Extend dlfcn tests

tests/Makefile

@@ -233,12 +233,23 @@ DYNAMIC_FLAGS+=\
 	-lc
 
 DEPS=../sysroot
+else
+DYNAMIC_FLAGS+=\
+	-Wl,-rpath=\$$ORIGIN
 endif
 
 bins_static/%: %.c $(DEPS)
 	mkdir -p "$$(dirname "$@")"
 	$(CC) "$<" -o "$@" $(FLAGS) $(STATIC_FLAGS)
 
+bins_dynamic/%.so: %.c $(DEPS)
+	mkdir -p "$$(dirname "$@")"
+	$(CC) "$<" -o "$@" -shared -fpic $(FLAGS) $(DYNAMIC_FLAGS)
+
+bins_dynamic/dlfcn: dlfcn.c bins_dynamic/sharedlib.so $(DEPS)
+	mkdir -p "$$(dirname "$@")"
+	$(CC) "$<" -o "$@" $(FLAGS) $(DYNAMIC_FLAGS)
+
 bins_dynamic/%: %.c $(DEPS)
 	mkdir -p "$$(dirname "$@")"
 	$(CC) "$<" -o "$@" $(FLAGS) $(DYNAMIC_FLAGS)

tests/dlfcn.c

@@ -5,24 +5,98 @@
 
 int add(int a, int b)
 {
-	return a + b;
+    return a + b;
 }
 
+void test_dlopen_null()
+{
+    void* handle = dlopen(NULL, RTLD_LAZY);
+    if (!handle) {
+        printf("dlopen(NULL) failed\n");
+        exit(1);
+    }
+    int (*f)(int, int) = dlsym(handle, "add");
+    if (!f) {
+        printf("dlsym(handle, add) failed\n");
+        exit(2);
+    }
+    int a = 22;
+    int b = 33;
+    printf("add(%d, %d) = %d\n", a, b, f(a, b));
+    dlclose(handle);
+}
+
+void test_dlopen_libc()
+{
+    void* handle = dlopen("libc.so.6", RTLD_LAZY);
+    if (!handle) {
+        printf("dlopen(libc.so.6) failed\n");
+        exit(1);
+    }
+    int (*f)(const char*) = dlsym(handle, "puts");
+    if (!f) {
+        printf("dlsym(handle, puts) failed\n");
+        exit(2);
+    }
+    f("puts from dlopened libc");
+    dlclose(handle);
+}
+
+
+void test_dlsym_function()
+{
+    void* handle = dlopen("sharedlib.so", RTLD_LAZY);
+    if (!handle) {
+        printf("dlopen(sharedlib.so) failed\n");
+        exit(1);
+    }
+    void (*f)() = dlsym(handle, "print");
+    if (!f) {
+        printf("dlsym(handle, print) failed\n");
+        exit(2);
+    }
+    f();
+    dlclose(handle);
+}
+
+void test_dlsym_global_var()
+{
+    void* handle = dlopen("sharedlib.so", RTLD_LAZY);
+    if (!handle) {
+        printf("dlopen(sharedlib.so) failed\n");
+        exit(1);
+    }
+    int* global_var = dlsym(handle, "global_var");
+    if (!global_var) {
+        printf("dlsym(handle, global_var) failed\n");
+        exit(2);
+    }
+    printf("main: global_var == %d\n", *global_var);
+    dlclose(handle);
+}
+
+void test_dlsym_tls_var()
+{
+    void* handle = dlopen("sharedlib.so", RTLD_LAZY);
+    if (!handle) {
+        printf("dlopen(sharedlib.so) failed\n");
+        exit(1);
+    }
+    int* tls_var = dlsym(handle, "tls_var");
+    if (!tls_var) {
+        printf("dlsym(handle, tls_var) failed\n");
+        exit(2);
+    }
+    printf("main: tls_var == %d\n", *tls_var);
+    dlclose(handle);
+}
 
 int main()
 {
-	void* handle = dlopen(NULL, RTLD_LAZY);
-	if (!handle) {
-		printf("dlopen(NULL) failed\n");
-		exit(1);
-	}
-	int (*f)(int, int) = dlsym(handle, "add");
-	if (!f) {
-		printf("dlsym(handle, add) failed\n");
-		exit(2);
-	}
-	int a = 22;
-	int b = 33;
-	printf("add(%d, %d) = %d\n", a, b, f(a, b));
+    test_dlopen_null();
+    test_dlopen_libc();
+    test_dlsym_function();
+    test_dlsym_global_var();
+    test_dlsym_tls_var();
 }
 

tests/expected/dlfcn.stdout

 add(22, 33) = 55
+puts from dlopened libc
+sharedlib: global_var == 42
+sharedlib: tls_var == 21
+main: global_var == 42
+main: tls_var == 21

tests/sharedlib.c

+#include <stdio.h>
+
+int global_var = 42;
+_Thread_local int tls_var = 21;
+
+void print()
+{
+    fprintf(stdout, "sharedlib: global_var == %d\n", global_var);
+    fprintf(stdout, "sharedlib: tls_var == %d\n", tls_var);
+}