Mac: stop using NXArchInfo as a vocabulary type

It's deprecated in macOS 13/iOS 16, so this is an incremental step towards using newly introduced APIs for those OSes.

Since the description field is no longer available in the new
mach-o/util.h API, stop using it, especially since architecture name is
sufficiently informative.

Bug: chromium:1420654
Change-Id: If2cec4f1fc88d13a71f011822bff61f173486b68
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/4322265
Reviewed-by: Mark Mentovai <mark@chromium.org>

src/common/mac/arch_utilities.cc

@@ -53,86 +53,44 @@
 #define CPU_SUBTYPE_ARM64_E (static_cast<cpu_subtype_t>(2))
 #endif  // CPU_SUBTYPE_ARM64_E
 
-namespace {
-
-const NXArchInfo* ArchInfo_arm64(cpu_subtype_t cpu_subtype) {
-  const char* name = NULL;
-  switch (cpu_subtype) {
-    case CPU_SUBTYPE_ARM64_ALL:
-      name = "arm64";
-      break;
-    case CPU_SUBTYPE_ARM64_E:
-      name = "arm64e";
-      break;
-    default:
-      return NULL;
-  }
-
-  NXArchInfo* arm64 = new NXArchInfo;
-  *arm64 = *NXGetArchInfoFromCpuType(CPU_TYPE_ARM,
-                                     CPU_SUBTYPE_ARM_V7);
-  arm64->name = name;
-  arm64->cputype = CPU_TYPE_ARM64;
-  arm64->cpusubtype = cpu_subtype;
-  arm64->description = "arm 64";
-  return arm64;
-}
-
-const NXArchInfo* ArchInfo_armv7s() {
-  NXArchInfo* armv7s = new NXArchInfo;
-  *armv7s = *NXGetArchInfoFromCpuType(CPU_TYPE_ARM,
-                                      CPU_SUBTYPE_ARM_V7);
-  armv7s->name = "armv7s";
-  armv7s->cpusubtype = CPU_SUBTYPE_ARM_V7S;
-  armv7s->description = "arm v7s";
-  return armv7s;
-}
-
-}  // namespace
-
-namespace google_breakpad {
-
-const NXArchInfo* BreakpadGetArchInfoFromName(const char* arch_name) {
+std::optional<ArchInfo> GetArchInfoFromName(const char* arch_name) {
   // TODO: Remove this when the OS knows about arm64.
   if (!strcmp("arm64", arch_name))
-    return BreakpadGetArchInfoFromCpuType(CPU_TYPE_ARM64,
-                                          CPU_SUBTYPE_ARM64_ALL);
+    return ArchInfo{CPU_TYPE_ARM64, CPU_SUBTYPE_ARM64_ALL};
 
   if (!strcmp("arm64e", arch_name))
-    return BreakpadGetArchInfoFromCpuType(CPU_TYPE_ARM64,
-                                          CPU_SUBTYPE_ARM64_E);
-
+    return ArchInfo{CPU_TYPE_ARM64, CPU_SUBTYPE_ARM64_E};
   // TODO: Remove this when the OS knows about armv7s.
   if (!strcmp("armv7s", arch_name))
-    return BreakpadGetArchInfoFromCpuType(CPU_TYPE_ARM, CPU_SUBTYPE_ARM_V7S);
+    return ArchInfo{CPU_TYPE_ARM, CPU_SUBTYPE_ARM_V7S};
 
-  return NXGetArchInfoFromName(arch_name);
+  const NXArchInfo* info = NXGetArchInfoFromName(arch_name);
+  if (info)
+    return ArchInfo{info->cputype, info->cpusubtype};
+  return std::nullopt;
 }
 
-const NXArchInfo* BreakpadGetArchInfoFromCpuType(cpu_type_t cpu_type,
-                                                 cpu_subtype_t cpu_subtype) {
+const char* GetNameFromCPUType(cpu_type_t cpu_type, cpu_subtype_t cpu_subtype) {
   // TODO: Remove this when the OS knows about arm64.
   if (cpu_type == CPU_TYPE_ARM64 && cpu_subtype == CPU_SUBTYPE_ARM64_ALL) {
-    static const NXArchInfo* arm64 = ArchInfo_arm64(cpu_subtype);
-    return arm64;
+    return "arm64";
   }
 
   if (cpu_type == CPU_TYPE_ARM64 && cpu_subtype == CPU_SUBTYPE_ARM64_E) {
-    static const NXArchInfo* arm64e = ArchInfo_arm64(cpu_subtype);
-    return arm64e;
+    return "arm64e";
   }
 
   // TODO: Remove this when the OS knows about armv7s.
   if (cpu_type == CPU_TYPE_ARM && cpu_subtype == CPU_SUBTYPE_ARM_V7S) {
-    static const NXArchInfo* armv7s = ArchInfo_armv7s();
-    return armv7s;
+    return "armv7s";
   }
 
-  return NXGetArchInfoFromCpuType(cpu_type, cpu_subtype);
+  const NXArchInfo* info = NXGetArchInfoFromCpuType(cpu_type, cpu_subtype);
+  if (info)
+    return info->name;
+  return kUnknownArchName;
 }
 
-}  // namespace google_breakpad
-
 // TODO(crbug.com/1242776): The "#ifndef __APPLE__" should be here, but the
 // system version of NXGetLocalArchInfo returns incorrect information on
 // x86_64 machines (treating them as just x86), so use the Breakpad version
@@ -207,7 +165,7 @@ const NXArchInfo kKnownArchitectures[] = {
 
 }  // namespace
 
-const NXArchInfo *NXGetLocalArchInfo(void) {
+ArchInfo GetLocalArchInfo(void) {
   Architecture arch;
 #if defined(__i386__)
   arch = kArch_i386;
@@ -222,7 +180,8 @@ const NXArchInfo *NXGetLocalArchInfo(void) {
 #else
   #error "Unsupported CPU architecture"
 #endif
-  return &kKnownArchitectures[arch];
+  NXArchInfo info = kKnownArchitectures[arch];
+  return {info.cputype, info.cpusubtype};
 }
 
 #ifndef __APPLE__

src/common/mac/arch_utilities.h

@@ -31,16 +31,26 @@
 #ifndef COMMON_MAC_ARCH_UTILITIES_H__
 #define COMMON_MAC_ARCH_UTILITIES_H__
 
-#include <mach-o/arch.h>
+#include <mach/machine.h>
 
-namespace google_breakpad {
+#include <optional>
 
-// Custom implementation of |NXGetArchInfoFromName| and
-// |NXGetArchInfoFromCpuType| that handle newer CPU on older OSes.
-const NXArchInfo* BreakpadGetArchInfoFromName(const char* arch_name);
-const NXArchInfo* BreakpadGetArchInfoFromCpuType(cpu_type_t cpu_type,
-                                                 cpu_subtype_t cpu_subtype);
+static constexpr const char* kUnknownArchName = "<Unknown architecture>";
 
-}  // namespace google_breakpad
+struct ArchInfo {
+  cpu_type_t cputype;
+  cpu_subtype_t cpusubtype;
+};
+
+// Returns architecture info if `arch_name` corresponds to a valid, known
+// architecture, and std::nullopt otherwise.
+std::optional<ArchInfo> GetArchInfoFromName(const char* arch_name);
+
+// Returns the name of the architecture specified by `cpu_type` and
+// `cpu_subtype`, or `kUnknownArchName` if it's unknown or invalid.
+const char* GetNameFromCPUType(cpu_type_t cpu_type, cpu_subtype_t cpu_subtype);
+
+// Returns the architecture of the machine this code is running on.
+ArchInfo GetLocalArchInfo();
 
 #endif  // COMMON_MAC_ARCH_UTILITIES_H__

src/common/mac/dump_syms.cc

@@ -221,11 +221,10 @@ bool DumpSymbols::ReadData(uint8_t* contents, size_t size,
   return true;
 }
 
-bool DumpSymbols::SetArchitecture(cpu_type_t cpu_type,
-                                  cpu_subtype_t cpu_subtype) {
+bool DumpSymbols::SetArchitecture(const ArchInfo& info) {
   // Find the best match for the architecture the user requested.
-  const SuperFatArch* best_match = FindBestMatchForArchitecture(
-      cpu_type, cpu_subtype);
+  const SuperFatArch* best_match =
+      FindBestMatchForArchitecture(info.cputype, info.cpusubtype);
   if (!best_match) return false;
 
   // Record the selected object file.
@@ -233,16 +232,6 @@ bool DumpSymbols::SetArchitecture(cpu_type_t cpu_type,
   return true;
 }
 
-bool DumpSymbols::SetArchitecture(const std::string& arch_name) {
-  bool arch_set = false;
-  const NXArchInfo* arch_info =
-      google_breakpad::BreakpadGetArchInfoFromName(arch_name.c_str());
-  if (arch_info) {
-    arch_set = SetArchitecture(arch_info->cputype, arch_info->cpusubtype);
-  }
-  return arch_set;
-}
-
 SuperFatArch* DumpSymbols::FindBestMatchForArchitecture(
     cpu_type_t cpu_type, cpu_subtype_t cpu_subtype) {
   // Check if all the object files can be converted to struct fat_arch.
@@ -402,8 +391,8 @@ bool DumpSymbols::CreateEmptyModule(scoped_ptr<Module>& module) {
       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)) {
+      ArchInfo local_arch = GetLocalArchInfo();
+      if (!SetArchitecture(local_arch)) {
         fprintf(stderr, "%s: object file contains more than one"
                 " architecture, none of which match the current"
                 " architecture; specify an architecture explicitly"
@@ -418,18 +407,16 @@ bool DumpSymbols::CreateEmptyModule(scoped_ptr<Module>& module) {
 
   // 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 = GetNameFromCPUType(
+      selected_object_file_->cputype, selected_object_file_->cpusubtype);
 
   // In certain cases, it is possible that architecture info can't be reliably
   // determined, e.g. new architectures that breakpad is unware of. In that
   // case, avoid crashing and return false instead.
-  if (selected_arch_info == NULL) {
+  if (selected_arch_name == kUnknownArchName) {
     return false;
   }
 
-  const char* selected_arch_name = selected_arch_info->name;
   if (strcmp(selected_arch_name, "i386") == 0)
     selected_arch_name = "x86";
 
@@ -540,16 +527,14 @@ bool DumpSymbols::ReadCFI(google_breakpad::Module* module,
       register_names = DwarfCFIToModule::RegisterNames::ARM64();
       break;
     default: {
-      const NXArchInfo* arch = google_breakpad::BreakpadGetArchInfoFromCpuType(
-          macho_reader.cpu_type(), macho_reader.cpu_subtype());
-      fprintf(stderr, "%s: cannot convert DWARF call frame information for ",
-              selected_object_name_.c_str());
-      if (arch)
-        fprintf(stderr, "architecture '%s'", arch->name);
-      else
-        fprintf(stderr, "architecture %d,%d",
-                macho_reader.cpu_type(), macho_reader.cpu_subtype());
-      fprintf(stderr, " to Breakpad symbol file: no register name table\n");
+      const char* arch_name = GetNameFromCPUType(macho_reader.cpu_type(),
+                                                 macho_reader.cpu_subtype());
+      fprintf(
+          stderr,
+          "%s: cannot convert DWARF call frame information for architecture "
+          "'%s' (%d, %d) to Breakpad symbol file: no register name table\n",
+          selected_object_name_.c_str(), arch_name, macho_reader.cpu_type(),
+          macho_reader.cpu_subtype());
       return false;
     }
   }

src/common/mac/dump_syms.h

@@ -43,6 +43,7 @@
 #include <vector>
 
 #include "common/byte_cursor.h"
+#include "common/mac/arch_utilities.h"
 #include "common/mac/macho_reader.h"
 #include "common/mac/super_fat_arch.h"
 #include "common/module.h"
@@ -82,26 +83,15 @@ class DumpSymbols {
   // problem reading |contents|, report it and return false.
   bool ReadData(uint8_t* contents, size_t size, const std::string& filename);
 
-  // If this dumper's file includes an object file for |cpu_type| and
-  // |cpu_subtype|, then select that object file for dumping, and return
-  // true. Otherwise, return false, and leave this dumper's selected
-  // architecture unchanged.
+  // If this dumper's file includes an object file for `info`, then select that
+  // object file for dumping, and return true. Otherwise, return false, and
+  // leave this dumper's selected architecture unchanged.
   //
   // By default, if this dumper's file contains only one object file, then
   // the dumper will dump those symbols; and if it contains more than one
   // object file, then the dumper will dump the object file whose
   // architecture matches that of this dumper program.
-  bool SetArchitecture(cpu_type_t cpu_type, cpu_subtype_t cpu_subtype);
-
-  // If this dumper's file includes an object file for |arch_name|, then select
-  // that object file for dumping, and return true. Otherwise, return false,
-  // and leave this dumper's selected architecture unchanged.
-  //
-  // By default, if this dumper's file contains only one object file, then
-  // the dumper will dump those symbols; and if it contains more than one
-  // object file, then the dumper will dump the object file whose
-  // architecture matches that of this dumper program.
-  bool SetArchitecture(const std::string& arch_name);
+  bool SetArchitecture(const ArchInfo& info);
 
   // Return a pointer to an array of SuperFatArch structures describing the
   // object files contained in this dumper's file. Set *|count| to the number

src/common/mac/macho_walker.cc

@@ -38,15 +38,15 @@
 
 #include <assert.h>
 #include <fcntl.h>
-#include <mach-o/arch.h>
 #include <mach-o/fat.h>
 #include <mach-o/loader.h>
 #include <string.h>
 #include <unistd.h>
 
+#include "common/mac/arch_utilities.h"
 #include "common/mac/byteswap.h"
-#include "common/mac/macho_walker.h"
 #include "common/mac/macho_utilities.h"
+#include "common/mac/macho_walker.h"
 
 namespace MacFileUtilities {
 
@@ -85,9 +85,8 @@ bool MachoWalker::WalkHeader(cpu_type_t cpu_type, cpu_subtype_t cpu_subtype) {
   cpu_subtype_t valid_cpu_subtype = cpu_subtype;
   // if |cpu_type| is 0, use the native cpu type.
   if (cpu_type == 0) {
-    const NXArchInfo* arch = NXGetLocalArchInfo();
-    assert(arch);
-    valid_cpu_type = arch->cputype;
+    ArchInfo arch = GetLocalArchInfo();
+    valid_cpu_type = arch.cputype;
     valid_cpu_subtype = CPU_SUBTYPE_MULTIPLE;
   }
   off_t offset;

src/tools/mac/dump_syms/dump_syms_tool.cc

@@ -67,7 +67,7 @@ struct Options {
 
   string srcPath;
   string dsymPath;
-  const NXArchInfo *arch;
+  std::optional<ArchInfo> arch;
   bool header_only;
   bool cfi;
   bool handle_inter_cu_refs;
@@ -121,11 +121,12 @@ static void CopyCFIDataBetweenModules(Module* to_module,
 }
 
 static bool SetArchitecture(DumpSymbols& dump_symbols,
-                            const NXArchInfo* arch,
+                            const ArchInfo& arch,
                             const std::string& filename) {
-  if (!dump_symbols.SetArchitecture(arch->cputype, arch->cpusubtype)) {
+  if (!dump_symbols.SetArchitecture(arch)) {
     fprintf(stderr, "%s: no architecture '%s' is present in file.\n",
-            filename.c_str(), arch->name);
+            filename.c_str(),
+            GetNameFromCPUType(arch.cputype, arch.cpusubtype));
     size_t available_size;
     const SuperFatArch* available =
         dump_symbols.AvailableArchitectures(&available_size);
@@ -135,14 +136,8 @@ static bool SetArchitecture(DumpSymbols& dump_symbols,
       fprintf(stderr, "architectures present in the file are:\n");
     for (size_t i = 0; i < available_size; i++) {
       const SuperFatArch* arch = &available[i];
-      const NXArchInfo* arch_info =
-          google_breakpad::BreakpadGetArchInfoFromCpuType(arch->cputype,
-                                                          arch->cpusubtype);
-      if (arch_info)
-        fprintf(stderr, "%s (%s)\n", arch_info->name, arch_info->description);
-      else
-        fprintf(stderr, "unrecognized cpu type 0x%x, subtype 0x%x\n",
-                arch->cputype, arch->cpusubtype);
+      fprintf(stderr, "%s\n",
+              GetNameFromCPUType(arch->cputype, arch->cpusubtype));
     }
     return false;
   }
@@ -173,7 +168,7 @@ static bool Start(const Options& options) {
     return false;
 
   if (options.arch &&
-      !SetArchitecture(dump_symbols, options.arch, primary_file)) {
+      !SetArchitecture(dump_symbols, *options.arch, primary_file)) {
     return false;
   }
 
@@ -193,7 +188,7 @@ static bool Start(const Options& options) {
       return false;
 
     if (options.arch &&
-        !SetArchitecture(dump_symbols, options.arch, options.srcPath)) {
+        !SetArchitecture(dump_symbols, *options.arch, options.srcPath)) {
       return false;
     }
     Module* cfi_module = NULL;
@@ -248,8 +243,7 @@ static void SetupOptions(int argc, const char *argv[], Options *options) {
         options->header_only = true;
         break;
       case 'a': {
-        const NXArchInfo *arch_info =
-            google_breakpad::BreakpadGetArchInfoFromName(optarg);
+        std::optional<ArchInfo> arch_info = GetArchInfoFromName(optarg);
         if (!arch_info) {
           fprintf(stderr, "%s: Invalid architecture: %s\n", argv[0], optarg);
           Usage(argc, argv);