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[clang] Make predefined expressions string literals under -fms-extensions
MSVC makes these string literals [1][2]. [1] https://godbolt.org/z/6vnTzbExx [2] https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=msvc-170 Fixes swiftlang#114 Reviewed By: aaron.ballman Differential Revision: https://reviews.llvm.org/D146764
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‎clang/docs/ReleaseNotes.rst

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@@ -416,6 +416,9 @@ Bug Fixes to C++ Support
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initialization.
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(`#61567 <https://github.com/llvm/llvm-project/issues/61567>`_)
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- Fix a crash when expanding a pack as the index of a subscript expression.
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- Some predefined expressions are now treated as string literals in MSVC
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compatibility mode.
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(`#114 <https://github.com/llvm/llvm-project/issues/114>`_)
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Bug Fixes to AST Handling
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^^^^^^^^^^^^^^^^^^^^^^^^^

‎clang/include/clang/AST/Expr.h

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@@ -1992,7 +1992,7 @@ class PredefinedExpr final
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private:
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PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
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StringLiteral *SL);
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bool IsTransparent, StringLiteral *SL);
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explicit PredefinedExpr(EmptyShell Empty, bool HasFunctionName);
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@@ -2007,8 +2007,12 @@ class PredefinedExpr final
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public:
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/// Create a PredefinedExpr.
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///
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/// If IsTransparent, the PredefinedExpr is transparently handled as a
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/// StringLiteral.
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static PredefinedExpr *Create(const ASTContext &Ctx, SourceLocation L,
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QualType FNTy, IdentKind IK, StringLiteral *SL);
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QualType FNTy, IdentKind IK, bool IsTransparent,
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StringLiteral *SL);
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/// Create an empty PredefinedExpr.
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static PredefinedExpr *CreateEmpty(const ASTContext &Ctx,
@@ -2018,6 +2022,8 @@ class PredefinedExpr final
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return static_cast<IdentKind>(PredefinedExprBits.Kind);
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}
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bool isTransparent() const { return PredefinedExprBits.IsTransparent; }
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SourceLocation getLocation() const { return PredefinedExprBits.Loc; }
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void setLocation(SourceLocation L) { PredefinedExprBits.Loc = L; }
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‎clang/include/clang/AST/IgnoreExpr.h

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@@ -166,6 +166,11 @@ inline Expr *IgnoreParensSingleStep(Expr *E) {
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return CE->getChosenSubExpr();
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}
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else if (auto *PE = dyn_cast<PredefinedExpr>(E)) {
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if (PE->isTransparent())
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return PE->getFunctionName();
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}
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return E;
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}
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‎clang/include/clang/AST/Stmt.h

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@@ -364,6 +364,10 @@ class alignas(void *) Stmt {
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/// for the predefined identifier.
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unsigned HasFunctionName : 1;
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/// True if this PredefinedExpr should be treated as a StringLiteral (for
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/// MSVC compatibility).
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unsigned IsTransparent : 1;
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/// The location of this PredefinedExpr.
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SourceLocation Loc;
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};

‎clang/include/clang/Basic/DiagnosticGroups.td

Lines changed: 2 additions & 1 deletion
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@@ -1190,6 +1190,7 @@ def MicrosoftCommentPaste : DiagGroup<"microsoft-comment-paste">;
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def MicrosoftEndOfFile : DiagGroup<"microsoft-end-of-file">;
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def MicrosoftInaccessibleBase : DiagGroup<"microsoft-inaccessible-base">;
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def MicrosoftStaticAssert : DiagGroup<"microsoft-static-assert">;
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def MicrosoftInitFromPredefined : DiagGroup<"microsoft-init-from-predefined">;
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// Aliases.
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def : DiagGroup<"msvc-include", [MicrosoftInclude]>;
@@ -1207,7 +1208,7 @@ def Microsoft : DiagGroup<"microsoft",
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MicrosoftFlexibleArray, MicrosoftExtraQualification, MicrosoftCast,
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MicrosoftConstInit, MicrosoftVoidPseudoDtor, MicrosoftAnonTag,
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MicrosoftCommentPaste, MicrosoftEndOfFile, MicrosoftStaticAssert,
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MicrosoftInconsistentDllImport]>;
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MicrosoftInitFromPredefined, MicrosoftInconsistentDllImport]>;
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def ClangClPch : DiagGroup<"clang-cl-pch">;
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‎clang/include/clang/Basic/DiagnosticSemaKinds.td

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@@ -112,6 +112,9 @@ def err_expr_not_string_literal : Error<"expression is not a string literal">;
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def ext_predef_outside_function : Warning<
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"predefined identifier is only valid inside function">,
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InGroup<DiagGroup<"predefined-identifier-outside-function">>;
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def ext_init_from_predefined : ExtWarn<
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"initializing an array from a '%0' predefined identifier is a Microsoft extension">,
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InGroup<MicrosoftInitFromPredefined>;
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def warn_float_overflow : Warning<
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"magnitude of floating-point constant too large for type %0; maximum is %1">,
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InGroup<LiteralRange>;

‎clang/lib/AST/ASTImporter.cpp

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@@ -7068,7 +7068,8 @@ ExpectedStmt ASTNodeImporter::VisitPredefinedExpr(PredefinedExpr *E) {
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return std::move(Err);
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return PredefinedExpr::Create(Importer.getToContext(), ToBeginLoc, ToType,
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E->getIdentKind(), ToFunctionName);
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E->getIdentKind(), E->isTransparent(),
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ToFunctionName);
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}
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ExpectedStmt ASTNodeImporter::VisitDeclRefExpr(DeclRefExpr *E) {

‎clang/lib/AST/Expr.cpp

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Original file line numberDiff line numberDiff line change
@@ -663,13 +663,14 @@ std::string SYCLUniqueStableNameExpr::ComputeName(ASTContext &Context,
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}
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PredefinedExpr::PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
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StringLiteral *SL)
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bool IsTransparent, StringLiteral *SL)
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: Expr(PredefinedExprClass, FNTy, VK_LValue, OK_Ordinary) {
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PredefinedExprBits.Kind = IK;
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assert((getIdentKind() == IK) &&
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"IdentKind do not fit in PredefinedExprBitfields!");
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bool HasFunctionName = SL != nullptr;
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PredefinedExprBits.HasFunctionName = HasFunctionName;
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PredefinedExprBits.IsTransparent = IsTransparent;
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PredefinedExprBits.Loc = L;
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if (HasFunctionName)
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setFunctionName(SL);
@@ -683,11 +684,11 @@ PredefinedExpr::PredefinedExpr(EmptyShell Empty, bool HasFunctionName)
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684685
PredefinedExpr *PredefinedExpr::Create(const ASTContext &Ctx, SourceLocation L,
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QualType FNTy, IdentKind IK,
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StringLiteral *SL) {
687+
bool IsTransparent, StringLiteral *SL) {
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bool HasFunctionName = SL != nullptr;
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void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(HasFunctionName),
689690
alignof(PredefinedExpr));
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return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
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return new (Mem) PredefinedExpr(L, FNTy, IK, IsTransparent, SL);
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}
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PredefinedExpr *PredefinedExpr::CreateEmpty(const ASTContext &Ctx,

‎clang/lib/Sema/SemaExpr.cpp

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@@ -3581,7 +3581,8 @@ ExprResult Sema::BuildPredefinedExpr(SourceLocation Loc,
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}
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}
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return PredefinedExpr::Create(Context, Loc, ResTy, IK, SL);
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return PredefinedExpr::Create(Context, Loc, ResTy, IK, LangOpts.MicrosoftExt,
3585+
SL);
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}
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ExprResult Sema::BuildSYCLUniqueStableNameExpr(SourceLocation OpLoc,

‎clang/lib/Sema/SemaInit.cpp

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@@ -174,6 +174,8 @@ static void updateStringLiteralType(Expr *E, QualType Ty) {
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E = GSE->getResultExpr();
175175
} else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
176176
E = CE->getChosenSubExpr();
177+
} else if (PredefinedExpr *PE = dyn_cast<PredefinedExpr>(E)) {
178+
E = PE->getFunctionName();
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} else {
178180
llvm_unreachable("unexpected expr in string literal init");
179181
}
@@ -8501,6 +8503,15 @@ ExprResult InitializationSequence::Perform(Sema &S,
85018503
<< Init->getSourceRange();
85028504
}
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if (S.getLangOpts().MicrosoftExt && Args.size() == 1 &&
8507+
isa<PredefinedExpr>(Args[0]) && Entity.getType()->isArrayType()) {
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// Produce a Microsoft compatibility warning when initializing from a
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// predefined expression since MSVC treats predefined expressions as string
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// literals.
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Expr *Init = Args[0];
8512+
S.Diag(Init->getBeginLoc(), diag::ext_init_from_predefined) << Init;
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}
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// OpenCL v2.0 s6.13.11.1. atomic variables can be initialized in global scope
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QualType ETy = Entity.getType();
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bool HasGlobalAS = ETy.hasAddressSpace() &&

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