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[clang][CallGraphSection] Add type id metadata to indirect call and targets #87573

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@Prabhuk Prabhuk commented Apr 3, 2024

Create and add generalized type identifier metadata to indirect calls,
and to functions that may be target to indirect calls.

Type identifiers will be used by the back-end to construct the call
graph section to precisely represent the possible targets for indirect calls.
The type information is deliberately pulled from the front-end to have extra
precision since some type information is lost at IR, and to ensure
consistent type identifiers between object files compiled at different
times (as C/C++ standards require language-level types to match).

Original RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-June/151044.html
Updated RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-July/151739.html

Created using spr 1.3.6-beta.1
@llvmbot llvmbot added clang Clang issues not falling into any other category clang:codegen llvm:SelectionDAG SelectionDAGISel as well llvm:ir labels Apr 3, 2024
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llvmbot commented Apr 3, 2024

@llvm/pr-subscribers-clang-codegen
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-llvm-ir

Author: Prabhuk (Prabhuk)

Changes

Create and add generalized type identifier metadata to indirect calls,
and to functions that may be target to indirect calls.

Type identifiers will be used by the back-end to construct the call
graph section to precisely represent the possible targets for indirect calls.
The type information is deliberately pulled from the front-end to have extra
precision since some type information is lost at IR, and to ensure
consistent type identifiers between object files compiled at different
times (as C/C++ standards require language-level types to match).

Original RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-June/151044.html
Updated RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-July/151739.html


Patch is 29.79 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/87573.diff

16 Files Affected:

  • (modified) clang/lib/CodeGen/CGCall.cpp (+22)
  • (modified) clang/lib/CodeGen/CGClass.cpp (+8-1)
  • (modified) clang/lib/CodeGen/CGExpr.cpp (+5)
  • (modified) clang/lib/CodeGen/CGExprCXX.cpp (+29-5)
  • (modified) clang/lib/CodeGen/CGObjCMac.cpp (+8)
  • (modified) clang/lib/CodeGen/CodeGenModule.cpp (+29-5)
  • (modified) clang/lib/CodeGen/CodeGenModule.h (+4)
  • (added) clang/test/CodeGen/call-graph-section-1.cpp (+110)
  • (added) clang/test/CodeGen/call-graph-section-2.cpp (+95)
  • (added) clang/test/CodeGen/call-graph-section-3.cpp (+52)
  • (added) clang/test/CodeGen/call-graph-section.c (+85)
  • (modified) llvm/include/llvm/IR/LLVMContext.h (+1)
  • (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (+6-4)
  • (modified) llvm/lib/IR/LLVMContext.cpp (+5)
  • (modified) llvm/lib/IR/Verifier.cpp (+5-2)
  • (modified) llvm/test/Verifier/operand-bundles.ll (+13)
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index f12765b826935b..51133b0a9d47cb 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -5681,6 +5681,28 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   AllocAlignAttrEmitter AllocAlignAttrEmitter(*this, TargetDecl, CallArgs);
   Attrs = AllocAlignAttrEmitter.TryEmitAsCallSiteAttribute(Attrs);
 
+  if (CGM.getCodeGenOpts().CallGraphSection) {
+    // FIXME: create operand bundle only for indirect calls, not for all
+
+    assert((TargetDecl && TargetDecl->getFunctionType() ||
+            Callee.getAbstractInfo().getCalleeFunctionProtoType()) &&
+           "cannot find callsite type");
+
+    QualType CST;
+    if (TargetDecl && TargetDecl->getFunctionType())
+      CST = QualType(TargetDecl->getFunctionType(), 0);
+    else if (const auto *FPT =
+                 Callee.getAbstractInfo().getCalleeFunctionProtoType())
+      CST = QualType(FPT, 0);
+
+    if (!CST.isNull()) {
+      auto *TypeIdMD = CGM.CreateMetadataIdentifierGeneralized(CST);
+      auto *TypeIdMDVal =
+          llvm::MetadataAsValue::get(getLLVMContext(), TypeIdMD);
+      BundleList.emplace_back("type", TypeIdMDVal);
+    }
+  }
+
   // Emit the actual call/invoke instruction.
   llvm::CallBase *CI;
   if (!InvokeDest) {
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 8c1c8ee455d2e6..2c347bd4359265 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -2247,7 +2247,14 @@ void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
   const CGFunctionInfo &Info = CGM.getTypes().arrangeCXXConstructorCall(
       Args, D, Type, ExtraArgs.Prefix, ExtraArgs.Suffix, PassPrototypeArgs);
   CGCallee Callee = CGCallee::forDirect(CalleePtr, GlobalDecl(D, Type));
-  EmitCall(Info, Callee, ReturnValueSlot(), Args, nullptr, false, Loc);
+  llvm::CallBase *CallOrInvoke = nullptr;
+  EmitCall(Info, Callee, ReturnValueSlot(), Args, &CallOrInvoke, false, Loc);
+
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && CallOrInvoke &&
+      CallOrInvoke->isIndirectCall())
+    CGM.CreateFunctionTypeMetadataForIcall(D->getType(), CallOrInvoke);
+
 
   // Generate vtable assumptions if we're constructing a complete object
   // with a vtable.  We don't do this for base subobjects for two reasons:
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 54432353e7420d..467a7cfe50e790 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -5953,6 +5953,11 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee
     }
   }
 
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && CallOrInvoke &&
+      CallOrInvoke->isIndirectCall())
+    CGM.CreateFunctionTypeMetadataForIcall(QualType(FnType, 0), CallOrInvoke);
+
   return Call;
 }
 
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index a4fb673284ceca..4cbffd7073867f 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -93,9 +93,17 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
       *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs);
   auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall(
       Args, FPT, CallInfo.ReqArgs, CallInfo.PrefixSize);
-  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr,
+  llvm::CallBase *CallOrInvoke = nullptr;        
+  auto Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke,
                   CE && CE == MustTailCall,
                   CE ? CE->getExprLoc() : SourceLocation());
+  
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && CallOrInvoke &&
+      CallOrInvoke->isIndirectCall())
+    CGM.CreateFunctionTypeMetadataForIcall(MD->getType(), CallOrInvoke);
+
+  return Call;                    
 }
 
 RValue CodeGenFunction::EmitCXXDestructorCall(
@@ -119,9 +127,17 @@ RValue CodeGenFunction::EmitCXXDestructorCall(
   CallArgList Args;
   commonEmitCXXMemberOrOperatorCall(*this, Dtor, This, ImplicitParam,
                                     ImplicitParamTy, CE, Args, nullptr);
-  return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(Dtor), Callee,
-                  ReturnValueSlot(), Args, nullptr, CE && CE == MustTailCall,
+  llvm::CallBase *CallOrInvoke = nullptr;
+  auto Call = EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(Dtor), Callee,
+                  ReturnValueSlot(), Args, &CallOrInvoke, CE && CE == MustTailCall,
                   CE ? CE->getExprLoc() : SourceLocation{});
+
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && CallOrInvoke &&
+      CallOrInvoke->isIndirectCall())
+    CGM.CreateFunctionTypeMetadataForIcall(DtorDecl->getType(), CallOrInvoke);
+
+  return Call;
 }
 
 RValue CodeGenFunction::EmitCXXPseudoDestructorExpr(
@@ -482,10 +498,18 @@ CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
 
   // And the rest of the call args
   EmitCallArgs(Args, FPT, E->arguments());
-  return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required,
+  llvm::CallBase *CallOrInvoke = nullptr;
+  auto Call = EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required,
                                                       /*PrefixSize=*/0),
-                  Callee, ReturnValue, Args, nullptr, E == MustTailCall,
+                  Callee, ReturnValue, Args, &CallOrInvoke, E == MustTailCall,
                   E->getExprLoc());
+
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && CallOrInvoke &&
+      CallOrInvoke->isIndirectCall())
+    CGM.CreateFunctionTypeMetadataForIcall(QualType(FPT, 0), CallOrInvoke);
+
+  return Call;                  
 }
 
 RValue
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 8a599c10e1caf1..291f5aff89ec22 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -2220,6 +2220,14 @@ CGObjCCommonMac::EmitMessageSend(CodeGen::CodeGenFunction &CGF,
   RValue rvalue = CGF.EmitCall(MSI.CallInfo, Callee, Return, ActualArgs,
                                &CallSite);
 
+  // Set type identifier metadata of indirect calls for call graph section.
+  if (CGM.getCodeGenOpts().CallGraphSection && Method && CallSite &&
+      CallSite->isIndirectCall()) {
+    if (const auto *FnType = Method->getFunctionType()) {
+      CGM.CreateFunctionTypeMetadataForIcall(QualType(FnType, 0), CallSite);
+    }
+  }
+
   // Mark the call as noreturn if the method is marked noreturn and the
   // receiver cannot be null.
   if (Method && Method->hasAttr<NoReturnAttr>() && !ReceiverCanBeNull) {
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 00b3bfcaa0bc25..e19bbee996f582 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2486,8 +2486,8 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
 
   // In the cross-dso CFI mode with canonical jump tables, we want !type
   // attributes on definitions only.
-  if (CodeGenOpts.SanitizeCfiCrossDso &&
-      CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
+  if ((CodeGenOpts.SanitizeCfiCrossDso &&
+      CodeGenOpts.SanitizeCfiCanonicalJumpTables) || CodeGenOpts.CallGraphSection) {
     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
       // Skip available_externally functions. They won't be codegen'ed in the
       // current module anyway.
@@ -2677,7 +2677,17 @@ static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
 
 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
                                                        llvm::Function *F) {
-  // Only if we are checking indirect calls.
+  bool EmittedMDIdGeneralized = false;
+  if (CodeGenOpts.CallGraphSection &&
+      (!F->hasLocalLinkage() ||
+       F->getFunction().hasAddressTaken(nullptr, /* IgnoreCallbackUses */ true,
+                                        /* IgnoreAssumeLikeCalls */ true,
+                                        /* IgnoreLLVMUsed */ false))) {
+    F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
+    EmittedMDIdGeneralized = true;
+  }
+
+  // Add additional metadata only if we are checking indirect calls with CFI.
   if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
     return;
 
@@ -2688,7 +2698,9 @@ void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
 
   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
   F->addTypeMetadata(0, MD);
-  F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
+  // Add the generalized identifier if not added already.
+  if (!EmittedMDIdGeneralized)
+    F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
 
   // Emit a hash-based bit set entry for cross-DSO calls.
   if (CodeGenOpts.SanitizeCfiCrossDso)
@@ -2696,6 +2708,17 @@ void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
       F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
 }
 
+void CodeGenModule::CreateFunctionTypeMetadataForIcall(const QualType &QT,
+                                                       llvm::CallBase *CB) {
+  // Only if needed for call graph section and only for indirect calls.
+  if (!(CodeGenOpts.CallGraphSection && CB && CB->isIndirectCall()))
+    return;
+
+  auto *MD = CreateMetadataIdentifierGeneralized(QT);
+  auto *MDN = llvm::MDNode::get(getLLVMContext(), MD);
+  CB->setMetadata(llvm::LLVMContext::MD_type, MDN);
+}
+
 void CodeGenModule::setKCFIType(const FunctionDecl *FD, llvm::Function *F) {
   llvm::LLVMContext &Ctx = F->getContext();
   llvm::MDBuilder MDB(Ctx);
@@ -2823,7 +2846,8 @@ void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
   // are non-canonical then we need type metadata in order to produce the local
   // jump table.
   if (!CodeGenOpts.SanitizeCfiCrossDso ||
-      !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
+      !CodeGenOpts.SanitizeCfiCanonicalJumpTables ||
+      CodeGenOpts.CallGraphSection)
     CreateFunctionTypeMetadataForIcall(FD, F);
 
   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 1cc447765e2c97..12ac8d0f57eecc 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1473,6 +1473,10 @@ class CodeGenModule : public CodeGenTypeCache {
   void CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
                                           llvm::Function *F);
 
+  /// Create and attach type metadata to the given call.
+  void CreateFunctionTypeMetadataForIcall(const QualType &QT,
+                                          llvm::CallBase *CB);
+
   /// Set type metadata to the given function.
   void setKCFIType(const FunctionDecl *FD, llvm::Function *F);
 
diff --git a/clang/test/CodeGen/call-graph-section-1.cpp b/clang/test/CodeGen/call-graph-section-1.cpp
new file mode 100644
index 00000000000000..25397e94422b7a
--- /dev/null
+++ b/clang/test/CodeGen/call-graph-section-1.cpp
@@ -0,0 +1,110 @@
+// Tests that we assign appropriate identifiers to indirect calls and targets
+// specifically for C++ class and instance methods.
+
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fcall-graph-section -S \
+// RUN: -emit-llvm -o %t %s
+// RUN: FileCheck --check-prefix=FT %s < %t
+// RUN: FileCheck --check-prefix=CST %s < %t
+
+////////////////////////////////////////////////////////////////////////////////
+// Class definitions (check for indirect target metadata)
+
+class Cls1 {
+public:
+  // FT-DAG: define {{.*}} ptr @_ZN4Cls18receiverEPcPf({{.*}} !type [[F_TCLS1RECEIVER:![0-9]+]]
+  static int *receiver(char *a, float *b) { return 0; }
+};
+
+class Cls2 {
+public:
+  int *(*fp)(char *, float *);
+
+  // FT-DAG: define {{.*}} i32 @_ZN4Cls22f1Ecfd({{.*}} !type [[F_TCLS2F1:![0-9]+]]
+  int f1(char a, float b, double c) { return 0; }
+
+  // FT-DAG: define {{.*}} ptr @_ZN4Cls22f2EPcPfPd({{.*}} !type [[F_TCLS2F2:![0-9]+]]
+  int *f2(char *a, float *b, double *c) { return 0; }
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f3E4Cls1({{.*}} !type [[F_TCLS2F3F4:![0-9]+]]
+  void f3(Cls1 a) {}
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f4E4Cls1({{.*}} !type [[F_TCLS2F3F4]]
+  void f4(const Cls1 a) {}
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f5EP4Cls1({{.*}} !type [[F_TCLS2F5:![0-9]+]]
+  void f5(Cls1 *a) {}
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f6EPK4Cls1({{.*}} !type [[F_TCLS2F6:![0-9]+]]
+  void f6(const Cls1 *a) {}
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f7ER4Cls1({{.*}} !type [[F_TCLS2F7:![0-9]+]]
+  void f7(Cls1 &a) {}
+
+  // FT-DAG: define {{.*}} void @_ZN4Cls22f8ERK4Cls1({{.*}} !type [[F_TCLS2F8:![0-9]+]]
+  void f8(const Cls1 &a) {}
+
+  // FT-DAG: define {{.*}} void @_ZNK4Cls22f9Ev({{.*}} !type [[F_TCLS2F9:![0-9]+]]
+  void f9() const {}
+};
+
+// FT-DAG: [[F_TCLS1RECEIVER]] = !{i64 0, !"_ZTSFPvS_S_E.generalized"}
+// FT-DAG: [[F_TCLS2F2]]   = !{i64 0, !"_ZTSFPvS_S_S_E.generalized"}
+// FT-DAG: [[F_TCLS2F1]]   = !{i64 0, !"_ZTSFicfdE.generalized"}
+// FT-DAG: [[F_TCLS2F3F4]] = !{i64 0, !"_ZTSFv4Cls1E.generalized"}
+// FT-DAG: [[F_TCLS2F5]]   = !{i64 0, !"_ZTSFvPvE.generalized"}
+// FT-DAG: [[F_TCLS2F6]]   = !{i64 0, !"_ZTSFvPKvE.generalized"}
+// FT-DAG: [[F_TCLS2F7]]   = !{i64 0, !"_ZTSFvR4Cls1E.generalized"}
+// FT-DAG: [[F_TCLS2F8]]   = !{i64 0, !"_ZTSFvRK4Cls1E.generalized"}
+// FT-DAG: [[F_TCLS2F9]]   = !{i64 0, !"_ZTSKFvvE.generalized"}
+
+////////////////////////////////////////////////////////////////////////////////
+// Callsites (check for indirect callsite operand bundles)
+
+// CST-LABEL: define {{.*}} @_Z3foov
+void foo() {
+  Cls2 ObjCls2;
+  ObjCls2.fp = &Cls1::receiver;
+
+  // CST: call noundef ptr %{{.*}} [ "type"(metadata !"_ZTSFPvS_S_E.generalized") ]
+  ObjCls2.fp(0, 0);
+
+  auto fp_f1 = &Cls2::f1;
+  auto fp_f2 = &Cls2::f2;
+  auto fp_f3 = &Cls2::f3;
+  auto fp_f4 = &Cls2::f4;
+  auto fp_f5 = &Cls2::f5;
+  auto fp_f6 = &Cls2::f6;
+  auto fp_f7 = &Cls2::f7;
+  auto fp_f8 = &Cls2::f8;
+  auto fp_f9 = &Cls2::f9;
+
+  Cls2 *ObjCls2Ptr = &ObjCls2;
+  Cls1 Cls1Param;
+
+  // CST: call noundef i32 %{{.*}} [ "type"(metadata !"_ZTSFicfdE.generalized") ]
+  (ObjCls2Ptr->*fp_f1)(0, 0, 0);
+
+  // CST: call noundef ptr %{{.*}} [ "type"(metadata !"_ZTSFPvS_S_S_E.generalized") ]
+  (ObjCls2Ptr->*fp_f2)(0, 0, 0);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFv4Cls1E.generalized") ]
+  (ObjCls2Ptr->*fp_f3)(Cls1Param);
+
+  // CST: call void  %{{.*}} [ "type"(metadata !"_ZTSFv4Cls1E.generalized") ]
+  (ObjCls2Ptr->*fp_f4)(Cls1Param);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvPvE.generalized") ]
+  (ObjCls2Ptr->*fp_f5)(&Cls1Param);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvPKvE.generalized") ]
+  (ObjCls2Ptr->*fp_f6)(&Cls1Param);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvR4Cls1E.generalized") ]
+  (ObjCls2Ptr->*fp_f7)(Cls1Param);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvRK4Cls1E.generalized") ]
+  (ObjCls2Ptr->*fp_f8)(Cls1Param);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSKFvvE.generalized") ]
+  (ObjCls2Ptr->*fp_f9)();
+}
diff --git a/clang/test/CodeGen/call-graph-section-2.cpp b/clang/test/CodeGen/call-graph-section-2.cpp
new file mode 100644
index 00000000000000..4187faea495bee
--- /dev/null
+++ b/clang/test/CodeGen/call-graph-section-2.cpp
@@ -0,0 +1,95 @@
+// Tests that we assign appropriate identifiers to indirect calls and targets
+// specifically for C++ templates.
+
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fcall-graph-section -S \
+// RUN: -emit-llvm -o %t %s
+// RUN: FileCheck --check-prefix=FT    %s < %t
+// RUN: FileCheck --check-prefix=CST   %s < %t
+// RUN: FileCheck --check-prefix=CHECK %s < %t
+
+////////////////////////////////////////////////////////////////////////////////
+// Class definitions and template classes (check for indirect target metadata)
+
+class Cls1 {};
+
+// Cls2 is instantiated with T=Cls1 in foo(). Following checks are for this
+// instantiation.
+template <class T>
+class Cls2 {
+public:
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f1Ev({{.*}} !type [[F_TCLS2F1:![0-9]+]]
+  void f1() {}
+
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f2ES0_({{.*}} !type [[F_TCLS2F2:![0-9]+]]
+  void f2(T a) {}
+
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f3EPS0_({{.*}} !type [[F_TCLS2F3:![0-9]+]]
+  void f3(T *a) {}
+
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f4EPKS0_({{.*}} !type [[F_TCLS2F4:![0-9]+]]
+  void f4(const T *a) {}
+
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f5ERS0_({{.*}} !type [[F_TCLS2F5:![0-9]+]]
+  void f5(T &a) {}
+
+  // FT: define {{.*}} void @_ZN4Cls2I4Cls1E2f6ERKS0_({{.*}} !type [[F_TCLS2F6:![0-9]+]]
+  void f6(const T &a) {}
+
+  // Mixed type function pointer member
+  T *(*fp)(T a, T *b, const T *c, T &d, const T &e);
+};
+
+// FT-DAG: [[F_TCLS2F1]] = !{i64 0, !"_ZTSFvvE.generalized"}
+// FT-DAG: [[F_TCLS2F2]] = !{i64 0, !"_ZTSFv4Cls1E.generalized"}
+// FT-DAG: [[F_TCLS2F3]] = !{i64 0, !"_ZTSFvPvE.generalized"}
+// FT-DAG: [[F_TCLS2F4]] = !{i64 0, !"_ZTSFvPKvE.generalized"}
+// FT-DAG: [[F_TCLS2F5]] = !{i64 0, !"_ZTSFvR4Cls1E.generalized"}
+// FT-DAG: [[F_TCLS2F6]] = !{i64 0, !"_ZTSFvRK4Cls1E.generalized"}
+
+////////////////////////////////////////////////////////////////////////////////
+// Callsites (check for indirect callsite operand bundles)
+
+template <class T>
+T *T_func(T a, T *b, const T *c, T &d, const T &e) { return b; }
+
+// CST-LABEL: define {{.*}} @_Z3foov
+void foo() {
+  // Methods for Cls2<Cls1> is checked above within the template description.
+  Cls2<Cls1> Obj;
+
+  // CHECK-DAG: define {{.*}} @_Z6T_funcI4Cls1EPT_S1_S2_PKS1_RS1_RS3_({{.*}} !type [[F_TFUNC_CLS1:![0-9]+]]
+  // CHECK-DAG: [[F_TFUNC_CLS1]] = !{i64 0, !"_ZTSFPv4Cls1S_PKvRS0_RKS0_E.generalized"}
+  Obj.fp = T_func<Cls1>;
+  Cls1 Cls1Obj;
+
+  // CST: call noundef ptr %{{.*}} [ "type"(metadata !"_ZTSFPv4Cls1S_PKvRS0_RKS0_E.generalized") ]
+  Obj.fp(Cls1Obj, &Cls1Obj, &Cls1Obj, Cls1Obj, Cls1Obj);
+
+  // Make indirect calls to Cls2's member methods
+  auto fp_f1 = &Cls2<Cls1>::f1;
+  auto fp_f2 = &Cls2<Cls1>::f2;
+  auto fp_f3 = &Cls2<Cls1>::f3;
+  auto fp_f4 = &Cls2<Cls1>::f4;
+  auto fp_f5 = &Cls2<Cls1>::f5;
+  auto fp_f6 = &Cls2<Cls1>::f6;
+
+  auto *Obj2Ptr = &Obj;
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvvE.generalized") ]
+  (Obj2Ptr->*fp_f1)();
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFv4Cls1E.generalized") ]
+  (Obj2Ptr->*fp_f2)(Cls1Obj);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvPvE.generalized") ]
+  (Obj2Ptr->*fp_f3)(&Cls1Obj);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvPKvE.generalized") ]
+  (Obj2Ptr->*fp_f4)(&Cls1Obj);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvR4Cls1E.generalized") ]
+  (Obj2Ptr->*fp_f5)(Cls1Obj);
+
+  // CST: call void %{{.*}} [ "type"(metadata !"_ZTSFvRK4Cls1E.generalized") ]
+  (Obj2Ptr->*fp_f6)(Cls1Obj);
+}
diff --git a/clang/test/CodeGen/call-graph-section-3.cpp b/clang/test/CodeGen/call-graph-section-3.cpp
new file mode 100644
index 00000000000000..77bb110c664ef6
--- /dev/null
+++ b/clang/test/CodeGen/call-graph-section-3.cpp
@@ -0,0 +1,52 @@
+// Tests that we assign appropriate identifiers to indirect calls and targets
+// specifically for virtual methods.
+
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fcall-graph-section -S \
+// RUN: -emit-llvm -o %t %s
+// RUN: FileCheck --check-prefix=FT %s < %t
+// RUN: FileCheck --check-prefix=CST %s < %t
+
+////////////////////////////////////////////////////////////////////////////////
+// Class definitions (check for indirect target metadata)
+
+class Base {
+public:
+  // FT-DAG: define {{.*}} @_ZN4Base2vfEPc({{.*}} !type [[F_TVF:![0-9]+]]
+  virtual int vf(char *a) { return 0; };
+};
+
+class Derived : public Base {
+public:
+  // FT-DAG: define {{.*}} @_ZN7Derived2vfEPc({{.*}} !type [[F_TVF]]
+  int vf(char *a) override { return 1; }...
[truncated]

clang/lib/CodeGen/CodeGenModule.cpp Outdated Show resolved Hide resolved
clang/lib/CodeGen/CodeGenModule.cpp Outdated Show resolved Hide resolved
Prabhuk pushed a commit to Prabhuk/llvm-project that referenced this pull request Apr 19, 2024
…argets

Create and add generalized type identifier metadata to indirect calls,
and to functions that may be target to indirect calls.

Type identifiers will be used by the back-end to construct the call
graph section to precisely represent the possible targets for indirect calls.
The type information is deliberately pulled from the front-end to have extra
precision since some type information is lost at IR, and to ensure
consistent type identifiers between object files compiled at different
times (as C/C++ standards require language-level types to match).

Original RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-June/151044.html
Updated RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-July/151739.html

Reviewed By:
morehouse

Differential Revision: https://reviews.llvm.org/D105909?id=358327

Pull Request: llvm#87573
Prabhuk and others added 3 commits April 22, 2024 11:34
Cleaner if checks.

Co-authored-by: Matt Arsenault <Matthew.Arsenault@amd.com>
Update the comments as suggested.

Co-authored-by: Matt Arsenault <Matthew.Arsenault@amd.com>
…ion. Removed type id emitting for Objective C.

Created using spr 1.3.6-beta.1
Created using spr 1.3.6-beta.1
Created using spr 1.3.6-beta.1
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@ilovepi ilovepi left a comment

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Can you split out the LLVM parts from the clang parts? The LLVM bits should land first, and then clang can make use of them in a later PR. This will also simplify review, since we can focus on the LLVM vs. Clang implementations in isolation.

clang/lib/CodeGen/CGCall.cpp Outdated Show resolved Hide resolved
clang/lib/CodeGen/CGCall.cpp Outdated Show resolved Hide resolved
clang/lib/CodeGen/CGExpr.cpp Show resolved Hide resolved
@@ -5693,6 +5699,36 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
AllocAlignAttrEmitter AllocAlignAttrEmitter(*this, TargetDecl, CallArgs);
Attrs = AllocAlignAttrEmitter.TryEmitAsCallSiteAttribute(Attrs);

if (CGM.getCodeGenOpts().CallGraphSection) {
// Create operand bundle only for indirect calls, not for all
if (callOrInvoke && *callOrInvoke && (*callOrInvoke)->isIndirectCall()) {
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@arsenm arsenm May 7, 2024

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This double null check, for what I assume is an std::optional<pointer> is really ugly, but I don't actually see where it's defined. Should either just not bother with the optional or without the second check?

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6 participants