Driver and option support for -gsplit-dwarf. This is a part of

the DWARF5 split dwarf proposal.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174349 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 49 insertions, 6 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index dbd25dfbea..71e50a5c9e 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2250,16 +2250,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                       D.CCLogDiagnosticsFilename : "-");
   }
 
-  // Use the last option from "-g" group. "-gline-tables-only" is
-  // preserved, all other debug options are substituted with "-g".
+  // Use the last option from "-g" group. "-gline-tables-only"
+  // is preserved, all other debug options are substituted with "-g".
   Args.ClaimAllArgs(options::OPT_g_Group);
   if (Arg *A = Args.getLastArg(options::OPT_g_Group)) {
-    if (A->getOption().matches(options::OPT_gline_tables_only)) {
+    if (A->getOption().matches(options::OPT_gline_tables_only))
       CmdArgs.push_back("-gline-tables-only");
-    } else if (!A->getOption().matches(options::OPT_g0) &&
-               !A->getOption().matches(options::OPT_ggdb0)) {
+    else if (!A->getOption().matches(options::OPT_g0) &&
+             !A->getOption().matches(options::OPT_ggdb0))
       CmdArgs.push_back("-g");
-    }
   }
 
   // We ignore flags -gstrict-dwarf and -grecord-gcc-switches for now.
@@ -2267,6 +2266,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (Args.hasArg(options::OPT_gcolumn_info))
     CmdArgs.push_back("-dwarf-column-info");
 
+  // -gsplit-dwarf should turn on -g and enable the backend dwarf
+  // splitting and extraction.
+  if (Args.hasArg(options::OPT_gsplit_dwarf)) {
+    CmdArgs.push_back("-g");
+    CmdArgs.push_back("-backend-option");
+    CmdArgs.push_back("-split-dwarf=Enable");
+  }
+
   Args.AddAllArgs(CmdArgs, options::OPT_ffunction_sections);
   Args.AddAllArgs(CmdArgs, options::OPT_fdata_sections);
 
@@ -5829,6 +5836,42 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
   C.addCommand(new Command(JA, *this, ToolChain.Linker.c_str(), CmdArgs));
 }
 
+void linuxtools::SplitDebug::ConstructJob(Compilation &C, const JobAction &JA,
+                                          const InputInfo &Output,
+                                          const InputInfoList &Inputs,
+                                          const ArgList &Args,
+                                          const char *LinkingOutput) const {
+  // Assert some invariants.
+  assert(Inputs.size() == 1 && "Unable to handle multiple inputs.");
+  const InputInfo &Input = Inputs[0];
+  assert(Input.isFilename() && "Unexpected verify input");
+
+  ArgStringList ExtractArgs;
+  ExtractArgs.push_back("--extract-dwo");
+
+  ArgStringList StripArgs;
+  StripArgs.push_back("--strip-dwo");
+
+  // Grabbing the output of the earlier compile step.
+  StripArgs.push_back(Input.getFilename());
+  ExtractArgs.push_back(Input.getFilename());
+
+  // Add an output for the extract.
+  SmallString<128> T(Inputs[0].getBaseInput());
+  llvm::sys::path::replace_extension(T, "dwo");
+  const char *OutFile = Args.MakeArgString(T);
+  ExtractArgs.push_back(OutFile);
+
+  const char *Exec =
+    Args.MakeArgString(getToolChain().GetProgramPath("objcopy"));
+
+  // First extract the dwo sections.
+  C.addCommand(new Command(JA, *this, Exec, ExtractArgs));
+
+  // Then remove them from the original .o file.
+  C.addCommand(new Command(JA, *this, Exec, StripArgs));
+}
+
 void minix::Assemble::ConstructJob(Compilation &C, const JobAction &JA,
                                    const InputInfo &Output,
                                    const InputInfoList &Inputs,