https://github.com/pfeodrippe updated https://github.com/llvm/llvm-project/pull/169251
>From 6f6245ef1ecc075a0a12d84c7e804a08d2f05a8c Mon Sep 17 00:00:00 2001 From: Paulo Feodrippe <[email protected]> Date: Sun, 23 Nov 2025 21:35:08 -0500 Subject: [PATCH] Fix static const member address reference --- clang/lib/CodeGen/CGExpr.cpp | 6 ++ clang/lib/CodeGen/CGExprConstant.cpp | 4 ++ clang/lib/CodeGen/CodeGenModule.cpp | 45 +++++++++++++++ clang/lib/CodeGen/CodeGenModule.h | 8 +++ .../test/Interpreter/static-const-member.cpp | 57 +++++++++++++++++++ .../unittests/Interpreter/InterpreterTest.cpp | 14 +++++ 6 files changed, 134 insertions(+) create mode 100644 clang/test/Interpreter/static-const-member.cpp diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index b33772919b8c8..9f3b7f686fe4e 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -3111,6 +3111,12 @@ static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF, return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl); } + // In incremental mode, ensure static data members with in-class initializers + // are materialized before use. This handles lvalue references that bypass + // constant evaluation (e.g., passing by reference to a function). + if (CGF.CGM.getLangOpts().IncrementalExtensions && VD->isStaticDataMember()) + VD = CGF.CGM.materializeStaticDataMember(VD); + llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD); if (VD->getTLSKind() != VarDecl::TLS_None) diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp index 6407afc3d9447..2a97f509b4b9b 100644 --- a/clang/lib/CodeGen/CGExprConstant.cpp +++ b/clang/lib/CodeGen/CGExprConstant.cpp @@ -2243,6 +2243,10 @@ ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) { } if (const auto *VD = dyn_cast<VarDecl>(D)) { + // In incremental mode, ensure static data members with in-class + // initializers are materialized on first odr-use (e.g., &Foo::member). + if (CGM.getLangOpts().IncrementalExtensions && VD->isStaticDataMember()) + VD = CGM.materializeStaticDataMember(VD); // We can never refer to a variable with local storage. if (!VD->hasLocalStorage()) { if (VD->isFileVarDecl() || VD->hasExternalStorage()) diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 645b78a599f89..eba02c980747e 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -6302,6 +6302,51 @@ CodeGenModule::getLLVMLinkageVarDefinition(const VarDecl *VD) { return getLLVMLinkageForDeclarator(VD, Linkage); } +const VarDecl *CodeGenModule::materializeStaticDataMember(const VarDecl *VD) { + if (!VD) + return VD; + + const VarDecl *DefinitionVD = VD->getDefinition(); + if (!DefinitionVD) + DefinitionVD = VD; + + // Only in-class static data members need materialization. Out-of-line + // definitions are emitted normally. + if (!DefinitionVD->isStaticDataMember() || DefinitionVD->isOutOfLine()) + return DefinitionVD; + + const VarDecl *InitVD = nullptr; + // Members without in-class initializers rely on out-of-class definitions. + if (!DefinitionVD->getAnyInitializer(InitVD) || !InitVD) + return DefinitionVD; + + auto NeedsMaterialization = [](llvm::GlobalValue *GV) { + if (!GV) + return true; + if (GV->isDeclaration()) + return true; + // Inline static members may be emitted as available_externally; upgrade + // to linkonce_odr so the JIT can resolve them. + if (auto *GVVar = llvm::dyn_cast<llvm::GlobalVariable>(GV)) + return GVVar->hasAvailableExternallyLinkage(); + return false; + }; + + GlobalDecl GD(InitVD); + StringRef MangledName = getMangledName(GD); + llvm::GlobalValue *GV = GetGlobalValue(MangledName); + + if (NeedsMaterialization(GV)) { + EmitGlobalVarDefinition(InitVD, /*IsTentative=*/false); + GV = GetGlobalValue(MangledName); + if (auto *GVVar = llvm::dyn_cast_or_null<llvm::GlobalVariable>(GV)) + if (GVVar->hasAvailableExternallyLinkage()) + GVVar->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage); + } + + return InitVD; +} + /// Replace the uses of a function that was declared with a non-proto type. /// We want to silently drop extra arguments from call sites static void replaceUsesOfNonProtoConstant(llvm::Constant *old, diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h index a253bcda2d06c..1ea582c03a8c6 100644 --- a/clang/lib/CodeGen/CodeGenModule.h +++ b/clang/lib/CodeGen/CodeGenModule.h @@ -1839,6 +1839,14 @@ class CodeGenModule : public CodeGenTypeCache { return TrapReasonBuilder(&getDiags(), DiagID, TR); } + /// Materialize a static data member with an in-class initializer on demand. + /// + /// In incremental contexts (e.g. clang-repl) a class can be defined in an + /// earlier partial translation unit, while the first odr-use (such as taking + /// the address) happens later. Ensure we emit a usable definition so the JIT + /// can resolve the symbol. + const VarDecl *materializeStaticDataMember(const VarDecl *VD); + private: bool shouldDropDLLAttribute(const Decl *D, const llvm::GlobalValue *GV) const; diff --git a/clang/test/Interpreter/static-const-member.cpp b/clang/test/Interpreter/static-const-member.cpp new file mode 100644 index 0000000000000..659b179e967ea --- /dev/null +++ b/clang/test/Interpreter/static-const-member.cpp @@ -0,0 +1,57 @@ +// RUN: cat %s | clang-repl | FileCheck %s +// Tests for static const member materialization in clang-repl. +// See https://github.com/llvm/llvm-project/issues/146956 + +extern "C" int printf(const char*, ...); + +struct Foo { static int const bar { 5 }; static int const baz { 10 }; }; + +// Test 1: Taking address of static const member +int const * p = &Foo::bar; +printf("Address test: %d\n", *p); +// CHECK: Address test: 5 + +// Test 2: Multiple static const members in same class +int const * q = &Foo::baz; +printf("Second member test: %d\n", *q); +// CHECK: Second member test: 10 + +// Test 3: static constexpr member (variant of in-class init) +struct Qux { static constexpr int val = 99; }; +int const *p3 = &Qux::val; +printf("Constexpr test: %d\n", *p3); +// CHECK: Constexpr test: 99 + +// Test 4: Passing static const member by reference (exercises CGExpr.cpp path) +void useRef(int const &x) { printf("Ref test: %d\n", x); } +useRef(Foo::bar); +// CHECK: Ref test: 5 + +// ============================================================================ +// Negative tests - cases that should NOT trigger materialization +// ============================================================================ + +// Test 5: Out-of-class definition (no need to materialize - already defined) +struct OutOfLine { static const int value; }; +const int OutOfLine::value = 23; +int const *p5 = &OutOfLine::value; +printf("Out-of-line test: %d\n", *p5); +// CHECK: Out-of-line test: 23 + +// Test 6: Non-const static member (normal code gen path) +struct NonConst { static int value; }; +int NonConst::value = 42; +int *p6 = &NonConst::value; +printf("Non-const test: %d\n", *p6); +// CHECK: Non-const test: 42 + +// ============================================================================ +// Edge case tests +// ============================================================================ + +// Test 7: Repeated address-of reuses same definition +int const *p7 = &Foo::bar; +printf("Reuse test: %d\n", (*p == *p7) ? 1 : 0); +// CHECK: Reuse test: 1 + +%quit diff --git a/clang/unittests/Interpreter/InterpreterTest.cpp b/clang/unittests/Interpreter/InterpreterTest.cpp index 9ff9092524d21..341e61563e6bf 100644 --- a/clang/unittests/Interpreter/InterpreterTest.cpp +++ b/clang/unittests/Interpreter/InterpreterTest.cpp @@ -443,4 +443,18 @@ TEST_F(InterpreterTest, TranslationUnit_CanonicalDecl) { sema.getASTContext().getTranslationUnitDecl()->getCanonicalDecl()); } +TEST_F(InterpreterTest, StaticConstMemberAddress) { + std::unique_ptr<Interpreter> Interp = createInterpreter(); + + llvm::cantFail( + Interp->ParseAndExecute("struct Foo { static int const bar { 5 }; };")); + + Value V; + llvm::cantFail(Interp->ParseAndExecute("int const * p = &Foo::bar; *p", &V)); + + ASSERT_TRUE(V.isValid()); + ASSERT_TRUE(V.hasValue()); + EXPECT_EQ(V.getInt(), 5); +} + } // end anonymous namespace _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
