cmd/cgo: silence unaligned-access

Clang 14+ introduced a warning when using mixed packed and unpacked structs.
This can cause problems when taking an address of the unpacked struct, which
may end up having a different alignment than expected.

This is not a problem in cgo, which does not take pointers from the packed
struct.

Fixes #62480

Change-Id: If5879eea5e1b77bc6dc7430f68f8c916bff9b090
Reviewed-on: https://go-review.googlesource.com/c/go/+/526915
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index 8e1b5d62fd702994b0c5a1e8fb55384f6561748e..ac68b77d195546663b03d0a67a09d4d02763f2f6 100644 (file)
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -910,6 +910,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
        fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Wunknown-pragmas\"\n")
        fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Wpragmas\"\n")
        fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Waddress-of-packed-member\"\n")
+       fmt.Fprintf(fgcc, "#pragma GCC diagnostic ignored \"-Wunaligned-access\"\n")
 
        fmt.Fprintf(fgcc, "extern void crosscall2(void (*fn)(void *), void *, int, size_t);\n")
        fmt.Fprintf(fgcc, "extern size_t _cgo_wait_runtime_init_done(void);\n")
@@ -1522,6 +1523,7 @@ extern char* _cgo_topofstack(void);
 #pragma GCC diagnostic ignored "-Wunknown-pragmas"
 #pragma GCC diagnostic ignored "-Wpragmas"
 #pragma GCC diagnostic ignored "-Waddress-of-packed-member"
+#pragma GCC diagnostic ignored "-Wunaligned-access"
 
 #include <errno.h>
 #include <string.h>