diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst --- a/clang/docs/ClangCommandLineReference.rst +++ b/clang/docs/ClangCommandLineReference.rst @@ -2154,6 +2154,10 @@ Emit full debug info for all types used by the program +.. option:: -feliminate-unused-debug-types, -fno-eliminate-unused-debug-types + +Suppress (or emit) debug info for types that are unused but defined by the program. + .. option:: -fstrict-aliasing, -fno-strict-aliasing .. option:: -fstrict-enums, -fno-strict-enums diff --git a/clang/docs/CommandGuide/clang.rst b/clang/docs/CommandGuide/clang.rst --- a/clang/docs/CommandGuide/clang.rst +++ b/clang/docs/CommandGuide/clang.rst @@ -433,6 +433,12 @@ never emit type information for types that are not referenced at all by the program. +.. option:: -feliminate-unused-debug-types + + By default, Clang does not emit type information for types that are defined + but not used in a program. To retain the debug info for these unused types, + the negation **-fno-eliminate-unused-debug-types** can be used. + .. option:: -fexceptions Enable generation of unwind information. This allows exceptions to be thrown diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2352,6 +2352,12 @@ Generate complete debug info. +.. option:: -feliminate-unused-debug-types + + By default, Clang does not emit type information for types that are defined + but not used in a program. To retain the debug info for these unused types, + the negation **-fno-eliminate-unused-debug-types** can be used. + Controlling Macro Debug Info Generation ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/include/clang/Basic/CodeGenOptions.h b/clang/include/clang/Basic/CodeGenOptions.h --- a/clang/include/clang/Basic/CodeGenOptions.h +++ b/clang/include/clang/Basic/CodeGenOptions.h @@ -388,6 +388,11 @@ bool hasReducedDebugInfo() const { return getDebugInfo() >= codegenoptions::DebugInfoConstructor; } + + /// Check if maybe unused type info should be emitted. + bool hasMaybeUnusedDebugInfo() const { + return getDebugInfo() >= codegenoptions::UnusedTypeInfo; + } }; } // end namespace clang diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -288,7 +288,6 @@ ///< template parameter descriptions in ///< forward declarations (versus just ///< including them in the name). - CODEGENOPT(EmitLLVMUseLists, 1, 0) ///< Control whether to serialize use-lists. CODEGENOPT(WholeProgramVTables, 1, 0) ///< Whether to apply whole-program @@ -313,7 +312,7 @@ VALUE_CODEGENOPT(SSPBufferSize, 32, 0) /// The kind of generated debug info. -ENUM_CODEGENOPT(DebugInfo, codegenoptions::DebugInfoKind, 3, codegenoptions::NoDebugInfo) +ENUM_CODEGENOPT(DebugInfo, codegenoptions::DebugInfoKind, 4, codegenoptions::NoDebugInfo) /// Whether to generate macro debug info. CODEGENOPT(MacroDebugInfo, 1, 0) diff --git a/clang/include/clang/Basic/DebugInfoOptions.h b/clang/include/clang/Basic/DebugInfoOptions.h --- a/clang/include/clang/Basic/DebugInfoOptions.h +++ b/clang/include/clang/Basic/DebugInfoOptions.h @@ -46,7 +46,11 @@ LimitedDebugInfo, /// Generate complete debug info. - FullDebugInfo + FullDebugInfo, + + /// Generate debug info for types that may be unused in the source + /// (-fno-eliminate-unused-debug-types). + UnusedTypeInfo, }; } // end namespace codegenoptions diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -931,6 +931,8 @@ Flags<[CC1Option]>, HelpText<"Do not elide types when printing diagnostics">; def feliminate_unused_debug_symbols : Flag<["-"], "feliminate-unused-debug-symbols">, Group; +defm eliminate_unused_debug_types : OptOutFFlag<"eliminate-unused-debug-types", + "Do not emit ", "Emit ", " debug info for defined but unused types">; def femit_all_decls : Flag<["-"], "femit-all-decls">, Group, Flags<[CC1Option]>, HelpText<"Emit all declarations, even if unused">; def femulated_tls : Flag<["-"], "femulated-tls">, Group, Flags<[CC1Option]>, @@ -3288,7 +3290,6 @@ defm fcheck_new : BooleanFFlag<"check-new">, Group; defm caller_saves : BooleanFFlag<"caller-saves">, Group; defm reorder_blocks : BooleanFFlag<"reorder-blocks">, Group; -defm eliminate_unused_debug_types : BooleanFFlag<"eliminate-unused-debug-types">, Group; defm branch_count_reg : BooleanFFlag<"branch-count-reg">, Group; defm default_inline : BooleanFFlag<"default-inline">, Group; defm fat_lto_objects : BooleanFFlag<"fat-lto-objects">, Group; diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -490,6 +490,9 @@ /// Emit the type explicitly casted to. void EmitExplicitCastType(QualType Ty); + /// Emit the type even if it might not be used. + void EmitAndRetainType(QualType Ty); + /// Emit C++ using declaration. void EmitUsingDecl(const UsingDecl &UD); diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -606,6 +606,7 @@ case codegenoptions::DebugInfoConstructor: case codegenoptions::LimitedDebugInfo: case codegenoptions::FullDebugInfo: + case codegenoptions::UnusedTypeInfo: EmissionKind = llvm::DICompileUnit::FullDebug; break; } @@ -4954,13 +4955,17 @@ DBuilder.finalize(); } +// Don't ignore in case of explicit cast where it is referenced indirectly. void CGDebugInfo::EmitExplicitCastType(QualType Ty) { - if (!CGM.getCodeGenOpts().hasReducedDebugInfo()) - return; + if (CGM.getCodeGenOpts().hasReducedDebugInfo()) + if (auto *DieTy = getOrCreateType(Ty, TheCU->getFile())) + DBuilder.retainType(DieTy); +} - if (auto *DieTy = getOrCreateType(Ty, TheCU->getFile())) - // Don't ignore in case of explicit cast where it is referenced indirectly. - DBuilder.retainType(DieTy); +void CGDebugInfo::EmitAndRetainType(QualType Ty) { + if (CGM.getCodeGenOpts().hasMaybeUnusedDebugInfo()) + if (auto *DieTy = getOrCreateType(Ty, TheCU->getFile())) + DBuilder.retainType(DieTy); } llvm::DebugLoc CGDebugInfo::SourceLocToDebugLoc(SourceLocation Loc) { diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp --- a/clang/lib/CodeGen/CGDecl.cpp +++ b/clang/lib/CodeGen/CGDecl.cpp @@ -100,11 +100,19 @@ case Decl::ObjCTypeParam: case Decl::Binding: llvm_unreachable("Declaration should not be in declstmts!"); - case Decl::Function: // void X(); case Decl::Record: // struct/union/class X; + case Decl::CXXRecord: // struct/union/class X; [C++] + if (CGDebugInfo *DI = getDebugInfo()) + if (cast(D).getDefinition()) + DI->EmitAndRetainType(getContext().getRecordType(cast(&D))); + return; case Decl::Enum: // enum X; + if (CGDebugInfo *DI = getDebugInfo()) + if (cast(D).getDefinition()) + DI->EmitAndRetainType(getContext().getEnumType(cast(&D))); + return; + case Decl::Function: // void X(); case Decl::EnumConstant: // enum ? { X = ? } - case Decl::CXXRecord: // struct/union/class X; [C++] case Decl::StaticAssert: // static_assert(X, ""); [C++0x] case Decl::Label: // __label__ x; case Decl::Import: @@ -157,12 +165,11 @@ case Decl::Typedef: // typedef int X; case Decl::TypeAlias: { // using X = int; [C++0x] - const TypedefNameDecl &TD = cast(D); - QualType Ty = TD.getUnderlyingType(); - + QualType Ty = cast(D).getUnderlyingType(); + if (CGDebugInfo *DI = getDebugInfo()) + DI->EmitAndRetainType(Ty); if (Ty->isVariablyModifiedType()) EmitVariablyModifiedType(Ty); - return; } } 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 @@ -5373,16 +5373,21 @@ Spec->hasDefinition()) DI->completeTemplateDefinition(*Spec); } LLVM_FALLTHROUGH; - case Decl::CXXRecord: - if (CGDebugInfo *DI = getModuleDebugInfo()) + case Decl::CXXRecord: { + CXXRecordDecl *CRD = cast(D); + if (CGDebugInfo *DI = getModuleDebugInfo()) { + if (CRD->hasDefinition()) + DI->EmitAndRetainType(getContext().getRecordType(cast(D))); if (auto *ES = D->getASTContext().getExternalSource()) if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never) - DI->completeUnusedClass(cast(*D)); + DI->completeUnusedClass(*CRD); + } // Emit any static data members, they may be definitions. - for (auto *I : cast(D)->decls()) + for (auto *I : CRD->decls()) if (isa(I) || isa(I)) EmitTopLevelDecl(I); break; + } // No code generation needed. case Decl::UsingShadow: case Decl::ClassTemplate: @@ -5568,6 +5573,25 @@ EmitOMPRequiresDecl(cast(D)); break; + case Decl::Typedef: + case Decl::TypeAlias: // using foo = bar; [C++11] + if (CGDebugInfo *DI = getModuleDebugInfo()) + DI->EmitAndRetainType( + getContext().getTypedefType(cast(D))); + break; + + case Decl::Record: + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (cast(D)->getDefinition()) + DI->EmitAndRetainType(getContext().getRecordType(cast(D))); + break; + + case Decl::Enum: + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (cast(D)->getDefinition()) + DI->EmitAndRetainType(getContext().getEnumType(cast(D))); + break; + default: // Make sure we handled everything we should, every other kind is a // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -976,6 +976,9 @@ case codegenoptions::FullDebugInfo: CmdArgs.push_back("-debug-info-kind=standalone"); break; + case codegenoptions::UnusedTypeInfo: + CmdArgs.push_back("-debug-info-kind=unused-types"); + break; default: break; } @@ -3821,6 +3824,11 @@ DebugInfoKind <= codegenoptions::DebugDirectivesOnly) DebugInfoKind = codegenoptions::DebugLineTablesOnly; + if (EmitDwarf && + Args.hasFlag(options::OPT_fno_eliminate_unused_debug_types, + options::OPT_feliminate_unused_debug_types, false)) + DebugInfoKind = codegenoptions::UnusedTypeInfo; + RenderDebugEnablingArgs(Args, CmdArgs, DebugInfoKind, DWARFVersion, DebuggerTuning); diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -767,6 +767,7 @@ .Case("constructor", codegenoptions::DebugInfoConstructor) .Case("limited", codegenoptions::LimitedDebugInfo) .Case("standalone", codegenoptions::FullDebugInfo) + .Case("unused-types", codegenoptions::UnusedTypeInfo) .Default(~0U); if (Val == ~0U) Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) diff --git a/clang/test/CodeGen/debug-info-unused-types.c b/clang/test/CodeGen/debug-info-unused-types.c new file mode 100644 --- /dev/null +++ b/clang/test/CodeGen/debug-info-unused-types.c @@ -0,0 +1,55 @@ +// RUN: %clang -fno-eliminate-unused-debug-types -g -emit-llvm -S -o - %s | FileCheck %s +// RUN: %clang -feliminate-unused-debug-types -g -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +// RUN: %clang -g -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +// RUN: %clang -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +typedef int my_int; +struct foo {}; +enum bar { BAR }; +union baz {}; + +void quux(void) { + typedef int x; + struct y {}; + enum z { Z }; + union w {}; +} + +// Check that debug info is emitted for the typedef, struct, enum, and union +// when -fno-eliminate-unused-debug-types and -g are set. + +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, name: "bar" +// CHECK: !DIEnumerator(name: "BAR" +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, name: "z" +// CHECK: !DIEnumerator(name: "Z" +// CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "my_int" +// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "foo" +// CHECK: !DICompositeType(tag: DW_TAG_union_type, name: "baz" +// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "y" +// CHECK: !DICompositeType(tag: DW_TAG_union_type, name: "w" + +// Check that debug info is not emitted for the typedef, struct, enum, and +// union when -fno-eliminate-unused-debug-types and -g are not set. These are +// the same checks as above with `NODBG-NOT` rather than `CHECK`. + +// NODBG-NOT: !DICompositeType(tag: DW_TAG_enumeration_type, name: "bar" +// NODBG-NOT: !DIEnumerator(name: "BAR" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_enumeration_type, name: "z" +// NODBG-NOT: !DIEnumerator(name: "Z" +// NODBG-NOT: !DIDerivedType(tag: DW_TAG_typedef, name: "my_int" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_structure_type, name: "foo" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_union_type, name: "baz" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_structure_type, name: "y" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_union_type, name: "w" + +// Check that debug info is not emitted for declarations. Obnoxious +// indentifiers are to avoid collisions with the SHA emittied as debug info. +struct unused_struct; +enum unused_enum; +union unused_union; +void b0(void) { + struct unused_local_struct; + enum unused_local_enum; + union unused_local_union; +} + +// NODBG-NOT: name: "unused_ diff --git a/clang/test/CodeGen/debug-info-unused-types.cpp b/clang/test/CodeGen/debug-info-unused-types.cpp new file mode 100644 --- /dev/null +++ b/clang/test/CodeGen/debug-info-unused-types.cpp @@ -0,0 +1,34 @@ +// RUN: %clang++ -fno-eliminate-unused-debug-types -g -emit-llvm -S -o - %s | FileCheck %s +// RUN: %clang++ -feliminate-unused-debug-types -g -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +// RUN: %clang++ -g -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +// RUN: %clang++ -emit-llvm -S -o - %s | FileCheck --check-prefix=NODBG %s +using foo = int; +class bar {}; +enum class baz { BAZ }; + +void quux() { + using x = int; + class y {}; + enum class z { Z }; +} + +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, name: "baz" +// CHECK: !DIEnumerator(name: "BAZ" +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, name: "z" +// CHECK: !DIEnumerator(name: "Z" +// CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "foo" +// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "bar" +// CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "y" + +// NODBG-NOT: !DICompositeType(tag: DW_TAG_enumeration_type, name: "baz" +// NODBG-NOT: !DIEnumerator(name: "BAZ" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_enumeration_type, name: "z" +// NODBG-NOT: !DIEnumerator(name: "Z" +// NODBG-NOT: !DIDerivedType(tag: DW_TAG_typedef, name: "foo" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_class_type, name: "bar" +// NODBG-NOT: !DICompositeType(tag: DW_TAG_class_type, name: "y" + +class unused_class; +enum class unused_enum_class; + +// NODBG-NOT: name: "unused_ diff --git a/clang/test/Driver/debug-options.c b/clang/test/Driver/debug-options.c --- a/clang/test/Driver/debug-options.c +++ b/clang/test/Driver/debug-options.c @@ -361,3 +361,12 @@ // GEMBED_2: error: invalid argument '-gembed-source' only allowed with '-gdwarf-5' // NOGEMBED_5-NOT: "-gembed-source" // NOGEMBED_2-NOT: error: invalid argument '-gembed-source' only allowed with '-gdwarf-5' +// +// RUN: %clang -### -g -fno-eliminate-unused-debug-types -c %s 2>&1 \ +// RUN: | FileCheck -check-prefix=DEBUG_UNUSED_TYPES %s +// DEBUG_UNUSED_TYPES: "-debug-info-kind=unused-types" +// DEBUG_UNUSED_TYPES-NOT: "-debug-info-kind=limited" +// RUN: %clang -### -g -feliminate-unused-debug-types -c %s 2>&1 \ +// RUN: | FileCheck -check-prefix=NO_DEBUG_UNUSED_TYPES %s +// NO_DEBUG_UNUSED_TYPES: "-debug-info-kind=constructor" +// NO_DEBUG_UNUSED_TYPES-NOT: "-debug-info-kind=unused-types"