Index: clang/docs/ReleaseNotes.rst =================================================================== --- clang/docs/ReleaseNotes.rst +++ clang/docs/ReleaseNotes.rst @@ -226,6 +226,8 @@ - Implemented `WG14 N2775 Literal suffixes for bit-precise integers `_. - Implemented the `*_WIDTH` macros to complete support for `WG14 N2412 Two's complement sign representation for C2x `_. +- Implemented `WG14 N2841 No function declarators without prototypes `_ + and `WG14 N2432 Remove support for function definitions with identifier lists `_. C++ Language Changes in Clang ----------------------------- Index: clang/include/clang/Basic/LangOptions.def =================================================================== --- clang/include/clang/Basic/LangOptions.def +++ clang/include/clang/Basic/LangOptions.def @@ -121,6 +121,7 @@ LANGOPT(GNUKeywords , 1, 1, "GNU keywords") VALUE_LANGOPT(GNUCVersion , 32, 0, "GNU C compatibility version") BENIGN_LANGOPT(ImplicitInt, 1, 0, "C89 implicit 'int'") +LANGOPT(StrictPrototypes , 1, 0, "require function types to have a prototype") LANGOPT(Digraphs , 1, 0, "digraphs") BENIGN_LANGOPT(HexFloats , 1, 0, "C99 hexadecimal float constants") LANGOPT(CXXOperatorNames , 1, 0, "C++ operator name keywords") Index: clang/lib/AST/ASTContext.cpp =================================================================== --- clang/lib/AST/ASTContext.cpp +++ clang/lib/AST/ASTContext.cpp @@ -4239,6 +4239,12 @@ QualType ASTContext::getFunctionNoProtoType(QualType ResultTy, const FunctionType::ExtInfo &Info) const { + // FIXME: This assertion cannot be enabled (yet) because the ObjC rewriter + // functionality creates a function without a prototype regardless of + // language mode (so it makes them even in C++). Once the rewriter has been + // fixed, this assertion can be enabled again. + //assert(!LangOpts.StrictPrototypes && "strict prototypes are disabled"); + // Unique functions, to guarantee there is only one function of a particular // structure. llvm::FoldingSetNodeID ID; @@ -11235,7 +11241,7 @@ // We really shouldn't be making a no-proto type here. - if (ArgTypes.empty() && Variadic && !getLangOpts().CPlusPlus) + if (ArgTypes.empty() && Variadic && !getLangOpts().StrictPrototypes) return getFunctionNoProtoType(ResType, EI); FunctionProtoType::ExtProtoInfo EPI; Index: clang/lib/Basic/LangOptions.cpp =================================================================== --- clang/lib/Basic/LangOptions.cpp +++ clang/lib/Basic/LangOptions.cpp @@ -116,6 +116,7 @@ Opts.ImplicitInt = Std.hasImplicitInt(); Opts.WChar = Std.isCPlusPlus(); Opts.Digraphs = Std.hasDigraphs(); + Opts.StrictPrototypes = Std.isCPlusPlus() || Std.isC2x(); Opts.HLSL = Lang == Language::HLSL; Index: clang/lib/Parse/ParseDecl.cpp =================================================================== --- clang/lib/Parse/ParseDecl.cpp +++ clang/lib/Parse/ParseDecl.cpp @@ -6661,8 +6661,11 @@ else if (RequiresArg) Diag(Tok, diag::err_argument_required_after_attribute); - HasProto = ParamInfo.size() || getLangOpts().CPlusPlus - || getLangOpts().OpenCL; + // OpenCL disallows variadic functions, so it also disallows a function + // without a prototype. However, it doesn't enforce strict prototypes + // because it allows function definitions with an identifier list. + HasProto = ParamInfo.size() || getLangOpts().StrictPrototypes || + getLangOpts().OpenCL; // If we have the closing ')', eat it. Tracker.consumeClose(); @@ -6799,7 +6802,7 @@ /// Note that identifier-lists are only allowed for normal declarators, not for /// abstract-declarators. bool Parser::isFunctionDeclaratorIdentifierList() { - return !getLangOpts().CPlusPlus + return !getLangOpts().StrictPrototypes && Tok.is(tok::identifier) && !TryAltiVecVectorToken() // K&R identifier lists can't have typedefs as identifiers, per C99 @@ -6833,6 +6836,10 @@ void Parser::ParseFunctionDeclaratorIdentifierList( Declarator &D, SmallVectorImpl &ParamInfo) { + // We should never reach this point in C2x or C++. + assert(!getLangOpts().StrictPrototypes && + "Cannot parse an identifier list in C2x or C++"); + // If there was no identifier specified for the declarator, either we are in // an abstract-declarator, or we are in a parameter declarator which was found // to be abstract. In abstract-declarators, identifier lists are not valid: Index: clang/lib/Sema/SemaDecl.cpp =================================================================== --- clang/lib/Sema/SemaDecl.cpp +++ clang/lib/Sema/SemaDecl.cpp @@ -8818,6 +8818,8 @@ (D.getDeclSpec().isTypeRep() && D.getDeclSpec().getRepAsType().get()->isFunctionProtoType()) || (!R->getAsAdjusted() && R->isFunctionProtoType()); + assert((HasPrototype || !SemaRef.getLangOpts().StrictPrototypes) && + "Strict prototypes are required"); NewFD = FunctionDecl::Create( SemaRef.Context, DC, D.getBeginLoc(), NameInfo, R, TInfo, SC, Index: clang/lib/Sema/SemaType.cpp =================================================================== --- clang/lib/Sema/SemaType.cpp +++ clang/lib/Sema/SemaType.cpp @@ -5270,8 +5270,11 @@ FunctionType::ExtInfo EI( getCCForDeclaratorChunk(S, D, DeclType.getAttrs(), FTI, chunkIndex)); - if (!FTI.NumParams && !FTI.isVariadic && !LangOpts.CPlusPlus - && !LangOpts.OpenCL) { + // OpenCL disallows variadic functions, so it also disallows a function + // without a prototype. However, it doesn't enforce strict prototypes + // because it allows function definitions with an identifier list. + if (!FTI.NumParams && !FTI.isVariadic && !LangOpts.StrictPrototypes && + !LangOpts.OpenCL) { // Simple void foo(), where the incoming T is the result type. T = Context.getFunctionNoProtoType(T, EI); } else { @@ -5290,8 +5293,10 @@ S.Diag(FTI.Params[0].IdentLoc, diag::err_ident_list_in_fn_declaration); D.setInvalidType(true); - // Recover by creating a K&R-style function type. - T = Context.getFunctionNoProtoType(T, EI); + // Recover by creating a K&R-style function type, if possible. + T = (!LangOpts.StrictPrototypes && !LangOpts.OpenCL) + ? Context.getFunctionNoProtoType(T, EI) + : Context.IntTy; break; } Index: clang/lib/StaticAnalyzer/Core/MemRegion.cpp =================================================================== --- clang/lib/StaticAnalyzer/Core/MemRegion.cpp +++ clang/lib/StaticAnalyzer/Core/MemRegion.cpp @@ -1031,17 +1031,21 @@ QualType T; if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten()) T = TSI->getType(); - if (T.isNull()) - T = getContext().VoidTy; - if (!T->getAs()) - T = getContext().getFunctionNoProtoType(T); - T = getContext().getBlockPointerType(T); - - const BlockCodeRegion *BTR = - getBlockCodeRegion(BD, Ctx.getCanonicalType(T), - STC->getAnalysisDeclContext()); - sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind, - BTR); + if (T.isNull() || !T->getAs()) + // If the type is invalid or is not a function type, we cannot get + // a block pointer type for it. This isn't ideal, but it's better + // than asserting in getBlockPointerType() or creating a function + // without a prototype in a language that has no such concept (like + // C++ or C2x). + sReg = getUnknownRegion(); + else { + T = getContext().getBlockPointerType(T); + + const BlockCodeRegion *BTR = getBlockCodeRegion( + BD, Ctx.getCanonicalType(T), STC->getAnalysisDeclContext()); + sReg = + getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind, BTR); + } } else { sReg = getGlobalsRegion(); Index: clang/test/Parser/c2x-attributes.c =================================================================== --- clang/test/Parser/c2x-attributes.c +++ clang/test/Parser/c2x-attributes.c @@ -1,5 +1,5 @@ -// RUN: %clang_cc1 -fsyntax-only -fdouble-square-bracket-attributes -verify -Wno-strict-prototypes %s -// RUN: %clang_cc1 -fsyntax-only -std=gnu2x -verify -Wno-strict-prototypes %s +// RUN: %clang_cc1 -fsyntax-only -fdouble-square-bracket-attributes -verify=expected,notc2x -Wno-strict-prototypes %s +// RUN: %clang_cc1 -fsyntax-only -std=gnu2x -verify=expected,c2x %s enum [[]] E { One [[]], @@ -59,7 +59,10 @@ void f5(int i [[]], [[]] int j, int [[]] k); -void f6(a, b) [[]] int a; int b; { // expected-error {{an attribute list cannot appear here}} +void f6(a, b) [[]] int a; int b; { // notc2x-error {{an attribute list cannot appear here}} \ + c2x-warning 2 {{type specifier missing, defaults to 'int'}} \ + c2x-error {{expected ';' after top level declarator}} \ + c2x-error {{expected identifier or '('}} } // FIXME: technically, an attribute list cannot appear here, but we currently @@ -67,7 +70,10 @@ // behavior given that we *don't* want to parse it as part of the K&R parameter // declarations. It is disallowed to avoid a parsing ambiguity we already // handle well. -int (*f7(a, b))(int, int) [[]] int a; int b; { +int (*f7(a, b))(int, int) [[]] int a; int b; { // c2x-warning 2 {{type specifier missing, defaults to 'int'}} \ + c2x-error {{expected ';' after top level declarator}} \ + c2x-error {{expected identifier or '('}} + return 0; } Index: clang/test/Parser/c2x-func-prototype.c =================================================================== --- /dev/null +++ clang/test/Parser/c2x-func-prototype.c @@ -0,0 +1,16 @@ +// RUN: %clang_cc1 -fsyntax-only -verify=c2x -std=c2x %s +// RUN: %clang_cc1 -Wno-strict-prototypes -fsyntax-only -verify -std=c17 %s +// expected-no-diagnostics + +// Functions with an identifier list are not supported in C2x. +void ident_list(a) // c2x-error {{expected ';' after top level declarator}} \ + c2x-warning {{type specifier missing, defaults to 'int'}} + int a; +{} // c2x-error {{expected identifier or '('}} + +// Functions with an empty parameter list are supported as though the function +// was declared with a parameter list of (void). Ensure they still parse. +void no_param_decl(); +void no_param_defn() {} +void (*var_of_type_with_no_param)(); +typedef void fn(); Index: clang/test/Sema/attr-c2x.c =================================================================== --- clang/test/Sema/attr-c2x.c +++ clang/test/Sema/attr-c2x.c @@ -20,7 +20,7 @@ void context_async_okay2(void *context [[clang::swift_async_context]], void *selfType, char **selfWitnessTable) [[clang::swiftasynccall]]; [[clang::ownership_returns(foo)]] void *f1(void); -[[clang::ownership_returns(foo)]] void *f2(); // expected-warning {{'ownership_returns' attribute only applies to non-K&R-style functions}} +[[clang::ownership_returns(foo)]] void *f2(); [[clang::unavailable("not available - replaced")]] void foo2(void); // expected-note {{'foo2' has been explicitly marked unavailable here}} void bar(void) { Index: clang/test/Sema/c2x-func-prototype.c =================================================================== --- /dev/null +++ clang/test/Sema/c2x-func-prototype.c @@ -0,0 +1,23 @@ +// RUN: %clang_cc1 -fsyntax-only -verify=c2x -std=c2x %s +// RUN: %clang_cc1 -Wno-strict-prototypes -fsyntax-only -verify -std=c17 %s +// expected-no-diagnostics + +void func(); // c2x-note {{'func' declared here}} +typedef void (*fp)(); + +void other_func(int i); + +void call(void) { + func(1, 2, 3); // c2x-error {{too many arguments to function call, expected 0, have 3}} + fp call_me = func; + call_me(1, 2, 3); // c2x-error {{too many arguments to function call, expected 0, have 3}} + + fp nope = other_func; // c2x-warning {{incompatible function pointer types initializing 'fp' (aka 'void (*)(void)') with an expression of type 'void (int)'}} +} + +// Ensure these function declarations do not merge in C2x. +void redecl1(); // c2x-note {{previous declaration is here}} +void redecl1(int i); // c2x-error {{conflicting types for 'redecl1'}} + +void redecl2(int i); // c2x-note {{previous declaration is here}} +void redecl2(); // c2x-error {{conflicting types for 'redecl2'}} Index: clang/tools/clang-import-test/clang-import-test.cpp =================================================================== --- clang/tools/clang-import-test/clang-import-test.cpp +++ clang/tools/clang-import-test/clang-import-test.cpp @@ -181,6 +181,7 @@ Inv->getLangOpts()->CPlusPlus = true; Inv->getLangOpts()->CPlusPlus11 = true; Inv->getHeaderSearchOpts().UseLibcxx = true; + Inv->getLangOpts()->StrictPrototypes = true; } if (isObjC(Id)) { Inv->getLangOpts()->ObjC = 1; Index: clang/www/c_status.html =================================================================== --- clang/www/c_status.html +++ clang/www/c_status.html @@ -725,7 +725,7 @@ Remove support for function definitions with identifier lists N2432 - No + Clang 15