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go/misc
Gernot Vormayr 84fce9832b cmd/cgo: fix check for conversion of ptr to struct field
According to the documentation "When passing a pointer to a field in a
struct, the Go memory in question is the memory occupied by the field,
not the entire struct.". checkAddr states that this should also work
with type conversions, which is implemented in isType. However,
ast.StarExpr must be enclosed in ast.ParenExpr according to the go spec
(see example below), which is not considered in the checks.

Example:
    // struct Si { int i; int *p; }; void f(struct I *x) {}
    import "C"
    type S {
        p *int
        i C.struct_Si
    }
    func main() {
        v := &S{new(int)}
        C.f((*C.struct_I)(&v.i)) // <- panic
    }

This example will cause cgo to emit a cgoCheck that checks the whole
struct S instead of just S.i causing the panic "cgo argument has Go
pointer to Go pointer".

This patch fixes this situation by adding support for ast.ParenExpr to
isType and adds a test, that fails without the fix.

Fixes #32970.

Change-Id: I15ea28c98f839e9fa708859ed107a2e5f1483133
Reviewed-on: https://go-review.googlesource.com/c/go/+/185098
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-07-09 19:21:43 +00:00
..
android misc/android: fix a typo in README 2019-05-17 06:01:17 +00:00
arm
cgo cmd/cgo: fix check for conversion of ptr to struct field 2019-07-09 19:21:43 +00:00
chrome/gophertool
ios misc/ios: add missing CGO_ENABLED=1 for running standalone tests 2019-06-15 06:19:57 +00:00
linkcheck
nacl crypto/ed25519: promote from golang.org/x/crypto/ed25519 2019-05-06 23:23:45 +00:00
reboot cmd/dist: add a test in misc/reboot to verify that the toolchain can self-bootstrap 2019-03-13 21:16:24 +00:00
swig
trace misc/trace: update trace_viewer_full.html 2018-04-26 20:26:23 +00:00
wasm syscall/js: replace TypedArrayOf with CopyBytesToGo/CopyBytesToJS 2019-05-24 09:38:37 +00:00
benchcmp
editors
go.mod misc: add go.mod file 2019-02-27 17:47:31 +00:00