1 Merge -fstandalone-debug from Clang r198655:
3 Implement a new -fstandalone-debug option. rdar://problem/15685848
4 It controls everything that -flimit-debug-info used to, plus the
5 vtable type optimization. The old -fno-limit-debug-info option is now an
6 alias to -fstandalone-debug and vice versa.
8 Standalone is the default on Darwin until dtrace is updated to work with
9 non-standalone debug info (rdar://problem/15758808).
11 Note: I kept the LimitedDebugInfo name in CodeGenOptions::DebugInfoKind
12 because NoStandaloneDebugInfo sounded even more confusing.
14 Introduced here: http://svnweb.freebsd.org/changeset/base/265477
16 Index: tools/clang/lib/CodeGen/CGDebugInfo.cpp
17 ===================================================================
18 --- tools/clang/lib/CodeGen/CGDebugInfo.cpp
19 +++ tools/clang/lib/CodeGen/CGDebugInfo.cpp
20 @@ -1456,13 +1456,13 @@ llvm::DIType CGDebugInfo::CreateType(const RecordT
21 // declaration. The completeType, completeRequiredType, and completeClassData
22 // callbacks will handle promoting the declaration to a definition.
24 + // Under -flimit-debug-info:
25 (DebugKind <= CodeGenOptions::LimitedDebugInfo &&
26 - // Under -flimit-debug-info, emit only a declaration unless the type is
27 - // required to be complete.
28 - !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
29 - // If the class is dynamic, only emit a declaration. A definition will be
30 - // emitted whenever the vtable is emitted.
31 - (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass()) || T) {
32 + // Emit only a forward declaration unless the type is required.
33 + ((!RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
34 + // If the class is dynamic, only emit a declaration. A definition will be
35 + // emitted whenever the vtable is emitted.
36 + (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass())))) {
37 llvm::DIDescriptor FDContext =
38 getContextDescriptor(cast<Decl>(RD->getDeclContext()));
40 Index: tools/clang/lib/Frontend/CompilerInvocation.cpp
41 ===================================================================
42 --- tools/clang/lib/Frontend/CompilerInvocation.cpp
43 +++ tools/clang/lib/Frontend/CompilerInvocation.cpp
44 @@ -295,7 +295,8 @@ static void ParseCommentArgs(CommentOptions &Opts,
47 static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
48 - DiagnosticsEngine &Diags) {
49 + DiagnosticsEngine &Diags,
50 + const TargetOptions &TargetOpts) {
51 using namespace options;
54 @@ -322,10 +323,16 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts,
55 Opts.setDebugInfo(CodeGenOptions::DebugLineTablesOnly);
56 } else if (Args.hasArg(OPT_g_Flag) || Args.hasArg(OPT_gdwarf_2) ||
57 Args.hasArg(OPT_gdwarf_3) || Args.hasArg(OPT_gdwarf_4)) {
58 - if (Args.hasFlag(OPT_flimit_debug_info, OPT_fno_limit_debug_info, true))
59 + bool Default = false;
60 + // Until dtrace (via CTF) can deal with distributed debug info,
61 + // Darwin defaults to standalone/full debug info.
62 + if (llvm::Triple(TargetOpts.Triple).isOSDarwin())
65 + if (Args.hasFlag(OPT_fstandalone_debug, OPT_fno_standalone_debug, Default))
66 + Opts.setDebugInfo(CodeGenOptions::FullDebugInfo);
68 Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo);
70 - Opts.setDebugInfo(CodeGenOptions::FullDebugInfo);
72 Opts.DebugColumnInfo = Args.hasArg(OPT_dwarf_column_info);
73 Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
74 @@ -1657,8 +1664,9 @@ bool CompilerInvocation::CreateFromArgs(CompilerIn
75 ParseFileSystemArgs(Res.getFileSystemOpts(), *Args);
76 // FIXME: We shouldn't have to pass the DashX option around here
77 InputKind DashX = ParseFrontendArgs(Res.getFrontendOpts(), *Args, Diags);
78 - Success = ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags)
80 + ParseTargetArgs(Res.getTargetOpts(), *Args);
81 + Success = ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags,
82 + Res.getTargetOpts()) && Success;
83 ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), *Args);
84 if (DashX != IK_AST && DashX != IK_LLVM_IR) {
85 ParseLangArgs(*Res.getLangOpts(), *Args, DashX, Diags);
86 @@ -1673,8 +1681,6 @@ bool CompilerInvocation::CreateFromArgs(CompilerIn
87 ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args, FileMgr, Diags);
88 ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args,
89 Res.getFrontendOpts().ProgramAction);
90 - ParseTargetArgs(Res.getTargetOpts(), *Args);
95 Index: tools/clang/lib/Driver/Tools.cpp
96 ===================================================================
97 --- tools/clang/lib/Driver/Tools.cpp
98 +++ tools/clang/lib/Driver/Tools.cpp
99 @@ -2995,8 +2995,8 @@ void Clang::ConstructJob(Compilation &C, const Job
100 Args.AddLastArg(CmdArgs, options::OPT_femit_all_decls);
101 Args.AddLastArg(CmdArgs, options::OPT_fformat_extensions);
102 Args.AddLastArg(CmdArgs, options::OPT_fheinous_gnu_extensions);
103 - Args.AddLastArg(CmdArgs, options::OPT_flimit_debug_info);
104 - Args.AddLastArg(CmdArgs, options::OPT_fno_limit_debug_info);
105 + Args.AddLastArg(CmdArgs, options::OPT_fstandalone_debug);
106 + Args.AddLastArg(CmdArgs, options::OPT_fno_standalone_debug);
107 Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names);
108 // AltiVec language extensions aren't relevant for assembling.
109 if (!isa<PreprocessJobAction>(JA) ||
110 Index: tools/clang/test/CodeGenCXX/debug-info-template-member.cpp
111 ===================================================================
112 --- tools/clang/test/CodeGenCXX/debug-info-template-member.cpp
113 +++ tools/clang/test/CodeGenCXX/debug-info-template-member.cpp
115 -// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s
116 +// RUN: %clang_cc1 -emit-llvm -g -fno-standalone-debug -triple x86_64-apple-darwin %s -o - | FileCheck %s
119 template <int i> int add(int j) {
120 Index: tools/clang/test/CodeGenCXX/debug-info-vtable-optzn.cpp
121 ===================================================================
122 --- tools/clang/test/CodeGenCXX/debug-info-vtable-optzn.cpp
123 +++ tools/clang/test/CodeGenCXX/debug-info-vtable-optzn.cpp
125 +// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s
127 +// This tests that the "emit debug info for a C++ class only in the
128 +// module that has its vtable" optimization is disabled by default on
131 +// CHECK: [ DW_TAG_member ] [lost]
134 + virtual bool f() = 0;
146 Index: tools/clang/test/CodeGenCXX/debug-info-namespace.cpp
147 ===================================================================
148 --- tools/clang/test/CodeGenCXX/debug-info-namespace.cpp
149 +++ tools/clang/test/CodeGenCXX/debug-info-namespace.cpp
151 -// RUN: %clang -g -S -emit-llvm %s -o - | FileCheck %s
152 -// RUN: %clang -g -gline-tables-only -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-GMLT %s
153 -// RUN: %clang -g -fno-limit-debug-info -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-NOLIMIT %s
154 +// RUN: %clang -g -fno-standalone-debug -S -emit-llvm %s -o - | FileCheck %s
155 +// RUN: %clang -g -gline-tables-only -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-GMLT %s
156 +// RUN: %clang -g -fstandalone-debug -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-NOLIMIT %s
160 Index: tools/clang/test/CodeGenCXX/debug-info-class-limited.cpp
161 ===================================================================
162 --- tools/clang/test/CodeGenCXX/debug-info-class-limited.cpp
163 +++ tools/clang/test/CodeGenCXX/debug-info-class-limited.cpp
165 -// RUN: %clang -emit-llvm -g -S %s -o - | FileCheck %s
166 +// RUN: %clang -emit-llvm -fno-standalone-debug -g -S %s -o - | FileCheck %s
168 namespace PR16214_1 {
169 // CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [def]
170 Index: tools/clang/test/CodeGenCXX/debug-info-method2.cpp
171 ===================================================================
172 --- tools/clang/test/CodeGenCXX/debug-info-method2.cpp
173 +++ tools/clang/test/CodeGenCXX/debug-info-method2.cpp
175 -// RUN: %clang_cc1 -flimit-debug-info -x c++ -g -S -emit-llvm < %s | FileCheck %s
176 +// RUN: %clang_cc1 -fno-standalone-debug -x c++ -g -S -emit-llvm < %s | FileCheck %s
178 // Preserve type qualifiers in -flimit-debug-info mode.
180 Index: tools/clang/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp
181 ===================================================================
182 --- tools/clang/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp
183 +++ tools/clang/test/CodeGenCXX/debug-info-dup-fwd-decl.cpp
185 -// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin -fno-limit-debug-info %s -o - | FileCheck %s
186 +// RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin -fstandalone-debug %s -o - | FileCheck %s
190 Index: tools/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
191 ===================================================================
192 --- tools/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
193 +++ tools/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
195 -// RUN: %clang_cc1 -triple x86_64-unk-unk -fno-limit-debug-info -o - -emit-llvm -g %s | FileCheck %s
196 +// RUN: %clang_cc1 -triple x86_64-unk-unk -fstandalone-debug -o - -emit-llvm -g %s | FileCheck %s
197 +// On Darwin, this should be the default:
198 +// RUN: %clang_cc1 -triple x86_64-apple-darwin -o - -emit-llvm -g %s | FileCheck %s
200 namespace rdar14101097_1 { // see also PR16214
201 // Check that we emit debug info for the definition of a struct if the
202 Index: tools/clang/test/CodeGenCXX/debug-info-template-limit.cpp
203 ===================================================================
204 --- tools/clang/test/CodeGenCXX/debug-info-template-limit.cpp
205 +++ tools/clang/test/CodeGenCXX/debug-info-template-limit.cpp
207 -// RUN: %clang -flimit-debug-info -emit-llvm -g -S %s -o - | FileCheck %s
208 +// RUN: %clang -fno-standalone-debug -emit-llvm -g -S %s -o - | FileCheck %s
210 // Check that this pointer type is TC<int>
211 // CHECK: ![[LINE:[0-9]+]] = {{.*}}"TC<int>", {{.*}} metadata !"_ZTS2TCIiE"} ; [ DW_TAG_class_type ]
212 Index: tools/clang/test/CodeGenCXX/debug-info-pubtypes.cpp
213 ===================================================================
214 --- tools/clang/test/CodeGenCXX/debug-info-pubtypes.cpp
215 +++ tools/clang/test/CodeGenCXX/debug-info-pubtypes.cpp
217 // REQUIRES: x86-64-registered-target
218 -// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -g -fno-limit-debug-info -S -mllvm -generate-dwarf-pub-sections=Enable %s -o - | FileCheck %s
219 +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -g -fstandalone-debug -S -mllvm -generate-dwarf-pub-sections=Enable %s -o - | FileCheck %s
221 // FIXME: This testcase shouldn't rely on assembly emission.
222 //CHECK: Lpubtypes_begin[[SECNUM:[0-9]:]]
223 Index: tools/clang/include/clang/Frontend/CodeGenOptions.h
224 ===================================================================
225 --- tools/clang/include/clang/Frontend/CodeGenOptions.h
226 +++ tools/clang/include/clang/Frontend/CodeGenOptions.h
227 @@ -50,12 +50,20 @@ class CodeGenOptions : public CodeGenOptionsBase {
231 - NoDebugInfo, // Don't generate debug info.
232 - DebugLineTablesOnly, // Emit only debug info necessary for generating
233 - // line number tables (-gline-tables-only).
234 - LimitedDebugInfo, // Limit generated debug info to reduce size
235 - // (-flimit-debug-info).
236 - FullDebugInfo // Generate complete debug info.
237 + NoDebugInfo, /// Don't generate debug info.
239 + DebugLineTablesOnly, /// Emit only debug info necessary for generating
240 + /// line number tables (-gline-tables-only).
242 + LimitedDebugInfo, /// Limit generated debug info to reduce size
243 + /// (-fno-standalone-debug). This emits
244 + /// forward decls for types that could be
245 + /// replaced with forward decls in the source
246 + /// code. For dynamic C++ classes type info
247 + /// is only emitted int the module that
248 + /// contains the classe's vtable.
250 + FullDebugInfo /// Generate complete debug info.
254 Index: tools/clang/include/clang/Driver/Options.td
255 ===================================================================
256 --- tools/clang/include/clang/Driver/Options.td
257 +++ tools/clang/include/clang/Driver/Options.td
258 @@ -549,8 +549,6 @@ def finstrument_functions : Flag<["-"], "finstrume
259 def fkeep_inline_functions : Flag<["-"], "fkeep-inline-functions">, Group<clang_ignored_f_Group>;
260 def flat__namespace : Flag<["-"], "flat_namespace">;
261 def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group<f_Group>;
262 -def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Group<f_Group>, Flags<[CC1Option]>,
263 - HelpText<"Limit debug information produced to reduce size of debug binary">;
264 def flimited_precision_EQ : Joined<["-"], "flimited-precision=">, Group<f_Group>;
265 def flto : Flag<["-"], "flto">, Group<f_Group>;
266 def fno_lto : Flag<["-"], "fno-lto">, Group<f_Group>;
267 @@ -645,8 +643,6 @@ def fno_inline : Flag<["-"], "fno-inline">, Group<
268 def fno_keep_inline_functions : Flag<["-"], "fno-keep-inline-functions">, Group<clang_ignored_f_Group>;
269 def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_Group>,
270 HelpText<"Disallow implicit conversions between vectors with a different number of elements or different element types">, Flags<[CC1Option]>;
271 -def fno_limit_debug_info : Flag<["-"], "fno-limit-debug-info">, Group<f_Group>, Flags<[CC1Option]>,
272 - HelpText<"Do not limit debug information produced to reduce size of debug binary">;
273 def fno_merge_all_constants : Flag<["-"], "fno-merge-all-constants">, Group<f_Group>,
274 Flags<[CC1Option]>, HelpText<"Disallow merging of constants">;
275 def fno_modules : Flag <["-"], "fno-modules">, Group<f_Group>,
276 @@ -774,6 +770,12 @@ def fno_signed_char : Flag<["-"], "fno-signed-char
277 def fsplit_stack : Flag<["-"], "fsplit-stack">, Group<f_Group>;
278 def fstack_protector_all : Flag<["-"], "fstack-protector-all">, Group<f_Group>;
279 def fstack_protector : Flag<["-"], "fstack-protector">, Group<f_Group>;
280 +def fstandalone_debug : Flag<["-"], "fstandalone-debug">, Group<f_Group>, Flags<[CC1Option]>,
281 + HelpText<"Emit full debug info for all types used by the program">;
282 +def fno_standalone_debug : Flag<["-"], "fno-standalone-debug">, Group<f_Group>, Flags<[CC1Option]>,
283 + HelpText<"Limit debug information produced to reduce size of debug binary">;
284 +def flimit_debug_info : Flag<["-"], "flimit-debug-info">, Alias<fno_standalone_debug>;
285 +def fno_limit_debug_info : Flag<["-"], "fno-limit-debug-info">, Alias<fstandalone_debug>;
286 def fstrict_aliasing : Flag<["-"], "fstrict-aliasing">, Group<f_Group>;
287 def fstrict_enums : Flag<["-"], "fstrict-enums">, Group<f_Group>, Flags<[CC1Option]>,
288 HelpText<"Enable optimizations based on the strict definition of an enum's "
289 Index: tools/clang/docs/tools/clang.pod
290 ===================================================================
291 --- tools/clang/docs/tools/clang.pod
292 +++ tools/clang/docs/tools/clang.pod
293 @@ -310,9 +310,23 @@ Currently equivalent to B<-O3>
296 Generate debug information. Note that Clang debug information works best at
297 -B<-O0>. At higher optimization levels, only line number information is
298 -currently available.
301 +=item B<-fstandalone-debug> B<-fno-standalone-debug>
303 +Clang supports a number of optimizations to reduce the size of debug
304 +information in the binary. They work based on the assumption that the
305 +debug type information can be spread out over multiple compilation
306 +units. For instance, Clang will not emit type definitions for types
307 +that are not needed by a module and could be replaced with a forward
308 +declaration. Further, Clang will only emit type info for a dynamic
309 +C++ class in the module that contains the vtable for the class.
311 +The B<-fstandalone-debug> option turns off these optimizations. This
312 +is useful when working with 3rd-party libraries that don't come with
313 +debug information. Note that Clang will never emit type information
314 +for types that are not referenced at all by the program.
316 =item B<-fexceptions>
318 Enable generation of unwind information, this allows exceptions to be thrown