cmd/cgo: fix handling of defs_linux.go

Instead of including <sys/types.h> to get size_t, instead include
the ISO C standard <stddef.h> header, which defines fewer additional
types at risk of colliding with the user code.  In particular, this
prevents collisions between <sys/types.h>'s userspace definitions with
the kernel definitions needed by defs_linux.go.

Also, -cdefs mode uses #pragma pack, so we can keep misaligned fields.

Fixes issue 8477.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://codereview.appspot.com/120610043

Committer: Ian Lance Taylor <iant@golang.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/misc/cgo/testcdefs/cdefstest.go b/misc/cgo/testcdefs/cdefstest.go
index e6305b77d..0804083a0 100644
--- a/misc/cgo/testcdefs/cdefstest.go
+++ b/misc/cgo/testcdefs/cdefstest.go
@@ -35,7 +35,25 @@ struct cdefsTest {
 	// Correct: -> Array [20][20]**int8 -> int8 **array[20][20]
 	char **array5[20][20];
 };
+
+// Test that packed structures can be translated to C correctly too.
+// See issue 8477.
+
+struct packedTest {
+	char first;
+	int second;
+	long long third;
+} __attribute__((packed));
+
+// Test that conflicting type definitions don't cause problems with cgo.
+// See issue 8477.
+
+typedef struct timespec {
+	double bogus;
+} pid_t;
+
 */
 import "C"
 
 type CdefsTest C.struct_cdefsTest
+type PackedTest C.struct_packedTest