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author | Russ Cox <rsc@golang.org> | 2014-09-24 16:55:26 -0400 |
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committer | Russ Cox <rsc@golang.org> | 2014-09-24 16:55:26 -0400 |
commit | 14c9b3be770b4a59a4113783600b8d4b06f5ccd3 (patch) | |
tree | bbfc37060802619fcfbe4ce647a6571e16e86448 /src/runtime/signals_plan9.h | |
parent | 8ca4b32a4ef76cacf6ac5a1ae0e2a1a1113490ee (diff) | |
download | go-14c9b3be770b4a59a4113783600b8d4b06f5ccd3.tar.gz |
cmd/cc, cmd/ld, runtime: disallow conservative data/bss objects
In linker, refuse to write conservative (array of pointers) as the
garbage collection type for any variable in the data/bss GC program.
In the linker, attach the Go type to an already-read C declaration
during dedup. This gives us Go types for C globals for free as long
as the cmd/dist-generated Go code contains the declaration.
(Most runtime C declarations have a corresponding Go declaration.
Both are bss declarations and so the linker dedups them.)
In cmd/dist, add a few more C files to the auto-Go-declaration list
in order to get Go type information for the C declarations into the linker.
In C compiler, mark all non-pointer-containing global declarations
and all string data as NOPTR. This allows them to exist in C files
without any corresponding Go declaration. Count C function pointers
as "non-pointer-containing", since we have no heap-allocated C functions.
In runtime, add NOPTR to the remaining pointer-containing declarations,
none of which refer to Go heap objects.
In runtime, also move os.Args and syscall.envs data into runtime-owned
variables. Otherwise, in programs that do not import os or syscall, the
runtime variables named os.Args and syscall.envs will be missing type
information.
I believe that this CL eliminates the final source of conservative GC scanning
in non-SWIG Go programs, and therefore...
Fixes issue 909.
LGTM=iant
R=iant
CC=golang-codereviews
https://codereview.appspot.com/149770043
Diffstat (limited to 'src/runtime/signals_plan9.h')
-rw-r--r-- | src/runtime/signals_plan9.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/runtime/signals_plan9.h b/src/runtime/signals_plan9.h index 818f508cf..4ee8e542c 100644 --- a/src/runtime/signals_plan9.h +++ b/src/runtime/signals_plan9.h @@ -2,6 +2,8 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. +#include "textflag.h" + #define N SigNotify #define K SigKill #define T SigThrow @@ -16,6 +18,7 @@ // If you add entries to this table, you must respect the prefix ordering // and also update the constant values is os_plan9.h. +#pragma dataflag NOPTR SigTab runtimeĀ·sigtab[] = { // Traps that we cannot be recovered. T, "sys: trap: debug exception", |