perf tools: Remove subcmd dependencies on strbuf

Introduce and use new astrcat() and astrcatf() functions which replace
the strbuf functionality for subcmd.

For now they duplicate strbuf's die-on-allocation-error policy.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/957d207e1254406fa11fc2e405e75a7e405aad8f.1450193761.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/exec_cmd.c

@@ -4,6 +4,7 @@
 #include "subcmd-config.h"
 
 #include <string.h>
+#include "subcmd-util.h"
 
 #define MAX_ARGS	32
 
@@ -21,14 +22,14 @@ void exec_cmd_init(const char *exec_name, const char *prefix,
 
 char *system_path(const char *path)
 {
-	struct strbuf d = STRBUF_INIT;
+	char *buf = NULL;
 
 	if (is_absolute_path(path))
 		return strdup(path);
 
-	strbuf_addf(&d, "%s/%s", subcmd_config.prefix, path);
-	path = strbuf_detach(&d, NULL);
-	return (char *)path;
+	astrcatf(&buf, "%s/%s", subcmd_config.prefix, path);
+
+	return buf;
 }
 
 const char *perf_extract_argv0_path(const char *argv0)
@@ -75,22 +76,22 @@ char *perf_exec_path(void)
 	return system_path(subcmd_config.exec_path);
 }
 
-static void add_path(struct strbuf *out, const char *path)
+static void add_path(char **out, const char *path)
 {
 	if (path && *path) {
 		if (is_absolute_path(path))
-			strbuf_addstr(out, path);
+			astrcat(out, path);
 		else
-			strbuf_addstr(out, make_nonrelative_path(path));
+			astrcat(out, make_nonrelative_path(path));
 
-		strbuf_addch(out, PATH_SEP);
+		astrcat(out, ":");
 	}
 }
 
 void setup_path(void)
 {
 	const char *old_path = getenv("PATH");
-	struct strbuf new_path = STRBUF_INIT;
+	char *new_path = NULL;
 	char *tmp = perf_exec_path();
 
 	add_path(&new_path, tmp);
@@ -98,13 +99,13 @@ void setup_path(void)
 	free(tmp);
 
 	if (old_path)
-		strbuf_addstr(&new_path, old_path);
+		astrcat(&new_path, old_path);
 	else
-		strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
+		astrcat(&new_path, "/usr/local/bin:/usr/bin:/bin");
 
-	setenv("PATH", new_path.buf, 1);
+	setenv("PATH", new_path, 1);
 
-	strbuf_release(&new_path);
+	free(new_path);
 }
 
 static const char **prepare_perf_cmd(const char **argv)

tools/perf/util/help.c

@@ -2,6 +2,7 @@
 #include "../builtin.h"
 #include "exec_cmd.h"
 #include "help.h"
+#include "subcmd-util.h"
 
 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
 {
@@ -119,8 +120,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 	int prefix_len;
 	DIR *dir = opendir(path);
 	struct dirent *de;
-	struct strbuf buf = STRBUF_INIT;
-	int len;
+	char *buf = NULL;
 
 	if (!dir)
 		return;
@@ -128,8 +128,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 		prefix = "perf-";
 	prefix_len = strlen(prefix);
 
-	strbuf_addf(&buf, "%s/", path);
-	len = buf.len;
+	astrcatf(&buf, "%s/", path);
 
 	while ((de = readdir(dir)) != NULL) {
 		int entlen;
@@ -137,9 +136,8 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 		if (prefixcmp(de->d_name, prefix))
 			continue;
 
-		strbuf_setlen(&buf, len);
-		strbuf_addstr(&buf, de->d_name);
-		if (!is_executable(buf.buf))
+		astrcat(&buf, de->d_name);
+		if (!is_executable(buf))
 			continue;
 
 		entlen = strlen(de->d_name) - prefix_len;
@@ -149,7 +147,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
 	}
 	closedir(dir);
-	strbuf_release(&buf);
+	free(buf);
 }
 
 void load_command_list(const char *prefix,

tools/perf/util/parse-options.c

@@ -1,4 +1,5 @@
 #include "util.h"
+#include "subcmd-util.h"
 #include "parse-options.h"
 #include "cache.h"
 #include "header.h"
@@ -8,7 +9,7 @@
 #define OPT_SHORT 1
 #define OPT_UNSET 2
 
-static struct strbuf error_buf = STRBUF_INIT;
+char *error_buf;
 
 static int opterror(const struct option *opt, const char *reason, int flags)
 {
@@ -576,19 +577,18 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o
 
 	/* build usage string if it's not provided */
 	if (subcommands && !usagestr[0]) {
-		struct strbuf buf = STRBUF_INIT;
+		char *buf = NULL;
+
+		astrcatf(&buf, "%s %s [<options>] {", subcmd_config.exec_name, argv[0]);
 
-		strbuf_addf(&buf, "%s %s [<options>] {",
-			    subcmd_config.exec_name, argv[0]);
 		for (int i = 0; subcommands[i]; i++) {
 			if (i)
-				strbuf_addstr(&buf, "|");
-			strbuf_addstr(&buf, subcommands[i]);
+				astrcat(&buf, "|");
+			astrcat(&buf, subcommands[i]);
 		}
-		strbuf_addstr(&buf, "}");
+		astrcat(&buf, "}");
 
-		usagestr[0] = strdup(buf.buf);
-		strbuf_release(&buf);
+		usagestr[0] = buf;
 	}
 
 	parse_options_start(&ctx, argc, argv, flags);
@@ -613,13 +613,11 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o
 		putchar('\n');
 		exit(130);
 	default: /* PARSE_OPT_UNKNOWN */
-		if (ctx.argv[0][1] == '-') {
-			strbuf_addf(&error_buf, "unknown option `%s'",
-				    ctx.argv[0] + 2);
-		} else {
-			strbuf_addf(&error_buf, "unknown switch `%c'",
-				    *ctx.opt);
-		}
+		if (ctx.argv[0][1] == '-')
+			astrcatf(&error_buf, "unknown option `%s'",
+				 ctx.argv[0] + 2);
+		else
+			astrcatf(&error_buf, "unknown switch `%c'", *ctx.opt);
 		usage_with_options(usagestr, options);
 	}
 
@@ -806,9 +804,9 @@ static int usage_with_options_internal(const char * const *usagestr,
 
 	setup_pager();
 
-	if (strbuf_avail(&error_buf)) {
-		fprintf(stderr, "  Error: %s\n", error_buf.buf);
-		strbuf_release(&error_buf);
+	if (error_buf) {
+		fprintf(stderr, "  Error: %s\n", error_buf);
+		zfree(&error_buf);
 	}
 
 	fprintf(stderr, "\n Usage: %s\n", *usagestr++);
@@ -852,11 +850,15 @@ void usage_with_options_msg(const char * const *usagestr,
 			    const struct option *opts, const char *fmt, ...)
 {
 	va_list ap;
+	char *tmp = error_buf;
 
 	va_start(ap, fmt);
-	strbuf_addv(&error_buf, fmt, ap);
+	if (vasprintf(&error_buf, fmt, ap) == -1)
+		die("vasprintf failed");
 	va_end(ap);
 
+	free(tmp);
+
 	usage_with_options_internal(usagestr, opts, 0, NULL);
 	exit(129);
 }

tools/perf/util/subcmd-util.h

@@ -0,0 +1,24 @@
+#ifndef __PERF_SUBCMD_UTIL_H
+#define __PERF_SUBCMD_UTIL_H
+
+#include <stdio.h>
+
+#define astrcatf(out, fmt, ...)						\
+({									\
+	char *tmp = *(out);						\
+	if (asprintf((out), "%s" fmt, tmp ?: "", ## __VA_ARGS__) == -1)	\
+		die("asprintf failed");					\
+	free(tmp);							\
+})
+
+static inline void astrcat(char **out, const char *add)
+{
+	char *tmp = *out;
+
+	if (asprintf(out, "%s%s", tmp ?: "", add) == -1)
+		die("asprintf failed");
+
+	free(tmp);
+}
+
+#endif /* __PERF_SUBCMD_UTIL_H */