fix: write pch cflags as a list instead of a map object

pylib/gyp/msvs_emulation.py

@@ -1057,13 +1057,18 @@ def GetFlagsModifications(
             pch_output = ["/Yc" + self._PchHeader()]
             if command == "cxx":
                 return (
-                    [("cflags_cc", map(expand_special, cflags_cc + pch_output))],
+                    [
+                        (
+                            "cflags_cc",
+                            [expand_special(x) for x in cflags_cc + pch_output],
+                        )
+                    ],
                     self.output_obj,
                     [],
                 )
             elif command == "cc":
                 return (
-                    [("cflags_c", map(expand_special, cflags_c + pch_output))],
+                    [("cflags_c", [expand_special(x) for x in cflags_c + pch_output])],
                     self.output_obj,
                     [],
                 )

test/fixtures/pch.cc

@@ -0,0 +1 @@
+#include "pch.h"

test/fixtures/pch.gyp

@@ -0,0 +1,13 @@
+{
+  'targets': [
+    {
+      'target_name': 'pch',
+      'type': 'executable',
+      'sources': [
+        'pch.cc',
+      ],
+      'msvs_precompiled_header': 'pch.h',
+      'msvs_precompiled_source': 'pch.cc',
+    },
+  ]
+}

test/fixtures/pch.h

@@ -0,0 +1 @@
+#pragma once

test/integration_test.py

@@ -11,7 +11,8 @@
 import gyp
 
 fixture_dir = os.path.join(os.path.dirname(__file__), "fixtures")
-gyp_file = os.path.join(os.path.dirname(__file__), "fixtures/integration.gyp")
+gyp_file = os.path.join(fixture_dir, "integration.gyp")
+pch_gyp_file = os.path.join(fixture_dir, "pch.gyp")
 
 if sys.platform == "win32":
     sysname = sys.platform
@@ -91,3 +92,16 @@ def test_msvs(self) -> None:
 
         assert_file(self, "test.vcproj", "msvs/test.vcproj")
         assert_file(self, "integration.sln", "msvs/integration.sln")
+
+    def test_ninja_precompiled_header(self) -> None:
+        try:
+            rc = gyp.main(["-f", "ninja", "--depth", fixture_dir, pch_gyp_file])
+        except ValueError as exc:
+            self.skipTest(str(exc))
+        assert rc == 0
+
+        with open(os.path.join(fixture_dir, "out/Default/obj/pch.ninja")) as in_file:
+            ninja_file = in_file.read()
+
+        assert "map object at" not in ninja_file
+        assert "/Ycpch.h" in ninja_file