Add -gcodeview and -gdwarf to control which type Clang emits

Summary:
By default, 'clang' emits dwarf and 'clang-cl' emits codeview.  You can
force emission of one or both by passing -gcodeview and -gdwarf to
either driver.

Reviewers: dblaikie, hans

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11742

llvm-svn: 244097

clang/include/clang/Driver/CLCompatOptions.td

@@ -157,9 +157,10 @@ def _SLASH_Zc_trigraphs : CLFlag<"Zc:trigraphs">,
   HelpText<"Enable trigraphs">, Alias<ftrigraphs>;
 def _SLASH_Zc_trigraphs_off : CLFlag<"Zc:trigraphs-">,
   HelpText<"Disable trigraphs (default)">, Alias<fno_trigraphs>;
-def _SLASH_Z7 : CLFlag<"Z7">, Alias<gline_tables_only>;
-def _SLASH_Zi : CLFlag<"Zi">, HelpText<"Enable debug information">,
-  Alias<gline_tables_only>;
+def _SLASH_Z7 : CLFlag<"Z7">,
+  HelpText<"Enable CodeView debug information in object files">;
+def _SLASH_Zi : CLFlag<"Zi">, Alias<_SLASH_Z7>,
+  HelpText<"Alias for /Z7. Does not produce PDBs.">;
 def _SLASH_Zp : CLJoined<"Zp">,
   HelpText<"Specify the default maximum struct packing alignment">,
   Alias<fpack_struct_EQ>;

clang/include/clang/Driver/Options.td

@@ -1096,6 +1096,13 @@ def gdwarf_3 : Flag<["-"], "gdwarf-3">, Group<g_Group>,
   HelpText<"Generate source-level debug information with dwarf version 3">, Flags<[CC1Option,CC1AsOption]>;
 def gdwarf_4 : Flag<["-"], "gdwarf-4">, Group<g_Group>,
   HelpText<"Generate source-level debug information with dwarf version 4">, Flags<[CC1Option,CC1AsOption]>;
+def gcodeview : Flag<["-"], "gcodeview">,
+  HelpText<"Generate CodeView debug information">,
+  Flags<[CC1Option, CC1AsOption, CoreOption]>;
+// Equivalent to our default dwarf version. Forces usual dwarf emission when
+// CodeView is enabled.
+def gdwarf : Flag<["-"], "gdwarf">, Alias<gdwarf_4>, Flags<[CoreOption]>;
+
 def gfull : Flag<["-"], "gfull">, Group<g_Group>;
 def gused : Flag<["-"], "gused">, Group<g_Group>;
 def gstabs : Joined<["-"], "gstabs">, Group<g_Group>, Flags<[Unsupported]>;

clang/include/clang/Frontend/CodeGenOptions.def

@@ -173,9 +173,14 @@ VALUE_CODEGENOPT(SSPBufferSize, 32, 0)
 /// The kind of generated debug info.
 ENUM_CODEGENOPT(DebugInfo, DebugInfoKind, 3, NoDebugInfo)
 
-/// Dwarf version.
+/// Dwarf version. Version zero indicates to LLVM that no DWARF should be
+/// emitted.
 VALUE_CODEGENOPT(DwarfVersion, 3, 0)
 
+/// Whether we should emit CodeView debug information. It's possible to emit
+/// CodeView and DWARF into the same object.
+CODEGENOPT(EmitCodeView, 1, 0)
+
 /// The kind of inlining to perform.
 ENUM_CODEGENOPT(Inlining, InliningMethod, 2, NoInlining)
 

clang/lib/CodeGen/CodeGenModule.cpp

@@ -369,11 +369,16 @@ void CodeGenModule::Release() {
       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
     EmitModuleLinkOptions();
   }
-  if (CodeGenOpts.DwarfVersion)
+  if (CodeGenOpts.DwarfVersion) {
     // We actually want the latest version when there are conflicts.
     // We can change from Warning to Latest if such mode is supported.
     getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
                               CodeGenOpts.DwarfVersion);
+  }
+  if (CodeGenOpts.EmitCodeView) {
+    // Indicate that we want CodeView in the metadata.
+    getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
+  }
   if (DebugInfo)
     // We support a single version in the linked module. The LLVM
     // parser will drop debug info with a different version number

clang/lib/Driver/Tools.cpp

@@ -3678,6 +3678,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
+  // Forward -gcodeview.
+  Args.AddLastArg(CmdArgs, options::OPT_gcodeview);
+
   // We ignore flags -gstrict-dwarf and -grecord-gcc-switches for now.
   Args.ClaimAllArgs(options::OPT_g_flags_Group);
   if (Args.hasFlag(options::OPT_gcolumn_info, options::OPT_gno_column_info,
@@ -5270,6 +5273,16 @@ void Clang::AddClangCLArgs(const ArgList &Args, ArgStringList &CmdArgs) const {
                    /*default=*/false))
     CmdArgs.push_back("-fno-rtti-data");
 
+  // Emit CodeView if -Z7 is present.
+  bool EmitCodeView = Args.hasArg(options::OPT__SLASH_Z7);
+  bool EmitDwarf = Args.hasArg(options::OPT_gdwarf);
+  // If we are emitting CV but not DWARF, don't build information that LLVM
+  // can't yet process.
+  if (EmitCodeView && !EmitDwarf)
+    CmdArgs.push_back("-gline-tables-only");
+  if (EmitCodeView)
+    CmdArgs.push_back("-gcodeview");
+
   const Driver &D = getToolChain().getDriver();
   EHFlags EH = parseClangCLEHFlags(D, Args);
   // FIXME: Do something with NoExceptC.
@@ -8820,7 +8833,7 @@ void visualstudio::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   CmdArgs.push_back("-nologo");
 
-  if (Args.hasArg(options::OPT_g_Group))
+  if (Args.hasArg(options::OPT_g_Group, options::OPT__SLASH_Z7))
     CmdArgs.push_back("-debug");
 
   bool DLL = Args.hasArg(options::OPT__SLASH_LD, options::OPT__SLASH_LDd,
@@ -8976,7 +8989,8 @@ std::unique_ptr<Command> visualstudio::Compiler::GetCommand(
         A->getOption().getID() == options::OPT_fdata_sections ? "/Gw" : "/Gw-");
   if (Args.hasArg(options::OPT_fsyntax_only))
     CmdArgs.push_back("/Zs");
-  if (Args.hasArg(options::OPT_g_Flag, options::OPT_gline_tables_only))
+  if (Args.hasArg(options::OPT_g_Flag, options::OPT_gline_tables_only,
+                  options::OPT__SLASH_Z7))
     CmdArgs.push_back("/Z7");
 
   std::vector<std::string> Includes =

clang/lib/Frontend/CompilerInvocation.cpp

@@ -410,6 +410,13 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
       Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo);
   }
   Opts.DebugColumnInfo = Args.hasArg(OPT_dwarf_column_info);
+  if (Args.hasArg(OPT_gcodeview)) {
+    Opts.EmitCodeView = true;
+    Opts.DwarfVersion = 0;
+  } else if (Opts.getDebugInfo() != CodeGenOptions::NoDebugInfo) {
+    // Default Dwarf version is 4 if we are generating debug information.
+    Opts.DwarfVersion = 4;
+  }
   Opts.SplitDwarfFile = Args.getLastArgValue(OPT_split_dwarf_file);
   if (Args.hasArg(OPT_gdwarf_2))
     Opts.DwarfVersion = 2;
@@ -417,9 +424,6 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
     Opts.DwarfVersion = 3;
   else if (Args.hasArg(OPT_gdwarf_4))
     Opts.DwarfVersion = 4;
-  else if (Opts.getDebugInfo() != CodeGenOptions::NoDebugInfo)
-    // Default Dwarf version is 4 if we are generating debug information.
-    Opts.DwarfVersion = 4;
 
   if (const Arg *A =
           Args.getLastArg(OPT_emit_llvm_uselists, OPT_no_emit_llvm_uselists))

clang/test/CodeGen/dwarf-version.c

@@ -2,10 +2,15 @@
 // RUN: %clang -target x86_64-linux-gnu -gdwarf-3 -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER3
 // RUN: %clang -target x86_64-linux-gnu -gdwarf-4 -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER4
 // RUN: %clang -target x86_64-linux-gnu -g -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER4
+// RUN: %clang -target x86_64-linux-gnu -gdwarf -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER4
 // RUN: %clang -target x86_64-apple-darwin -g -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER2
 // RUN: %clang -target powerpc-unknown-openbsd -g -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER2
 // RUN: %clang -target powerpc-unknown-freebsd -g -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER2
 // RUN: %clang -target i386-pc-solaris -g -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER2
+//
+// Test what -gcodeview and -gdwarf do on Windows.
+// RUN: %clang -target i686-pc-windows-msvc -gcodeview -S -emit-llvm -o - %s | FileCheck %s --check-prefix=NODWARF --check-prefix=CODEVIEW
+// RUN: %clang -target i686-pc-windows-msvc -gdwarf -gcodeview -S -emit-llvm -o - %s | FileCheck %s --check-prefix=VER4 --check-prefix=CODEVIEW
 int main (void) {
   return 0;
 }
@@ -13,3 +18,7 @@ int main (void) {
 // VER2: !{i32 2, !"Dwarf Version", i32 2}
 // VER3: !{i32 2, !"Dwarf Version", i32 3}
 // VER4: !{i32 2, !"Dwarf Version", i32 4}
+
+// NODWARF-NOT: !"Dwarf Version"
+// CODEVIEW: !{i32 2, !"CodeView", i32 1}
+// NODWARF-NOT: !"Dwarf Version"

clang/test/Driver/cl-options.c

@@ -360,6 +360,19 @@
 // RUN: %clang_cl /Zc:threadSafeInit /c -### -- %s 2>&1 | FileCheck -check-prefix=ThreadSafeStatics %s
 // ThreadSafeStatics-NOT: "-fno-threadsafe-statics"
 
+// RUN: %clang_cl /Zi /c -### -- %s 2>&1 | FileCheck -check-prefix=Zi %s
+// Zi: "-gline-tables-only"
+// Zi: "-gcodeview"
+
+// RUN: %clang_cl /Z7 /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7 %s
+// Z7: "-gline-tables-only"
+// Z7: "-gcodeview"
+
+// RUN: %clang_cl /Z7 -gdwarf /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7_gdwarf %s
+// Z7_gdwarf: "-gline-tables-only"
+// Z7_gdwarf: "-gcodeview"
+// Z7_gdwarf: "-gdwarf-4"
+
 // RUN: %clang_cl -fmsc-version=1800 -TP -### -- %s 2>&1 | FileCheck -check-prefix=CXX11 %s
 // CXX11: -std=c++11