cgo: bug fixes

* Add documentation about array arguments.  Fixes issue 1125.
* Do not interpret x, y := z, w as special errno form.  Fixes issue 952.
* Fix nested Go calls (brainman).  Fixes issue 907.

R=r
CC=golang-dev
https://golang.org/cl/2214044

diff --git a/misc/cgo/stdio/test.go b/misc/cgo/stdio/test.go
index 490eb93c64b4412f54e8cf7dbbcf0f5d32581c00..639d77b8546a602d4654fdf25c2194101ffd9a6a 100644 (file)
--- a/misc/cgo/stdio/test.go
+++ b/misc/cgo/stdio/test.go
@@ -19,6 +19,13 @@ enum {
        Enum1 = 1,
        Enum2 = 2,
 };
+
+typedef unsigned char uuid_t[20];
+
+void uuid_generate(uuid_t x) {
+       x[0] = 0;
+}
+
 */
 import "C"
 import (
@@ -30,6 +37,11 @@ const EINVAL = C.EINVAL /* test #define */
 
 var KILO = C.KILO
 
+func uuidgen() {
+       var uuid C.uuid_t
+       C.uuid_generate(&uuid[0])
+}
+
 func Size(name string) (int64, os.Error) {
        var st C.struct_stat
        p := C.CString(name)
@@ -73,10 +85,20 @@ func TestErrno() {
        n, err := Strtol("asdf", 123)
        if n != 0 || err != os.EINVAL {
                println("Strtol: ", n, err)
-               panic("bad atoi2")
+               panic("bad strtol")
        }
 }
 
+func TestMultipleAssign() {
+       p := C.CString("123")
+       n, m := C.strtol(p, nil, 345), C.strtol(p, nil, 10)
+       if n != 0 || m != 234 {
+               println("Strtol x2: ", n, m)
+               panic("bad strtol x2")
+       }
+       C.free(unsafe.Pointer(p))
+}
+
 var (
        uint  = (C.uint)(0)
        ulong C.ulong

diff --git a/src/cmd/cgo/ast.go b/src/cmd/cgo/ast.go
index 827d158ab39356928ba9e15c347570058973a90c..79c1557b32bf6aec029cf5ed71719d3203e4e4f4 100644 (file)
--- a/src/cmd/cgo/ast.go
+++ b/src/cmd/cgo/ast.go
@@ -314,7 +314,7 @@ func (f *File) walk(x interface{}, context string, visit func(*File, interface{}
                f.walk(&n.X, "expr", visit)
        case *ast.AssignStmt:
                f.walk(n.Lhs, "expr", visit)
-               if len(n.Lhs) == 2 {
+               if len(n.Lhs) == 2 && len(n.Rhs) == 1 {
                        f.walk(n.Rhs, "as2", visit)
                } else {
                        f.walk(n.Rhs, "expr", visit)

diff --git a/src/cmd/cgo/doc.go b/src/cmd/cgo/doc.go
index dce8e86828ed036898107700bffb9919b394a188..0f9204d7ffaa9decbe641d28d458a8aa01bf54b5 100644 (file)
--- a/src/cmd/cgo/doc.go
+++ b/src/cmd/cgo/doc.go
@@ -27,6 +27,12 @@ C identifiers or field names that are keywords in Go can be
 accessed by prefixing them with an underscore: if x points at
 a C struct with a field named "type", x._type accesses the field.
 
+The standard C numeric types are available under the names
+C.char, C.schar (signed char), C.uchar (unsigned char),
+C.short, C.ushort (unsigned short), C.int, C.uint (unsigned int),
+C.long, C.ulong (unsigned long), C.longlong (long long),
+C.ulonglong (unsigned long long), C.float, C.double.
+
 To access a struct, union, or enum type directly, prefix it with
 struct_, union_, or enum_, as in C.struct_stat.
 
@@ -36,6 +42,12 @@ C errno variable as an os.Error.  For example:
 
        n, err := C.atoi("abc")
 
+In C, a function argument written as a fixed size array
+actually requires a pointer to the first element of the array.
+C compilers are aware of this calling convention and adjust
+the call accordingly, but Go cannot.  In Go, you must pass
+the pointer to the first element explicitly: C.f(&x[0]).
+
 Cgo transforms the input file into four output files: two Go source
 files, a C file for 6c (or 8c or 5c), and a C file for gcc.
 

diff --git a/src/pkg/runtime/cgocall.c b/src/pkg/runtime/cgocall.c
index f673d1b6ecce535e1cf2d177d89a9c6fb87605d0..7571694d9a32c064bfbcc7c0fb8028fa5a12ec2c 100644 (file)
--- a/src/pkg/runtime/cgocall.c
+++ b/src/pkg/runtime/cgocall.c
@@ -53,16 +53,16 @@ cgocall(void (*fn)(void*), void *arg)
 void
 cgocallback(void (*fn)(void), void *arg, int32 argsize)
 {
-       Gobuf oldsched;
+       Gobuf oldsched, oldg1sched;
        G *g1;
        void *sp;
 
        if(g != m->g0)
                throw("bad g in cgocallback");
 
-       oldsched = m->sched;
-
        g1 = m->curg;
+       oldsched = m->sched;
+       oldg1sched = g1->sched;
 
        startcgocallback(g1);
 
@@ -78,6 +78,7 @@ cgocallback(void (*fn)(void), void *arg, int32 argsize)
        endcgocallback(g1);
 
        m->sched = oldsched;
+       g1->sched = oldg1sched;
 }
 
 void