misc/cgo/testcshared: test -buildmode=c-shared

Followed the same test pattern in misc/cgo/testcarchive.

Change-Id: I2f863b5c24a28f0b38b0128ed3e8a92c17fb5b9f
Reviewed-on: https://go-review.googlesource.com/8985Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

misc/cgo/testcshared/main0.c

+// 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.
+
+#include <stdint.h>
+#include <stdio.h>
+
+// Tests libgo.so to export the following functions.
+//   int8_t DidInitRun();
+//   int8_t DidMainRun();
+//   int32_t FromPkg();
+int main(void) {
+  int8_t ran_init = DidInitRun();
+  if (!ran_init) {
+    fprintf(stderr, "ERROR: DidInitRun returned unexpected results: %d\n",
+            ran_init);
+    return 1;
+  }
+  int8_t ran_main = DidMainRun();
+  if (ran_main) {
+    fprintf(stderr, "ERROR: DidMainRun returned unexpected results: %d\n",
+            ran_main);
+    return 1;
+  }
+  int32_t from_pkg = FromPkg();
+  if (from_pkg != 1024) {
+    fprintf(stderr, "ERROR: FromPkg=%d, want %d\n", from_pkg, 1024);
+    return 1;
+  }
+  // test.bash looks for "PASS" to ensure this program has reached the end. 
+  printf("PASS\n");
+  return 0;
+}

misc/cgo/testcshared/main1.c

+// 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.
+
+#include <stdint.h>
+#include <stdio.h>
+#include <dlfcn.h>
+
+int check_int8(void* handle, const char* fname, int8_t want) {
+  int8_t (*fn)();
+  fn = (int8_t (*)())dlsym(handle, fname);
+  if (!fn) {
+    fprintf(stderr, "ERROR: missing %s: %s\n", fname, dlerror());
+    return 1;
+  }
+  signed char ret = fn();
+  if (ret != want) {
+    fprintf(stderr, "ERROR: %s=%d, want %d\n", fname, ret, want);
+    return 1;
+  }
+  return 0;
+}
+
+int check_int32(void* handle, const char* fname, int32_t want) {
+  int32_t (*fn)();
+  fn = (int32_t (*)())dlsym(handle, fname);
+  if (!fn) {
+    fprintf(stderr, "ERROR: missing %s: %s\n", fname, dlerror());
+    return 1;
+  }
+  int32_t ret = fn();
+  if (ret != want) {
+    fprintf(stderr, "ERROR: %s=%d, want %d\n", fname, ret, want);
+    return 1;
+  }
+  return 0;
+}
+
+// Tests libgo.so to export the following functions.
+//   int8_t DidInitRun() // returns true
+//   int8_t DidMainRun() // returns true
+//   int32_t FromPkg() // returns 1024
+int main(int argc, char** argv) {
+  void* handle = dlopen(argv[1], RTLD_LAZY | RTLD_GLOBAL);
+  if (!handle) {
+    fprintf(stderr, "ERROR: failed to open the shared library: %s\n",
+		    dlerror());
+    return 2;
+  }
+
+  int ret = 0;
+  ret = check_int8(handle, "DidInitRun", 1);
+  if (ret != 0) {
+    return ret;
+  }
+
+  ret = check_int8(handle, "DidMainRun", 0);
+  if (ret != 0) {
+    return ret;
+  }
+
+  ret = check_int32(handle, "FromPkg", 1024);
+  if (ret != 0) {
+   return ret;
+  }
+  // test.bash looks for "PASS" to ensure this program has reached the end. 
+  printf("PASS\n");
+  return 0;
+}

misc/cgo/testcshared/src/libgo/libgo.go

+// 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 (
+	_ "p"
+	"syscall"
+	"time"
+)
+
+import "C"
+
+var initCh = make(chan int, 1)
+var ranMain bool
+
+func init() {
+	// emulate an exceedingly slow package initialization function
+	time.Sleep(100 * time.Millisecond)
+	initCh <- 42
+}
+
+func main() {
+	ranMain = true
+	panic("FAIL: main ran")
+}
+
+//export DidInitRun
+func DidInitRun() bool {
+	select {
+	case x := <-initCh:
+		if x != 42 {
+			// Just in case initCh was not correctly made.
+			println("want init value of 42, got: ", x)
+			syscall.Exit(2)
+		}
+		return true
+	default:
+		return false
+	}
+}
+
+//export DidMainRun
+func DidMainRun() bool {
+	return ranMain
+}

misc/cgo/testcshared/src/p/p.go

+// 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 p
+
+import "C"
+
+//export FromPkg
+func FromPkg() int32 { return 1024 }

misc/cgo/testcshared/test.bash

+#!/usr/bin/env bash
+# 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.
+
+set -e
+
+function cleanup() {
+	rm libgo.so testp
+}
+trap cleanup EXIT
+
+GOPATH=$(pwd) go build -buildmode=c-shared -o libgo.so src/libgo/libgo.go
+
+$(go env CC) $(go env GOGCCFLAGS) -o testp main0.c libgo.so
+output=$(LD_LIBRARY_PATH=$LD_LIBRARY_PATH:. ./testp)
+# testp prints PASS at the end of its execution.
+if [ "$output" != "PASS" ]; then
+	echo "FAIL: got $output"
+	exit 1
+fi
+
+$(go env CC) $(go env GOGCCFLAGS) -o testp main1.c -ldl
+output=$(./testp ./libgo.so) 
+# testp prints PASS at the end of its execution.
+if [ "$output" != "PASS" ]; then
+	echo "FAIL: got $output"
+	exit 1
+fi