[PATCH 3/9] perf symbol: Add filename__has_section()

[Namhyung Kim <namhyung@kernel.org>]

The filename__has_section() is to check if the given section name is in
the binary.  It'd be used for checking debug info for srcline.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/symbol-elf.c     | 28 ++++++++++++++++++++++++++++
 tools/perf/util/symbol-minimal.c |  5 +++++
 tools/perf/util/symbol.h         |  1 +
 3 files changed, 34 insertions(+)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 80345695b136..96767d1b3f1c 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -233,6 +233,34 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 	return NULL;
 }
 
+bool filename__has_section(const char *filename, const char *sec)
+{
+	int fd;
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr;
+	bool found = false;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return false;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (elf == NULL)
+		goto out;
+
+	if (gelf_getehdr(elf, &ehdr) == NULL)
+		goto elf_out;
+
+	found = !!elf_section_by_name(elf, &ehdr, &shdr, sec, NULL);
+
+elf_out:
+	elf_end(elf);
+out:
+	close(fd);
+	return found;
+}
+
 static int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
 {
 	size_t i, phdrnum;
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index f9eb0bee7f15..de84da3b0d96 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -385,3 +385,8 @@ char *dso__demangle_sym(struct dso *dso __maybe_unused,
 {
 	return NULL;
 }
+
+bool filename__has_section(const char *filename, const char *sec)
+{
+	return false;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index e297de14184c..f735108c4d4e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -165,6 +165,7 @@ int modules__parse(const char *filename, void *arg,
 					 u64 start, u64 size));
 int filename__read_debuglink(const char *filename, char *debuglink,
 			     size_t size);
+bool filename__has_section(const char *filename, const char *sec);
 
 struct perf_env;
 int symbol__init(struct perf_env *env);
-- 
2.39.0.314.g84b9a713c41-goog