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| author | Iskander Sharipov <quasilyte@gmail.com> | 2018-12-28 21:40:04 +0300 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2019-02-26 23:08:15 +0000 |
| commit | c1050a8e54e1e1c06aa02ccf2b36c13a95666121 (patch) | |
| tree | 395ae7452f2fdca55743b0bd0049be1fad280f04 /src | |
| parent | 3a9037368e28e3c5cf587d8780af6b0b8659f91e (diff) | |
| download | go-c1050a8e54e1e1c06aa02ccf2b36c13a95666121.tar.xz | |
cmd/compile: don't generate newobject call for 0-sized types
Emit &runtime.zerobase instead of a call to newobject for
allocations of zero sized objects in walk.go.
Fixes #29446
Change-Id: I11b67981d55009726a17c2e582c12ce0c258682e
Reviewed-on: https://go-review.googlesource.com/c/155840
Run-TryBot: Iskander Sharipov <quasilyte@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/gc/walk.go | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go index 57bf8a1e0e..1d6321212e 100644 --- a/src/cmd/compile/internal/gc/walk.go +++ b/src/cmd/compile/internal/gc/walk.go @@ -1940,6 +1940,16 @@ func callnew(t *types.Type) *Node { yyerror("%v is go:notinheap; heap allocation disallowed", t) } dowidth(t) + + if t.Size() == 0 { + // Return &runtime.zerobase if we know that the requested size is 0. + // This is what runtime.mallocgc would return. + z := newname(Runtimepkg.Lookup("zerobase")) + z.SetClass(PEXTERN) + z.Type = t + return typecheck(nod(OADDR, z, nil), ctxExpr) + } + fn := syslook("newobject") fn = substArgTypes(fn, t) v := mkcall1(fn, types.NewPtr(t), nil, typename(t)) |