code review 9738047: runtime: Add shared library support (linux/amd64)

misc/cgo/testshared/mainadv.c

Index: misc/cgo/testshared/mainadv.c
===================================================================
new file mode 100644
--- /dev/null
+++ b/misc/cgo/testshared/mainadv.c
@@ -0,0 +1,67 @@
+// Copyright 2013 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 <stdio.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+
+static __thread int tlsvar;
+
+static void *threaded_callback(void *callback) {
+	int v = ((int (*)(void))(callback))();
+	if(v != 42) {
+		fprintf(stderr, "Incorrect result from Go function, expected %d, got %d\n", 42, v);
+		exit(1);
+	}
+	return NULL;
+}
+
+int main() {
+	void *handle;
+	int (*callback)(void);
+	char *error;
+	int err;
+	pthread_attr_t attr;
+	pthread_t p;
+
+	tlsvar = 1234;
+
+	handle = dlopen("libgoshared.so", RTLD_LAZY);
+	if(!handle) {
+		fprintf(stderr, "Failed to load go shared library: %s\n", dlerror());
+		return 1;
+	}
+
+	callback = (int (*)(void))dlsym(handle, "Go_callback");
+	if((error = dlerror()) != NULL)  {
+		fprintf(stderr, "Failed to find callback symbol: %s\n", error);
+		return 1;
+	}
+
+	pthread_attr_init(&attr);
+	err = pthread_create(&p, &attr, threaded_callback, callback);
+	if(err != 0) {
+		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
+		exit(1);
+	}
+	int v = (*callback)();
+	if(v != 42) {
+		fprintf(stderr, "Incorrect result from Go function, expected %d, got %d\n", 42, v);
+		exit(1);
+	}
+
+	err = pthread_join(p, NULL);
+	if(err != 0) {
+		fprintf(stderr, "runtime/cgo: pthread_join failed: %s\n", strerror(err));
+		exit(1);
+	}
+	if(tlsvar != 1234) {
+		fprintf(stderr, "Corrupt TLS variable, expected %d, got %d\n", 1234, tlsvar);
+		exit(1);
+	}
+
+	exit(0);
+}