compiler: error on func declaration/definition
Long long long ago Go permitted writing
func F()
in one file and writing
func F() {}
in another file. This was removed from the language, and that is now
considered to be a multiple definition error. Gccgo never caught up
to that, and it has been permitting this invalid code for some time.
Stop permitting it, so that we give correct errors. Since we've
supported it for a long time, the compiler uses it in a couple of
cases: it predeclares the hash/equal methods if it decides to create
them while compiling another function, and it predeclares main.main as
a mechanism for getting the right warning if a program uses the wrong
signature for main. For simplicity, keep those existing uses.
This required a few minor changes in libgo which were relying,
unnecessarily, on the current behavior.
Change-Id: Ie8835aad9775ec6417cad766f42336adde60dc79
Reviewed-on: https://go-review.googlesource.com/93083
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/go/gogo.cc b/go/gogo.cc
index 11ac338..0eac199 100644
--- a/go/gogo.cc
+++ b/go/gogo.cc
@@ -7762,33 +7762,29 @@
go_unreachable();
case Named_object::NAMED_OBJECT_FUNC:
- if (new_object->is_function_declaration())
- {
- if (!new_object->func_declaration_value()->asm_name().empty())
- go_error_at(Linemap::unknown_location(),
- ("sorry, not implemented: "
- "__asm__ for function definitions"));
- Function_type* old_type = old_object->func_value()->type();
- Function_type* new_type =
- new_object->func_declaration_value()->type();
- if (old_type->is_valid_redeclaration(new_type, &reason))
- return old_object;
- }
break;
case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
{
- if (new_object->is_function())
+ // We declare the hash and equality functions before defining
+ // them, because we sometimes see that we need the declaration
+ // while we are in the middle of a different function. We
+ // declare the main function before the user defines it, to
+ // give better error messages.
+ if (new_object->is_function()
+ && ((Linemap::is_predeclared_location(old_object->location())
+ && Linemap::is_predeclared_location(new_object->location()))
+ || (Gogo::unpack_hidden_name(old_object->name()) == "main"
+ && Linemap::is_unknown_location(old_object->location()))))
{
Function_type* old_type =
old_object->func_declaration_value()->type();
Function_type* new_type = new_object->func_value()->type();
if (old_type->is_valid_redeclaration(new_type, &reason))
{
- if (!old_object->func_declaration_value()->asm_name().empty())
- go_error_at(Linemap::unknown_location(),
- ("sorry, not implemented: "
- "__asm__ for function definitions"));
+ Function_declaration* fd =
+ old_object->func_declaration_value();
+ go_assert(fd->asm_name().empty());
old_object->set_function_value(new_object->func_value());
this->named_objects_.push_back(old_object);
return old_object;
@@ -7810,8 +7806,10 @@
old_object->set_is_redefinition();
new_object->set_is_redefinition();
- go_inform(old_object->location(), "previous definition of %qs was here",
- n.c_str());
+ if (!Linemap::is_unknown_location(old_object->location())
+ && !Linemap::is_predeclared_location(old_object->location()))
+ go_inform(old_object->location(), "previous definition of %qs was here",
+ n.c_str());
return old_object;
}
diff --git a/libgo/go/runtime/extern.go b/libgo/go/runtime/extern.go
index 36787e3..b3afd10 100644
--- a/libgo/go/runtime/extern.go
+++ b/libgo/go/runtime/extern.go
@@ -157,10 +157,6 @@
import "runtime/internal/sys"
-// Gosched yields the processor, allowing other goroutines to run. It does not
-// suspend the current goroutine, so execution resumes automatically.
-func Gosched()
-
// Caller reports file and line number information about function invocations on
// the calling goroutine's stack. The argument skip is the number of stack frames
// to ascend, with 0 identifying the caller of Caller. (For historical reasons the
diff --git a/libgo/go/runtime/stubs.go b/libgo/go/runtime/stubs.go
index efb0373..bda2c69 100644
--- a/libgo/go/runtime/stubs.go
+++ b/libgo/go/runtime/stubs.go
@@ -306,10 +306,6 @@
support_aes = v
}
-// Here for gccgo until we port lock_*.go.
-func lock(l *mutex)
-func unlock(l *mutex)
-
// Here for gccgo.
func errno() int
@@ -317,9 +313,6 @@
func entersyscall(int32)
func entersyscallblock(int32)
-// Here for gccgo until we port mgc.go.
-func GC()
-
// For gccgo to call from C code, so that the C code and the Go code
// can share the memstats variable for now.
//go:linkname getMstats runtime.getMstats
@@ -327,16 +320,6 @@
return &memstats
}
-// Temporary for gccgo until we port mem_GOOS.go.
-func sysAlloc(n uintptr, sysStat *uint64) unsafe.Pointer
-func sysFree(v unsafe.Pointer, n uintptr, sysStat *uint64)
-
-// Temporary for gccgo until we port malloc.go
-func persistentalloc(size, align uintptr, sysStat *uint64) unsafe.Pointer
-
-// Temporary for gccgo until we port mheap.go
-func setprofilebucket(p unsafe.Pointer, b *bucket)
-
// Get signal trampoline, written in C.
func getSigtramp() uintptr
diff --git a/libgo/misc/cgo/test/issue9400/gccgo.go b/libgo/misc/cgo/test/issue9400/gccgo.go
index 0ef3a8c..a9b62b0 100644
--- a/libgo/misc/cgo/test/issue9400/gccgo.go
+++ b/libgo/misc/cgo/test/issue9400/gccgo.go
@@ -16,6 +16,8 @@
// without writing more assembly code, which we haven't bothered to
// do. So this is not much of a test.
+var Baton int32
+
func RewindAndSetgid() {
atomic.StoreInt32(&Baton, 1)
for atomic.LoadInt32(&Baton) != 0 {
diff --git a/libgo/misc/cgo/test/issue9400/stubs.go b/libgo/misc/cgo/test/issue9400/stubs.go
index 60193dc..7b50cef 100644
--- a/libgo/misc/cgo/test/issue9400/stubs.go
+++ b/libgo/misc/cgo/test/issue9400/stubs.go
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build !gccgo
+
package issue9400
var Baton int32
