From c44757105021d1429f9430d5ff0da45b02b9f741 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Tue, 7 Jan 2014 01:19:08 +0000 Subject: [PATCH] Implement a new -fstandalone-debug option. rdar://problem/15685848 It controls everything that -flimit-debug-info used to, plus the vtable type optimization. The old -fno-limit-debug-info option is now an alias to -fstandalone-debug and vice versa. Standalone is the default on Darwin until dtrace is updated to work with non-standalone debug info (rdar://problem/15758808). Note: I kept the LimitedDebugInfo name in CodeGenOptions::DebugInfoKind because NoStandaloneDebugInfo sounded even more confusing. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198655 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/tools/clang.pod | 19 +++++++++++----- include/clang/Driver/Options.td | 10 +++++---- include/clang/Frontend/CodeGenOptions.h | 20 ++++++++++++----- lib/CodeGen/CGDebugInfo.cpp | 12 +++++----- lib/Driver/Tools.cpp | 4 ++-- lib/Frontend/CompilerInvocation.cpp | 22 ++++++++++++------- test/CodeGenCXX/debug-info-class-limited.cpp | 2 +- test/CodeGenCXX/debug-info-class-nolimit.cpp | 4 +++- test/CodeGenCXX/debug-info-dup-fwd-decl.cpp | 2 +- test/CodeGenCXX/debug-info-method2.cpp | 2 +- test/CodeGenCXX/debug-info-namespace.cpp | 6 ++--- test/CodeGenCXX/debug-info-pubtypes.cpp | 2 +- test/CodeGenCXX/debug-info-template-limit.cpp | 2 +- .../CodeGenCXX/debug-info-template-member.cpp | 2 +- test/CodeGenCXX/debug-info-vtable-optzn.cpp | 21 ++++++++++++++++++ 15 files changed, 88 insertions(+), 42 deletions(-) create mode 100644 test/CodeGenCXX/debug-info-vtable-optzn.cpp diff --git a/docs/tools/clang.pod b/docs/tools/clang.pod index c051005c90..1f3a3ec0ac 100644 --- a/docs/tools/clang.pod +++ b/docs/tools/clang.pod @@ -312,12 +312,19 @@ Currently equivalent to B<-O3> Generate debug information. Note that Clang debug information works best at B<-O0>. -=item B<-flimit-debug-info> B<-fno-limit-debug-info> - -By default Clang does not emit type definitions for types that are not -needed by the module and could be replaced with a forward -declaration. By specifying B<-fno-limit-debug-info> this optimization -can be turned off. Note that Clang will never emit type information +=item B<-fstandalone-debug> B<-fno-standalone-debug> + +Clang supports a number of optimizations to reduce the size of debug +information in the binary. They work based on the assumption that the +debug type information can be spread out over multiple compilation +units. For instance, Clang will not emit type definitions for types +that are not needed by a module and could be replaced with a forward +declaration. Further, Clang will only emit type info for a dynamic +C++ class in the module that contains the vtable for the class. + +The B<-fstandalone-debug> option turns off these optimizations. This +is useful when working with 3rd-party libraries that don't come with +debug information. Note that Clang will never emit type information for types that are not referenced at all by the program. =item B<-fexceptions> diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td index b0f0588b34..e1930a2e95 100644 --- a/include/clang/Driver/Options.td +++ b/include/clang/Driver/Options.td @@ -559,8 +559,6 @@ def finstrument_functions : Flag<["-"], "finstrument-functions">, Group def fkeep_inline_functions : Flag<["-"], "fkeep-inline-functions">, Group; def flat__namespace : Flag<["-"], "flat_namespace">; def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group; -def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Group, Flags<[CC1Option]>, - HelpText<"Limit debug information produced to reduce size of debug binary">; def flimited_precision_EQ : Joined<["-"], "flimited-precision=">, Group; def flto : Flag<["-"], "flto">, Group; def fno_lto : Flag<["-"], "fno-lto">, Group; @@ -654,8 +652,6 @@ def fno_inline : Flag<["-"], "fno-inline">, Group, Flags<[CC1Opti def fno_keep_inline_functions : Flag<["-"], "fno-keep-inline-functions">, Group; def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group, HelpText<"Disallow implicit conversions between vectors with a different number of elements or different element types">, Flags<[CC1Option]>; -def fno_limit_debug_info : Flag<["-"], "fno-limit-debug-info">, Group, Flags<[CC1Option]>, - HelpText<"Do not limit debug information produced to reduce size of debug binary">; def fno_merge_all_constants : Flag<["-"], "fno-merge-all-constants">, Group, Flags<[CC1Option]>, HelpText<"Disallow merging of constants">; def fno_modules : Flag <["-"], "fno-modules">, Group, @@ -783,6 +779,12 @@ def fno_signed_char : Flag<["-"], "fno-signed-char">, Flags<[CC1Option]>, def fsplit_stack : Flag<["-"], "fsplit-stack">, Group; def fstack_protector_all : Flag<["-"], "fstack-protector-all">, Group; def fstack_protector : Flag<["-"], "fstack-protector">, Group; +def fstandalone_debug : Flag<["-"], "fstandalone-debug">, Group, Flags<[CC1Option]>, + HelpText<"Emit full debug info for all types used by the program">; +def fno_standalone_debug : Flag<["-"], "fno-standalone-debug">, Group, Flags<[CC1Option]>, + HelpText<"Limit debug information produced to reduce size of debug binary">; +def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Alias; +def fno_limit_debug_info : Flag<["-"], "fno-limit-debug-info">, Alias; def fstrict_aliasing : Flag<["-"], "fstrict-aliasing">, Group; def fstrict_enums : Flag<["-"], "fstrict-enums">, Group, Flags<[CC1Option]>, HelpText<"Enable optimizations based on the strict definition of an enum's " diff --git a/include/clang/Frontend/CodeGenOptions.h b/include/clang/Frontend/CodeGenOptions.h index 6c5d399f1e..da97e5c956 100644 --- a/include/clang/Frontend/CodeGenOptions.h +++ b/include/clang/Frontend/CodeGenOptions.h @@ -50,12 +50,20 @@ public: }; enum DebugInfoKind { - NoDebugInfo, // Don't generate debug info. - DebugLineTablesOnly, // Emit only debug info necessary for generating - // line number tables (-gline-tables-only). - LimitedDebugInfo, // Limit generated debug info to reduce size - // (-flimit-debug-info). - FullDebugInfo // Generate complete debug info. + NoDebugInfo, /// Don't generate debug info. + + DebugLineTablesOnly, /// Emit only debug info necessary for generating + /// line number tables (-gline-tables-only). + + LimitedDebugInfo, /// Limit generated debug info to reduce size + /// (-fno-standalone-debug). This emits + /// forward decls for types that could be + /// replaced with forward decls in the source + /// code. For dynamic C++ classes type info + /// is only emitted int the module that + /// contains the classe's vtable. + + FullDebugInfo /// Generate complete debug info. }; enum TLSModel { diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp index c12e2949bf..1897627f93 100644 --- a/lib/CodeGen/CGDebugInfo.cpp +++ b/lib/CodeGen/CGDebugInfo.cpp @@ -1464,13 +1464,13 @@ llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty) { // declaration. The completeType, completeRequiredType, and completeClassData // callbacks will handle promoting the declaration to a definition. if (T || + // Under -flimit-debug-info: (DebugKind <= CodeGenOptions::LimitedDebugInfo && - // Under -flimit-debug-info, emit only a declaration unless the type is - // required to be complete. - !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) || - // If the class is dynamic, only emit a declaration. A definition will be - // emitted whenever the vtable is emitted. - (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass())) { + // Emit only a forward declaration unless the type is required. + ((!RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) || + // If the class is dynamic, only emit a declaration. A definition will be + // emitted whenever the vtable is emitted. + (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass())))) { llvm::DIDescriptor FDContext = getContextDescriptor(cast(RD->getDeclContext())); if (!T) diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp index dd2d507a4d..1ee5e563a2 100644 --- a/lib/Driver/Tools.cpp +++ b/lib/Driver/Tools.cpp @@ -2945,8 +2945,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, // Forward -f (flag) options which we can pass directly. Args.AddLastArg(CmdArgs, options::OPT_femit_all_decls); Args.AddLastArg(CmdArgs, options::OPT_fheinous_gnu_extensions); - Args.AddLastArg(CmdArgs, options::OPT_flimit_debug_info); - Args.AddLastArg(CmdArgs, options::OPT_fno_limit_debug_info); + Args.AddLastArg(CmdArgs, options::OPT_fstandalone_debug); + Args.AddLastArg(CmdArgs, options::OPT_fno_standalone_debug); Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names); // AltiVec language extensions aren't relevant for assembling. if (!isa(JA) || diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp index 3065e1769b..dc4aad74b9 100644 --- a/lib/Frontend/CompilerInvocation.cpp +++ b/lib/Frontend/CompilerInvocation.cpp @@ -296,7 +296,8 @@ static void ParseCommentArgs(CommentOptions &Opts, ArgList &Args) { } static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, - DiagnosticsEngine &Diags) { + DiagnosticsEngine &Diags, + const TargetOptions &TargetOpts) { using namespace options; bool Success = true; @@ -323,10 +324,16 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, Opts.setDebugInfo(CodeGenOptions::DebugLineTablesOnly); } else if (Args.hasArg(OPT_g_Flag) || Args.hasArg(OPT_gdwarf_2) || Args.hasArg(OPT_gdwarf_3) || Args.hasArg(OPT_gdwarf_4)) { - if (Args.hasFlag(OPT_flimit_debug_info, OPT_fno_limit_debug_info, true)) - Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo); - else + bool Default = false; + // Until dtrace (via CTF) can deal with distributed debug info, + // Darwin defaults to standalone/full debug info. + if (llvm::Triple(TargetOpts.Triple).isOSDarwin()) + Default = true; + + if (Args.hasFlag(OPT_fstandalone_debug, OPT_fno_standalone_debug, Default)) Opts.setDebugInfo(CodeGenOptions::FullDebugInfo); + else + Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo); } Opts.DebugColumnInfo = Args.hasArg(OPT_dwarf_column_info); Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file); @@ -1662,8 +1669,9 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res, ParseFileSystemArgs(Res.getFileSystemOpts(), *Args); // FIXME: We shouldn't have to pass the DashX option around here InputKind DashX = ParseFrontendArgs(Res.getFrontendOpts(), *Args, Diags); - Success = ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags) - && Success; + ParseTargetArgs(Res.getTargetOpts(), *Args); + Success = ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags, + Res.getTargetOpts()) && Success; ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), *Args); if (DashX != IK_AST && DashX != IK_LLVM_IR) { ParseLangArgs(*Res.getLangOpts(), *Args, DashX, Diags); @@ -1678,8 +1686,6 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res, ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args, FileMgr, Diags); ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args, Res.getFrontendOpts().ProgramAction); - ParseTargetArgs(Res.getTargetOpts(), *Args); - return Success; } diff --git a/test/CodeGenCXX/debug-info-class-limited.cpp b/test/CodeGenCXX/debug-info-class-limited.cpp index a4b9f46ec6..9bf295e9b9 100644 --- a/test/CodeGenCXX/debug-info-class-limited.cpp +++ b/test/CodeGenCXX/debug-info-class-limited.cpp @@ -1,4 +1,4 @@ -// RUN: %clang -emit-llvm -g -S %s -o - | FileCheck %s +// RUN: %clang -emit-llvm -fno-standalone-debug -g -S %s -o - | FileCheck %s namespace PR16214_1 { // CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [def] diff --git a/test/CodeGenCXX/debug-info-class-nolimit.cpp b/test/CodeGenCXX/debug-info-class-nolimit.cpp index ce72bd347c..7a6ee4d441 100644 --- a/test/CodeGenCXX/debug-info-class-nolimit.cpp +++ b/test/CodeGenCXX/debug-info-class-nolimit.cpp @@ -1,4 +1,6 @@ -// RUN: %clang_cc1 -triple x86_64-unk-unk -fno-limit-debug-info -o - -emit-llvm -g %s | FileCheck %s +// RUN: %clang_cc1 -triple x86_64-unk-unk -fstandalone-debug -o - -emit-llvm -g %s | FileCheck %s +// On Darwin, this should be the default: +// RUN: %clang_cc1 -triple x86_64-apple-darwin -o - -emit-llvm -g %s | FileCheck %s namespace rdar14101097_1 { // see also PR16214 // Check that we emit debug info for the definition of a struct if the diff --git a/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp b/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp index 04fe7a03e1..1b9a055527 100644 --- a/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp +++ b/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin -fno-limit-debug-info %s -o - | FileCheck %s +// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin -fstandalone-debug %s -o - | FileCheck %s class Test { diff --git a/test/CodeGenCXX/debug-info-method2.cpp b/test/CodeGenCXX/debug-info-method2.cpp index a927c49d30..a365312b25 100644 --- a/test/CodeGenCXX/debug-info-method2.cpp +++ b/test/CodeGenCXX/debug-info-method2.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -flimit-debug-info -x c++ -g -S -emit-llvm < %s | FileCheck %s +// RUN: %clang_cc1 -fno-standalone-debug -x c++ -g -S -emit-llvm < %s | FileCheck %s // rdar://10336845 // Preserve type qualifiers in -flimit-debug-info mode. diff --git a/test/CodeGenCXX/debug-info-namespace.cpp b/test/CodeGenCXX/debug-info-namespace.cpp index a2d7ede164..0fec2e4567 100644 --- a/test/CodeGenCXX/debug-info-namespace.cpp +++ b/test/CodeGenCXX/debug-info-namespace.cpp @@ -1,6 +1,6 @@ -// RUN: %clang -g -S -emit-llvm %s -o - | FileCheck %s -// RUN: %clang -g -gline-tables-only -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-GMLT %s -// RUN: %clang -g -fno-limit-debug-info -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-NOLIMIT %s +// RUN: %clang -g -fno-standalone-debug -S -emit-llvm %s -o - | FileCheck %s +// RUN: %clang -g -gline-tables-only -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-GMLT %s +// RUN: %clang -g -fstandalone-debug -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-NOLIMIT %s namespace A { #line 1 "foo.cpp" diff --git a/test/CodeGenCXX/debug-info-pubtypes.cpp b/test/CodeGenCXX/debug-info-pubtypes.cpp index 192a99435b..4643db0a49 100644 --- a/test/CodeGenCXX/debug-info-pubtypes.cpp +++ b/test/CodeGenCXX/debug-info-pubtypes.cpp @@ -1,5 +1,5 @@ // REQUIRES: x86-registered-target -// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -g -fno-limit-debug-info -S -mllvm -generate-dwarf-pub-sections=Enable %s -o - | FileCheck %s +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -g -fstandalone-debug -S -mllvm -generate-dwarf-pub-sections=Enable %s -o - | FileCheck %s // FIXME: This testcase shouldn't rely on assembly emission. //CHECK: Lpubtypes_begin[[SECNUM:[0-9]:]] diff --git a/test/CodeGenCXX/debug-info-template-limit.cpp b/test/CodeGenCXX/debug-info-template-limit.cpp index 34e4373a75..6b158573c0 100644 --- a/test/CodeGenCXX/debug-info-template-limit.cpp +++ b/test/CodeGenCXX/debug-info-template-limit.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -emit-llvm -flimit-debug-info -cxx-abi itanium -g %s -o - | FileCheck %s +// RUN: %clang_cc1 -emit-llvm -fno-standalone-debug -cxx-abi itanium -g %s -o - | FileCheck %s // Check that this pointer type is TC // CHECK: ![[LINE:[0-9]+]] = {{.*}}"TC", {{.*}} metadata !"_ZTS2TCIiE"} ; [ DW_TAG_class_type ] diff --git a/test/CodeGenCXX/debug-info-template-member.cpp b/test/CodeGenCXX/debug-info-template-member.cpp index 9ac1befc10..7a2b4c2b54 100644 --- a/test/CodeGenCXX/debug-info-template-member.cpp +++ b/test/CodeGenCXX/debug-info-template-member.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s +// RUN: %clang_cc1 -emit-llvm -g -fno-standalone-debug -triple x86_64-apple-darwin %s -o - | FileCheck %s struct MyClass { template int add(int j) { diff --git a/test/CodeGenCXX/debug-info-vtable-optzn.cpp b/test/CodeGenCXX/debug-info-vtable-optzn.cpp new file mode 100644 index 0000000000..8a6d4ff3e0 --- /dev/null +++ b/test/CodeGenCXX/debug-info-vtable-optzn.cpp @@ -0,0 +1,21 @@ +// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s +// +// This tests that the "emit debug info for a C++ class only in the +// module that has its vtable" optimization is disabled by default on +// Darwin. +// +// CHECK: [ DW_TAG_member ] [lost] +class A +{ + virtual bool f() = 0; + int lost; +}; + +class B : public A +{ + B *g(); +}; + +B *B::g() { + return this; +} -- 2.40.0