[BRP] Take a step towards enforcing raw_ptr/ref in Renderer code

We intend to exclude only a handful specific sub-directories (for perf
reasons). This CL removes the broad exclusions from the rewriter and
the enforcing clang plugin.

There is a risk that by the time the plugin rolls into Chromium,
someone will add a raw pointer, which will cause the plugin
to error out and block the roll-out. Therefore, add those broad
exclusions into BUILD.gn temporarily -- they'll be removed after
the plugin rolls, once we confirm that all pointers in those
directories are properly rewritten.

In other words, this CL doesn't change the clang plugin enforcement
behavior.

Bug: 40064499, 331846123
Change-Id: Ia95e8df846d167521a5ac43cc63e556002702ee9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5600329
Auto-Submit: Bartek Nowierski <[email protected]>
Reviewed-by: Takuto Ikuta <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Commit-Queue: Bartek Nowierski <[email protected]>
Reviewed-by: Keishi Hattori <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1312344}

PRESUBMIT.py

@@ -7172,11 +7172,21 @@ def _IsMiraclePtrDisallowed(input_api, affected_file):
     if not _IsCPlusPlusFile(input_api, path):
         return False
 
-    # Renderer code is generally allowed to use MiraclePtr.
-    # These directories, however, are specifically disallowed.
+    # Renderer-only code is generally allowed to use MiraclePtr. These
+    # directories, however, are specifically disallowed, for perf reasons.
     if ("third_party/blink/renderer/core/" in path
             or "third_party/blink/renderer/platform/heap/" in path
-            or "third_party/blink/renderer/platform/wtf/" in path):
+            or "third_party/blink/renderer/platform/wtf/" in path
+            or "third_party/blink/renderer/platform/fonts/" in path):
+        return True
+
+    # The below paths are an explicitly listed subset of Renderer-only code,
+    # because the plan is to Oilpanize it.
+    # TODO(crbug.com/330759291): Remove once Oilpanization is completed or
+    # abandoned.
+    if ("third_party/blink/renderer/core/paint/" in path
+            or "third_party/blink/renderer/platform/graphics/compositing/" in path
+            or "third_party/blink/renderer/platform/graphics/paint/" in path):
         return True
 
     # We assume that everything else may be used outside of Renderer processes.

PRESUBMIT_test.py

@@ -4841,6 +4841,18 @@ def testDisallowedCases(self):
         MockAffectedFile(
             'test3/third_party/blink/renderer/platform/wtf/foo.cc',
             ['raw_ptr<int>']),
+        MockAffectedFile(
+            'test4/third_party/blink/renderer/platform/fonts/foo.h',
+            ['raw_ptr<int>']),
+        MockAffectedFile(
+            'test5/third_party/blink/renderer/core/paint/foo.cc',
+            ['raw_ptr<int>']),
+        MockAffectedFile(
+            'test6/third_party/blink/renderer/platform/graphics/compositing/foo.h',
+            ['raw_ptr<int>']),
+        MockAffectedFile(
+            'test7/third_party/blink/renderer/platform/graphics/paint/foo.cc',
+            ['raw_ptr<int>']),
     ]
     mock_output_api = MockOutputApi()
     errors = PRESUBMIT.CheckRawPtrUsage(mock_input_api, mock_output_api)

build/config/clang/BUILD.gn

@@ -53,6 +53,18 @@ config("find_bad_constructs") {
       "-Xclang",
       "disable-check-raw-ptr-to-stack-allocated-error",
 
+      # TODO(https://crbug.com/40064499): Remove when clang plugin rolls with
+      # updated RawPtrManualPathsToIgnore.h and we confirm that these
+      # directories are fully rewritten.
+      "-Xclang",
+      "-plugin-arg-find-bad-constructs",
+      "-Xclang",
+      "raw-ptr-exclude-path=/renderer/",
+      "-Xclang",
+      "-plugin-arg-find-bad-constructs",
+      "-Xclang",
+      "raw-ptr-exclude-path=third_party/blink/public/web/",
+
       # TODO(crbug.com/40944547): Remove when raw_ptr check has been
       # enabled for the dawn repo.
       "-Xclang",

tools/clang/plugins/RawPtrManualPathsToIgnore.h

@@ -70,29 +70,19 @@ constexpr const char* const kRawPtrManualPathsToIgnore[] = {
     // Exclude dir that should hold C headers.
     "mojo/public/c/",
 
-    // Exclude code that only runs inside a renderer process - renderer
-    // processes are excluded for now from the MiraclePtr project scope,
-    // because they are sensitive to performance regressions (to a much higher
-    // degree than, say, the Browser process).
+    // Renderer-only code is generally allowed to use MiraclePtr. These
+    // directories, however, are specifically disallowed, for perf reasons.
     //
     // Note that some renderer-only directories are already excluded
-    // elsewhere - for example "v8/" is excluded in another part of this
-    // file.
-    //
-    // The common/ directories must be included in the rewrite as they contain
-    // code
-    // that is also used from the browser process.
+    // elsewhere - for example "v8/" is excluded, because it's in another
+    // repository.
     //
     // Also, note that isInThirdPartyLocation AST matcher in
-    // RewriteRawPtrFields.cpp explicitly includes third_party/blink
-    // (because it is in the same git repository as the rest of Chromium),
-    // but we go ahead and exclude most of it below (as Renderer-only code).
-    "/renderer/",                     // (e.g. //content/renderer/ or
-                                      // //components/visitedlink/renderer/
-                                      //  or //third_party/blink/renderer)",
-    "third_party/blink/public/web/",  // TODO: Consider renaming this directory
-                                      // to",
-                                      // public/renderer?",
+    // RewriteRawPtrFields.cpp explicitly allows third_party/blink
+    "third_party/blink/renderer/core/",
+    "third_party/blink/renderer/platform/heap/",
+    "third_party/blink/renderer/platform/wtf/",
+    "third_party/blink/renderer/platform/fonts/",
     // The below paths are an explicitly listed subset of Renderer-only code,
     // because the plan is to Oilpanize it.
     // TODO(crbug.com/330759291): Remove once Oilpanization is completed or

tools/clang/raw_ptr_plugin/RawPtrManualPathsToIgnore.h

@@ -70,29 +70,20 @@ constexpr const char* const kRawPtrManualPathsToIgnore[] = {
     // Exclude dir that should hold C headers.
     "mojo/public/c/",
 
-    // Exclude code that only runs inside a renderer process - renderer
-    // processes are excluded for now from the MiraclePtr project scope,
-    // because they are sensitive to performance regressions (to a much higher
-    // degree than, say, the Browser process).
+    // Renderer-only code is generally allowed to use MiraclePtr. These
+    // directories, however, are specifically disallowed, for perf reasons.
     //
     // Note that some renderer-only directories are already excluded
-    // elsewhere - for example "v8/" is excluded in another part of this
-    // file.
-    //
-    // The common/ directories must be included in the rewrite as they contain
-    // code
-    // that is also used from the browser process.
+    // elsewhere - for example "v8/" is excluded, because it's in another
+    // repository.
     //
     // Also, note that isInThirdPartyLocation AST matcher in
-    // RewriteRawPtrFields.cpp explicitly includes third_party/blink
-    // (because it is in the same git repository as the rest of Chromium),
-    // but we go ahead and exclude most of it below (as Renderer-only code).
-    "/renderer/",                     // (e.g. //content/renderer/ or
-                                      // //components/visitedlink/renderer/
-                                      //  or //third_party/blink/renderer)",
-    "third_party/blink/public/web/",  // TODO: Consider renaming this directory
-                                      // to",
-                                      // public/renderer?",
+    // RewriteRawPtrFields.cpp explicitly allows third_party/blink
+    "third_party/blink/renderer/core/",
+    "third_party/blink/renderer/platform/heap/",
+    "third_party/blink/renderer/platform/wtf/",
+    "third_party/blink/renderer/platform/fonts/",
+
     // The below paths are an explicitly listed subset of Renderer-only code,
     // because the plan is to Oilpanize it.
     // TODO(crbug.com/330759291): Remove once Oilpanization is completed or