all: Fix possible uninitialized variable uses

I wasn't especifying the optimization level and the default, despite
using -Wall, was for this so simple case not to be warned about, so
now I'm using -O2.

Alexandre provided a patch initializing the variables to NULL, so that
when we called cus__delete it would bail out and not possibly act on
a random value, I preferred to add extra goto labels and do the exit
path only on the resources that were successfully allocated/initialized,
avoiding, for instance, to call dwarves_exit() if dwarves_init() wasn't
called, which wasn't a problem so far, but could be in the future.

Reported-by: Alexandre Vassalotti <alexandre@peadrop.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

codiff.c

@@ -733,7 +733,6 @@ static struct argp codiff__argp = {
 int main(int argc, char *argv[])
 {
 	int remaining, err, rc = EXIT_FAILURE;
-	struct cus *old_cus, *new_cus;
 	char *old_filename, *new_filename;
 	char *filenames[2];
 	struct stat st;
@@ -754,7 +753,7 @@ failure:
 
 	if (dwarves__init(0)) {
 		fputs("codiff: insufficient memory\n", stderr);
-		return EXIT_FAILURE;
+		goto out;
 	}
 
 	if (show_function_diffs == 0 && show_struct_diffs == 0 &&
@@ -762,16 +761,16 @@ failure:
 		show_function_diffs = show_struct_diffs = 1;
 
 	structs_printed = strlist__new(false);
-	old_cus = cus__new();
-	new_cus = cus__new();
+	struct cus *old_cus = cus__new(),
+		   *new_cus = cus__new();
 	if (old_cus == NULL || new_cus == NULL || structs_printed == NULL) {
 		fputs("codiff: insufficient memory\n", stderr);
-		return EXIT_FAILURE;
+		goto out_cus_delete;
 	}
 
 	if (stat(old_filename, &st) != 0) {
 		fprintf(stderr, "codiff: %s (%s)\n", strerror(errno), old_filename);
-		return EXIT_FAILURE;
+		goto out_cus_delete;
 	}
 
 	filenames[1] = NULL;
@@ -781,13 +780,13 @@ failure:
 		err = cus__load_file(old_cus, &conf_load, old_filename);
 		if (err != 0) {
 			cus__print_error_msg("codiff", old_cus, old_filename, err);
-			return EXIT_FAILURE;
+			goto out_cus_delete_priv;
 		}
 	}
 
 	if (stat(new_filename, &st) != 0) {
 		fprintf(stderr, "codiff: %s (%s)\n", strerror(errno), new_filename);
-		return EXIT_FAILURE;
+		goto out_cus_delete_priv;
 	}
 
 	/* If old_file is a character device, leave its cus empty */
@@ -795,7 +794,7 @@ failure:
 		err = cus__load_file(new_cus, &conf_load, new_filename);
 		if (err != 0) {
 			cus__print_error_msg("codiff", new_cus, new_filename, err);
-			return EXIT_FAILURE;
+			goto out_cus_delete_priv;
 		}
 	}
 
@@ -810,12 +809,14 @@ failure:
 	}
 
 	rc = EXIT_SUCCESS;
-out:
+out_cus_delete_priv:
 	cus__for_each_cu(old_cus, cu_delete_priv, NULL, NULL);
 	cus__for_each_cu(new_cus, cu_delete_priv, NULL, NULL);
+out_cus_delete:
 	cus__delete(old_cus);
 	cus__delete(new_cus);
 	strlist__delete(structs_printed);
 	dwarves__exit();
+out:
 	return rc;
 }

dwarves_reorganize.c

@@ -245,7 +245,7 @@ static void class__move_member(struct class *class, struct class_member *dest,
 				list_prepare_entry(from, class__tags(class),
 						   tag.node);
 		struct class_member *tmp;
-		uint8_t orig_tail_from_bit_hole;
+		uint8_t orig_tail_from_bit_hole = 0;
 		LIST_HEAD(from_list);
 
 		if (verbose)

pahole.c

@@ -1118,7 +1118,6 @@ dump_it:
 int main(int argc, char *argv[])
 {
 	int err, remaining, rc = EXIT_FAILURE;
-	struct cus *cus;
 
 	if (argp_parse(&pahole__argp, argc, argv, 0, &remaining, NULL) ||
 	    remaining == argc) {
@@ -1126,26 +1125,33 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
-	cus = cus__new();
-	if (dwarves__init(cacheline_size) || cus == NULL) {
+	if (dwarves__init(cacheline_size)) {
 		fputs("pahole: insufficient memory\n", stderr);
 		goto out;
 	}
 
+	struct cus *cus = cus__new();
+	if (cus == NULL) {
+		fputs("pahole: insufficient memory\n", stderr);
+		goto out_dwarves_exit;
+	}
+
 	conf_load.steal = pahole_stealer;
 
 	err = cus__load_files(cus, &conf_load, argv + remaining);
 	if (err != 0) {
 		fputs("pahole: No debugging information found\n", stderr);
-		goto out;
+		goto out_cus_delete;
 	}
 
 	if (stats_formatter != NULL)
 		print_stats();
 	rc = EXIT_SUCCESS;
-out:
+out_cus_delete:
 	cus__delete(cus);
 	structures__delete();
+out_dwarves_exit:
 	dwarves__exit();
+out:
 	return rc;
 }

pfunct.c

@@ -613,7 +613,6 @@ static struct argp pfunct__argp = {
 int main(int argc, char *argv[])
 {
 	int err, remaining, rc = EXIT_FAILURE;
-	struct cus *cus;
 
 	if (argp_parse(&pfunct__argp, argc, argv, 0, &remaining, NULL) ||
 	    remaining == argc) {
@@ -624,15 +623,20 @@ int main(int argc, char *argv[])
 	if (symtab_name != NULL)
 		return elf_symtabs__show(argv + remaining);
 
-	cus = cus__new();
-	if (dwarves__init(0) || cus == NULL) {
+	if (dwarves__init(0)) {
 		fputs("pfunct: insufficient memory\n", stderr);
 		goto out;
 	}
 
+	struct cus *cus = cus__new();
+	if (cus == NULL) {
+		fputs("pfunct: insufficient memory\n", stderr);
+		goto out_dwarves_exit;
+	}
+
 	err = cus__load_files(cus, &conf_load, argv + remaining);
 	if (err != 0)
-		goto out;
+		goto out_cus_delete;
 
 	cus__for_each_cu(cus, cu_unique_iterator, NULL, NULL);
 
@@ -647,9 +651,11 @@ int main(int argc, char *argv[])
 		print_fn_stats(formatter);
 
 	rc = EXIT_SUCCESS;
-out:
+out_cus_delete:
 	cus__delete(cus);
 	fn_stats__delete_list();
+out_dwarves_exit:
 	dwarves__exit();
+out:
 	return rc;
 }

pglobal.c

@@ -290,16 +290,20 @@ int main(int argc, char *argv[])
                 goto out;
 	}
 
-	struct cus *cus = cus__new();
-
-	if (dwarves__init(0) || cus == NULL) {
+	if (dwarves__init(0)) {
 		fputs("pglobal: insufficient memory\n", stderr);
 		goto out;
 	}
 
+	struct cus *cus = cus__new();
+	if (cus == NULL) {
+		fputs("pglobal: insufficient memory\n", stderr);
+		goto out_dwarves_exit;
+	}
+
 	err = cus__load_files(cus, NULL, argv + remaining);
 	if (err != 0)
-		goto out;
+		goto out_cus_delete;
 
 	if (walk_var) {
 		cus__for_each_cu(cus, cu_extvar_iterator, NULL, NULL);
@@ -311,8 +315,10 @@ int main(int argc, char *argv[])
 
 	tdestroy(tree, free_node);
 	rc = EXIT_SUCCESS;
-out:
+out_cus_delete:
 	cus__delete(cus);
+out_dwarves_exit:
 	dwarves__exit();
+out:
 	return rc;
 }