From: Russ Cox Date: Thu, 2 Nov 2023 12:15:44 +0000 (-0400) Subject: cmd/cgo: disable #cgo noescape/nocallback until Go 1.23 X-Git-Tag: go1.22rc1~450 X-Git-Url: http://www.git.cypherpunks.ru/?a=commitdiff_plain;h=607e020150f1bba84beec11aceadbc42abf33986;p=gostls13.git cmd/cgo: disable #cgo noescape/nocallback until Go 1.23 Go 1.21 and earlier do not understand this line, causing "go mod vendor" of //go:build go1.22-tagged code that uses this feature to fail. The solution is to include the go/build change to skip over the line in Go 1.22 (making "go mod vendor" from Go 1.22 onward work with this change) and then wait to deploy the cgo change until Go 1.23, at which point Go 1.21 and earlier will be unsupported. For #56378. Fixes #63293. Change-Id: Ifa08b134eac5a6aa15d67dad0851f00e15e1e58b Reviewed-on: https://go-review.googlesource.com/c/go/+/539235 LUCI-TryBot-Result: Go LUCI Reviewed-by: Cherry Mui Reviewed-by: Bryan Mills --- diff --git a/doc/go1.22.html b/doc/go1.22.html index 8652951274..287ee77bb5 100644 --- a/doc/go1.22.html +++ b/doc/go1.22.html @@ -39,24 +39,7 @@ Do not send CLs removing the interior tags from such phrases.

Cgo

-

The special comment that precedes - import "C" may now include two - new #cgo directives. -

    -
  • - #cgo noescape cFunctionName - tells cgo that Go pointers passed to the C function - cFunctionName do not escape. -
    • -
  • - #cgo nocallback cFunctionName - tells cgo that the C function cFunctionName does - not call any Go functions. -
    • -
- See the cgo - documentation for more details. -

+

Runtime

diff --git a/src/cmd/cgo/doc.go b/src/cmd/cgo/doc.go index 1f635d7c09..c2e375165c 100644 --- a/src/cmd/cgo/doc.go +++ b/src/cmd/cgo/doc.go @@ -420,30 +420,6 @@ passing uninitialized C memory to Go code if the Go code is going to store pointer values in it. Zero out the memory in C before passing it to Go. -# Optimizing calls of C code - -When passing a Go pointer to a C function the compiler normally ensures -that the Go object lives on the heap. If the C function does not keep -a copy of the Go pointer, and never passes the Go pointer back to Go code, -then this is unnecessary. The #cgo noescape directive may be used to tell -the compiler that no Go pointers escape via the named C function. -If the noescape directive is used and the C function does not handle the -pointer safely, the program may crash or see memory corruption. - -For example: - - // #cgo noescape cFunctionName - -When a Go function calls a C function, it prepares for the C function to -call back to a Go function. the #cgo nocallback directive may be used to -tell the compiler that these preparations are not necessary. -If the nocallback directive is used and the C function does call back into -Go code, the program will panic. - -For example: - - // #cgo nocallback cFunctionName - # Special cases A few special C types which would normally be represented by a pointer diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go index d30056ec84..6e7556de96 100644 --- a/src/cmd/cgo/gcc.go +++ b/src/cmd/cgo/gcc.go @@ -94,8 +94,10 @@ func (f *File) ProcessCgoDirectives() { directive := fields[1] funcName := fields[2] if directive == "nocallback" { + fatalf("#cgo nocallback disabled until Go 1.23") f.NoCallbacks[funcName] = true } else if directive == "noescape" { + fatalf("#cgo noescape disabled until Go 1.23") f.NoEscapes[funcName] = true } } diff --git a/src/cmd/cgo/internal/test/test.go b/src/cmd/cgo/internal/test/test.go index 9a6c6d82ce..9b3790eb11 100644 --- a/src/cmd/cgo/internal/test/test.go +++ b/src/cmd/cgo/internal/test/test.go @@ -117,7 +117,8 @@ int add(int x, int y) { // escape vs noescape -#cgo noescape handleGoStringPointerNoescape +// TODO(#56378): enable in Go 1.23: +// #cgo noescape handleGoStringPointerNoescape void handleGoStringPointerNoescape(void *s) {} void handleGoStringPointerEscape(void *s) {} diff --git a/src/cmd/cgo/internal/testerrors/testdata/notmatchedcfunction.go b/src/cmd/cgo/internal/testerrors/testdata/notmatchedcfunction.go index 46afeefcc0..5ec9ec5d4a 100644 --- a/src/cmd/cgo/internal/testerrors/testdata/notmatchedcfunction.go +++ b/src/cmd/cgo/internal/testerrors/testdata/notmatchedcfunction.go @@ -5,7 +5,8 @@ package main /* -// ERROR MESSAGE: #cgo noescape noMatchedCFunction: no matched C function +// TODO(#56378): change back to "#cgo noescape noMatchedCFunction: no matched C function" in Go 1.23 +// ERROR MESSAGE: #cgo noescape disabled until Go 1.23 #cgo noescape noMatchedCFunction */ import "C" diff --git a/src/runtime/crash_cgo_test.go b/src/runtime/crash_cgo_test.go index 20e3b75d79..5d0750e8f4 100644 --- a/src/runtime/crash_cgo_test.go +++ b/src/runtime/crash_cgo_test.go @@ -754,6 +754,7 @@ func TestNeedmDeadlock(t *testing.T) { } func TestCgoNoCallback(t *testing.T) { + t.Skip("TODO(#56378): enable in Go 1.23") got := runTestProg(t, "testprogcgo", "CgoNoCallback") want := "function marked with #cgo nocallback called back into Go" if !strings.Contains(got, want) { @@ -762,6 +763,7 @@ func TestCgoNoCallback(t *testing.T) { } func TestCgoNoEscape(t *testing.T) { + t.Skip("TODO(#56378): enable in Go 1.23") got := runTestProg(t, "testprogcgo", "CgoNoEscape") want := "OK\n" if got != want { diff --git a/src/runtime/testdata/testprogcgo/cgonocallback.go b/src/runtime/testdata/testprogcgo/cgonocallback.go index 8cbbfd1957..c13bf271a4 100644 --- a/src/runtime/testdata/testprogcgo/cgonocallback.go +++ b/src/runtime/testdata/testprogcgo/cgonocallback.go @@ -8,8 +8,7 @@ package main // But it do callback to go in this test, Go should crash here. /* -#cgo nocallback runCShouldNotCallback - +// TODO(#56378): #cgo nocallback runCShouldNotCallback extern void runCShouldNotCallback(); */ import "C" diff --git a/src/runtime/testdata/testprogcgo/cgonoescape.go b/src/runtime/testdata/testprogcgo/cgonoescape.go index 056be44889..f5eebac677 100644 --- a/src/runtime/testdata/testprogcgo/cgonoescape.go +++ b/src/runtime/testdata/testprogcgo/cgonoescape.go @@ -13,7 +13,7 @@ package main // 2. less than 100 new allocated heap objects after invoking withoutNoEscape 100 times. /* -#cgo noescape runCWithNoEscape +// TODO(#56378): #cgo noescape runCWithNoEscape void runCWithNoEscape(void *p) { }