diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst --- a/clang/docs/ClangCommandLineReference.rst +++ b/clang/docs/ClangCommandLineReference.rst @@ -2114,6 +2114,10 @@ Emit full debug info for all types used by the program +.. option:: -feliminate-unused-debug-types, -fno-eliminate-unused-debug-types + +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 declared + 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 @@ -2314,6 +2314,12 @@ Generate complete debug info. +.. option:: -feliminate-unused-debug-types + + By default, Clang does not emit type information for types that are declared + 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.def b/clang/include/clang/Basic/CodeGenOptions.def --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -288,6 +288,8 @@ ///< template parameter descriptions in ///< forward declarations (versus just ///< including them in the name). +CODEGENOPT(DebugUnusedTypes, 1, 0) /// < Whether to emit typedefs that may be + /// < unused. CODEGENOPT(EmitLLVMUseLists, 1, 0) ///< Control whether to serialize use-lists. 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 @@ -3343,7 +3343,10 @@ 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 eliminate_unused_debug_types : + BooleanFFlag<"eliminate-unused-debug-types">, Group, + Flags<[CC1Option]>, + HelpText<"Emit debug info for types, even if they may be unreferenced">; 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/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -5370,16 +5370,21 @@ Spec->hasDefinition()) DI->completeTemplateDefinition(*Spec); } LLVM_FALLTHROUGH; - case Decl::CXXRecord: - if (CGDebugInfo *DI = getModuleDebugInfo()) - if (auto *ES = D->getASTContext().getExternalSource()) + case Decl::CXXRecord: { + CXXRecordDecl *CRD = cast(D); + if (CGDebugInfo *DI = getModuleDebugInfo()) { + if (getCodeGenOpts().DebugUnusedTypes && CRD->hasDefinition()) + DI->completeUnusedClass(*CRD); + else 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: @@ -5565,6 +5570,31 @@ EmitOMPRequiresDecl(cast(D)); break; + case Decl::Typedef: + case Decl::TypeAlias: // using foo = bar; [C++11] + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().DebugUnusedTypes) { + QualType QT = getContext().getTypedefType(cast(D)); + DI->EmitExplicitCastType(QT); + } + break; + + case Decl::Record: + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().DebugUnusedTypes) { + QualType QT = getContext().getRecordType(cast(D)); + DI->EmitExplicitCastType(QT); + } + break; + + case Decl::Enum: + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().DebugUnusedTypes) { + QualType QT = getContext().getEnumType(cast(D)); + DI->EmitExplicitCastType(QT); + } + 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 @@ -5145,6 +5145,8 @@ // Forward -f (flag) options which we can pass directly. Args.AddLastArg(CmdArgs, options::OPT_femit_all_decls); + Args.AddLastArg(CmdArgs, options::OPT_feliminate_unused_debug_types); + Args.AddLastArg(CmdArgs, options::OPT_fno_eliminate_unused_debug_types); Args.AddLastArg(CmdArgs, options::OPT_fheinous_gnu_extensions); Args.AddLastArg(CmdArgs, options::OPT_fdigraphs, options::OPT_fno_digraphs); Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names); 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 @@ -765,6 +765,7 @@ Opts.DebugTypeExtRefs = Args.hasArg(OPT_dwarf_ext_refs); Opts.DebugExplicitImport = Args.hasArg(OPT_dwarf_explicit_import); Opts.DebugFwdTemplateParams = Args.hasArg(OPT_debug_forward_template_params); + Opts.DebugUnusedTypes = Args.hasArg(OPT_fno_eliminate_unused_debug_types); Opts.EmbedSource = Args.hasArg(OPT_gembed_source); Opts.ForceDwarfFrameSection = Args.hasArg(OPT_fforce_dwarf_frame); 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 +1,30 @@ +// 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 {}; + +// Check that debug info is emitted for the typedef, struct, enum, and union +// when -fno-eliminate-unused-debug-types and -g are set. + +// CHECK: !3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "bar", file: !4, line: 7, baseType: !5, size: 32, elements: !6) +// CHECK: !5 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned) +// CHECK: !7 = !DIEnumerator(name: "BAR", value: 0, isUnsigned: true) +// CHECK: !9 = !DIDerivedType(tag: DW_TAG_typedef, name: "my_int", file: !4, line: 5, baseType: !10) +// CHECK: !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +// CHECK: !11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "foo", file: !4, line: 6, elements: !12) +// CHECK: !13 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "baz", file: !4, line: 8, elements: !12) + +// 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. + +// NODBG-NOT: !3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "bar", file: !4, line: 7, baseType: !5, size: 32, elements: !6) +// NODBG-NOT: !5 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned) +// NODBG-NOT: !7 = !DIEnumerator(name: "BAR", value: 0, isUnsigned: true) +// NODBG-NOT: !9 = !DIDerivedType(tag: DW_TAG_typedef, name: "my_int", file: !4, line: 5, baseType: !10) +// NODBG-NOT: !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +// NODBG-NOT: !11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "foo", file: !4, line: 6, elements: !12) +// NODBG-NOT: !13 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "baz", file: !4, line: 8, elements: !12) 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 +1,19 @@ +// 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 }; + +// CHECK: !3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "baz", file: !4, line: 7, baseType: !5, size: 32, flags: DIFlagEnumClass, elements: !6, identifier: "_ZTS3baz") +// CHECK: !5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +// CHECK: !7 = !DIEnumerator(name: "BAZ", value: 0) +// CHECK: !9 = !DIDerivedType(tag: DW_TAG_typedef, name: "foo", file: !4, line: 5, baseType: !5) +// CHECK: !10 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "bar", file: !4, line: 6, size: 8, flags: DIFlagTypePassByValue, elements: !11, identifier: "_ZTS3bar") + +// NODBG-NOT: !3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "baz", file: !4, line: 7, baseType: !5, size: 32, flags: DIFlagEnumClass, elements: !6, identifier: "_ZTS3baz") +// NODBG-NOT: !5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +// NODBG-NOT: !7 = !DIEnumerator(name: "BAZ", value: 0) +// NODBG-NOT: !9 = !DIDerivedType(tag: DW_TAG_typedef, name: "foo", file: !4, line: 5, baseType: !5) +// NODBG-NOT: !10 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "bar", file: !4, line: 6, size: 8, flags: DIFlagTypePassByValue, elements: !11, identifier: "_ZTS3bar")