diff --git a/clang/include/clang/AST/Attr.h b/clang/include/clang/AST/Attr.h --- a/clang/include/clang/AST/Attr.h +++ b/clang/include/clang/AST/Attr.h @@ -162,6 +162,21 @@ } }; +class DeclOrStmtAttr : public InheritableAttr { +protected: + DeclOrStmtAttr(ASTContext &Context, const AttributeCommonInfo &CommonInfo, + attr::Kind AK, bool IsLateParsed, + bool InheritEvenIfAlreadyPresent) + : InheritableAttr(Context, CommonInfo, AK, IsLateParsed, + InheritEvenIfAlreadyPresent) {} + +public: + static bool classof(const Attr *A) { + return A->getKind() >= attr::FirstDeclOrStmtAttr && + A->getKind() <= attr::LastDeclOrStmtAttr; + } +}; + class InheritableParamAttr : public InheritableAttr { protected: InheritableParamAttr(ASTContext &Context, diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -570,6 +570,9 @@ /// attributes, but have historically been written on declarations. class DeclOrTypeAttr : InheritableAttr; +/// A attribute is either a declaration attribute or a statement attribute. +class DeclOrStmtAttr : InheritableAttr; + /// A target-specific attribute. This class is meant to be used as a mixin /// with InheritableAttr or Attr depending on the attribute's needs. class TargetSpecificAttr { @@ -1317,9 +1320,12 @@ let Documentation = [LikelihoodDocs]; } -def NoMerge : StmtAttr { +def NoMerge : DeclOrStmtAttr { let Spellings = [Clang<"nomerge">]; let Documentation = [NoMergeDocs]; + let InheritEvenIfAlreadyPresent = 1; + let Subjects = SubjectList<[Function], ErrorDiag, "functions and statements">; + let SimpleHandler = 1; } def FastCall : DeclOrTypeAttr { diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/include/clang/Basic/AttrDocs.td @@ -386,7 +386,11 @@ identical code sequences that raise an exception or terminate the program. Tail merging normally reduces the precision of source location information, making stack traces less useful for debugging. This attribute gives the user control -over the tradeoff between code size and debug information precision. +over the tradeoff between code size and debug information precision. + +``nomerge`` attribute can also be used as function attribute to prevent all +calls to the specified function from merging. It has no effect on indirect +calls. }]; } diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp --- a/clang/lib/CodeGen/CGCall.cpp +++ b/clang/lib/CodeGen/CGCall.cpp @@ -1968,6 +1968,8 @@ FuncAttrs.addAttribute(llvm::Attribute::NoReturn); NBA = Fn->getAttr(); } + if (!AttrOnCallSite && TargetDecl->hasAttr()) + FuncAttrs.addAttribute(llvm::Attribute::NoMerge); } // 'const', 'pure' and 'noalias' attributed functions are also nounwind. @@ -4978,11 +4980,13 @@ Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex, llvm::Attribute::StrictFP); - // Add call-site nomerge attribute if exists. - if (InNoMergeAttributedStmt) - Attrs = - Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex, - llvm::Attribute::NoMerge); + // Add nomerge attribute to the call-site if the callee function doesn't have + // the attribute. + if (const FunctionDecl *FD = dyn_cast_or_null(TargetDecl)) + if (!FD->hasAttr() && InNoMergeAttributedStmt) + Attrs = Attrs.addAttribute(getLLVMContext(), + llvm::AttributeList::FunctionIndex, + llvm::Attribute::NoMerge); // Apply some call-site-specific attributes. // TODO: work this into building the attribute set. diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1749,6 +1749,9 @@ B.addAttribute(llvm::Attribute::MinSize); } + if (D->hasAttr()) + B.addAttribute(llvm::Attribute::NoMerge); + F->addAttributes(llvm::AttributeList::FunctionIndex, B); unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -7910,6 +7910,9 @@ handleSimpleAttributeWithExclusions(S, D, AL); break; + case ParsedAttr::AT_NoMerge: + handleSimpleAttribute(S, D, AL); + break; case ParsedAttr::AT_Visibility: handleVisibilityAttr(S, D, AL, false); break; diff --git a/clang/test/CodeGen/attr-nomerge.cpp b/clang/test/CodeGen/attr-nomerge.cpp --- a/clang/test/CodeGen/attr-nomerge.cpp +++ b/clang/test/CodeGen/attr-nomerge.cpp @@ -1,9 +1,23 @@ // RUN: %clang_cc1 -S -emit-llvm %s -triple x86_64-unknown-linux-gnu -o - | FileCheck %s -bool bar(); -void f(bool, bool); +class A { +public: + [[clang::nomerge]] A(); + [[clang::nomerge]] ~A(); + [[clang::nomerge]] void f(); + [[clang::nomerge]] virtual void g(); + [[clang::nomerge]] static void f1(); +}; -void foo(int i) { +class B : public A { +public: + void g() override; +}; + +[[clang::nomerge]] bool bar(); +[[clang::nomerge]] void f(bool, bool); + +void foo(int i, A *ap, B *bp) { [[clang::nomerge]] bar(); [[clang::nomerge]] (i = 4, bar()); [[clang::nomerge]] (void)(bar()); @@ -12,18 +26,68 @@ [[clang::nomerge]] for (bar(); bar(); bar()) {} [[clang::nomerge]] { asm("nop"); } bar(); + + ap->g(); + bp->g(); + + A a; + a.f(); + a.g(); + A::f1(); + + B b; + b.g(); +} + +int g(int i); + +void something() { + g(1); +} + +[[clang::nomerge]] int g(int i); + +void something_else() { + g(1); +} + +int g(int i) { return i; } + +void something_else_again() { + g(1); } -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR:[0-9]+]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call void @_Z1fbb({{.*}}) #[[NOMERGEATTR]] -// CHECK: call void @"_ZZ3fooiENK3$_0clEv"(%class.anon* {{[^,]*}} %ref.tmp) #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call zeroext i1 @_Z3barv() #[[NOMERGEATTR]] -// CHECK: call void asm {{.*}} #[[NOMERGEATTR2:[0-9]+]] -// CHECK: call zeroext i1 @_Z3barv() -// CHECK: attributes #[[NOMERGEATTR]] = { nomerge } -// CHECK: attributes #[[NOMERGEATTR2]] = { nomerge nounwind } + +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call void @_Z1fbb({{.*}}){{$}} +// CHECK: call void @"_ZZ3fooiP1AP1BENK3$_0clEv"{{.*}} #[[ATTR0:[0-9]+]] +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: call void asm sideeffect "nop"{{.*}} #[[ATTR1:[0-9]+]] +// CHECK: call zeroext i1 @_Z3barv(){{$}} +// CHECK: %[[AG:.*]] = load void (%class.A*)*, void (%class.A*)** +// CHECK-NEXT: call void %[[AG]](%class.A* nonnull dereferenceable +// CHECK: %[[BG:.*]] = load void (%class.B*)*, void (%class.B*)** +// CHECK-NEXT: call void %[[BG]](%class.B* nonnull dereferenceable + + +// CHECK-DAG: declare zeroext i1 @_Z3barv() #[[ATTR2:[0-9]+]] +// CHECK-DAG: declare void @_Z1fbb(i1 zeroext, i1 zeroext) #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1AC1Ev{{.*}} #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1A1fEv{{.*}} #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1A1gEv{{.*}} #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1A2f1Ev{{.*}} #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1AC2Ev{{.*}} #[[ATTR2]] +// CHECK-DAG: declare void @_ZN1AD1Ev{{.*}} #[[ATTR3:[0-9]+]] +// CHECK-DAG: declare void @_ZN1AD2Ev{{.*}} #[[ATTR3]] +// CHECK-DAG: define i32 @_Z1gi(i32 %i) #[[ATTR4:[0-9]+]] { + +// CHECK-DAG: attributes #[[ATTR0]] = {{{.*}}nomerge{{.*}}} +// CHECK-DAG: attributes #[[ATTR1]] = {{{.*}}nomerge{{.*}}} +// CHECK-DAG: attributes #[[ATTR2]] = {{{.*}}nomerge{{.*}}} +// CHECK-DAG: attributes #[[ATTR3]] = {{{.*}}nomerge{{.*}}} +// CHECK-DAG: attributes #[[ATTR4]] = {{{.*}}nomerge{{.*}}} diff --git a/clang/test/Misc/pragma-attribute-supported-attributes-list.test b/clang/test/Misc/pragma-attribute-supported-attributes-list.test --- a/clang/test/Misc/pragma-attribute-supported-attributes-list.test +++ b/clang/test/Misc/pragma-attribute-supported-attributes-list.test @@ -92,6 +92,7 @@ // CHECK-NEXT: NoEscape (SubjectMatchRule_variable_is_parameter) // CHECK-NEXT: NoInline (SubjectMatchRule_function) // CHECK-NEXT: NoInstrumentFunction (SubjectMatchRule_function) +// CHECK-NEXT: NoMerge (SubjectMatchRule_function) // CHECK-NEXT: NoMicroMips (SubjectMatchRule_function) // CHECK-NEXT: NoMips16 (SubjectMatchRule_function) // CHECK-NEXT: NoSanitize (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_variable_is_global) diff --git a/clang/test/Sema/attr-nomerge.cpp b/clang/test/Sema/attr-nomerge.cpp --- a/clang/test/Sema/attr-nomerge.cpp +++ b/clang/test/Sema/attr-nomerge.cpp @@ -8,10 +8,10 @@ int x; [[clang::nomerge]] x = 10; // expected-warning {{nomerge attribute is ignored because there exists no call expression inside the statement}} - [[clang::nomerge]] label: bar(); // expected-error {{'nomerge' attribute cannot be applied to a declaration}} + [[clang::nomerge]] label: bar(); // expected-error {{'nomerge' attribute only applies to functions and statements}} } -int f(); +[[clang::nomerge]] int f(); -[[clang::nomerge]] static int i = f(); // expected-error {{'nomerge' attribute cannot be applied to a declaration}} +[[clang::nomerge]] static int i = f(); // expected-error {{'nomerge' attribute only applies to functions and statements}} diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp --- a/clang/utils/TableGen/ClangAttrEmitter.cpp +++ b/clang/utils/TableGen/ClangAttrEmitter.cpp @@ -2693,6 +2693,7 @@ { "ATTR", "Attr" }, { "TYPE_ATTR", "TypeAttr" }, { "STMT_ATTR", "StmtAttr" }, + { "DECL_OR_STMT_ATTR", "DeclOrStmtAttr" }, { "INHERITABLE_ATTR", "InheritableAttr" }, { "DECL_OR_TYPE_ATTR", "DeclOrTypeAttr" }, { "INHERITABLE_PARAM_ATTR", "InheritableParamAttr" }, @@ -3779,7 +3780,8 @@ OS << (Attr.isSubClassOf("TypeAttr") || Attr.isSubClassOf("DeclOrTypeAttr")) << ";\n"; OS << " IsStmt = "; - OS << Attr.isSubClassOf("StmtAttr") << ";\n"; + OS << (Attr.isSubClassOf("StmtAttr") || Attr.isSubClassOf("DeclOrStmtAttr")) + << ";\n"; OS << " IsKnownToGCC = "; OS << IsKnownToGCC(Attr) << ";\n"; OS << " IsSupportedByPragmaAttribute = "; diff --git a/llvm/include/llvm/IR/Attributes.td b/llvm/include/llvm/IR/Attributes.td --- a/llvm/include/llvm/IR/Attributes.td +++ b/llvm/include/llvm/IR/Attributes.td @@ -124,7 +124,7 @@ /// Function is called early and/or often, so lazy binding isn't worthwhile. def NonLazyBind : EnumAttr<"nonlazybind">; -/// Disable merging for call sites +/// Disable merging for specified functions or call sites. def NoMerge : EnumAttr<"nomerge">; /// Pointer is known to be not null.