ccanlint: report valgrind "definite" leaks.

This is complicated by valgrind's limited options, and our desire not to run
valgrind twice (it's already the slowest part of the tests).

Ideally I'd like a different error code for each kind of error.  I
could parse and pretty-print the XML output, but instead I just parse
the human-readable (which is fragile).

tools/ccanlint/ccanlint.h

@@ -168,6 +168,9 @@ struct ccan_file {
 
 	/* Compiled with coverage information. */
 	char *cov_compiled;
+
+	/* Leak output from valgrind. */
+	char *leak_info;
 };
 
 /* A new ccan_file, with the given name (talloc_steal onto returned value). */

tools/ccanlint/tests/run_tests_valgrind.c

@@ -3,6 +3,8 @@
 #include <ccan/talloc/talloc.h>
 #include <ccan/str/str.h>
 #include <ccan/foreach/foreach.h>
+#include <ccan/grab_file/grab_file.h>
+#include <ccan/str_talloc/str_talloc.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -27,6 +29,67 @@ static const char *can_run_vg(struct manifest *m)
 	return NULL;
 }
 
+/* Example output:
+==2749== Conditional jump or move depends on uninitialised value(s)
+==2749==    at 0x4026C60: strnlen (mc_replace_strmem.c:263)
+==2749==    by 0x40850E3: vfprintf (vfprintf.c:1614)
+==2749==    by 0x408EACF: printf (printf.c:35)
+==2749==    by 0x8048465: main (in /tmp/foo)
+==2749== 
+==2749== 1 bytes in 1 blocks are definitely lost in loss record 1 of 1
+==2749==    at 0x4025BD3: malloc (vg_replace_malloc.c:236)
+==2749==    by 0x8048444: main (in /tmp/foo)
+==2749== 
+*/
+
+static bool blank_line(const char *line)
+{
+	return line[strspn(line, "=0123456789 ")] == '\0';
+}
+
+static char *get_leaks(const char *output, char **errs)
+{
+	char *leaks = talloc_strdup(output, "");
+	unsigned int i, num;
+	char **lines = strsplit(output, output, "\n", &num);
+
+	*errs = talloc_strdup(output, "");
+	for (i = 0; i < num; i++) {
+		if (strstr(lines[i], " lost ")) {
+			/* A leak... */
+			if (strstr(lines[i], " definitely lost ")) {
+				/* Definite leak, report. */
+				while (lines[i] && !blank_line(lines[i])) {
+					leaks = talloc_append_string(leaks,
+								     lines[i]);
+					leaks = talloc_append_string(leaks,
+								     "\n");
+					i++;
+				}
+			} else
+				/* Not definite, ignore. */
+				while (lines[i] && !blank_line(lines[i]))
+					i++;
+		} else {
+			/* A real error. */
+			while (lines[i] && !blank_line(lines[i])) {
+				*errs = talloc_append_string(*errs, lines[i]);
+				*errs = talloc_append_string(*errs, "\n");
+				i++;
+			}
+		}
+	}
+	if (!leaks[0]) {
+		talloc_free(leaks);
+		leaks = NULL;
+	}
+	if (!(*errs)[0]) {
+		talloc_free(*errs);
+		*errs = NULL;
+	}
+	return leaks;
+}
+
 /* FIXME: Run examples, too! */
 static void do_run_tests_vg(struct manifest *m,
 			     bool keep,
@@ -37,16 +100,31 @@ static void do_run_tests_vg(struct manifest *m,
 	struct list_head *list;
 	char *cmdout;
 
+	/* This is slow, so we run once but grab leak info. */
 	score->total = 0;
 	foreach_ptr(list, &m->run_tests, &m->api_tests) {
 		list_for_each(list, i, list) {
+			char *output, *err;
 			score->total++;
+			/* FIXME: Valgrind's output sucks.  XML is unreadable by
+			 * humans, and you can't have both. */
 			if (run_command(score, timeleft, &cmdout,
-					"valgrind -q --error-exitcode=100%s %s",
+					"valgrind -q --leak-check=full"
+					" --log-fd=3 %s %s"
+					" 3> valgrind.log",
 					run_tests_vg.options ?
 					run_tests_vg.options : "",
 					i->compiled)) {
-				score->score++;
+				output = grab_file(i, "valgrind.log", NULL);
+				if (!output || output[0] == '\0') {
+					err = NULL;
+				} else {
+					i->leak_info = get_leaks(output, &err);
+				}
+				if (err) {
+					score_file_error(score, i, 0, err);
+				} else
+					score->score++;
 			} else {
 				score_file_error(score, i, 0, cmdout);
 			}
@@ -57,6 +135,30 @@ static void do_run_tests_vg(struct manifest *m,
 		score->pass = true;
 }
 
+static void do_leakcheck_vg(struct manifest *m,
+			    bool keep,
+			    unsigned int *timeleft,
+			    struct score *score)
+{
+	struct ccan_file *i;
+	struct list_head *list;
+	bool leaks = false;
+
+	foreach_ptr(list, &m->run_tests, &m->api_tests) {
+		list_for_each(list, i, list) {
+			if (i->leak_info) {
+				score_file_error(score, i, 0, i->leak_info);
+				leaks = true;
+			}
+		}
+	}
+
+	if (!leaks) {
+		score->score = 1;
+		score->pass = true;
+	}
+}
+
 /* Gcc's warn_unused_result is fascist bullshit. */
 #define doesnt_matter()
 
@@ -85,3 +187,11 @@ struct ccanlint run_tests_vg = {
 };
 
 REGISTER_TEST(run_tests_vg, &run_tests, NULL);
+
+struct ccanlint run_tests_vg_leak = {
+	.key = "valgrind-leaks",
+	.name = "Module's run and api tests leak memory",
+	.check = do_leakcheck_vg,
+};
+
+REGISTER_TEST(run_tests_vg_leak, &run_tests_vg, NULL);