build,win: enable ARM64 PGO

Author: StefanStojanovic

common.gypi

@@ -12,6 +12,7 @@
     'msvs_multi_core_compile': '0',   # we do enable multicore compiles, but not using the V8 way
     'enable_pgo_generate%': '0',
     'enable_pgo_use%': '0',
+    'clang_profile_lib%': '',
     'python%': 'python',
 
     'node_shared%': 'false',
@@ -270,25 +271,34 @@
                   },
                 },
               },],
-              ['enable_pgo_generate=="true"', {
-                'msvs_settings': {
-                  'VCCLCompilerTool': {
-                    'AdditionalOptions': ['-fprofile-generate'],
-                  },
-                  'VCLinkerTool': {
-                    'AdditionalOptions': ['-fprofile-generate'],
-                  },
-                },
-              },],
-              ['enable_pgo_use=="true"', {
-                'msvs_settings': {
-                  'VCCLCompilerTool': {
-                    'AdditionalOptions': ['-fprofile-use=$(SolutionDir)node.profdata'],
-                  },
-                  'VCLinkerTool': {
-                    'AdditionalOptions': ['-fprofile-use=$(SolutionDir)node.profdata'],
-                  },
-                },
+            ],
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'conditions': [
+                  ['enable_pgo_generate=="true"', {
+                    'msvs_settings': {
+                      'VCCLCompilerTool': {
+                        'AdditionalOptions': ['-fprofile-generate'],
+                      },
+                      'VCLinkerTool': {
+                        'AdditionalOptions': [
+                          '/NODEFAULTLIB:clang_rt.profile.lib',
+                          '"<(clang_profile_lib)"',
+                        ],
+                      },
+                    },
+                  },],
+                  ['enable_pgo_use=="true"', {
+                    'msvs_settings': {
+                      'VCCLCompilerTool': {
+                        'AdditionalOptions': ['-fprofile-use=$(SolutionDir)node.profdata'],
+                      },
+                      'VCLinkerTool': {
+                        'AdditionalOptions': ['-fprofile-use=$(SolutionDir)node.profdata'],
+                      },
+                    },
+                  },],
+                ],
               },],
             ],
           },],

configure.py

@@ -1940,6 +1940,24 @@ def configure_node(o):
   o['variables']['enable_pgo_generate'] = b(options.enable_pgo_generate)
   o['variables']['enable_pgo_use']      = b(options.enable_pgo_use)
 
+  if flavor == 'win' and (options.enable_pgo_generate or options.enable_pgo_use):
+    lib_suffix = 'aarch64' if target_arch == 'arm64' else 'x86_64'
+    lib_name = f'clang_rt.profile-{lib_suffix}.lib'
+    msvc_dir = target_arch  # 'x64' or 'arm64'
+
+    vc_tools_dir = os.environ.get('VCToolsInstallDir', '')
+    if vc_tools_dir:
+      clang_profile_lib = os.path.join(vc_tools_dir, 'lib', msvc_dir, lib_name)
+      if os.path.isfile(clang_profile_lib):
+        o['variables']['clang_profile_lib'] = clang_profile_lib
+      else:
+        raise Exception(
+          f'PGO profile runtime library not found at {clang_profile_lib}. '
+          'Ensure the ClangCL toolset is installed.')
+    else:
+      raise Exception(
+        'VCToolsInstallDir not set. Run from a Visual Studio command prompt.')
+
   if flavor != 'win' and options.enable_thin_lto:
     raise Exception(
       'Use --enable-lto instead.')