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>

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

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();

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

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