[RFC PATCH 4/8] perf: Make alias handler to check return value of strbuf

[Masami Hiramatsu <mhiramat@kernel.org>]

Make alias handler and sq_quote_argv to check the return
value of strbuf APIs.
In sq_quote_argv() calls die(), but this fix handles strbuf
failure as a special case and returns to caller, since
the caller - handle_alias() also has to check the return
value of other strbuf APIs and those checks can be merged
to one if() statement.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 tools/perf/perf.c       |    8 +++++---
 tools/perf/util/quote.c |   36 ++++++++++++++++++++----------------
 tools/perf/util/quote.h |    2 +-
 3 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 83ffe7c..7970008 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -309,9 +309,11 @@ static int handle_alias(int *argcp, const char ***argv)
 			if (*argcp > 1) {
 				struct strbuf buf;
 
-				strbuf_init(&buf, PATH_MAX);
-				strbuf_addstr(&buf, alias_string);
-				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
+				if (strbuf_init(&buf, PATH_MAX) < 0 ||
+				    strbuf_addstr(&buf, alias_string) < 0 ||
+				    sq_quote_argv(&buf, (*argv) + 1,
+						  PATH_MAX) < 0)
+					die("Failed to allocate memory.");
 				free(alias_string);
 				alias_string = buf.buf;
 			}
diff --git a/tools/perf/util/quote.c b/tools/perf/util/quote.c
index 01f0324..c6d4ee2 100644
--- a/tools/perf/util/quote.c
+++ b/tools/perf/util/quote.c
@@ -17,38 +17,42 @@ static inline int need_bs_quote(char c)
 	return (c == '\'' || c == '!');
 }
 
-static void sq_quote_buf(struct strbuf *dst, const char *src)
+static int sq_quote_buf(struct strbuf *dst, const char *src)
 {
 	char *to_free = NULL;
+	int ret;
 
 	if (dst->buf == src)
 		to_free = strbuf_detach(dst, NULL);
 
-	strbuf_addch(dst, '\'');
-	while (*src) {
+	ret = strbuf_addch(dst, '\'');
+	while (!ret && *src) {
 		size_t len = strcspn(src, "'!");
-		strbuf_add(dst, src, len);
+		ret = strbuf_add(dst, src, len);
 		src += len;
-		while (need_bs_quote(*src)) {
-			strbuf_addstr(dst, "'\\");
-			strbuf_addch(dst, *src++);
-			strbuf_addch(dst, '\'');
-		}
+		while (!ret && need_bs_quote(*src))
+			ret = strbuf_addf(dst, "'\\%c\'", *src++);
 	}
-	strbuf_addch(dst, '\'');
+	if (!ret)
+		ret = strbuf_addch(dst, '\'');
 	free(to_free);
+
+	return ret;
 }
 
-void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
+int sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
 {
-	int i;
+	int i, ret;
 
 	/* Copy into destination buffer. */
-	strbuf_grow(dst, 255);
-	for (i = 0; argv[i]; ++i) {
-		strbuf_addch(dst, ' ');
-		sq_quote_buf(dst, argv[i]);
+	ret = strbuf_grow(dst, 255);
+	for (i = 0; !ret && argv[i]; ++i) {
+		ret = strbuf_addch(dst, ' ');
+		if (ret)
+			break;
+		ret = sq_quote_buf(dst, argv[i]);
 		if (maxlen && dst->len > maxlen)
 			die("Too many or long arguments");
 	}
+	return ret;
 }
diff --git a/tools/perf/util/quote.h b/tools/perf/util/quote.h
index 3340c9c..e1ec191 100644
--- a/tools/perf/util/quote.h
+++ b/tools/perf/util/quote.h
@@ -24,6 +24,6 @@
  * sq_quote() in a real application.
  */
 
-void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
+int sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
 
 #endif /* __PERF_QUOTE_H */