cmd/compile: record InlCost in export data

Previously, we were treating cross-package function calls as free for
inlining budgeting.

In theory, we should be able to recompute InlCost from the
exported/reimported function bodies. However, that process mutates the
structure of the Node AST enough that it doesn't preserve InlCost. To
avoid unexpected issues, just record and restore InlCost in the export
data.

Fixes #19261.

Change-Id: Iac2bc0d32d4f948b64524aca657051f9fc96d92d
Reviewed-on: https://go-review.googlesource.com/70151
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>

diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go
index a009f2b6bfd58e5e3bbc540563fde06dca56b662..c8bbd79d262049b83f4e39fca567b3f234789e8a 100644 (file)
--- a/src/cmd/compile/internal/gc/bexport.go
+++ b/src/cmd/compile/internal/gc/bexport.go
@@ -377,6 +377,7 @@ func export(out *bufio.Writer, trace bool) int {
                                p.tracef("\n----\nfunc { %#v }\n", f.Inl)
                        }
                        p.int(i)
+                       p.int(int(f.InlCost))
                        p.stmtList(f.Inl)
                        if p.trace {
                                p.tracef("\n")

diff --git a/src/cmd/compile/internal/gc/bimport.go b/src/cmd/compile/internal/gc/bimport.go
index 7456c42a49a1364c9de184ed7cbba990d36af1f1..19b5f5a051e3f69aeca08e41d50bb62576a0634b 100644 (file)
--- a/src/cmd/compile/internal/gc/bimport.go
+++ b/src/cmd/compile/internal/gc/bimport.go
@@ -187,6 +187,7 @@ func Import(imp *types.Pkg, in *bufio.Reader) {
                // them only for functions with inlineable bodies. funchdr does
                // parameter renaming which doesn't matter if we don't have a body.
 
+               inlCost := p.int()
                if f := p.funcList[i]; f != nil {
                        // function not yet imported - read body and set it
                        funchdr(f)
@@ -200,6 +201,7 @@ func Import(imp *types.Pkg, in *bufio.Reader) {
                                body = []*Node{nod(OEMPTY, nil, nil)}
                        }
                        f.Func.Inl.Set(body)
+                       f.Func.InlCost = int32(inlCost)
                        funcbody()
                } else {
                        // function already imported - read body but discard declarations

diff --git a/test/fixedbugs/issue19261.dir/p.go b/test/fixedbugs/issue19261.dir/p.go
new file mode 100644 (file)
index 0000000..1c44d8a
--- /dev/null
+++ b/test/fixedbugs/issue19261.dir/p.go
@@ -0,0 +1,24 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func F() { // ERROR "can inline F"
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+}
+
+func G() {
+       F() // ERROR "inlining call to F"
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+}

diff --git a/test/fixedbugs/issue19261.dir/q.go b/test/fixedbugs/issue19261.dir/q.go
new file mode 100644 (file)
index 0000000..9f3550a
--- /dev/null
+++ b/test/fixedbugs/issue19261.dir/q.go
@@ -0,0 +1,17 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package q
+
+import "./p"
+
+func H() {
+       p.F() // ERROR "inlining call to p.F"
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+       print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+}

diff --git a/test/fixedbugs/issue19261.go b/test/fixedbugs/issue19261.go
new file mode 100644 (file)
index 0000000..61cff6e
--- /dev/null
+++ b/test/fixedbugs/issue19261.go
@@ -0,0 +1,7 @@
+// errorcheckdir -0 -m
+
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored