangelistptr
+ DW_FORM_string = 0x08 // string
+ DW_FORM_block = 0x09 // block
+ DW_FORM_block1 = 0x0a // block
+ DW_FORM_data1 = 0x0b // constant
+ DW_FORM_flag = 0x0c // flag
+ DW_FORM_sdata = 0x0d // constant
+ DW_FORM_strp = 0x0e // string
+ DW_FORM_udata = 0x0f // constant
+ DW_FORM_ref_addr = 0x10 // reference
+ DW_FORM_ref1 = 0x11 // reference
+ DW_FORM_ref2 = 0x12 // reference
+ DW_FORM_ref4 = 0x13 // reference
+ DW_FORM_ref8 = 0x14 // reference
+ DW_FORM_ref_udata = 0x15 // reference
+ DW_FORM_indirect = 0x16 // (see Section 7.5.3)
)
// Table 24 (#operands, notes)
const (
- DW_OP_addr = 0x03
- DW_OP_deref = 0x06
- DW_OP_const1u = 0x08
- DW_OP_const1s = 0x09
- DW_OP_const2u = 0x0a
- DW_OP_const2s = 0x0b
- DW_OP_const4u = 0x0c
- DW_OP_const4s = 0x0d
- DW_OP_const8u = 0x0e
- DW_OP_const8s = 0x0f
- DW_OP_constu = 0x10
- DW_OP_consts = 0x11
- DW_OP_dup = 0x12
- DW_OP_drop = 0x13
- DW_OP_over = 0x14
- DW_OP_pick = 0x15
- DW_OP_swap = 0x16
- DW_OP_rot = 0x17
- DW_OP_xderef = 0x18
- DW_OP_abs = 0x19
- DW_OP_and = 0x1a
- DW_OP_div = 0x1b
- DW_OP_minus = 0x1c
- DW_OP_mod = 0x1d
- DW_OP_mul = 0x1e
- DW_OP_neg = 0x1f
- DW_OP_not = 0x20
- DW_OP_or = 0x21
- DW_OP_plus = 0x22
- DW_OP_plus_uconst = 0x23
- DW_OP_shl = 0x24
- DW_OP_shr = 0x25
- DW_OP_shra = 0x26
- DW_OP_xor = 0x27
- DW_OP_skip = 0x2f
- DW_OP_bra = 0x28
- DW_OP_eq = 0x29
- DW_OP_ge = 0x2a
- DW_OP_gt = 0x2b
- DW_OP_le = 0x2c
- DW_OP_lt = 0x2d
- DW_OP_ne = 0x2e
- DW_OP_lit0 = 0x30
- DW_OP_lit31 = 0x4f
- DW_OP_reg0 = 0x50
- DW_OP_reg31 = 0x6f
- DW_OP_breg0 = 0x70
- DW_OP_breg31 = 0x8f
- DW_OP_regx = 0x90
- DW_OP_fbreg = 0x91
- DW_OP_bregx = 0x92
- DW_OP_piece = 0x93
- DW_OP_deref_size = 0x94
- DW_OP_xderef_size = 0x95
- DW_OP_nop = 0x96
- DW_OP_push_object_address = 0x97
- DW_OP_call2 = 0x98
- DW_OP_call4 = 0x99
- DW_OP_call_ref = 0x9a
- DW_OP_form_tls_address = 0x9b
- DW_OP_call_frame_cfa = 0x9c
- DW_OP_bit_piece = 0x9d
+ DW_OP_addr = 0x03 // 1 constant address (size target specific)
+ DW_OP_deref = 0x06 // 0
+ DW_OP_const1u = 0x08 // 1 1-byte constant
+ DW_OP_const1s = 0x09 // 1 1-byte constant
+ DW_OP_const2u = 0x0a // 1 2-byte constant
+ DW_OP_const2s = 0x0b // 1 2-byte constant
+ DW_OP_const4u = 0x0c // 1 4-byte constant
+ DW_OP_const4s = 0x0d // 1 4-byte constant
+ DW_OP_const8u = 0x0e // 1 8-byte constant
+ DW_OP_const8s = 0x0f // 1 8-byte constant
+ DW_OP_constu = 0x10 // 1 ULEB128 constant
+ DW_OP_consts = 0x11 // 1 SLEB128 constant
+ DW_OP_dup = 0x12 // 0
+ DW_OP_drop = 0x13 // 0
+ DW_OP_over = 0x14 // 0
+ DW_OP_pick = 0x15 // 1 1-byte stack index
+ DW_OP_swap = 0x16 // 0
+ DW_OP_rot = 0x17 // 0
+ DW_OP_xderef = 0x18 // 0
+ DW_OP_abs = 0x19 // 0
+ DW_OP_and = 0x1a // 0
+ DW_OP_div = 0x1b // 0
+ DW_OP_minus = 0x1c // 0
+ DW_OP_mod = 0x1d // 0
+ DW_OP_mul = 0x1e // 0
+ DW_OP_neg = 0x1f // 0
+ DW_OP_not = 0x20 // 0
+ DW_OP_or = 0x21 // 0
+ DW_OP_plus = 0x22 // 0
+ DW_OP_plus_uconst = 0x23 // 1 ULEB128 addend
+ DW_OP_shl = 0x24 // 0
+ DW_OP_shr = 0x25 // 0
+ DW_OP_shra = 0x26 // 0
+ DW_OP_xor = 0x27 // 0
+ DW_OP_skip = 0x2f // 1 signed 2-byte constant
+ DW_OP_bra = 0x28 // 1 signed 2-byte constant
+ DW_OP_eq = 0x29 // 0
+ DW_OP_ge = 0x2a // 0
+ DW_OP_gt = 0x2b // 0
+ DW_OP_le = 0x2c // 0
+ DW_OP_lt = 0x2d // 0
+ DW_OP_ne = 0x2e // 0
+ DW_OP_lit0 = 0x30 // 0 ...
+ DW_OP_lit31 = 0x4f // 0 literals 0..31 = (DW_OP_lit0 + literal)
+ DW_OP_reg0 = 0x50 // 0 ..
+ DW_OP_reg31 = 0x6f // 0 reg 0..31 = (DW_OP_reg0 + regnum)
+ DW_OP_breg0 = 0x70 // 1 ...
+ DW_OP_breg31 = 0x8f // 1 SLEB128 offset base register 0..31 = (DW_OP_breg0 + regnum)
+ DW_OP_regx = 0x90 // 1 ULEB128 register
+ DW_OP_fbreg = 0x91 // 1 SLEB128 offset
+ DW_OP_bregx = 0x92 // 2 ULEB128 register followed by SLEB128 offset
+ DW_OP_piece = 0x93 // 1 ULEB128 size of piece addressed
+ DW_OP_deref_size = 0x94 // 1 1-byte size of data retrieved
+ DW_OP_xderef_size = 0x95 // 1 1-byte size of data retrieved
+ DW_OP_nop = 0x96 // 0
+ DW_OP_push_object_address = 0x97 // 0
+ DW_OP_call2 = 0x98 // 1 2-byte offset of DIE
+ DW_OP_call4 = 0x99 // 1 4-byte offset of DIE
+ DW_OP_call_ref = 0x9a // 1 4- or 8-byte offset of DIE
+ DW_OP_form_tls_address = 0x9b // 0
+ DW_OP_call_frame_cfa = 0x9c // 0
+ DW_OP_bit_piece = 0x9d // 2
DW_OP_lo_user = 0xe0
DW_OP_hi_user = 0xff
)
@@ -371,16 +377,17 @@
// Table 31
const (
- DW_LANG_C89 = 0x0001
- DW_LANG_C = 0x0002
- DW_LANG_Ada83 = 0x0003
- DW_LANG_C_plus_plus = 0x0004
- DW_LANG_Cobol74 = 0x0005
- DW_LANG_Cobol85 = 0x0006
- DW_LANG_Fortran77 = 0x0007
- DW_LANG_Fortran90 = 0x0008
- DW_LANG_Pascal83 = 0x0009
- DW_LANG_Modula2 = 0x000a
+ DW_LANG_C89 = 0x0001
+ DW_LANG_C = 0x0002
+ DW_LANG_Ada83 = 0x0003
+ DW_LANG_C_plus_plus = 0x0004
+ DW_LANG_Cobol74 = 0x0005
+ DW_LANG_Cobol85 = 0x0006
+ DW_LANG_Fortran77 = 0x0007
+ DW_LANG_Fortran90 = 0x0008
+ DW_LANG_Pascal83 = 0x0009
+ DW_LANG_Modula2 = 0x000a
+ // Dwarf3
DW_LANG_Java = 0x000b
DW_LANG_C99 = 0x000c
DW_LANG_Ada95 = 0x000d
@@ -390,10 +397,13 @@
DW_LANG_ObjC_plus_plus = 0x0011
DW_LANG_UPC = 0x0012
DW_LANG_D = 0x0013
- DW_LANG_Python = 0x0014
- DW_LANG_Go = 0x0016
- DW_LANG_lo_user = 0x8000
- DW_LANG_hi_user = 0xffff
+ // Dwarf4
+ DW_LANG_Python = 0x0014
+ // Dwarf5
+ DW_LANG_Go = 0x0016
+
+ DW_LANG_lo_user = 0x8000
+ DW_LANG_hi_user = 0xffff
)
// Table 32
@@ -435,15 +445,16 @@
// Table 37
const (
- DW_LNS_copy = 0x01
- DW_LNS_advance_pc = 0x02
- DW_LNS_advance_line = 0x03
- DW_LNS_set_file = 0x04
- DW_LNS_set_column = 0x05
- DW_LNS_negate_stmt = 0x06
- DW_LNS_set_basic_block = 0x07
- DW_LNS_const_add_pc = 0x08
- DW_LNS_fixed_advance_pc = 0x09
+ DW_LNS_copy = 0x01
+ DW_LNS_advance_pc = 0x02
+ DW_LNS_advance_line = 0x03
+ DW_LNS_set_file = 0x04
+ DW_LNS_set_column = 0x05
+ DW_LNS_negate_stmt = 0x06
+ DW_LNS_set_basic_block = 0x07
+ DW_LNS_const_add_pc = 0x08
+ DW_LNS_fixed_advance_pc = 0x09
+ // Dwarf3
DW_LNS_set_prologue_end = 0x0a
DW_LNS_set_epilogue_begin = 0x0b
DW_LNS_set_isa = 0x0c
@@ -469,32 +480,37 @@
// Table 40.
const (
- DW_CFA_nop = 0x00
- DW_CFA_set_loc = 0x01
- DW_CFA_advance_loc1 = 0x02
- DW_CFA_advance_loc2 = 0x03
- DW_CFA_advance_loc4 = 0x04
- DW_CFA_offset_extended = 0x05
- DW_CFA_restore_extended = 0x06
- DW_CFA_undefined = 0x07
- DW_CFA_same_value = 0x08
- DW_CFA_register = 0x09
- DW_CFA_remember_state = 0x0a
- DW_CFA_restore_state = 0x0b
- DW_CFA_def_cfa = 0x0c
- DW_CFA_def_cfa_register = 0x0d
- DW_CFA_def_cfa_offset = 0x0e
- DW_CFA_def_cfa_expression = 0x0f
- DW_CFA_expression = 0x10
- DW_CFA_offset_extended_sf = 0x11
- DW_CFA_def_cfa_sf = 0x12
- DW_CFA_def_cfa_offset_sf = 0x13
- DW_CFA_val_offset = 0x14
- DW_CFA_val_offset_sf = 0x15
- DW_CFA_val_expression = 0x16
- DW_CFA_lo_user = 0x1c
- DW_CFA_hi_user = 0x3f
- DW_CFA_advance_loc = 0x1 << 6
- DW_CFA_offset = 0x2 << 6
- DW_CFA_restore = 0x3 << 6
+ // operand,...
+ DW_CFA_nop = 0x00
+ DW_CFA_set_loc = 0x01 // address
+ DW_CFA_advance_loc1 = 0x02 // 1-byte delta
+ DW_CFA_advance_loc2 = 0x03 // 2-byte delta
+ DW_CFA_advance_loc4 = 0x04 // 4-byte delta
+ DW_CFA_offset_extended = 0x05 // ULEB128 register, ULEB128 offset
+ DW_CFA_restore_extended = 0x06 // ULEB128 register
+ DW_CFA_undefined = 0x07 // ULEB128 register
+ DW_CFA_same_value = 0x08 // ULEB128 register
+ DW_CFA_register = 0x09 // ULEB128 register, ULEB128 register
+ DW_CFA_remember_state = 0x0a
+ DW_CFA_restore_state = 0x0b
+
+ DW_CFA_def_cfa = 0x0c // ULEB128 register, ULEB128 offset
+ DW_CFA_def_cfa_register = 0x0d // ULEB128 register
+ DW_CFA_def_cfa_offset = 0x0e // ULEB128 offset
+ DW_CFA_def_cfa_expression = 0x0f // BLOCK
+ DW_CFA_expression = 0x10 // ULEB128 register, BLOCK
+ DW_CFA_offset_extended_sf = 0x11 // ULEB128 register, SLEB128 offset
+ DW_CFA_def_cfa_sf = 0x12 // ULEB128 register, SLEB128 offset
+ DW_CFA_def_cfa_offset_sf = 0x13 // SLEB128 offset
+ DW_CFA_val_offset = 0x14 // ULEB128, ULEB128
+ DW_CFA_val_offset_sf = 0x15 // ULEB128, SLEB128
+ DW_CFA_val_expression = 0x16 // ULEB128, BLOCK
+
+ DW_CFA_lo_user = 0x1c
+ DW_CFA_hi_user = 0x3f
+
+ // Opcodes that take an addend operand.
+ DW_CFA_advance_loc = 0x1 << 6 // +delta
+ DW_CFA_offset = 0x2 << 6 // +register (ULEB128 offset)
+ DW_CFA_restore = 0x3 << 6 // +register
)
diff --git a/src/cmd/internal/ld/elf.go b/src/cmd/internal/ld/elf.go
index 32c9aeb..9e85885 100644
--- a/src/cmd/internal/ld/elf.go
+++ b/src/cmd/internal/ld/elf.go
@@ -776,6 +776,7 @@
// we use EABI on both linux/arm and freebsd/arm.
// 32-bit architectures
case '5':
+ // we use EABI on both linux/arm and freebsd/arm.
if HEADTYPE == Hlinux || HEADTYPE == Hfreebsd {
ehdr.flags = 0x5000002 // has entry point, Version5 EABI
}
@@ -1071,7 +1072,7 @@
ELF_NOTE_NETBSD_NAMESZ = 7
ELF_NOTE_NETBSD_DESCSZ = 4
ELF_NOTE_NETBSD_TAG = 1
- ELF_NOTE_NETBSD_VERSION = 599000000
+ ELF_NOTE_NETBSD_VERSION = 599000000 /* NetBSD 5.99 */
)
var ELF_NOTE_NETBSD_NAME = []byte("NetBSD\x00")
@@ -1671,7 +1672,7 @@
Addstring(shstrtab, ".shstrtab")
- if Debug['d'] == 0 {
+ if Debug['d'] == 0 { /* -d suppresses dynamic loader format */
Addstring(shstrtab, ".interp")
Addstring(shstrtab, ".hash")
Addstring(shstrtab, ".got")
@@ -1919,7 +1920,7 @@
Segtext.Filelen += uint64(o)
}
- if Debug['d'] == 0 {
+ if Debug['d'] == 0 { /* -d suppresses dynamic loader format */
/* interpreter */
sh := elfshname(".interp")
diff --git a/src/cmd/internal/ld/go.go b/src/cmd/internal/ld/go.go
index 1ad3bff..dd2ba9f 100644
--- a/src/cmd/internal/ld/go.go
+++ b/src/cmd/internal/ld/go.go
@@ -37,8 +37,8 @@
* package import data
*/
type Import struct {
- hash *Import
- prefix string
+ hash *Import // next in hash table
+ prefix string // "type", "var", "func", "const"
name string
def string
file string
diff --git a/src/cmd/internal/ld/ldelf.go b/src/cmd/internal/ld/ldelf.go
index ce52f12..a02ec60 100644
--- a/src/cmd/internal/ld/ldelf.go
+++ b/src/cmd/internal/ld/ldelf.go
@@ -265,8 +265,8 @@
type ElfObj struct {
f *Biobuf
- base int64
- length int64
+ base int64 // offset in f where ELF begins
+ length int64 // length of ELF
is64 int
name string
e binary.ByteOrder
@@ -624,7 +624,7 @@
}
sect = &elfobj.sect[sym.shndx:][0]
if sect.sym == nil {
- if strings.HasPrefix(sym.name, ".Linfo_string") {
+ if strings.HasPrefix(sym.name, ".Linfo_string") { // clang does this
continue
}
Diag("%s: sym#%d: ignoring %s in section %d (type %d)", pn, i, sym.name, sym.shndx, sym.type_)
@@ -901,7 +901,7 @@
case ElfSymBindLocal:
if Thearch.Thechar == '5' && (strings.HasPrefix(sym.name, "$a") || strings.HasPrefix(sym.name, "$d")) {
- // binutils for arm generate these elfmapping
+ // binutils for arm generate these mapping
// symbols, ignore these
break
}
diff --git a/src/cmd/internal/ld/ldmacho.go b/src/cmd/internal/ld/ldmacho.go
index 14e9923..9ed4093 100644
--- a/src/cmd/internal/ld/ldmacho.go
+++ b/src/cmd/internal/ld/ldmacho.go
@@ -41,8 +41,8 @@
type LdMachoObj struct {
f *Biobuf
- base int64
- length int64
+ base int64 // off in f where Mach-O begins
+ length int64 // length of Mach-O
is64 bool
name string
e binary.ByteOrder
diff --git a/src/cmd/internal/ld/ldpe.go b/src/cmd/internal/ld/ldpe.go
index bd33fce..18d39d4 100644
--- a/src/cmd/internal/ld/ldpe.go
+++ b/src/cmd/internal/ld/ldpe.go
@@ -58,7 +58,7 @@
IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16
IMAGE_SYM_CLASS_REGISTER_PARAM = 17
IMAGE_SYM_CLASS_BIT_FIELD = 18
- IMAGE_SYM_CLASS_FAR_EXTERNAL = 68
+ IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */
IMAGE_SYM_CLASS_BLOCK = 100
IMAGE_SYM_CLASS_FUNCTION = 101
IMAGE_SYM_CLASS_END_OF_STRUCT = 102
diff --git a/src/cmd/internal/ld/lib.go b/src/cmd/internal/ld/lib.go
index 7fd76b9..2822454 100644
--- a/src/cmd/internal/ld/lib.go
+++ b/src/cmd/internal/ld/lib.go
@@ -129,15 +129,15 @@
const (
MAXIO = 8192
- MINFUNC = 16
+ MINFUNC = 16 // minimum size for a function
)
type Segment struct {
- Rwx uint8
- Vaddr uint64
- Length uint64
- Fileoff uint64
- Filelen uint64
+ Rwx uint8 // permission as usual unix bits (5 = r-x etc)
+ Vaddr uint64 // virtual address
+ Length uint64 // length in memory
+ Fileoff uint64 // file offset
+ Filelen uint64 // length on disk
Sect *Section
}
@@ -253,6 +253,8 @@
var coutbuf Biobuf
const (
+ // Whether to assume that the external linker is "gold"
+ // (http://sourceware.org/ml/binutils/2008-03/msg00162.html).
AssumeGoldLinker = 0
)
@@ -1137,7 +1139,7 @@
type Chain struct {
sym *LSym
up *Chain
- limit int
+ limit int // limit on entry to sym
}
var morestack *LSym
diff --git a/src/cmd/internal/ld/pe.go b/src/cmd/internal/ld/pe.go
index 7af1e5a..40bfc23 100644
--- a/src/cmd/internal/ld/pe.go
+++ b/src/cmd/internal/ld/pe.go
@@ -95,8 +95,15 @@
}
const (
- PEBASE = 0x00400000
+ PEBASE = 0x00400000
+
+ // SectionAlignment must be greater than or equal to FileAlignment.
+ // The default is the page size for the architecture.
PESECTALIGN = 0x1000
+
+ // FileAlignment should be a power of 2 between 512 and 64 K, inclusive.
+ // The default is 512. If the SectionAlignment is less than
+ // the architecture's page size, then FileAlignment must match SectionAlignment.
PEFILEALIGN = 2 << 8
)
@@ -921,7 +928,7 @@
if pe64 != 0 {
fh.SizeOfOptionalHeader = uint16(binary.Size(&oh64))
fh.Characteristics |= IMAGE_FILE_LARGE_ADDRESS_AWARE
- oh64.Magic = 0x20b
+ oh64.Magic = 0x20b // PE32+
} else {
fh.SizeOfOptionalHeader = uint16(binary.Size(&oh))
fh.Characteristics |= IMAGE_FILE_32BIT_MACHINE
diff --git a/src/cmd/internal/obj/arm/5.out.go b/src/cmd/internal/obj/arm/5.out.go
index 424dd3d..d187367 100644
--- a/src/cmd/internal/obj/arm/5.out.go
+++ b/src/cmd/internal/obj/arm/5.out.go
@@ -44,7 +44,7 @@
)
const (
- REG_R0 = obj.RBaseARM + iota
+ REG_R0 = obj.RBaseARM + iota // must be 16-aligned
REG_R1
REG_R2
REG_R3
@@ -60,7 +60,8 @@
REG_R13
REG_R14
REG_R15
- REG_F0
+
+ REG_F0 // must be 16-aligned
REG_F1
REG_F2
REG_F3
@@ -76,28 +77,37 @@
REG_F13
REG_F14
REG_F15
- REG_FPSR
+
+ REG_FPSR // must be 2-aligned
REG_FPCR
- REG_CPSR
+
+ REG_CPSR // must be 2-aligned
REG_SPSR
+
MAXREG
- REGRET = REG_R0
- REGEXT = REG_R10
- REGG = REGEXT - 0
- REGM = REGEXT - 1
+ REGRET = REG_R0
+ /* compiler allocates R1 up as temps */
+ /* compiler allocates register variables R3 up */
+ /* compiler allocates external registers R10 down */
+ REGEXT = REG_R10
+ /* these two registers are declared in runtime.h */
+ REGG = REGEXT - 0
+ REGM = REGEXT - 1
+
REGCTXT = REG_R7
REGTMP = REG_R11
REGSP = REG_R13
REGLINK = REG_R14
REGPC = REG_R15
- NFREG = 16
+
+ NFREG = 16
+ /* compiler allocates register variables F0 up */
+ /* compiler allocates external registers F7 down */
FREGRET = REG_F0
FREGEXT = REG_F7
FREGTMP = REG_F15
)
-/* compiler allocates register variables F0 up */
-/* compiler allocates external registers F7 down */
const (
C_NONE = iota
C_REG
@@ -108,37 +118,46 @@
C_FREG
C_PSR
C_FCR
- C_RCON
- C_NCON
- C_SCON
+
+ C_RCON /* 0xff rotated */
+ C_NCON /* ~RCON */
+ C_SCON /* 0xffff */
C_LCON
C_LCONADDR
C_ZFCON
C_SFCON
C_LFCON
+
C_RACON
C_LACON
+
C_SBRA
C_LBRA
- C_HAUTO
- C_FAUTO
- C_HFAUTO
- C_SAUTO
+
+ C_HAUTO /* halfword insn offset (-0xff to 0xff) */
+ C_FAUTO /* float insn offset (0 to 0x3fc, word aligned) */
+ C_HFAUTO /* both H and F */
+ C_SAUTO /* -0xfff to 0xfff */
C_LAUTO
+
C_HOREG
C_FOREG
C_HFOREG
C_SOREG
C_ROREG
- C_SROREG
+ C_SROREG /* both nil and R */
C_LOREG
+
C_PC
C_SP
C_HREG
- C_ADDR
+
+ C_ADDR /* reference to relocatable address */
C_TEXTSIZE
+
C_GOK
- C_NCLASS
+
+ C_NCLASS /* must be the last */
)
const (
@@ -156,7 +175,13 @@
ACMN
AORR
ABIC
+
AMVN
+
+ /*
+ * Do not reorder or fragment the conditional branch
+ * opcodes, or the predication code will break
+ */
ABEQ
ABNE
ABCS
@@ -173,6 +198,7 @@
ABLT
ABGT
ABLE
+
AMOVWD
AMOVWF
AMOVDW
@@ -181,6 +207,7 @@
AMOVDF
AMOVF
AMOVD
+
ACMPF
ACMPD
AADDF
@@ -195,6 +222,7 @@
ASQRTD
AABSF
AABSD
+
ASRL
ASRA
ASLL
@@ -204,6 +232,7 @@
ADIV
AMOD
AMODU
+
AMOVB
AMOVBS
AMOVBU
@@ -214,46 +243,64 @@
AMOVM
ASWPBU
ASWPW
+
ARFE
ASWI
AMULA
+
AWORD
ABCASE
ACASE
+
AMULL
AMULAL
AMULLU
AMULALU
+
ABX
ABXRET
ADWORD
+
ALDREX
ASTREX
ALDREXD
ASTREXD
+
APLD
+
ACLZ
+
AMULWT
AMULWB
AMULAWT
AMULAWB
+
ADATABUNDLE
ADATABUNDLEEND
- AMRC
+
+ AMRC // MRC/MCR
+
ALAST
+
+ // aliases
AB = obj.AJMP
ABL = obj.ACALL
)
/* scond byte */
const (
- C_SCOND = (1 << 4) - 1
- C_SBIT = 1 << 4
- C_PBIT = 1 << 5
- C_WBIT = 1 << 6
- C_FBIT = 1 << 7
- C_UBIT = 1 << 7
- C_SCOND_XOR = 14
+ C_SCOND = (1 << 4) - 1
+ C_SBIT = 1 << 4
+ C_PBIT = 1 << 5
+ C_WBIT = 1 << 6
+ C_FBIT = 1 << 7 /* psr flags-only */
+ C_UBIT = 1 << 7 /* up bit, unsigned bit */
+
+ // These constants are the ARM condition codes encodings,
+ // XORed with 14 so that C_SCOND_NONE has value 0,
+ // so that a zeroed Prog.scond means "always execute".
+ C_SCOND_XOR = 14
+
C_SCOND_EQ = 0 ^ C_SCOND_XOR
C_SCOND_NE = 1 ^ C_SCOND_XOR
C_SCOND_HS = 2 ^ C_SCOND_XOR
@@ -270,13 +317,10 @@
C_SCOND_LE = 13 ^ C_SCOND_XOR
C_SCOND_NONE = 14 ^ C_SCOND_XOR
C_SCOND_NV = 15 ^ C_SCOND_XOR
- SHIFT_LL = 0 << 5
- SHIFT_LR = 1 << 5
- SHIFT_AR = 2 << 5
- SHIFT_RR = 3 << 5
-)
-/*
- * this is the ranlib header
- */
-var SYMDEF string
+ /* D_SHIFT type */
+ SHIFT_LL = 0 << 5
+ SHIFT_LR = 1 << 5
+ SHIFT_AR = 2 << 5
+ SHIFT_RR = 3 << 5
+)
diff --git a/src/cmd/internal/obj/arm/asm5.go b/src/cmd/internal/obj/arm/asm5.go
index 980bbeb..b801bd7 100644
--- a/src/cmd/internal/obj/arm/asm5.go
+++ b/src/cmd/internal/obj/arm/asm5.go
@@ -350,8 +350,8 @@
if out != nil {
out[0] = ((uint32(p.Scond)&C_SCOND)^C_SCOND_XOR)<<28 | 0x03c0013f | (uint32(p.To.Reg)&15)<<12 | (uint32(p.To.Reg)&15)<<16 // BIC $0xc000000f, Rx
if p.As == AB {
- out[1] = ((uint32(p.Scond)&C_SCOND)^C_SCOND_XOR)<<28 | 0x012fff10 | (uint32(p.To.Reg)&15)<<0 // BX Rx // ABL
- } else {
+ out[1] = ((uint32(p.Scond)&C_SCOND)^C_SCOND_XOR)<<28 | 0x012fff10 | (uint32(p.To.Reg)&15)<<0 // BX Rx
+ } else { // ABL
out[1] = ((uint32(p.Scond)&C_SCOND)^C_SCOND_XOR)<<28 | 0x012fff30 | (uint32(p.To.Reg)&15)<<0 // BLX Rx
}
}
@@ -473,7 +473,8 @@
break
}
- if (p.To.Type == obj.TYPE_MEM && p.To.Reg != REG_R13 && p.To.Reg != REG_R9) || (p.From.Type == obj.TYPE_MEM && p.From.Reg != REG_R13 && p.From.Reg != REG_R9) { // MOVW Rx, X(Ry), y != 13 && y != 9 // MOVW X(Rx), Ry, x != 13 && x != 9
+ if (p.To.Type == obj.TYPE_MEM && p.To.Reg != REG_R13 && p.To.Reg != REG_R9) || // MOVW Rx, X(Ry), y != 13 && y != 9
+ (p.From.Type == obj.TYPE_MEM && p.From.Reg != REG_R13 && p.From.Reg != REG_R9) { // MOVW X(Rx), Ry, x != 13 && x != 9
var a *obj.Addr
if p.To.Type == obj.TYPE_MEM {
a = &p.To
diff --git a/src/cmd/internal/obj/objfile.go b/src/cmd/internal/obj/objfile.go
index ef17d72..e69e246 100644
--- a/src/cmd/internal/obj/objfile.go
+++ b/src/cmd/internal/obj/objfile.go
@@ -2,6 +2,102 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// Writing of Go object files.
+//
+// Originally, Go object files were Plan 9 object files, but no longer.
+// Now they are more like standard object files, in that each symbol is defined
+// by an associated memory image (bytes) and a list of relocations to apply
+// during linking. We do not (yet?) use a standard file format, however.
+// For now, the format is chosen to be as simple as possible to read and write.
+// It may change for reasons of efficiency, or we may even switch to a
+// standard file format if there are compelling benefits to doing so.
+// See golang.org/s/go13linker for more background.
+//
+// The file format is:
+//
+// - magic header: "\x00\x00go13ld"
+// - byte 1 - version number
+// - sequence of strings giving dependencies (imported packages)
+// - empty string (marks end of sequence)
+// - sequence of defined symbols
+// - byte 0xff (marks end of sequence)
+// - magic footer: "\xff\xffgo13ld"
+//
+// All integers are stored in a zigzag varint format.
+// See golang.org/s/go12symtab for a definition.
+//
+// Data blocks and strings are both stored as an integer
+// followed by that many bytes.
+//
+// A symbol reference is a string name followed by a version.
+// An empty name corresponds to a nil LSym* pointer.
+//
+// Each symbol is laid out as the following fields (taken from LSym*):
+//
+// - byte 0xfe (sanity check for synchronization)
+// - type [int]
+// - name [string]
+// - version [int]
+// - flags [int]
+// 1 dupok
+// - size [int]
+// - gotype [symbol reference]
+// - p [data block]
+// - nr [int]
+// - r [nr relocations, sorted by off]
+//
+// If type == STEXT, there are a few more fields:
+//
+// - args [int]
+// - locals [int]
+// - nosplit [int]
+// - flags [int]
+// 1 leaf
+// 2 C function
+// - nlocal [int]
+// - local [nlocal automatics]
+// - pcln [pcln table]
+//
+// Each relocation has the encoding:
+//
+// - off [int]
+// - siz [int]
+// - type [int]
+// - add [int]
+// - xadd [int]
+// - sym [symbol reference]
+// - xsym [symbol reference]
+//
+// Each local has the encoding:
+//
+// - asym [symbol reference]
+// - offset [int]
+// - type [int]
+// - gotype [symbol reference]
+//
+// The pcln table has the encoding:
+//
+// - pcsp [data block]
+// - pcfile [data block]
+// - pcline [data block]
+// - npcdata [int]
+// - pcdata [npcdata data blocks]
+// - nfuncdata [int]
+// - funcdata [nfuncdata symbol references]
+// - funcdatasym [nfuncdata ints]
+// - nfile [int]
+// - file [nfile symbol references]
+//
+// The file layout and meaning of type integers are architecture-independent.
+//
+// TODO(rsc): The file format is good for a first pass but needs work.
+// - There are SymID in the object file that should really just be strings.
+// - The actual symbol memory images are interlaced with the symbol
+// metadata. They should be separated, to reduce the I/O required to
+// load just the metadata.
+// - The symbol references should be shortened, either with a symbol
+// table or by using a simple backward index to an earlier mentioned symbol.
+
package obj
import (
diff --git a/src/cmd/internal/obj/ppc64/9.out.go b/src/cmd/internal/obj/ppc64/9.out.go
index d3d54fd..90377ff 100644
--- a/src/cmd/internal/obj/ppc64/9.out.go
+++ b/src/cmd/internal/obj/ppc64/9.out.go
@@ -39,11 +39,10 @@
const (
NSNAME = 8
NSYM = 50
- NREG = 32
- NFREG = 32
+ NREG = 32 /* number of general registers */
+ NFREG = 32 /* number of floating point registers */
)
-// avoid conflict with ucontext.h. sigh.
const (
REG_R0 = obj.RBasePPC64 + iota
REG_R1
@@ -77,6 +76,7 @@
REG_R29
REG_R30
REG_R31
+
REG_F0 = obj.RBasePPC64 + 32 + iota - 32
REG_F1
REG_F2
@@ -109,8 +109,10 @@
REG_F29
REG_F30
REG_F31
+
REG_SPECIAL = obj.RBasePPC64 + 64
- REG_CR0 = obj.RBasePPC64 + 64 + iota - 65
+
+ REG_CR0 = obj.RBasePPC64 + 64 + iota - 65
REG_CR1
REG_CR2
REG_CR3
@@ -118,37 +120,41 @@
REG_CR5
REG_CR6
REG_CR7
+
REG_MSR = obj.RBasePPC64 + 72 + iota - 73
REG_FPSCR
REG_CR
- REG_SPR0 = obj.RBasePPC64 + 1024
- REG_DCR0 = obj.RBasePPC64 + 2048
- REG_XER = REG_SPR0 + 1
- REG_LR = REG_SPR0 + 8
- REG_CTR = REG_SPR0 + 9
- REGZERO = REG_R0
+
+ REG_SPR0 = obj.RBasePPC64 + 1024 // first of 1024 registers
+ REG_DCR0 = obj.RBasePPC64 + 2048 // first of 1024 registers
+
+ REG_XER = REG_SPR0 + 1
+ REG_LR = REG_SPR0 + 8
+ REG_CTR = REG_SPR0 + 9
+
+ REGZERO = REG_R0 /* set to zero */
REGSP = REG_R1
REGSB = REG_R2
REGRET = REG_R3
- REGARG = -1
- REGRT1 = REG_R3
- REGRT2 = REG_R4
- REGMIN = REG_R7
- REGCTXT = REG_R11
- REGTLS = REG_R13
+ REGARG = -1 /* -1 disables passing the first argument in register */
+ REGRT1 = REG_R3 /* reserved for runtime, duffzero and duffcopy */
+ REGRT2 = REG_R4 /* reserved for runtime, duffcopy */
+ REGMIN = REG_R7 /* register variables allocated from here to REGMAX */
+ REGCTXT = REG_R11 /* context for closures */
+ REGTLS = REG_R13 /* C ABI TLS base pointer */
REGMAX = REG_R27
- REGEXT = REG_R30
- REGG = REG_R30
- REGTMP = REG_R31
+ REGEXT = REG_R30 /* external registers allocated from here down */
+ REGG = REG_R30 /* G */
+ REGTMP = REG_R31 /* used by the linker */
FREGRET = REG_F0
- FREGMIN = REG_F17
- FREGMAX = REG_F26
- FREGEXT = REG_F26
- FREGCVI = REG_F27
- FREGZERO = REG_F28
- FREGHALF = REG_F29
- FREGONE = REG_F30
- FREGTWO = REG_F31
+ FREGMIN = REG_F17 /* first register variable */
+ FREGMAX = REG_F26 /* last register variable for 9g only */
+ FREGEXT = REG_F26 /* first external register */
+ FREGCVI = REG_F27 /* floating conversion constant */
+ FREGZERO = REG_F28 /* both float and double */
+ FREGHALF = REG_F29 /* double */
+ FREGONE = REG_F30 /* double */
+ FREGTWO = REG_F31 /* double */
)
/*
@@ -166,6 +172,7 @@
)
const (
+ /* mark flags */
LABEL = 1 << 0
LEAF = 1 << 1
FLOAT = 1 << 2
@@ -183,19 +190,19 @@
C_REG
C_FREG
C_CREG
- C_SPR
+ C_SPR /* special processor register */
C_ZCON
- C_SCON
- C_UCON
- C_ADDCON
- C_ANDCON
- C_LCON
- C_DCON
- C_SACON
+ C_SCON /* 16 bit signed */
+ C_UCON /* 32 bit signed, low 16 bits 0 */
+ C_ADDCON /* -0x8000 <= v < 0 */
+ C_ANDCON /* 0 < v <= 0xFFFF */
+ C_LCON /* other 32 */
+ C_DCON /* other 64 (could subdivide further) */
+ C_SACON /* $n(REG) where n <= int16 */
C_SECON
- C_LACON
+ C_LACON /* $n(REG) where int16 < n <= int32 */
C_LECON
- C_DACON
+ C_DACON /* $n(REG) where int32 < n */
C_SBRA
C_LBRA
C_SAUTO
@@ -214,7 +221,8 @@
C_GOK
C_ADDR
C_TEXTSIZE
- C_NCLASS
+
+ C_NCLASS /* must be the last */
)
const (
@@ -414,6 +422,7 @@
ASYNC
AXOR
AXORCC
+
ADCBF
ADCBI
ADCBST
@@ -430,9 +439,13 @@
ATLBIEL
ATLBSYNC
ATW
+
ASYSCALL
AWORD
+
ARFCI
+
+ /* optional on 32-bit */
AFRES
AFRESCC
AFRSQRTE
@@ -443,9 +456,12 @@
AFSQRTCC
AFSQRTS
AFSQRTSCC
+
+ /* 64-bit */
+
ACNTLZD
ACNTLZDCC
- ACMPW
+ ACMPW /* CMP with L=0 */
ACMPWU
ADIVD
ADIVDCC
@@ -457,6 +473,7 @@
ADIVDUV
AEXTSW
AEXTSWCC
+ /* AFCFIW; AFCFIWCC */
AFCFID
AFCFIDCC
AFCTID
@@ -498,6 +515,8 @@
ASRDCC
ASTDCCC
ATD
+
+ /* 64-bit pseudo operation */
ADWORD
AREMD
AREMDCC
@@ -507,8 +526,13 @@
AREMDUCC
AREMDUV
AREMDUVCC
+
+ /* more 64-bit operations */
AHRFID
+
ALAST
+
+ // aliases
ABR = obj.AJMP
ABL = obj.ACALL
ARETURN = obj.ARET
diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go
index 9e227c4..470f6f9 100644
--- a/src/cmd/internal/obj/ppc64/asm9.go
+++ b/src/cmd/internal/obj/ppc64/asm9.go
@@ -1331,6 +1331,7 @@
}
const (
+ /* each rhs is OPVCC(_, _, _, _) */
OP_ADD = 31<<26 | 266<<1 | 0<<10 | 0
OP_ADDI = 14<<26 | 0<<1 | 0<<10 | 0
OP_ADDIS = 15<<26 | 0<<1 | 0<<10 | 0
diff --git a/src/cmd/internal/obj/x86/6.out.go b/src/cmd/internal/obj/x86/6.out.go
index 0e13698..495ecd2 100644
--- a/src/cmd/internal/obj/x86/6.out.go
+++ b/src/cmd/internal/obj/x86/6.out.go
@@ -264,6 +264,7 @@
AXORB
AXORL
AXORW
+
AFMOVB
AFMOVBP
AFMOVD
@@ -278,6 +279,7 @@
AFMOVWP
AFMOVX
AFMOVXP
+
AFCOMB
AFCOMBP
AFCOMD
@@ -292,38 +294,46 @@
AFUCOM
AFUCOMP
AFUCOMPP
+
AFADDDP
AFADDW
AFADDL
AFADDF
AFADDD
+
AFMULDP
AFMULW
AFMULL
AFMULF
AFMULD
+
AFSUBDP
AFSUBW
AFSUBL
AFSUBF
AFSUBD
+
AFSUBRDP
AFSUBRW
AFSUBRL
AFSUBRF
AFSUBRD
+
AFDIVDP
AFDIVW
AFDIVL
AFDIVF
AFDIVD
+
AFDIVRDP
AFDIVRW
AFDIVRL
AFDIVRF
AFDIVRD
+
AFXCHD
AFFREE
+
AFLDCW
AFLDENV
AFRSTOR
@@ -331,6 +341,7 @@
AFSTCW
AFSTENV
AFSTSW
+
AF2XM1
AFABS
AFCHS
@@ -361,6 +372,8 @@
AFXTRACT
AFYL2X
AFYL2XP1
+
+ // extra 32-bit operations
ACMPXCHGB
ACMPXCHGL
ACMPXCHGW
@@ -382,6 +395,8 @@
AXADDB
AXADDL
AXADDW
+
+ // conditional move
ACMOVLCC
ACMOVLCS
ACMOVLEQ
@@ -430,6 +445,8 @@
ACMOVWPC
ACMOVWPL
ACMOVWPS
+
+ // 64-bit
AADCQ
AADDQ
AANDQ
@@ -481,6 +498,8 @@
AXADDQ
AXCHGQ
AXORQ
+
+ // media
AADDPD
AADDPS
AADDSD
@@ -682,6 +701,7 @@
AUNPCKLPS
AXORPD
AXORPS
+
APF2IW
APF2IL
API2FW
@@ -690,25 +710,32 @@
ARETFL
ARETFQ
ASWAPGS
+
AMODE
ACRC32B
ACRC32Q
AIMUL3Q
+
APREFETCHT0
APREFETCHT1
APREFETCHT2
APREFETCHNTA
+
AMOVQL
ABSWAPL
ABSWAPQ
+
AAESENC
AAESENCLAST
AAESDEC
AAESDECLAST
AAESIMC
AAESKEYGENASSIST
+
APSHUFD
APCLMULQDQ
+
+ // from 386
AJCXZW
AFCMOVCC
AFCMOVCS
@@ -722,6 +749,7 @@
AFCOMIP
AFUCOMI
AFUCOMIP
+
ALAST
)
@@ -743,6 +771,7 @@
REG_R13B
REG_R14B
REG_R15B
+
REG_AX = obj.RBaseAMD64 + 16 + iota - 17
REG_CX
REG_DX
@@ -759,12 +788,16 @@
REG_R13
REG_R14
REG_R15
+
REG_AH = obj.RBaseAMD64 + 32 + iota - 33
REG_CH
REG_DH
REG_BH
+
REG_F0 = obj.RBaseAMD64 + 36
+
REG_M0 = obj.RBaseAMD64 + 44
+
REG_X0 = obj.RBaseAMD64 + 52 + iota - 39
REG_X1
REG_X2
@@ -781,31 +814,37 @@
REG_X13
REG_X14
REG_X15
+
REG_CS = obj.RBaseAMD64 + 68 + iota - 55
REG_SS
REG_DS
REG_ES
REG_FS
REG_GS
- REG_GDTR
- REG_IDTR
- REG_LDTR
- REG_MSW
- REG_TASK
- REG_CR = obj.RBaseAMD64 + 79
- REG_DR = obj.RBaseAMD64 + 95
- REG_TR = obj.RBaseAMD64 + 103
+
+ REG_GDTR /* global descriptor table register */
+ REG_IDTR /* interrupt descriptor table register */
+ REG_LDTR /* local descriptor table register */
+ REG_MSW /* machine status word */
+ REG_TASK /* task register */
+
+ REG_CR = obj.RBaseAMD64 + 79
+ REG_DR = obj.RBaseAMD64 + 95
+ REG_TR = obj.RBaseAMD64 + 103
+
REG_TLS = obj.RBaseAMD64 + 111 + iota - 69
+
MAXREG
+
REGARG = -1
REGRET = REG_AX
FREGRET = REG_X0
REGSP = REG_SP
REGTMP = REG_DI
REGCTXT = REG_DX
- REGEXT = REG_R15
- FREGMIN = REG_X0 + 5
- FREGEXT = REG_X0 + 15
+ REGEXT = REG_R15 /* compiler allocates external registers R15 down */
+ FREGMIN = REG_X0 + 5 /* first register variable */
+ FREGEXT = REG_X0 + 15 /* first external register */
T_TYPE = 1 << 0
T_INDEX = 1 << 1
T_OFFSET = 1 << 2
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 4ec4b25..ae47801 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -40,7 +40,21 @@
// Instruction layout.
const (
- MaxAlign = 32
+ MaxAlign = 32 // max data alignment
+
+ // Loop alignment constants:
+ // want to align loop entry to LoopAlign-byte boundary,
+ // and willing to insert at most MaxLoopPad bytes of NOP to do so.
+ // We define a loop entry as the target of a backward jump.
+ //
+ // gcc uses MaxLoopPad = 10 for its 'generic x86-64' config,
+ // and it aligns all jump targets, not just backward jump targets.
+ //
+ // As of 6/1/2012, the effect of setting MaxLoopPad = 10 here
+ // is very slight but negative, so the alignment is disabled by
+ // setting MaxLoopPad = 0. The code is here for reference and
+ // for future experiments.
+ //
LoopAlign = 16
MaxLoopPad = 0
FuncAlign = 16
@@ -173,7 +187,7 @@
Zm_r_3d
Zm_r_xm_nr
Zr_m_xm_nr
- Zibm_r
+ Zibm_r /* mmx1,mmx2/mem64,imm8 */
Zmb_r
Zaut_r
Zo_m
@@ -194,28 +208,30 @@
)
const (
- Px = 0
- Px1 = 1 // symbolic; exact value doesn't matter
- P32 = 0x32
- Pe = 0x66
- Pm = 0x0f
- Pq = 0xff
- Pb = 0xfe
- Pf2 = 0xf2
- Pf3 = 0xf3
- Pq3 = 0x67
- Pw = 0x48
- Pw8 = 0x90 // symbolic; exact value doesn't matter
- Py = 0x80
- Py1 = 0x81 // symbolic; exact value doesn't matter
- Py3 = 0x83 // symbolic; exact value doesn't matter
- Rxf = 1 << 9
- Rxt = 1 << 8
- Rxw = 1 << 3
- Rxr = 1 << 2
- Rxx = 1 << 1
- Rxb = 1 << 0
- Maxand = 10
+ Px = 0
+ Px1 = 1 // symbolic; exact value doesn't matter
+ P32 = 0x32 /* 32-bit only */
+ Pe = 0x66 /* operand escape */
+ Pm = 0x0f /* 2byte opcode escape */
+ Pq = 0xff /* both escapes: 66 0f */
+ Pb = 0xfe /* byte operands */
+ Pf2 = 0xf2 /* xmm escape 1: f2 0f */
+ Pf3 = 0xf3 /* xmm escape 2: f3 0f */
+ Pq3 = 0x67 /* xmm escape 3: 66 48 0f */
+ Pw = 0x48 /* Rex.w */
+ Pw8 = 0x90 // symbolic; exact value doesn't matter
+ Py = 0x80 /* defaults to 64-bit mode */
+ Py1 = 0x81 // symbolic; exact value doesn't matter
+ Py3 = 0x83 // symbolic; exact value doesn't matter
+
+ Rxf = 1 << 9 /* internal flag for Rxr on from */
+ Rxt = 1 << 8 /* internal flag for Rxr on to */
+ Rxw = 1 << 3 /* =1, 64-bit operand size */
+ Rxr = 1 << 2 /* extend modrm reg */
+ Rxx = 1 << 1 /* extend sib index */
+ Rxb = 1 << 0 /* extend modrm r/m, sib base, or opcode reg */
+
+ Maxand = 10 /* in -a output width of the byte codes */
)
var ycover [Ymax * Ymax]uint8
