mac-arm64: Allow target_cpu = "mac_universal" to create universal builds

When building for macOS and configured with target_cpu =
"mac_universal", bi-architecture x86_64/arm64 output will be produced.

mac_universal is, so far, a “Crashpad special” that will only work with
mini_chromium and the standalone Crashpad build, and not the in-Chromium
build. It exists to support Keystone, which intends to ship as
x86_64/arm64 universal.

Includes:

Update mini_chromium to e0008f2714a76c7f2a3854fa75774427a886d6b9

e0008f2714a7 mac-arm64: Allow target_cpu = "mac_universal" to create
             universal builds

Bug: crashpad:345
Change-Id: I5ff2dce5ffae58186e33757aa94587f8eca20b99
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2387410
Commit-Queue: Mark Mentovai <mark@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>

DEPS

@@ -42,7 +42,7 @@ deps = {
       '7bde79cc274d06451bf65ae82c012a5d3e476b5a',
   'crashpad/third_party/mini_chromium/mini_chromium':
       Var('chromium_git') + '/chromium/mini_chromium@' +
-      'f3cfec80ca521881c97629adf6fcdf21158d635d',
+      'e0008f2714a76c7f2a3854fa75774427a886d6b9',
   'crashpad/third_party/libfuzzer/src':
       Var('chromium_git') + '/chromium/llvm-project/compiler-rt/lib/fuzzer.git@' +
       'fda403cf93ecb8792cb1d061564d89a6553ca020',

snapshot/BUILD.gn

@@ -232,7 +232,8 @@ static_library("snapshot") {
     ]
   }
 
-  if (current_cpu == "x86" || current_cpu == "x64") {
+  if (current_cpu == "x86" || current_cpu == "x64" ||
+      (crashpad_is_mac && current_cpu == "mac_universal")) {
     sources += [
       "x86/cpuid_reader.cc",
       "x86/cpuid_reader.h",

snapshot/x86/cpuid_reader.cc

@@ -16,7 +16,6 @@
 
 #include <stddef.h>
 
-#include "build/build_config.h"
 #include "snapshot/cpu_context.h"
 
 #if defined(OS_WIN)
@@ -24,6 +23,8 @@
 #include <intrin.h>
 #endif  // OS_WIN
 
+#if defined(ARCH_CPU_X86_FAMILY)
+
 namespace crashpad {
 namespace internal {
 
@@ -132,3 +133,5 @@ void CpuidReader::Cpuid(uint32_t cpuinfo[4], uint32_t leaf) const {
 
 }  // namespace internal
 }  // namespace crashpad
+
+#endif  // ARCH_CPU_X86_FAMILY

snapshot/x86/cpuid_reader.h

@@ -19,6 +19,10 @@
 
 #include <string>
 
+#include "build/build_config.h"
+
+#if defined(ARCH_CPU_X86_FAMILY)
+
 namespace crashpad {
 namespace internal {
 
@@ -65,4 +69,6 @@ class CpuidReader {
 }  // namespace internal
 }  // namespace crashpad
 
+#endif  // ARCH_CPU_X86_FAMILY
+
 #endif  // CRASHPAD_SNAPSHOT_X86_CPUID_READER_H_

util/BUILD.gn

@@ -131,6 +131,15 @@ if (crashpad_is_mac || crashpad_is_ios) {
         "--arch",
         "arm64",
       ]
+    } else if (crashpad_is_mac && current_cpu == "mac_universal") {
+      args += [
+        "--arch",
+        "x86_64",
+        "--arch",
+        "arm64",
+      ]
+    } else {
+      assert(false, "Unsupported architecture")
     }
   }
 

util/mach/mig.py

@@ -14,22 +14,88 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+import shutil
 import sys
+import tempfile
 
 import mig_fix
 import mig_gen
 
 
-def main(args):
-    parsed = mig_gen.parse_args(args)
+def _try_remove(*paths):
+    for path in paths:
+        try:
+            os.remove(path)
+        except OSError:
+            pass
 
-    interface = mig_gen.MigInterface(parsed.user_c, parsed.server_c,
-                                     parsed.user_h, parsed.server_h)
-    mig_gen.generate_interface(parsed.defs, interface, parsed.include,
-                               parsed.sdk, parsed.clang_path, parsed.mig_path,
-                               parsed.migcom_path, parsed.arch)
+
+def _generate_and_fix(user_c, server_c, user_h, server_h, defs, include, sdk,
+                      clang_path, mig_path, migcom_path, arch):
+    interface = mig_gen.MigInterface(user_c, server_c, user_h, server_h)
+    mig_gen.generate_interface(defs, interface, include, sdk, clang_path,
+                               mig_path, migcom_path, arch)
     mig_fix.fix_interface(interface)
 
 
+def _wrap_arch_guards(file, arch):
+    contents = '#if defined(__%s__)\n' % arch
+    contents += open(file, 'r').read()
+    contents += '\n#endif  /* __%s__ */\n' % arch
+    return contents
+
+
+def _write_file(path, data):
+    with open(path, 'w') as file:
+        file.write(data)
+
+
+def main(args):
+    parsed = mig_gen.parse_args(args, multiple_arch=True)
+
+    _try_remove(parsed.user_c, parsed.server_c, parsed.user_h, parsed.server_h)
+
+    if len(parsed.arch) <= 1:
+        _generate_and_fix(parsed.user_c, parsed.server_c, parsed.user_h,
+                          parsed.server_h, parsed.defs, parsed.include,
+                          parsed.sdk, parsed.clang_path, parsed.mig_path,
+                          parsed.migcom_path,
+                          parsed.arch[0] if len(parsed.arch) >= 1 else None)
+        return 0
+
+    # Run mig once per architecture, and smush everything together, wrapped in
+    # in architecture-specific #if guards.
+
+    user_c_data = ''
+    server_c_data = ''
+    user_h_data = ''
+    server_h_data = ''
+
+    for arch in parsed.arch:
+        # Python 3: use tempfile.TempDirectory instead
+        temp_dir = tempfile.mkdtemp(prefix=os.path.basename(sys.argv[0]) + '_')
+        try:
+            user_c = os.path.join(temp_dir, os.path.basename(parsed.user_c))
+            server_c = os.path.join(temp_dir, os.path.basename(parsed.server_c))
+            user_h = os.path.join(temp_dir, os.path.basename(parsed.user_h))
+            server_h = os.path.join(temp_dir, os.path.basename(parsed.server_h))
+            _generate_and_fix(user_c, server_c, user_h, server_h, parsed.defs,
+                              parsed.include, parsed.sdk, parsed.clang_path,
+                              parsed.mig_path, parsed.migcom_path, arch)
+
+            user_c_data += _wrap_arch_guards(user_c, arch)
+            server_c_data += _wrap_arch_guards(server_c, arch)
+            user_h_data += _wrap_arch_guards(user_h, arch)
+            server_h_data += _wrap_arch_guards(server_h, arch)
+        finally:
+            shutil.rmtree(temp_dir)
+
+    _write_file(parsed.user_c, user_c_data)
+    _write_file(parsed.server_c, server_c_data)
+    _write_file(parsed.user_h, user_h_data)
+    _write_file(parsed.server_h, server_h_data)
+
+
 if __name__ == '__main__':
     sys.exit(main(sys.argv[1:]))

util/mach/mig_gen.py

@@ -59,17 +59,25 @@ def generate_interface(defs,
     subprocess.check_call(command)
 
 
-def parse_args(args):
+def parse_args(args, multiple_arch=False):
     parser = argparse.ArgumentParser()
-    parser.add_argument('--clang-path', help='Path to Clang')
+    parser.add_argument('--clang-path', help='Path to clang')
     parser.add_argument('--mig-path', help='Path to mig')
     parser.add_argument('--migcom-path', help='Path to migcom')
-    parser.add_argument('--arch', help='Target architecture')
+    if not multiple_arch:
+        parser.add_argument('--arch', help='Target architecture')
+    else:
+        parser.add_argument(
+            '--arch',
+            default=[],
+            action='append',
+            help='Target architecture (may appear multiple times)')
     parser.add_argument('--sdk', help='Path to SDK')
-    parser.add_argument('--include',
-                        default=[],
-                        action='append',
-                        help='Additional include directory')
+    parser.add_argument(
+        '--include',
+        default=[],
+        action='append',
+        help='Additional include directory (may appear multiple times)')
     parser.add_argument('defs')
     parser.add_argument('user_c')
     parser.add_argument('server_c')