Fix Mac Breakpad host tools to build in Linux cross-compile

src/common/mac/dump_syms.cc

 // -*- mode: c++ -*-
 
 // Copyright (c) 2011, 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
@@ skipping 18 matching lines @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
 
 // dump_syms.mm: Create a symbol file for use with minidumps
 
 #include "common/mac/dump_syms.h"
 
 #include <assert.h>
-#include <Foundation/Foundation.h>
+#include <libgen.h>
 #include <mach-o/arch.h>
 #include <mach-o/fat.h>
 #include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #include <ostream>
 #include <string>
 #include <vector>
 
 #include "common/dwarf/bytereader-inl.h"
 #include "common/dwarf/dwarf2reader.h"
 #include "common/dwarf_cfi_to_module.h"
 #include "common/dwarf_cu_to_module.h"
 #include "common/dwarf_line_to_module.h"
@@ skipping 25 matching lines @@
 using google_breakpad::StabsReader;
 using google_breakpad::StabsToModule;
 using google_breakpad::scoped_ptr;
 using std::make_pair;
 using std::pair;
 using std::string;
 using std::vector;
 
 namespace google_breakpad {
 
-bool DumpSymbols::Read(NSString *filename) {
-  if (![[NSFileManager defaultManager] fileExistsAtPath:filename]) {
+bool DumpSymbols::Read(const string &filename) {
+  struct stat st;
+  if (stat(filename.c_str(), &st) == -1) {
     fprintf(stderr, "Object file does not exist: %s\n",

[Mark Mentovai, 2015/09/11 15:49:50]

Not necessarily—use strerror(errno) for the real error.

[Ted Mielczarek, 2015/09/15 12:58:36]

Done.

-            [filename fileSystemRepresentation]);
+            filename.c_str());
     return false;
   }
 
-  input_pathname_ = [filename retain];
+  input_pathname_ = filename;
 
   // Does this filename refer to a dSYM bundle?
-  NSBundle *bundle = [NSBundle bundleWithPath:input_pathname_];
-
-  if (bundle) {
+  string contents_path = input_pathname_ + "/Contents/Resources/DWARF";
+  if (S_ISDIR(st.st_mode) &&
+      access(contents_path.c_str(), F_OK) == 0) {
     // Filenames referring to bundles usually have names of the form

[Mark Mentovai, 2015/09/11 15:49:50]

This is totally hokey. It seems to break down if the .dSYM bundle is renamed.

If we’re not going to read the Info.plist (and I’m guessing we’re not, unless
you want to include CF for non-Mac), then it’s probably more reliable to just
look for the single file in Contents/Resources/DWARF. We can fail if more than
one file exists in there, and if there’s only one, it’s got to be the winner.

[Ted Mielczarek, 2015/09/15 12:58:36]

Done.

     // "<basename>.dSYM"; however, if the user has specified a wrapper
     // suffix (the WRAPPER_SUFFIX and WRAPPER_EXTENSION build settings),
     // then the name may have the form "<basename>.<extension>.dSYM". In
     // either case, the resource name for the file containing the DWARF
     // info within the bundle is <basename>.
     //
     // Since there's no way to tell how much to strip off, remove one
     // extension at a time, and use the first one that
-    // pathForResource:ofType:inDirectory likes.
-    NSString *base_name = [input_pathname_ lastPathComponent];
-    NSString *dwarf_resource;
+    // exists under Contents/Resources/DWARF.
+    string base_name = input_pathname_;
+    base_name = basename(&base_name[0]);
+
+    string dwarf_resource;
 
     do {
-      NSString *new_base_name = [base_name stringByDeletingPathExtension];
-
-      // If stringByDeletingPathExtension returned the name unchanged, then
-      // there's nothing more for us to strip off --- lose.
-      if ([new_base_name isEqualToString:base_name]) {
+      size_t lastindex = base_name.find_last_of(".");
+      if (lastindex == string::npos) {
+        // there's nothing more for us to strip off --- lose.
         fprintf(stderr, "Unable to find DWARF-bearing file in bundle: %s\n",
-                [input_pathname_ fileSystemRepresentation]);
+                input_pathname_.c_str());
         return false;
       }
 
       // Take the shortened result as our new base_name.
-      base_name = new_base_name;
+      base_name = base_name.substr(0, lastindex);
 
       // Try to find a DWARF resource in the bundle under the new base_name.
-      dwarf_resource = [bundle pathForResource:base_name
-                        ofType:nil inDirectory:@"DWARF"];
-    } while (!dwarf_resource);
+      dwarf_resource = contents_path + "/" + base_name;
+    } while (access(dwarf_resource.c_str(), F_OK) == -1);
 
-    object_filename_ = [dwarf_resource retain];
+    object_filename_ = dwarf_resource;
   } else {
-    object_filename_ = [input_pathname_ retain];
+    object_filename_ = input_pathname_;
   }
 
   // Read the file's contents into memory.
-  //
-  // The documentation for dataWithContentsOfMappedFile says:
-  //
-  //     Because of file mapping restrictions, this method should only be
-  //     used if the file is guaranteed to exist for the duration of the
-  //     data object’s existence. It is generally safer to use the
-  //     dataWithContentsOfFile: method.
-  //
-  // I gather this means that OS X doesn't have (or at least, that method
-  // doesn't use) a form of mapping like Linux's MAP_PRIVATE, where the
-  // process appears to get its own copy of the data, and changes to the
-  // file don't affect memory and vice versa).
-  NSError *error;
-  contents_ = [NSData dataWithContentsOfFile:object_filename_
-                                     options:0
-                                       error:&error];
-  if (!contents_) {
+  bool read_ok = false;
+  string error;
+  if (stat(object_filename_.c_str(), &st) != -1) {
+    FILE* f = fopen(object_filename_.c_str(), "rb");
+    if (f) {
+      contents_.resize(st.st_size);
+      read_ok = (fread(&contents_[0], st.st_size, 1, f) == 1);

[Mark Mentovai, 2015/09/11 15:49:50]

No read loop?

Generally it’s preferable to read until you hit EOF, instead of calling stat()
to figure out how much to read.

[Ted Mielczarek, 2015/09/15 12:58:36]

Done.

+      if (!read_ok) {
+        error = strerror(errno);
+      }
+      fclose(f);
+    } else {
+      error = strerror(errno);
+    }
+  }
+
+  if (!read_ok) {
     fprintf(stderr, "Error reading object file: %s: %s\n",
-            [object_filename_ fileSystemRepresentation],
-            [[error localizedDescription] UTF8String]);
-    return false;
-  }
-  [contents_ retain];
-
-  // Get the list of object files present in the file.
-  FatReader::Reporter fat_reporter([object_filename_
-                                    fileSystemRepresentation]);
-  FatReader fat_reader(&fat_reporter);
-  if (!fat_reader.Read(reinterpret_cast<const uint8_t *>([contents_ bytes]),
-                       [contents_ length])) {
+            object_filename_.c_str(),
+            error.c_str());
     return false;
   }
 
+  // Get the list of object files present in the file.
+  FatReader::Reporter fat_reporter(object_filename_);
+  FatReader fat_reader(&fat_reporter);
+  if (!fat_reader.Read(&contents_[0],
+                       contents_.size())) {
+    return false;
+  }
+
   // Get our own copy of fat_reader's object file list.
   size_t object_files_count;
   const SuperFatArch *object_files =
     fat_reader.object_files(&object_files_count);
   if (object_files_count == 0) {
     fprintf(stderr, "Fat binary file contains *no* architectures: %s\n",
-            [object_filename_ fileSystemRepresentation]);
+            object_filename_.c_str());
     return false;
   }
   object_files_.resize(object_files_count);
   memcpy(&object_files_[0], object_files,
          sizeof(SuperFatArch) * object_files_count);
 
   return true;
 }
 
 bool DumpSymbols::SetArchitecture(cpu_type_t cpu_type,
@@ skipping 62 matching lines @@
   // TODO(erikchen): If it becomes necessary, we can copy the implementation of
   // NXFindBestFatArch, located at
   // http://web.mit.edu/darwin/src/modules/cctools/libmacho/arch.c.
   fprintf(stderr, "Failed to find an exact match for an object file with cpu "
       "type: %d and cpu subtype: %d. Furthermore, at least one object file is "
       "larger than 2**32.\n", cpu_type, cpu_subtype);
   return NULL;
 }
 
 string DumpSymbols::Identifier() {
-  FileID file_id([object_filename_ fileSystemRepresentation]);
+  FileID file_id(object_filename_.c_str());
   unsigned char identifier_bytes[16];
   cpu_type_t cpu_type = selected_object_file_->cputype;
   cpu_subtype_t cpu_subtype = selected_object_file_->cpusubtype;
   if (!file_id.MachoIdentifier(cpu_type, cpu_subtype, identifier_bytes)) {
     fprintf(stderr, "Unable to calculate UUID of mach-o binary %s!\n",
-            [object_filename_ fileSystemRepresentation]);
+            object_filename_.c_str());
     return "";
   }
 
   char identifier_string[40];
   FileID::ConvertIdentifierToString(identifier_bytes, identifier_string,
                                     sizeof(identifier_string));
 
   string compacted(identifier_string);
   for(size_t i = compacted.find('-'); i != string::npos;
       i = compacted.find('-', i))
@@ skipping 241 matching lines @@
     if (object_files_.size() == 1)
       selected_object_file_ = &object_files_[0];
     else {
       // Look for an object file whose architecture matches our own.
       const NXArchInfo *local_arch = NXGetLocalArchInfo();
       if (!SetArchitecture(local_arch->cputype, local_arch->cpusubtype)) {
         fprintf(stderr, "%s: object file contains more than one"
                 " architecture, none of which match the current"
                 " architecture; specify an architecture explicitly"
                 " with '-a ARCH' to resolve the ambiguity\n",
-                [object_filename_ fileSystemRepresentation]);
+                object_filename_.c_str());
         return false;
       }
     }
   }
 
   assert(selected_object_file_);
 
   // Find the name of the selected file's architecture, to appear in
   // the MODULE record and in error messages.
   const NXArchInfo *selected_arch_info =
       google_breakpad::BreakpadGetArchInfoFromCpuType(
           selected_object_file_->cputype, selected_object_file_->cpusubtype);
 
   const char *selected_arch_name = selected_arch_info->name;
   if (strcmp(selected_arch_name, "i386") == 0)
     selected_arch_name = "x86";
 
   // Produce a name to use in error messages that includes the
   // filename, and the architecture, if there is more than one.
-  selected_object_name_ = [object_filename_ UTF8String];
+  selected_object_name_ = object_filename_;
   if (object_files_.size() > 1) {
     selected_object_name_ += ", architecture ";
     selected_object_name_ + selected_arch_name;
   }
 
   // Compute a module name, to appear in the MODULE record.
-  NSString *module_name = [object_filename_ lastPathComponent];
+  string module_name = object_filename_;
+  module_name = basename(&module_name[0]);
 
   // Choose an identifier string, to appear in the MODULE record.
   string identifier = Identifier();
   if (identifier.empty())
     return false;
   identifier += "0";
 
   // Create a module to hold the debugging information.
-  scoped_ptr<Module> module(new Module([module_name UTF8String],
+  scoped_ptr<Module> module(new Module(module_name,
                                        "mac",
                                        selected_arch_name,
                                        identifier));
 
   // Parse the selected object file.
   mach_o::Reader::Reporter reporter(selected_object_name_);
   mach_o::Reader reader(&reporter);
-  if (!reader.Read(reinterpret_cast<const uint8_t *>([contents_ bytes])
+  if (!reader.Read(&contents_[0]
                    + selected_object_file_->offset,
                    selected_object_file_->size,
                    selected_object_file_->cputype,
                    selected_object_file_->cpusubtype))
     return false;
 
   // Walk its load commands, and deal with whatever is there.
   LoadCommandDumper load_command_dumper(*this, module.get(), reader,
                                         symbol_data_, handle_inter_cu_refs_);
   if (!reader.WalkLoadCommands(&load_command_dumper))
@@ skipping 10 matching lines @@
   if (ReadSymbolData(&module) && module) {
     bool res = module->Write(stream, symbol_data_);
     delete module;
     return res;
   }
 
   return false;
 }
 
 }  // namespace google_breakpad