[NFC][CodeGen][CFI] Add GeneralizePointers parameter to GeneralizeFunctionType #158191

vitalybuka · 2025-09-12T04:45:43Z

For #158193

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

llvmbot · 2025-09-12T04:46:15Z

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: Vitaly Buka (vitalybuka)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/158191.diff

1 Files Affected:

(modified) clang/lib/CodeGen/CodeGenModule.cpp (+22-14)

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index acd77c5aca89c..c647003ff389d 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2343,8 +2343,11 @@ llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
 // 'void *'.
-static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
-  if (!Ty->isPointerType())
+static QualType GeneralizeType(ASTContext &Ctx, QualType Ty,
+                               bool GeneralizePointers) {
+  // TODO: Add other generalizations.
+
+  if (!GeneralizePointers || !Ty->isPointerType())
     return Ty;
 
   return Ctx.getPointerType(
@@ -2353,26 +2356,29 @@ static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
 }
 
 // Apply type generalization to a FunctionType's return and argument types
-static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
+static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty,
+                                       bool GeneralizePointers) {
   if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
     SmallVector<QualType, 8> GeneralizedParams;
     for (auto &Param : FnType->param_types())
-      GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
+      GeneralizedParams.push_back(
+          GeneralizeType(Ctx, Param, GeneralizePointers));
 
-    return Ctx.getFunctionType(GeneralizeType(Ctx, FnType->getReturnType()),
-                               GeneralizedParams, FnType->getExtProtoInfo());
+    return Ctx.getFunctionType(
+        GeneralizeType(Ctx, FnType->getReturnType(), GeneralizePointers),
+        GeneralizedParams, FnType->getExtProtoInfo());
   }
 
   if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
     return Ctx.getFunctionNoProtoType(
-        GeneralizeType(Ctx, FnType->getReturnType()));
+        GeneralizeType(Ctx, FnType->getReturnType(), GeneralizePointers));
 
   llvm_unreachable("Encountered unknown FunctionType");
 }
 
 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T, StringRef Salt) {
-  if (getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
-    T = GeneralizeFunctionType(getContext(), T);
+  T = GeneralizeFunctionType(
+      getContext(), T, getCodeGenOpts().SanitizeCfiICallGeneralizePointers);
   if (auto *FnType = T->getAs<FunctionProtoType>())
     T = getContext().getFunctionType(
         FnType->getReturnType(), FnType->getParamTypes(),
@@ -3041,10 +3047,12 @@ void CodeGenModule::createFunctionTypeMetadataForIcall(const FunctionDecl *FD,
   if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
     return;
 
-  QualType FnType = FD->getType();
+  QualType FnType = GeneralizeFunctionType(getContext(), FD->getType(),
+                                           /*GeneralizePointers=*/false);
   llvm::Metadata *MD = CreateMetadataIdentifierForType(FnType);
   F->addTypeMetadata(0, MD);
-  FnType = GeneralizeFunctionType(getContext(), FnType);
+  FnType = GeneralizeFunctionType(getContext(), FD->getType(),
+                                  /*GeneralizePointers=*/true);
   F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FnType));
 
   // Emit a hash-based bit set entry for cross-DSO calls.
@@ -7938,10 +7946,10 @@ CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
 
 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForFnType(QualType T) {
   assert(isa<FunctionType>(T));
-  if (getCodeGenOpts().SanitizeCfiICallGeneralizePointers) {
-    T = GeneralizeFunctionType(getContext(), T);
+  T = GeneralizeFunctionType(
+      getContext(), T, getCodeGenOpts().SanitizeCfiICallGeneralizePointers);
+  if (getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
     return CreateMetadataIdentifierGeneralized(T);
-  }
   return CreateMetadataIdentifierForType(T);
 }

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

Copilot

Pull Request Overview

This PR adds a GeneralizePointers parameter to the GeneralizeFunctionType function to control whether pointer types should be generalized during CFI (Control Flow Integrity) type processing. This change supports issue #158193 by making pointer generalization configurable rather than relying solely on compiler options.

Key changes:

Added GeneralizePointers boolean parameter to both GeneralizeType and GeneralizeFunctionType functions
Updated all call sites to explicitly pass the generalization flag
Simplified conditional logic in CreateKCFITypeId and CreateMetadataIdentifierForFnType

clang/lib/CodeGen/CodeGenModule.cpp

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

llvm-ci · 2025-09-13T00:22:44Z

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-4 while building clang at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/27353

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang-Unit :: ./AllClangUnitTests/30/48' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/tools/clang/unittests/./AllClangUnitTests-Clang-Unit-86245-30-48.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=48 GTEST_SHARD_INDEX=30 /Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/tools/clang/unittests/./AllClangUnitTests
--

Script:
--
/Volumes/RAMDisk/buildbot-root/aarch64-darwin/build/tools/clang/unittests/./AllClangUnitTests --gtest_filter=TimeProfilerTest.ConstantEvaluationCxx20
--
/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/unittests/Support/TimeProfilerTest.cpp:247: Failure
Expected equality of these values:
  R"(
Frontend (test.cc)
| ParseDeclarationOrFunctionDefinition (test.cc:2:1)
| ParseDeclarationOrFunctionDefinition (test.cc:6:1)
| | ParseFunctionDefinition (slow_func)
| | | EvaluateAsRValue (<test.cc:8:21>)
| | | EvaluateForOverflow (<test.cc:8:21, col:25>)
| | | EvaluateForOverflow (<test.cc:8:30, col:32>)
| | | EvaluateAsRValue (<test.cc:9:14>)
| | | EvaluateForOverflow (<test.cc:9:9, col:14>)
| | | isPotentialConstantExpr (slow_namespace::slow_func)
| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
| ParseDeclarationOrFunctionDefinition (test.cc:16:1)
| | ParseFunctionDefinition (slow_test)
| | | EvaluateAsInitializer (slow_value)
| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>)
| | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>)
| ParseDeclarationOrFunctionDefinition (test.cc:22:1)
| | EvaluateAsConstantExpr (<test.cc:23:31, col:57>)
| | EvaluateAsRValue (<test.cc:22:14, line:23:58>)
| ParseDeclarationOrFunctionDefinition (test.cc:25:1)
| | EvaluateAsInitializer (slow_init_list)
| PerformPendingInstantiations
)"
    Which is: "\nFrontend (test.cc)\n| ParseDeclarationOrFunctionDefinition (test.cc:2:1)\n| ParseDeclarationOrFunctionDefinition (test.cc:6:1)\n| | ParseFunctionDefinition (slow_func)\n| | | EvaluateAsRValue (<test.cc:8:21>)\n| | | EvaluateForOverflow (<test.cc:8:21, col:25>)\n| | | EvaluateForOverflow (<test.cc:8:30, col:32>)\n| | | EvaluateAsRValue (<test.cc:9:14>)\n| | | EvaluateForOverflow (<test.cc:9:9, col:14>)\n| | | isPotentialConstantExpr (slow_namespace::slow_func)\n| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)\n| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)\n| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)\n| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)\n| ParseDeclarationOrFunctionDefinition (test.cc:16:1)\n| | ParseFunctionDefinition (slow_test)\n| | | EvaluateAsInitializer (slow_value)\n| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>)\n| | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>)\n| ParseDeclarationOrFunctionDefinition (test.cc:22:1)\n| | EvaluateAsConstantExpr (<test.cc:23:31, col:57>)\n| | EvaluateAsRValue (<test.cc:22:14, line:23:58>)\n| ParseDeclarationOrFunctionDefinition (test.cc:25:1)\n| | EvaluateAsInitializer (slow_init_list)\n| PerformPendingInstantiations\n"
  buildTraceGraph(Json)
    Which is: "\nFrontend (test.cc)\n| ParseDeclarationOrFunctionDefinition (test.cc:2:1)\n| ParseDeclarationOrFunctionDefinition (test.cc:6:1)\n| | ParseFunctionDefinition (slow_func)\n| | | EvaluateAsRValue (<test.cc:8:21>)\n| | | EvaluateForOverflow (<test.cc:8:21, col:25>)\n| | | EvaluateForOverflow (<test.cc:8:30, col:32>)\n| | | EvaluateAsRValue (<test.cc:9:14>)\n| | | EvaluateForOverflow (<test.cc:9:9, col:14>)\n| | | isPotentialConstantExpr (slow_namespace::slow_func)\n| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)\n| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)\n| | | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)\n| | | | | EvaluateAsRValue (<test.cc:8:21, col:25>)\n| ParseDeclarationOrFunctionDefinition (test.cc:16:1)\n| | ParseFunctionDefinition (slow_test)\n| | | EvaluateAsInitializer (slow_value)\n| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>)\n| | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>)\n| ParseDeclarationOrFunctionDefinition (test.cc:22:1)\n| | EvaluateAsConstantExpr (<test.cc:23:31, col:57>)\n| | EvaluateAsRValue (<test.cc:22:14, line:23:58>)\n| ParseDeclarationOrFunctionDefinition (test.cc:25:1)\n| | EvaluateAsInitializer (slow_init_list)\n| PerformPendingInstantiations\n"
With diff:
@@ -12,6 +12,6 @@
 | | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
 | | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
-| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
-| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
+| | | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
+| | | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
...

vitalybuka added 2 commits September 11, 2025 21:45

[𝘀𝗽𝗿] changes to main this commit is based on

77240d3

Created using spr 1.3.6 [skip ci]

[𝘀𝗽𝗿] initial version

e3a587c

Created using spr 1.3.6

llvmbot added clang Clang issues not falling into any other category clang:codegen IR generation bugs: mangling, exceptions, etc. labels Sep 12, 2025

vitalybuka requested review from fmayer, pcc and thurstond September 12, 2025 04:48

thurstond approved these changes Sep 12, 2025

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vitalybuka added 4 commits September 11, 2025 22:02

[𝘀𝗽𝗿] changes introduced through rebase

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newline

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[𝘀𝗽𝗿] changes introduced through rebase

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vitalybuka requested a review from Copilot September 12, 2025 05:22

Copilot AI reviewed Sep 12, 2025

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bulbazord and others added 3 commits September 12, 2025 16:44

[𝘀𝗽𝗿] changes introduced through rebase

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vitalybuka changed the base branch from users/vitalybuka/spr/main.nfccodegencfi-add-generalizepointers-parameter-to-generalizefunctiontype to main September 12, 2025 23:49

vitalybuka enabled auto-merge (squash) September 12, 2025 23:49

vitalybuka merged commit a5bff94 into main Sep 13, 2025
9 checks passed

vitalybuka deleted the users/vitalybuka/spr/nfccodegencfi-add-generalizepointers-parameter-to-generalizefunctiontype branch September 13, 2025 00:13

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[NFC][CodeGen][CFI] Add GeneralizePointers parameter to GeneralizeFunctionType #158191

[NFC][CodeGen][CFI] Add GeneralizePointers parameter to GeneralizeFunctionType #158191

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[NFC][CodeGen][CFI] Add GeneralizePointers parameter to GeneralizeFunctionType #158191

[NFC][CodeGen][CFI] Add GeneralizePointers parameter to GeneralizeFunctionType #158191

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