[RFC v2] perf tools: Try to find cross-built objdump path

[Namhyung Kim <namhyung@kernel.org>]

From: Namhyung Kim <namhyung.kim@lge.com>

As we have architecture information of saved perf.data file, we can
try to find cross-built objdump path.

The triplets are incomplete and maybe need some regexp works.

Cc: Irina Tirdea <irina.tirdea@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
v2: don't modify env string

 tools/perf/Makefile           |   2 +
 tools/perf/arch/common.c      |  42 +++++++++++++++++
 tools/perf/builtin-annotate.c |   3 ++
 tools/perf/util/annotate.c    | 103 ++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/annotate.h    |  10 ++++
 5 files changed, 160 insertions(+)
 create mode 100644 tools/perf/arch/common.c

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 5973f383eb8e..b189229eb576 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -412,6 +412,8 @@ LIB_OBJS += $(OUTPUT)ui/helpline.o
 LIB_OBJS += $(OUTPUT)ui/hist.o
 LIB_OBJS += $(OUTPUT)ui/stdio/hist.o
 
+LIB_OBJS += $(OUTPUT)arch/common.o
+
 BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
 BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
 # Benchmark modules
diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
new file mode 100644
index 000000000000..c3872427d135
--- /dev/null
+++ b/tools/perf/arch/common.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+
+const char * const arm_triplets[] = {
+	"arm-eabi-",
+	"arm-unknown-linux-",
+	"arm-unknown-linux-gnu-",
+	"arm-unknown-linux-gnueabi-",
+	NULL
+};
+
+const char * const powerpc_triplets[] = {
+	"powerpc-unknown-linux-gnu-",
+	"powerpc64-unknown-linux-gnu-",
+	NULL
+};
+
+const char * const s390_triplets[] = {
+	"s390-ibm-linux-",
+	NULL
+};
+
+const char * const sh_triplets[] = {
+	"sh-unknown-linux-gnu-",
+	"sh64-unknown-linux-gnu-",
+	NULL
+};
+
+const char * const sparc_triplets[] = {
+	"sparc-unknown-linux-gnu-",
+	"sparc64-unknown-linux-gnu-",
+	NULL
+};
+
+const char * const x86_triplets[] = {
+	"x86_64-pc-linux-gnu-",
+	"x86_64-unknown-linux-gnu-",
+	"i686-pc-linux-gnu-",
+	"i586-pc-linux-gnu-",
+	"i486-pc-linux-gnu-",
+	"i386-pc-linux-gnu-",
+	NULL
+};
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 9ea38540b873..20fe9bb6505b 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -186,6 +186,9 @@ static int __cmd_annotate(struct perf_annotate *ann)
 			goto out_delete;
 	}
 
+	if (!objdump_path)
+		try_objdump_path(session);
+
 	ret = perf_session__process_events(session, &ann->tool);
 	if (ret)
 		goto out_delete;
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index f0a910371377..df17c443e3b3 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -15,6 +15,7 @@
 #include "debug.h"
 #include "annotate.h"
 #include <pthread.h>
+#include <sys/utsname.h>
 
 const char 	*disassembler_style;
 const char	*objdump_path;
@@ -1140,3 +1141,105 @@ int symbol__tty_annotate(struct symbol *sym, struct map *map, int evidx,
 
 	return 0;
 }
+
+static bool lookup_path(char *name)
+{
+	bool found = false;
+	char *path, *tmp;
+	char buf[PATH_MAX];
+	char *env = getenv("PATH");
+
+	if (!env)
+		return false;
+
+	env = strdup(env);
+	if (!env)
+		return false;
+
+	path = strtok_r(env, ":", &tmp);
+	while (path) {
+		scnprintf(buf, sizeof(buf), "%s%s", path, name);
+		if (access(buf, F_OK) == 0) {
+			found = true;
+			break;
+		}
+		strtok_r(NULL, ":", &tmp);
+	}
+	free(env);
+	return found;
+}
+
+static int lookup_triplets(const char **triplets, const char *name)
+{
+	int i;
+	char buf[PATH_MAX];
+
+	for (i = 0; triplets[i] != NULL; i++) {
+		scnprintf(buf, sizeof(buf), "%s%s", triplets[i], name);
+		if (lookup_path(buf))
+			return i;
+	}
+	return -1;
+}
+
+static char *try_binutils_path(struct perf_session *session, const char *name)
+{
+	int idx;
+	char *arch, *env;
+	struct utsname uts;
+	const char **path_list;
+	char buf[PATH_MAX];
+
+	if (uname(&uts) < 0)
+		return NULL;
+
+	/*
+	 * We don't need to try to find objdump path for native system.
+	 * Just use default "objdump".
+	 */
+	if (!strcmp(uts.machine, session->header.env.arch))
+		return NULL;
+
+	env = getenv("CROSS_COMPILE");
+	if (env) {
+		scnprintf(buf, sizeof(buf), "%s%s", env, name);
+		if (buf[0] == '/') {
+			if (access(buf, F_OK) == 0)
+				return strdup(buf);
+
+			return NULL;
+		}
+
+		if (lookup_path(buf))
+			return strdup(buf);
+	}
+
+	arch = session->header.env.arch;
+
+	if (!strcmp(arch, "arm"))
+		path_list = arm_triplets;
+	else if (!strcmp(arch, "powerpc"))
+		path_list = powerpc_triplets;
+	else if (!strcmp(arch, "sh"))
+		path_list = sh_triplets;
+	else if (!strcmp(arch, "s390"))
+		path_list = s390_triplets;
+	else if (!strcmp(arch, "sparc"))
+		path_list = sparc_triplets;
+	else if (!strcmp(arch, "x86"))
+		path_list = x86_triplets;
+	else
+		BUG_ON(1);
+
+	idx = lookup_triplets(path_list, name);
+	if (idx < 0)
+		return NULL;
+
+	scnprintf(buf, sizeof(buf), path_list[idx], name);
+	return strdup(buf);
+}
+
+void try_objdump_path(struct perf_session *session)
+{
+	objdump_path = try_binutils_path(session, "objdump");
+}
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 9b5b21e7b032..cbf2d9537320 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include "types.h"
 #include "symbol.h"
+#include "session.h"
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include <pthread.h>
@@ -156,4 +157,13 @@ int symbol__tui_annotate(struct symbol *sym, struct map *map, int evidx,
 extern const char	*disassembler_style;
 extern const char	*objdump_path;
 
+extern const char *arm_triplets[];
+extern const char *powerpc_triplets[];
+extern const char *sh_triplets[];
+extern const char *s390_triplets[];
+extern const char *sparc_triplets[];
+extern const char *x86_triplets[];
+
+void try_objdump_path(struct perf_session *session);
+
 #endif	/* __PERF_ANNOTATE_H */
-- 
1.7.11.4