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| author | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2019-09-05 11:15:59 +0700 |
|---|---|---|
| committer | Matthew Dempsky <mdempsky@google.com> | 2019-09-06 01:35:46 +0000 |
| commit | 1406ece4461cc042c9340efbe331e2d7f6db2f8e (patch) | |
| tree | 77b1f371e4ce73c8956f047abc461546e38c3552 /src | |
| parent | c99598cbd3aa5eab2971ee449b5685f299b89755 (diff) | |
| download | go-git-1406ece4461cc042c9340efbe331e2d7f6db2f8e.tar.gz | |
cmd/compile: preserve loop depth when evaluating block
Add block method to preserve loop depth when evaluating statements in a
block, so escape analysis can handle looping label more precisely.
Updates #22438
Change-Id: I39b306544a6c0ee3fcbebbe0d0ee735cb71773e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/193517
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/gc/escape.go | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/src/cmd/compile/internal/gc/escape.go b/src/cmd/compile/internal/gc/escape.go index c03e50628d..d2e096d0f0 100644 --- a/src/cmd/compile/internal/gc/escape.go +++ b/src/cmd/compile/internal/gc/escape.go @@ -201,7 +201,7 @@ func (e *Escape) walkFunc(fn *Node) { e.curfn = fn e.loopDepth = 1 - e.stmts(fn.Nbody) + e.block(fn.Nbody) } // Below we implement the methods for walking the AST and recording @@ -284,14 +284,14 @@ func (e *Escape) stmt(n *Node) { case OIF: e.discard(n.Left) - e.stmts(n.Nbody) - e.stmts(n.Rlist) + e.block(n.Nbody) + e.block(n.Rlist) case OFOR, OFORUNTIL: e.loopDepth++ e.discard(n.Left) e.stmt(n.Right) - e.stmts(n.Nbody) + e.block(n.Nbody) e.loopDepth-- case ORANGE: @@ -311,7 +311,7 @@ func (e *Escape) stmt(n *Node) { } } - e.stmts(n.Nbody) + e.block(n.Nbody) e.loopDepth-- case OSWITCH: @@ -340,13 +340,13 @@ func (e *Escape) stmt(n *Node) { } e.discards(cas.List) - e.stmts(cas.Nbody) + e.block(cas.Nbody) } case OSELECT: for _, cas := range n.List.Slice() { e.stmt(cas.Left) - e.stmts(cas.Nbody) + e.block(cas.Nbody) } case OSELRECV: e.assign(n.Left, n.Right, "selrecv", n) @@ -398,12 +398,18 @@ func (e *Escape) stmt(n *Node) { } func (e *Escape) stmts(l Nodes) { - // TODO(mdempsky): Preserve and restore e.loopDepth? See also #22438. for _, n := range l.Slice() { e.stmt(n) } } +// block is like stmts, but preserves loopDepth. +func (e *Escape) block(l Nodes) { + old := e.loopDepth + e.stmts(l) + e.loopDepth = old +} + // expr models evaluating an expression n and flowing the result into // hole k. func (e *Escape) expr(k EscHole, n *Node) { |