r198655 - Implement a new -fstandalone-debug option. rdar://problem/15685848
Adrian Prantl
aprantl at apple.com
Mon Jan 6 17:19:09 PST 2014
Author: adrian
Date: Mon Jan 6 19:19:08 2014
New Revision: 198655
URL: http://llvm.org/viewvc/llvm-project?rev=198655&view=rev
Log:
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.
Added:
cfe/trunk/test/CodeGenCXX/debug-info-vtable-optzn.cpp
Modified:
cfe/trunk/docs/tools/clang.pod
cfe/trunk/include/clang/Driver/Options.td
cfe/trunk/include/clang/Frontend/CodeGenOptions.h
cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
cfe/trunk/lib/Driver/Tools.cpp
cfe/trunk/lib/Frontend/CompilerInvocation.cpp
cfe/trunk/test/CodeGenCXX/debug-info-class-limited.cpp
cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp
cfe/trunk/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp
cfe/trunk/test/CodeGenCXX/debug-info-method2.cpp
cfe/trunk/test/CodeGenCXX/debug-info-namespace.cpp
cfe/trunk/test/CodeGenCXX/debug-info-pubtypes.cpp
cfe/trunk/test/CodeGenCXX/debug-info-template-limit.cpp
cfe/trunk/test/CodeGenCXX/debug-info-template-member.cpp
Modified: cfe/trunk/docs/tools/clang.pod
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/tools/clang.pod?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/docs/tools/clang.pod (original)
+++ cfe/trunk/docs/tools/clang.pod Mon Jan 6 19:19:08 2014
@@ -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>
+=item B<-fstandalone-debug> B<-fno-standalone-debug>
-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
+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>
Modified: cfe/trunk/include/clang/Driver/Options.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/include/clang/Driver/Options.td (original)
+++ cfe/trunk/include/clang/Driver/Options.td Mon Jan 6 19:19:08 2014
@@ -559,8 +559,6 @@ def finstrument_functions : Flag<["-"],
def fkeep_inline_functions : Flag<["-"], "fkeep-inline-functions">, Group<clang_ignored_f_Group>;
def flat__namespace : Flag<["-"], "flat_namespace">;
def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group<f_Group>;
-def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Group<f_Group>, Flags<[CC1Option]>,
- HelpText<"Limit debug information produced to reduce size of debug binary">;
def flimited_precision_EQ : Joined<["-"], "flimited-precision=">, Group<f_Group>;
def flto : Flag<["-"], "flto">, Group<f_Group>;
def fno_lto : Flag<["-"], "fno-lto">, Group<f_Group>;
@@ -654,8 +652,6 @@ def fno_inline : Flag<["-"], "fno-inline
def fno_keep_inline_functions : Flag<["-"], "fno-keep-inline-functions">, Group<clang_ignored_f_Group>;
def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_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<f_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<f_Group>,
Flags<[CC1Option]>, HelpText<"Disallow merging of constants">;
def fno_modules : Flag <["-"], "fno-modules">, Group<f_Group>,
@@ -783,6 +779,12 @@ def fno_signed_char : Flag<["-"], "fno-s
def fsplit_stack : Flag<["-"], "fsplit-stack">, Group<f_Group>;
def fstack_protector_all : Flag<["-"], "fstack-protector-all">, Group<f_Group>;
def fstack_protector : Flag<["-"], "fstack-protector">, Group<f_Group>;
+def fstandalone_debug : Flag<["-"], "fstandalone-debug">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Emit full debug info for all types used by the program">;
+def fno_standalone_debug : Flag<["-"], "fno-standalone-debug">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Limit debug information produced to reduce size of debug binary">;
+def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Alias<fno_standalone_debug>;
+def fno_limit_debug_info : Flag<["-"], "fno-limit-debug-info">, Alias<fstandalone_debug>;
def fstrict_aliasing : Flag<["-"], "fstrict-aliasing">, Group<f_Group>;
def fstrict_enums : Flag<["-"], "fstrict-enums">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Enable optimizations based on the strict definition of an enum's "
Modified: cfe/trunk/include/clang/Frontend/CodeGenOptions.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/CodeGenOptions.h?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/include/clang/Frontend/CodeGenOptions.h (original)
+++ cfe/trunk/include/clang/Frontend/CodeGenOptions.h Mon Jan 6 19:19:08 2014
@@ -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 {
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Mon Jan 6 19:19:08 2014
@@ -1464,13 +1464,13 @@ llvm::DIType CGDebugInfo::CreateType(con
// 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<Decl>(RD->getDeclContext()));
if (!T)
Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Mon Jan 6 19:19:08 2014
@@ -2945,8 +2945,8 @@ void Clang::ConstructJob(Compilation &C,
// 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<PreprocessJobAction>(JA) ||
Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original)
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Mon Jan 6 19:19:08 2014
@@ -296,7 +296,8 @@ static void ParseCommentArgs(CommentOpti
}
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(CodeGenOpti
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(
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(
ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args, FileMgr, Diags);
ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args,
Res.getFrontendOpts().ProgramAction);
- ParseTargetArgs(Res.getTargetOpts(), *Args);
-
return Success;
}
Modified: cfe/trunk/test/CodeGenCXX/debug-info-class-limited.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-class-limited.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-class-limited.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-class-limited.cpp Mon Jan 6 19:19:08 2014
@@ -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]
Modified: cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp Mon Jan 6 19:19:08 2014
@@ -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
Modified: cfe/trunk/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp Mon Jan 6 19:19:08 2014
@@ -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
{
Modified: cfe/trunk/test/CodeGenCXX/debug-info-method2.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-method2.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-method2.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-method2.cpp Mon Jan 6 19:19:08 2014
@@ -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.
Modified: cfe/trunk/test/CodeGenCXX/debug-info-namespace.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-namespace.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-namespace.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-namespace.cpp Mon Jan 6 19:19:08 2014
@@ -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"
Modified: cfe/trunk/test/CodeGenCXX/debug-info-pubtypes.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-pubtypes.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-pubtypes.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-pubtypes.cpp Mon Jan 6 19:19:08 2014
@@ -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]:]]
Modified: cfe/trunk/test/CodeGenCXX/debug-info-template-limit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-template-limit.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-template-limit.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-template-limit.cpp Mon Jan 6 19:19:08 2014
@@ -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<int>
// CHECK: ![[LINE:[0-9]+]] = {{.*}}"TC<int>", {{.*}} metadata !"_ZTS2TCIiE"} ; [ DW_TAG_class_type ]
Modified: cfe/trunk/test/CodeGenCXX/debug-info-template-member.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-template-member.cpp?rev=198655&r1=198654&r2=198655&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-template-member.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-template-member.cpp Mon Jan 6 19:19:08 2014
@@ -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 i> int add(int j) {
Added: cfe/trunk/test/CodeGenCXX/debug-info-vtable-optzn.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-vtable-optzn.cpp?rev=198655&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-vtable-optzn.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/debug-info-vtable-optzn.cpp Mon Jan 6 19:19:08 2014
@@ -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;
+}
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