libgo patch committed: Work around escaping closure in runtime/export_test.go

[Ian Lance Taylor]

This libgo patch by Cherry Zhang works around some escaping code in
runtime/export_test.go.  When compiling the runtime, local variables
and closures may not be heap allocated.  In one test, there is a go
statement with a closure.  In the gc compiler, it distinguishes
capturing variable by value vs. by address, and rewrites it to passing
the captured values as arguments.  Currently we don't have this in
gccgo, and the escape analysis decides to heap allocate the closure
and also the captured variables, which is not allowed.  Work around it
by passing the variables explicitly.

This is in preparation of turning on escape analysis for the runtime.

Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 256418)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-5cae6a4e0849a3586ee7ce9c915c1520a17db982
+c18c6bd80e0995827ad3396eb1c2401451de88fd
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: libgo/go/runtime/export_test.go
===================================================================
--- libgo/go/runtime/export_test.go     (revision 256366)
+++ libgo/go/runtime/export_test.go     (working copy)
@@ -123,15 +123,15 @@ func RunSchedLocalQueueEmptyTest(iters i
        // can lead to underutilization (both runnable Gs and idle Ps coexist
        // for arbitrary long time).
        done := make(chan bool, 1)
-       p := new(p)
+       _p_ := new(p)
        gs := make([]g, 2)
        ready := new(uint32)
        for i := 0; i < iters; i++ {
                *ready = 0
                next0 := (i & 1) == 0
                next1 := (i & 2) == 0
-               runqput(p, &gs[0], next0)
-               go func() {
+               runqput(_p_, &gs[0], next0)
+               go func(done chan bool, p *p, ready *uint32, next0, next1 bool) 
{
                        for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
                        }
                        if runqempty(p) {
@@ -139,13 +139,13 @@ func RunSchedLocalQueueEmptyTest(iters i
                                throw("queue is empty")
                        }
                        done <- true
-               }()
+               }(done, _p_, ready, next0, next1)
                for atomic.Xadd(ready, 1); atomic.Load(ready) != 2; {
                }
-               runqput(p, &gs[1], next1)
-               runqget(p)
+               runqput(_p_, &gs[1], next1)
+               runqget(_p_)
                <-done
-               runqget(p)
+               runqget(_p_)
        }
 }