blob: dac7f20f5c186faf9aa09136015f9553fcc7b3ca [file] [log] [blame]
// names.cc -- Names used by gofrontend generated code.
// Copyright 2017 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.
#include "go-system.h"
#include "gogo.h"
#include "go-encode-id.h"
#include "types.h"
#include "expressions.h"
// This file contains functions that generate names that appear in the
// assembly code. This is not used for names that appear only in the
// debug info.
// Our external names may contain only ASCII alphanumeric characters,
// underscore, and dot. (According to the GCC sources, dot is not
// permitted in assembler symbols on VxWorks and MMIX. We will not
// support those systems.) Go identifiers cannot contain dot, but Go
// package paths can. Both Go identifiers and package paths can, of
// course, contain all sorts of Unicode characters.
//
// The gc compiler uses names like "pkg.F", and it seems convenient to
// emulate that. Therefore, we will use dot to separate different
// components of names.
//
// Since package paths can contain dot, to avoid ambiguity we must
// encode package paths such that they do not contain any dot. The
// natural way to do this is to encode forbidden characters, including
// dot, using a notation based on underscore. We will, of course,
// have to encode underscore itself.
//
// Since we will be using an underscore encoding for the package path,
// it seems reasonable to use the same encoding for Go identifiers.
// This has the disadvantage that encoded Go identifiers will appear
// to be valid Go identifiers with funny spellings, but it seems like
// the best available approach.
//
// Therefore, in the following discussion we may assume that none of
// the names under discussion contain a dot. All of the names we
// generate for Go identifiers (that don't use //export or
// //go:linkname) will contain at least one dot, as discussed below.
// We assume that none of the non-Go symbols in the final link will
// contain a dot, so we don't worry about conflicts.
//
// We first describe the basic symbol names, used to represent Go
// functions and variables.
//
// The external name for a normal Go symbol NAME, a function or
// variable, is simply "PKGPATH.NAME". Note that NAME is not the
// packed form used for the "hidden" name internally in the compiler;
// it is the name that appears in the source code. Both PKGPATH and
// NAME will be encoded as described below. The encoding process
// ensures that neither encoded string can contain a dot, and neither
// will start with a digit (NAME is a Go identifier that can't contain
// a dot or start with a digit anyhow). The encoding process means
// that these external names contain exactly one dot and do not start
// with a dot.
//
// The external name for a method NAME for a named type TYPE is
// "PKGPATH.TYPE.NAME". Both NAME and TYPE are simple Go identifiers.
// Unlike the gc compiler, the external name does not indicate whether
// this is a pointer method or a value method; a named type can not
// have both a pointer and value method with the same name, so there
// is no ambiguity. PKGPATH is the package path of the package in
// which TYPE is defined. PKGPATH, TYPE, and NAME are encoded, and
// cannot be empty or contain a dot or start with a digit. These
// external names contain exactly two dots, not consecutive, and they
// do not start with a dot.
//
// It's uncommon, but the use of type literals with embedded fields
// can cause us to have methods on unnamed types. The external names
// for these are also PKGPATH.TYPELIT.NAME, where TYPELIT is an
// approximately readable version of the type literal, described
// below. A TYPELIT will always contain characters that cannot appear
// in a Go identifier, so TYPELIT can never be confused with a TYPE
// name. There is no ambiguity as long as encoded type literals are
// unambiguous.
//
// Also uncommon is an external name that must refer to a named type
// defined within a function. While such a type can not have methods
// itself, it can pick up embedded methods, and those methods need
// names. These are treated as a kind of type literal written as,
// before type literal encoding, FNNAME.TYPENAME(INDEX) or, for a
// method, TYPE.MNAME.TYPENAME(INDEX). INDEX is the index of that
// named type within the function, as a single function can have
// multiple types with the same name. This is unambiguous as
// parentheses can not appear in a type literal in this form (they can
// only appear in interface method declarations).
//
// That is the end of the list of basic names. The remaining names
// exist for special purposes, and are differentiated from the basic
// names by containing two consecutive dots.
//
// The hash function for a type is treated as a method whose name is
// ".hash". That is, the method name begins with a dot. The effect
// is that there will be two consecutive dots in the name; the name
// will always end with "..hash".
//
// Similarly the equality function for a type is treated as a method
// whose name is ".eq".
//
// The function descriptor for a function is the same as the name of
// the function with an added suffix "..f".
//
// A thunk for a go or defer statement is treated as a function whose
// name is ".thunkNN", unencoded, where NN is a sequence of digits
// (these functions are never globally visible). Thus the final name
// of a thunk will be PKGPATH..thunkNN (PKGPATH is encoded).
//
// An init function is treated as a function whose name is ".initNN",
// unencoded, where NN is a sequence of digits (these functions are
// never globally visible). Thus the final name of an init function
// will be PKGPATH..initNN (PKGPATH is encoded).
//
// A nested function is given the name of outermost enclosing function
// or method with an added suffix "..funcNN", unencoded, where NN is a
// sequence of digits. Note that the function descriptor of a nested
// function, if needed, will end with "..funcNN..f".
//
// A recover thunk is the same as the name of the function with an
// added suffix "..r".
//
// The name of a type descriptor for a named type is
// PKGPATH.TYPENAME..d (PKGPATH and TYPENAME are encoded).
//
// The name of a type descriptor for a pointer to a named type is
// PKGPATH.TYPENAME..p (PKGPATH and TYPENAME are encoded).
//
// The name of a type descriptor for an unnamed type is type..TYPELIT.
// That is, the string "type.." followed by the encoded type literal.
// These names are common symbols, in the linker's sense of the word
// common: in the final executable there is only one instance of the
// type descriptor for a given unnamed type.
//
// The name of the GC symbol for a named type is PKGPATH.TYPE..g
// (PKGPATH and TYPE are encoded).
//
// The name of the GC symbol for an unnamed type is type..TYPELIT..g.
// These are common symbols.
//
// The name of a ptrmask symbol is gcbits..B32 where B32 is an
// encoding of the ptrmask bits using only ASCII letters. These are
// common symbols.
//
// An interface method table for assigning the non-interface type TYPE
// to the interface type ITYPE is named imt..ITYPE..TYPE. If ITYPE or
// TYPE is a named type, they are written as PKGPATH.TYPE (where both
// PKGPATH and TYPE are encoded). Otherwise they are written as a
// type literal. An interface method table for a pointer method set
// uses pimt instead of imt.
//
// The names of composite literal initializers, including the GC root
// variable, are not referenced. They must not conflict with any C
// language names, but the names are otherwise unimportant. They are
// named "go..CNN" where NN is a sequence of digits. The names do not
// include the PKGPATH.
//
// The map zero value, a common symbol that represents the zero value
// of a map, is named simply "go..zerovalue". The name does not
// include the PKGPATH.
//
// The import function for the main package is referenced by C code,
// and is named __go_init_main. For other packages it is
// PKGPATH..import. If a package doesn't need an init function, it
// will have a dummy one, named ~PKGPATH.
//
// In each package there is a list of all the type descriptors defined
// in this package. The name of the list is PKGPATH..types.
//
// In the main package it gathers all the type descriptor lists in a
// single list, named go..typelists.
//
// The type literal encoding is essentially a single line version of
// the type literal, such as "struct { pkgpath.i int; J int }". In
// this representation unexported names use their pkgpath, exported
// names omit it.
//
// The type literal encoding is not quite valid Go, as some aspects of
// compiler generated types can not be represented. For example,
// incomparable struct types have an extra field "{x}". Struct tags
// can contain any character, which will be underscore encoded as
// usual. In the unusual case of a curly brace or a backslash in a
// struct tag, the brace or backslash will be backslash quoted, before
// underscore encoding.
//
// Many of these names will be visible in the debugger. The debugger
// will be given these names before applying any underscore encoding.
// These user names do not have to be unique--they are only used by
// the debugger, not the linker--so this is OK. However, there is an
// exception: if the name would otherwise include characters that
// can't normally appear in an identifier, then the user name will
// also be underscore encoded. This avoids problems with
// communicating the debug info to the assembler and with handling the
// debug info in the debugger. A Go-aware debugger will need to know
// whether to apply underscore decoding to a name before showing it to
// the user. We indicate this by adding a prefix of "g.", and
// assuming that cases of a package path of "g" are unusual. This
// prefix will only appear in the user name, not the assembler name.
//
// The underscore encoding is, naturally, an underscore followed by
// other characters. As there are various characters that commonly
// appear in type literals and in package paths, we have a set of
// short encodings. Then we have general encodings for other
// characters.
//
// __ - '_'
// _0 - '.'
// _1 - '/'
// _2 - '*'
// _3 - ','
// _4 - '{'
// _5 - '}'
// _6 - '['
// _7 - ']'
// _8 - '('
// _9 - ')'
// _a - '"'
// _b - ' '
// _c - ';'
//
// Other non-alphanumeric ASCII characters are encoded as _xNN, where
// NN is the hex value for the character. If an encoded name would
// otherwise start with a digit, this encoding is also used for the
// leading digit.
//
// Non-ASCII Unicode characters are encoded as _u and four hex digits
// or _U and eight digits, just as in the language only using _u and
// _U instead of \u and \U.
//
// Demangling these names is straightforward:
// - replace _xXX with an ASCII character
// - replace _uXXXX with a unicode character
// - replace _UXXXXXXXX with a unicode character
// - replace _C per the table above
// That will get you as close as possible to a readable name.
// Set BNAME to the name to use for an exported function, a method, or
// a function/method declaration. GO_NAME is the name that appears in
// the Go code. PACKAGE is the package where the function is defined,
// and is NULL for the package being compiled. For a method, RTYPE is
// the method's receiver type; for a function, RTYPE is NULL.
void
Gogo::function_backend_name(const std::string& go_name,
const Package* package, const Type* rtype,
Backend_name* bname)
{
if (rtype != NULL)
rtype->deref()->backend_name(this, bname);
else if (package == NULL)
bname->add(this->pkgpath());
else
bname->add(package->pkgpath());
size_t pos = Gogo::special_name_pos(go_name);
if (pos == std::string::npos)
bname->add(Gogo::unpack_hidden_name(go_name));
else
{
if (pos > 0)
bname->add(go_name.substr(0, pos));
bname->set_suffix(go_name.substr(pos));
}
}
// Set BNAME to the name to use for a function descriptor. These
// symbols are globally visible.
void
Gogo::function_descriptor_backend_name(Named_object* no,
Backend_name* bname)
{
if (no->is_function())
no->func_value()->backend_name(this, no, bname);
else if (no->is_function_declaration())
no->func_declaration_value()->backend_name(this, no, bname);
else
go_unreachable();
bname->append_suffix("..f");
}
// Return the name to use for a generated stub method. A stub method
// is used as the method table entry for a promoted method of an
// embedded type. MNAME is the method name. PACKAGE is the package
// where the type that needs this stub method is defined. These
// functions are globally visible.
//
// This returns a name that acts like a Go identifier, as though the
// stub method were written in Go as an explicitly defined method that
// simply calls the promoted method. The name we return here will
// eventually be passed to function_backend_name, which will return a
// name that includes the receiver type.
//
// We construct a unique method name and append "..stub".
// function_backend_name will look for the "..stub" and turn that into
// an unencoded suffix. The rest of the name will be encoded as
// usual.
std::string
Gogo::stub_method_name(const Package* package, const std::string& mname)
{
if (!Gogo::is_hidden_name(mname))
return mname + "..stub";
const std::string& ppkgpath(package == NULL
? this->pkgpath()
: package->pkgpath());
std::string mpkgpath = Gogo::hidden_name_pkgpath(mname);
if (mpkgpath == ppkgpath)
return Gogo::unpack_hidden_name(mname) + "..stub";
// We are creating a stub method for an unexported method of an
// imported embedded type. A single type can have multiple promoted
// methods with the same unexported name, if it embeds types from
// different packages. We need to disambiguate the method name.
// This produces an unambiguous name because even though MPKGPATH
// can be anything, we know that MNAME does not contain a dot. The
// dot we return here, between MPKGPATH and MNAME, will wind up
// being underscore encoded.
std::string ret(mpkgpath);
ret.push_back('.');
ret.append(Gogo::unpack_hidden_name(mname));
ret.append("..stub");
return ret;
}
// Set BNAME to the name of the hash function for TYPE.
void
Gogo::hash_function_name(const Type* type, Backend_name* bname)
{
if (type->named_type() != NULL)
type->backend_name(this, bname);
else
{
bname->add(this->pkgpath());
type->backend_name(this, bname);
}
bname->set_suffix("..hash");
}
// Set BNAME to the name of the equal function for TYPE. If NAME is
// not NULL it is the name of the type.
void
Gogo::equal_function_name(const Type* type, const Named_type* name,
Backend_name* bname)
{
if (name != NULL)
name->backend_name(this, bname);
else
{
bname->add(this->pkgpath());
type->backend_name(this, bname);
}
bname->set_suffix("..eq");
}
// Set BNAME to the name to use for a global variable. GO_NAME is the
// name that appears in the Go code. PACKAGE is the package where the
// variable is defined, and is NULL for the package being compiled.
void
Gogo::global_var_backend_name(const std::string& go_name,
const Package* package,
Backend_name* bname)
{
if (package == NULL)
bname->add(this->pkgpath());
else
bname->add(package->pkgpath());
bname->add(Gogo::unpack_hidden_name(go_name));
}
// Return an erroneous name that indicates that an error has already
// been reported. This name will act like a Go identifier.
std::string
Gogo::erroneous_name()
{
go_assert(saw_errors());
static int erroneous_count;
char name[50];
snprintf(name, sizeof name, ".erroneous%d", erroneous_count);
++erroneous_count;
return name;
}
// Return whether a name is an erroneous name.
bool
Gogo::is_erroneous_name(const std::string& name)
{
return name.compare(0, 10, ".erroneous") == 0;
}
// Return a name for a thunk object. This name will act like a Go
// identifier. The name returned here will eventually be passed to
// function_backend_name, which will pull off the ..thunk as an
// unencoded suffix.
std::string
Gogo::thunk_name()
{
static int thunk_count;
char thunk_name[50];
snprintf(thunk_name, sizeof thunk_name, "..thunk%d", thunk_count);
++thunk_count;
// We don't want to return a name that starts with a dot, as that
// will confuse Gogo::is_hidden_name. And we don't want to change
// ..thunk, which fits our general theme and is used by code like
// runtime.Callers. But the prefix doesn't matter, as the actual
// name will include the package path.
std::string ret = "go";
return ret + thunk_name;
}
// Return whether a function is a thunk.
bool
Gogo::is_thunk(const Named_object* no)
{
const std::string& name(no->name());
size_t i = name.rfind("..thunk");
if (i == std::string::npos)
return false;
return Gogo::is_digits(name.substr(i + 7));
}
// Return the name to use for an init function. There can be multiple
// functions named "init" so each one needs a different name.
std::string
Gogo::init_function_name()
{
static int init_count;
char buf[30];
snprintf(buf, sizeof buf, "..init%d", init_count);
++init_count;
return this->pkgpath() + buf;
}
// Return the name to use for a nested function. This name acts like
// a Go identifier. This name will be rewritten by
// Function::backend_name.
std::string
Gogo::nested_function_name(Named_object* enclosing)
{
std::string prefix;
unsigned int index;
if (enclosing == NULL)
{
// A function literal at top level, as in
// var f = func() {}
static unsigned int toplevel_index;
++toplevel_index;
index = toplevel_index;
prefix = ".go";
}
else
{
while (true)
{
Named_object* parent = enclosing->func_value()->enclosing();
if (parent == NULL)
break;
enclosing = parent;
}
const Typed_identifier* rcvr =
enclosing->func_value()->type()->receiver();
if (rcvr != NULL)
{
Backend_name bname;
rcvr->type()->backend_name(this, &bname);
prefix = bname.name();
prefix.push_back('.');
}
prefix.append(Gogo::unpack_hidden_name(enclosing->name()));
index = enclosing->func_value()->next_nested_function_index();
}
char buf[30];
snprintf(buf, sizeof buf, "..func%u", index);
return prefix + buf;
}
// Return the name to use for a sink function, a function whose name
// is simply underscore. We don't really need these functions but we
// do have to generate them for error checking.
std::string
Gogo::sink_function_name()
{
static int sink_count;
char buf[30];
snprintf(buf, sizeof buf, ".sink%d", sink_count);
++sink_count;
return buf;
}
// Return the name to use for a redefined function. These functions
// are erroneous but we still generate them for further error
// checking.
std::string
Gogo::redefined_function_name()
{
static int redefinition_count;
char buf[30];
snprintf(buf, sizeof buf, ".redefined%d", redefinition_count);
++redefinition_count;
return buf;
}
// Return the name to use for a recover thunk for the function NAME.
// If the function is a method, RTYPE is the receiver type. This is a
// name that acts like a Go identifier.
std::string
Gogo::recover_thunk_name(const std::string& name, const Type* rtype)
{
std::string ret;
if (rtype != NULL)
{
Backend_name bname;
rtype->deref()->backend_name(this, &bname);
ret = bname.name();
ret.append(1, '.');
}
if (Gogo::special_name_pos(name) != std::string::npos)
ret.append(name);
else
ret.append(Gogo::unpack_hidden_name(name));
ret.append("..r");
return ret;
}
// Return the name to use for a GC root variable. The GC root
// variable is a composite literal that is passed to
// runtime.registerGCRoots. There is at most one of these variables
// per compilation.
std::string
Gogo::gc_root_name()
{
return "go..C0";
}
// Return the name to use for a composite literal or string
// initializer. This is a local name never referenced outside of this
// file.
std::string
Gogo::initializer_name()
{
static unsigned int counter;
char buf[30];
++counter;
snprintf(buf, sizeof buf, "go..C%u", counter);
return buf;
}
// Return the assembler name of the variable used to represent the
// zero value of a map. This is a globally visible common symbol.
std::string
Gogo::map_zero_value_name()
{
return "go..zerovalue";
}
// Return the name to use for the import control function. This name
// is handled specially by Function::backend_name. It is not encoded
// further.
const std::string&
Gogo::get_init_fn_name()
{
if (this->init_fn_name_.empty())
{
go_assert(this->package_ != NULL);
if (this->is_main_package())
{
// Use a name that the runtime knows.
this->init_fn_name_ = "__go_init_main";
}
else
{
std::string s = this->pkgpath_symbol();
s.append("..import");
this->init_fn_name_ = s;
}
}
return this->init_fn_name_;
}
// Return the name for a dummy init function, which is not a real
// function but only for tracking transitive import.
std::string
Gogo::dummy_init_fn_name()
{
return "~" + this->pkgpath_symbol();
}
// Return the package path symbol from an init function name, which
// can be a real init function or a dummy one.
std::string
Gogo::pkgpath_symbol_from_init_fn_name(std::string name)
{
go_assert(!name.empty());
if (name[0] == '~')
return name.substr(1);
size_t pos = name.find("..import");
if (pos != std::string::npos)
return name.substr(0, pos);
go_unreachable();
}
// Set BNAME to a name for a type to use in a symbol. Return a name
// for a type to use in a symbol. These names appear in symbol names
// in the assembler file for things like type descriptors and methods.
void
Type::backend_name(Gogo* gogo, Backend_name* bname) const
{
// Special case top level named types to get nicer name encodings
// for this common case.
const Named_type* nt = this->unalias()->named_type();
if (nt != NULL && !nt->is_builtin())
{
unsigned int index;
if (nt->in_function(&index) == NULL)
{
const Named_object* no = nt->named_object();
if (no->package() == NULL)
bname->add(gogo->pkgpath());
else
bname->add(no->package()->pkgpath());
bname->add(Gogo::unpack_hidden_name(no->name()));
return;
}
}
std::string name;
bool is_non_identifier = false;
// The do_symbol_name virtual function will set RET to the mangled
// name before encoding.
this->do_mangled_name(gogo, &name, &is_non_identifier);
bname->add(name);
if (is_non_identifier)
bname->set_is_non_identifier();
}
// The mangled name is implemented as a method on each instance of
// Type.
void
Error_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
ret->append("{error}");
*is_non_identifier = true;
}
void
Void_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
ret->append("{void}");
*is_non_identifier = true;
}
void
Boolean_type::do_mangled_name(Gogo*, std::string* ret, bool*) const
{
ret->append("bool");
}
void
Integer_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
char buf[100];
snprintf(buf, sizeof buf, "%s%si%d",
this->is_abstract_ ? "{abstract}" : "",
this->is_unsigned_ ? "u" : "",
this->bits_);
ret->append(buf);
if (this->is_abstract_)
*is_non_identifier = true;
}
void
Float_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
char buf[100];
snprintf(buf, sizeof buf, "%sfloat%d",
this->is_abstract_ ? "{abstract}" : "",
this->bits_);
ret->append(buf);
if (this->is_abstract_)
*is_non_identifier = true;
}
void
Complex_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
char buf[100];
snprintf(buf, sizeof buf, "%sc%d",
this->is_abstract_ ? "{abstract}" : "",
this->bits_);
ret->append(buf);
if (this->is_abstract_)
*is_non_identifier = true;
}
void
String_type::do_mangled_name(Gogo*, std::string* ret, bool*) const
{
ret->append("string");
}
void
Function_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
ret->append("func");
if (this->receiver_ != NULL)
{
ret->push_back('(');
this->append_mangled_name(this->receiver_->type(), gogo, ret,
is_non_identifier);
ret->append(")");
}
ret->push_back('(');
const Typed_identifier_list* params = this->parameters();
if (params != NULL)
{
bool first = true;
for (Typed_identifier_list::const_iterator p = params->begin();
p != params->end();
++p)
{
if (first)
first = false;
else
ret->push_back(',');
if (this->is_varargs_ && p + 1 == params->end())
ret->append("...");
this->append_mangled_name(p->type(), gogo, ret,
is_non_identifier);
}
}
ret->push_back(')');
ret->push_back('(');
const Typed_identifier_list* results = this->results();
if (results != NULL)
{
bool first = true;
for (Typed_identifier_list::const_iterator p = results->begin();
p != results->end();
++p)
{
if (first)
first = false;
else
ret->append(",");
this->append_mangled_name(p->type(), gogo, ret, is_non_identifier);
}
}
ret->push_back(')');
*is_non_identifier = true;
}
void
Pointer_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
ret->push_back('*');
this->append_mangled_name(this->to_type_, gogo, ret, is_non_identifier);
*is_non_identifier = true;
}
void
Nil_type::do_mangled_name(Gogo*, std::string* ret,
bool* is_non_identifier) const
{
ret->append("{nil}");
*is_non_identifier = true;
}
void
Struct_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
ret->append("struct{");
if (this->is_struct_incomparable_)
ret->append("{x}");
const Struct_field_list* fields = this->fields_;
if (fields != NULL)
{
bool first = true;
for (Struct_field_list::const_iterator p = fields->begin();
p != fields->end();
++p)
{
if (first)
first = false;
else
ret->push_back(';');
if (!p->is_anonymous())
{
Gogo::append_possibly_hidden_name(ret, p->field_name());
ret->push_back(' ');
}
const Type* ft = p->type();
const Named_type* nt = ft->named_type();
if (p->is_anonymous() && nt != NULL && nt->is_builtin())
{
// For an embedded field with a builtin type, we must
// include a package path. Otherwise embedding builtin
// types in different packages will produce identical
// types, which shouldn't happen because the builtin
// types are not exported.
ret->append(gogo->pkgpath());
ret->push_back('.');
nt->append_symbol_type_name(gogo, true, ret, is_non_identifier);
}
else if (p->is_anonymous() && nt != NULL && nt->is_alias())
{
// For an anonymous field with an alias type, the field name
// is the alias name.
nt->append_symbol_type_name(gogo, true, ret, is_non_identifier);
}
else
this->append_mangled_name(ft, gogo, ret, is_non_identifier);
if (p->has_tag())
{
// Use curly braces around a struct tag, since they are
// unambiguous here and struct tags rarely contain curly
// braces.
ret->push_back('{');
ret->append(go_mangle_struct_tag(p->tag()));
ret->push_back('}');
}
}
}
ret->push_back('}');
*is_non_identifier = true;
}
void
Array_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
ret->push_back('[');
if (this->length_ != NULL)
{
Numeric_constant nc;
if (!this->length_->numeric_constant_value(&nc))
{
go_assert(saw_errors());
return;
}
mpz_t val;
if (!nc.to_int(&val))
{
go_assert(saw_errors());
return;
}
char *s = mpz_get_str(NULL, 10, val);
ret->append(s);
free(s);
mpz_clear(val);
if (this->is_array_incomparable_)
ret->append("x");
}
ret->push_back(']');
this->append_mangled_name(this->element_type_, gogo, ret, is_non_identifier);
*is_non_identifier = true;
}
void
Map_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
ret->append("map[");
this->append_mangled_name(this->key_type_, gogo, ret, is_non_identifier);
ret->push_back(']');
this->append_mangled_name(this->val_type_, gogo, ret, is_non_identifier);
*is_non_identifier = true;
}
void
Channel_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
if (!this->may_send_)
ret->append("<-");
ret->append("chan");
if (!this->may_receive_)
ret->append("<-");
ret->push_back(' ');
this->append_mangled_name(this->element_type_, gogo, ret, is_non_identifier);
*is_non_identifier = true;
}
void
Interface_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
go_assert(this->methods_are_finalized_);
ret->append("interface{");
const Typed_identifier_list* methods = this->all_methods_;
if (methods != NULL && !this->seen_)
{
this->seen_ = true;
bool first = true;
for (Typed_identifier_list::const_iterator p = methods->begin();
p != methods->end();
++p)
{
if (first)
first = false;
else
ret->push_back(';');
if (!p->name().empty())
{
Gogo::append_possibly_hidden_name(ret, p->name());
ret->push_back(' ');
}
this->append_mangled_name(p->type(), gogo, ret, is_non_identifier);
}
this->seen_ = false;
}
ret->push_back('}');
*is_non_identifier = true;
}
void
Named_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool* is_non_identifier) const
{
this->append_symbol_type_name(gogo, false, ret, is_non_identifier);
}
void
Forward_declaration_type::do_mangled_name(Gogo* gogo, std::string* ret,
bool *is_non_identifier) const
{
if (this->is_defined())
this->append_mangled_name(this->real_type(), gogo, ret, is_non_identifier);
else
{
const Named_object* no = this->named_object();
if (no->package() == NULL)
ret->append(gogo->pkgpath());
else
ret->append(no->package()->pkgpath());
ret->push_back('.');
ret->append(Gogo::unpack_hidden_name(no->name()));
}
}
// Append the symbol name for a named type to RET. For an alias we
// normally use the real name, but if USE_ALIAS is true we use the
// alias name itself.
void
Named_type::append_symbol_type_name(Gogo* gogo, bool use_alias,
std::string* ret,
bool* is_non_identifier) const
{
if (this->is_error_)
return;
if (this->is_alias_ && !use_alias)
{
if (this->seen_alias_)
return;
this->seen_alias_ = true;
this->append_mangled_name(this->type_, gogo, ret, is_non_identifier);
this->seen_alias_ = false;
return;
}
Named_object* no = this->named_object_;
std::string name;
if (this->is_builtin())
go_assert(this->in_function_ == NULL);
else
{
if (this->in_function_ != NULL)
{
const Typed_identifier* rcvr =
this->in_function_->func_value()->type()->receiver();
if (rcvr != NULL)
{
Backend_name bname;
rcvr->type()->deref()->backend_name(gogo, &bname);
ret->append(bname.name());
if (bname.is_non_identifier())
*is_non_identifier = true;
}
else if (this->in_function_->package() == NULL)
ret->append(gogo->pkgpath());
else
ret->append(this->in_function_->package()->pkgpath());
ret->push_back('.');
ret->append(Gogo::unpack_hidden_name(this->in_function_->name()));
}
else
{
if (no->package() == NULL)
ret->append(gogo->pkgpath());
else
ret->append(no->package()->pkgpath());
}
ret->push_back('.');
}
ret->append(Gogo::unpack_hidden_name(no->name()));
if (this->in_function_ != NULL && this->in_function_index_ > 0)
{
char buf[30];
snprintf(buf, sizeof buf, ".i%u", this->in_function_index_);
ret->append(buf);
}
}
// Given a name which may or may not have been hidden, append the
// appropriate version of the name to the result string.
void
Gogo::append_possibly_hidden_name(std::string *result, const std::string& name)
{
if (!Gogo::is_hidden_name(name))
*result += name;
else
*result += name.substr(1);
}
// Set BNAME to the name for the type descriptor symbol for TYPE.
// This can be a global, common, or local symbol, depending. NT is
// not NULL if it is the name to use.
void
Gogo::type_descriptor_backend_name(const Type* type, Named_type* nt,
Backend_name* bname)
{
// The type descriptor symbol for the unsafe.Pointer type is defined
// in libgo/runtime/go-unsafe-pointer.c, so just use a reference to
// that symbol for all unsafe pointer types.
if (type->is_unsafe_pointer_type())
{
bname->set_asm_name("unsafe.Pointer..d");
return;
}
bool is_pointer = false;
if (nt == NULL && type->points_to() != NULL)
{
nt = type->points_to()->unalias()->named_type();
is_pointer = true;
}
if (nt == NULL)
{
// Sanity check: we should never generate a type descriptor for
// an unnamed primitive type. For those we should always be
// using a named type, like "int".
go_assert(!type->is_basic_type());
type->backend_name(this, bname);
bname->set_prefix("type..");
}
else
{
nt->backend_name(this, bname);
bname->set_suffix(is_pointer ? "..p" : "..d");
}
}
// Return the name of the type descriptor list symbol of a package.
// This is passed directly to the backend without further encoding.
std::string
Gogo::type_descriptor_list_symbol(const std::string& pkgpath_symbol)
{
return pkgpath_symbol + "..types";
}
// Return the name of the list of all type descriptor lists. This is
// only used in the main package. This is passed directly to the
// backend without further encoding.
std::string
Gogo::typelists_symbol()
{
return "go..typelists";
}
// Return the assembler name for the GC symbol for a type. This is
// used to initialize the gcdata field of a type descriptor. This is
// a local name never referenced outside of this assembly file. (Note
// that some type descriptors will initialize the gcdata field with a
// name generated by ptrmask_symbol_name rather than this method.)
// This is passed directly to the backend without further encoding.
std::string
Gogo::gc_symbol_name(Type* type)
{
Backend_name bname;
this->type_descriptor_backend_name(type, type->named_type(), &bname);
bname.append_suffix("..g");
return bname.asm_name();
}
// Return the assembler name for a ptrmask variable. PTRMASK_SYM_NAME
// is a base32 string encoding the ptrmask (as returned by
// Ptrmask::symname in types.cc). This name is used to intialize the
// gcdata field of a type descriptor. These names are globally
// visible. (Note that some type descriptors will initialize the
// gcdata field with a name generated by gc_symbol_name rather than
// this method.) This is passed directly to the backend without
// further encoding.
std::string
Gogo::ptrmask_symbol_name(const std::string& ptrmask_sym_name)
{
return "gcbits.." + ptrmask_sym_name;
}
// Return the assembler name to use for an interface method table used
// for the ordinary type TYPE converted to the interface type ITYPE.
// IS_POINTER is true if this is for the method set for a pointer
// receiver. This is passed directly to the backend without further
// encoding.
std::string
Gogo::interface_method_table_name(Interface_type* itype, Type* type,
bool is_pointer)
{
Backend_name iname;
itype->backend_name(this, &iname);
Backend_name tname;
type->backend_name(this, &tname);
return ((is_pointer ? "pimt.." : "imt..")
+ iname.asm_name()
+ ".."
+ tname.asm_name());
}
// If NAME is a special name with a ".." suffix, return the position
// of that suffix. This is needed because various special names use
// "..SUFFIX", but unpack_hidden_name just looks for '.', and because
// we don't want to encode the suffix.
size_t
Gogo::special_name_pos(const std::string& name)
{
size_t pos = name.rfind("..");
if (pos == std::string::npos)
return pos;
std::string suffix(name.substr(pos));
if (suffix == "..hash"
|| suffix == "..eq"
|| suffix == "..stub"
|| suffix == "..d"
|| suffix == "..f"
|| suffix == "..r"
|| suffix == "..import")
return pos;
if ((suffix.compare(2, 4, "func") == 0
|| suffix.compare(2, 4, "init") == 0)
&& Gogo::is_digits(suffix.substr(6)))
return pos;
if (suffix.compare(2, 5, "thunk") == 0
&& Gogo::is_digits(suffix.substr(7)))
return pos;
return std::string::npos;
}
// Return whether the string is non-empty and contains only digits.
bool
Gogo::is_digits(const std::string& s)
{
if (s.empty())
return false;
for (size_t i = 0; i < s.size(); ++i)
if (s[i] < '0' || s[i] > '9')
return false;
return true;
}
// Class Backend_name.
// Get the user visible name.
std::string
Backend_name::name() const
{
if (this->is_asm_name_)
return this->components_[0];
// If there is some character in the name that can't appear in an
// identifier, use the assembler name as the user name. This avoids
// possible problems in the assembler or debugger. The usual
// demangling scheme will still work. We use a prefix of "g." to
// tell the debugger about this.
if (this->is_non_identifier_)
return "g." + this->asm_name();
std::string ret;
if (this->prefix_ != NULL)
ret.append(this->prefix_);
for (int i = 0; i < this->count_; i++)
{
if (i > 0)
ret.push_back('.');
ret.append(this->components_[i]);
}
if (!this->suffix_.empty())
ret.append(this->suffix_);
return ret;
}
// Get the assembler name.
std::string
Backend_name::asm_name() const
{
if (this->is_asm_name_)
return this->components_[0];
std::string ret;
if (this->prefix_ != NULL)
ret.append(this->prefix_);
for (int i = 0; i < this->count_; i++)
{
if (i > 0)
ret.push_back('.');
ret.append(go_encode_id(this->components_[i]));
}
if (!this->suffix_.empty())
ret.append(this->suffix_);
return ret;
}
// Get the assembler name, or the empty string if it is the same as
// the user visible name.
std::string
Backend_name::optional_asm_name() const
{
if (this->is_asm_name_)
return "";
if (this->is_non_identifier_)
return this->asm_name();
for (int i = 0; i < this->count_; i++)
if (go_id_needs_encoding(this->components_[i]))
return this->asm_name();
return "";
}