Re: Go patches committed: merge recent changes to gofrontend

[Ian Lance Taylor]

On Wed, May 10, 2017 at 5:37 PM, Andrew Pinski <apin...@cavium.com> wrote:
> On Wed, May 10, 2017 at 10:26 AM, Ian Lance Taylor <i...@golang.org> wrote:
>> I have committed a large patch to update the Go frontend and libgo to
>> the recent changes in the gofrontend repository.  I had postponed
>> merging changes during the GCC 7 release process.  I am now merging
>> all the changes that were pending during that period.  Although this
>> is a merged patch, the changes can be seen individually in the
>> gofrontend repo (https://go.googlesource.com/gofrontend).  They are
>> also listed below.
>>
>> This is a fairly significant patch that brings in the concurrent
>> garbage collector used in the Go 1.8 runtime.  This significantly
>> reduces pauses due to garbage collection while running a Go program.
>>
>> This patch also brings in experimental support for AIX for gccgo,
>> contributed by Matthieu Sarter and others at Atos Infogérance.
>>
>> The actual patch is too large for this e-mail patch, but I have
>> attached all the changes to the gcc/go directory.
>>
>> Ian
>
>
> This causes a build failure on aarch64-linux-gnu:
> ../../../gcc/libgo/runtime/proc.c: In function ‘runtime_malg’:
> ../../../gcc/libgo/runtime/proc.c:729:43: warning: implicit
> declaration of function ‘mstats’; did you mean ‘mstart1’?
> [-Wimplicit-function-declaration]
>     void *p = runtime_sysAlloc(stacksize, &mstats()->other_sys);
>                                            ^~~~~~
>                                            mstart1
> ../../../gcc/libgo/runtime/proc.c:729:51: error: invalid type argument
> of ‘->’ (have ‘int’)
>     void *p = runtime_sysAlloc(stacksize, &mstats()->other_sys);

Sorry about that.  I intended to test on a non-split-stack system, but
I forgot.  This patch fixes the build problem and lets most of the
testsuite pass.  I still see two test failures on non-split-stack that
I need to look into (index0-out and runtime on 32-bit systems).  Patch
tested on x86_64-pc-linux-gnu with and without split-stack enabled.
Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 247948)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-3c1258156a2ae483c5cc523cb7a3c3374cbe7c2c
+d5bfa6cebb19a154cbfbc53f6e647d2ca7adef68
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: libgo/go/runtime/runtime2.go
===================================================================
--- libgo/go/runtime/runtime2.go        (revision 247931)
+++ libgo/go/runtime/runtime2.go        (working copy)
@@ -793,3 +793,10 @@ type g_ucontext_t [(_sizeof_ucontext_t +
 // sigset is the Go version of the C type sigset_t.
 // _sigset_t is defined by the Makefile from <signal.h>.
 type sigset _sigset_t
+
+// getMemstats returns a pointer to the internal memstats variable,
+// for C code.
+//go:linkname getMemstats runtime.getMemstats
+func getMemstats() *mstats {
+       return &memstats
+}
Index: libgo/runtime/proc.c
===================================================================
--- libgo/runtime/proc.c        (revision 247848)
+++ libgo/runtime/proc.c        (working copy)
@@ -406,6 +406,8 @@ extern void globrunqput(G*)
   __asm__(GOSYM_PREFIX "runtime.globrunqput");
 extern P* pidleget(void)
   __asm__(GOSYM_PREFIX "runtime.pidleget");
+extern struct mstats* getMemstats(void)
+  __asm__(GOSYM_PREFIX "runtime.getMemstats");
 
 bool runtime_isstarted;
 
@@ -726,7 +728,7 @@ runtime_malg(bool allocatestack, bool si
                 // 32-bit mode, the Go allocation space is all of
                 // memory anyhow.
                if(sizeof(void*) == 8) {
-                       void *p = runtime_sysAlloc(stacksize, 
&mstats()->other_sys);
+                       void *p = runtime_sysAlloc(stacksize, 
&getMemstats()->stacks_sys);
                        if(p == nil)
                                runtime_throw("runtime: cannot allocate memory 
for goroutine stack");
                        *ret_stack = (byte*)p;
Index: libgo/runtime/stack.c
===================================================================
--- libgo/runtime/stack.c       (revision 247848)
+++ libgo/runtime/stack.c       (working copy)
@@ -80,7 +80,6 @@ static void doscanstack1(G *gp, void *gc
                        scanstackblock(sp, (uintptr)(spsize), gcw);
        }
 #else
-       M *mp;
        byte* bottom;
        byte* top;