Provide helper wrappers for basename(3) and dirname(3)

This hides the need to provide mutable C strings, and unifies
existing basename calls and variations in a single location.

Change-Id: Idfb449c47b1421f1a751efc3d7404f15f8b369ca
Reviewed-on: https://chromium-review.googlesource.com/725731
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

8 files changed, 113 insertions, 23 deletions

diff --git a/src/common/linux/dump_symbols.cc b/src/common/linux/dump_symbols.cc
index 13a545f3..4e9afd2e 100644
--- a/src/common/linux/dump_symbols.cc
+++ b/src/common/linux/dump_symbols.cc
@@ -66,6 +66,7 @@
 #include "common/linux/file_id.h"
 #include "common/memory_allocator.h"
 #include "common/module.h"
+#include "common/path_helper.h"
 #include "common/scoped_ptr.h"
 #ifndef NO_STABS_SUPPORT
 #include "common/stabs_reader.h"
@@ -877,16 +878,6 @@ const char* ElfArchitecture(const typename ElfClass::Ehdr* elf_header) {
   }
 }
 
-// Return the non-directory portion of FILENAME: the portion after the
-// last slash, or the whole filename if there are no slashes.
-string BaseFileName(const string &filename) {
-  // Lots of copies!  basename's behavior is less than ideal.
-  char* c_filename = strdup(filename.c_str());
-  string base = basename(c_filename);
-  free(c_filename);
-  return base;
-}
-
 template<typename ElfClass>
 bool SanitizeDebugFile(const typename ElfClass::Ehdr* debug_elf_header,
                        const string& debuglink_file,
@@ -937,7 +928,7 @@ bool InitModuleForElfClass(const typename ElfClass::Ehdr* elf_header,
     return false;
   }
 
-  string name = BaseFileName(obj_filename);
+  string name = google_breakpad::BaseName(obj_filename);
   string os = "Linux";
   // Add an extra "0" at the end.  PDB files on Windows have an 'age'
   // number appended to the end of the file identifier; this isn't
diff --git a/src/common/mac/dump_syms.cc b/src/common/mac/dump_syms.cc
index eb927292..66757cda 100644
--- a/src/common/mac/dump_syms.cc
+++ b/src/common/mac/dump_syms.cc
@@ -38,7 +38,6 @@
 #include <assert.h>
 #include <dirent.h>
 #include <errno.h>
-#include <libgen.h>
 #include <mach-o/arch.h>
 #include <mach-o/fat.h>
 #include <stdint.h>
@@ -60,6 +59,7 @@
 #include "common/mac/arch_utilities.h"
 #include "common/mac/macho_reader.h"
 #include "common/module.h"
+#include "common/path_helper.h"
 #include "common/scoped_ptr.h"
 #include "common/stabs_reader.h"
 #include "common/stabs_to_module.h"
@@ -370,8 +370,7 @@ bool DumpSymbols::CreateEmptyModule(scoped_ptr<Module>& module) {
   }
 
   // Compute a module name, to appear in the MODULE record.
-  string module_name = object_filename_;
-  module_name = basename(&module_name[0]);
+  string module_name = google_breakpad::BaseName(object_filename_);
 
   // Choose an identifier string, to appear in the MODULE record.
   string identifier = Identifier();
diff --git a/src/common/path_helper.cc b/src/common/path_helper.cc
new file mode 100644
index 00000000..60fe34ff
--- /dev/null
+++ b/src/common/path_helper.cc
@@ -0,0 +1,54 @@
+// Copyright 2017, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "common/path_helper.h"
+
+#include <assert.h>
+#include <libgen.h>
+#include <string.h>
+
+namespace google_breakpad {
+
+string BaseName(const string& path) {
+  char* path_tmp = strdup(path.c_str());
+  assert(path_tmp);
+  string result(basename(path_tmp));
+  free(path_tmp);
+  return result;
+}
+
+string DirName(const string& path) {
+  char* path_tmp = strdup(path.c_str());
+  assert(path_tmp);
+  string result(dirname(path_tmp));
+  free(path_tmp);
+  return result;
+}
+
+}  // namespace google_breakpad
diff --git a/src/common/path_helper.h b/src/common/path_helper.h
new file mode 100644
index 00000000..2166ba01
--- /dev/null
+++ b/src/common/path_helper.h
@@ -0,0 +1,44 @@
+// Copyright 2017, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef GOOGLE_BREAKPAD_COMMON_PATH_HELPER_H
+#define GOOGLE_BREAKPAD_COMMON_PATH_HELPER_H
+
+#include <string>
+
+#include "common/using_std_string.h"
+
+namespace google_breakpad {
+
+string BaseName(const string& path);
+string DirName(const string& path);
+
+}  // namespace google_breakpad
+
+#endif  // GOOGLE_BREAKPAD_COMMON_PATH_HELPER_H
diff --git a/src/processor/microdump_stackwalk.cc b/src/processor/microdump_stackwalk.cc
index 46c4127e..220396ed 100644
--- a/src/processor/microdump_stackwalk.cc
+++ b/src/processor/microdump_stackwalk.cc
@@ -38,6 +38,7 @@
 #include <string>
 #include <vector>
 
+#include "common/path_helper.h"
 #include "common/scoped_ptr.h"
 #include "common/using_std_string.h"
 #include "google_breakpad/processor/basic_source_line_resolver.h"
@@ -130,7 +131,7 @@ static void Usage(int argc, const char *argv[], bool error) {
           "\n"
           "  -m         Output in machine-readable format\n"
           "  -s         Output stack contents\n",
-          basename(argv[0]));
+          google_breakpad::BaseName(argv[0]).c_str());
 }
 
 static void SetupOptions(int argc, const char *argv[], Options* options) {
diff --git a/src/processor/minidump_stackwalk.cc b/src/processor/minidump_stackwalk.cc
index b127c882..acf80972 100644
--- a/src/processor/minidump_stackwalk.cc
+++ b/src/processor/minidump_stackwalk.cc
@@ -40,6 +40,7 @@
 #include <string>
 #include <vector>
 
+#include "common/path_helper.h"
 #include "common/scoped_ptr.h"
 #include "common/using_std_string.h"
 #include "google_breakpad/processor/basic_source_line_resolver.h"
@@ -128,7 +129,7 @@ static void Usage(int argc, const char *argv[], bool error) {
           "\n"
           "  -m         Output in machine-readable format\n"
           "  -s         Output stack contents\n",
-          basename(argv[0]));
+          google_breakpad::BaseName(argv[0]).c_str());
 }
 
 static void SetupOptions(int argc, const char *argv[], Options* options) {
diff --git a/src/tools/linux/md2core/minidump-2-core.cc b/src/tools/linux/md2core/minidump-2-core.cc
index 6a9e28eb..8cc07a6e 100644
--- a/src/tools/linux/md2core/minidump-2-core.cc
+++ b/src/tools/linux/md2core/minidump-2-core.cc
@@ -46,6 +46,7 @@
 
 #include "common/linux/memory_mapped_file.h"
 #include "common/minidump_type_helper.h"
+#include "common/path_helper.h"
 #include "common/scoped_ptr.h"
 #include "common/using_std_string.h"
 #include "google_breakpad/common/breakpad_types.h"
@@ -133,7 +134,7 @@ Usage(int argc, const char* argv[]) {
           "             lookups to be done in this directory rather than the filesystem\n"
           "             layout as it exists in the crashing image.  This path should end\n"
           "             with a slash if it's a directory.  e.g. /var/lib/breakpad/\n"
-          "", basename(argv[0]));
+          "", google_breakpad::BaseName(argv[0]).c_str());
 }
 
 static void
@@ -1132,9 +1133,8 @@ AugmentMappings(const Options& options, CrashedProcess* crashinfo,
 
       // Decide whether we use the filename or the SONAME (where the SONAME tends
       // to be a symlink to the actual file).
-      string basename = options.use_filename ? sig_filename : old_filename;
-      size_t slash = basename.find_last_of('/');
-      new_filename += basename.substr(slash == string::npos ? 0 : slash + 1);
+      new_filename += google_breakpad::BaseName(
+          options.use_filename ? sig_filename : old_filename);
 
       if (filename != new_filename) {
         if (options.verbose) {
diff --git a/src/tools/mac/dump_syms/macho_dump.cc b/src/tools/mac/dump_syms/macho_dump.cc
index d882bbe8..6e784ca7 100644
--- a/src/tools/mac/dump_syms/macho_dump.cc
+++ b/src/tools/mac/dump_syms/macho_dump.cc
@@ -34,7 +34,6 @@
 
 #include <errno.h>
 #include <fcntl.h>
-#include <libgen.h>
 #include <mach-o/arch.h>
 #include <sys/mman.h>
 #include <stdint.h>
@@ -49,6 +48,7 @@
 #include "common/byte_cursor.h"
 #include "common/mac/arch_utilities.h"
 #include "common/mac/macho_reader.h"
+#include "common/path_helper.h"
 
 using google_breakpad::ByteBuffer;
 using std::ostringstream;
@@ -85,7 +85,7 @@ class DumpSection: public mach_o::Reader::SectionHandler {
            section.contents.Size());
     return true;
   }
-         
+
  private:
   int index_;
 };
@@ -191,7 +191,7 @@ void DumpFile(const char *filename) {
 }  // namespace
 
 int main(int argc, char **argv) {
-  program_name = basename(argv[0]);
+  program_name = google_breakpad::BaseName(argv[0]);
   if (argc == 1) {
     fprintf(stderr, "Usage: %s FILE ...\n"
             "Dump the contents of the Mach-O or fat binary files "