misc/cgo/testsigfwd: move to runtime/testprog/testprogcgo

This migrates testsigfwd, which uses some one-off build
infrastructure, to be part of the runtime's testprogcgo.

The test is largely unchanged. Because it's part of a larger binary,
this CL renames a few things and gates the constructor-time signal
handler registration on an environment variable. This CL also replaces
an errant fmt.Errorf with fmt.Fprintf.

For #37486, since it eliminates a non-go-test from dist.

Change-Id: I0efd146ea0a0a3f0b361431349a419af0f0ecc61
Reviewed-on: https://go-review.googlesource.com/c/go/+/443068
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

1 files changed, 0 insertions, 62 deletions

diff --git a/misc/cgo/testsigfwd/main.go b/misc/cgo/testsigfwd/main.go
deleted file mode 100644
index 1d8633971d..0000000000
--- a/misc/cgo/testsigfwd/main.go
+++ /dev/null
@@ -1,62 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-import "fmt"
-
-/*
-#include <signal.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
-int *p;
-static void sigsegv() {
-	*p = 1;
-	fprintf(stderr, "ERROR: C SIGSEGV not thrown on caught?.\n");
-	exit(2);
-}
-
-static void segvhandler(int signum) {
-	if (signum == SIGSEGV) {
-		fprintf(stdout, "ok\ttestsigfwd\n");
-		exit(0);  // success
-	}
-}
-
-static void __attribute__ ((constructor)) sigsetup(void) {
-	struct sigaction act;
-
-	memset(&act, 0, sizeof act);
-	act.sa_handler = segvhandler;
-	sigaction(SIGSEGV, &act, NULL);
-}
-*/
-import "C"
-
-var p *byte
-
-func f() (ret bool) {
-	defer func() {
-		if recover() == nil {
-			fmt.Errorf("ERROR: couldn't raise SIGSEGV in Go.")
-			C.exit(2)
-		}
-		ret = true
-	}()
-	*p = 1
-	return false
-}
-
-func main() {
-	// Test that the signal originating in Go is handled (and recovered) by Go.
-	if !f() {
-		fmt.Errorf("couldn't recover from SIGSEGV in Go.")
-		C.exit(2)
-	}
-
-	// Test that the signal originating in C is handled by C.
-	C.sigsegv()
-}