Merge pull request #3350 from adrian-prantl/25498103

Debug info diet!

Author: adrian-prantl

include/swift/AST/IRGenOptions.h

@@ -48,7 +48,9 @@ enum class IRGenOutputKind : unsigned {
 enum class IRGenDebugInfoKind : unsigned {
   None,       /// No debug info.
   LineTables, /// Line tables only.
-  Normal      /// Line tables + DWARF types.
+  ASTTypes,   /// Line tables + AST type references.
+  DwarfTypes, /// Line tables + AST type references + DWARF types.
+  Normal = ASTTypes /// The setting LLDB prefers.
 };
 
 enum class IRGenEmbedMode : unsigned {

include/swift/Option/Options.td

@@ -293,12 +293,16 @@ def Oplayground : Flag<["-"], "Oplayground">, Group<O_Group>,
 def g_Group : OptionGroup<"<debug info options>">;
 
 def g : Flag<["-"], "g">, Group<g_Group>, Flags<[FrontendOption]>,
-  HelpText<"Emit debug info">;
+  HelpText<"Emit debug info. "
+           "This is the preferred setting for debugging with LLDB.">;
 def gnone : Flag<["-"], "gnone">, Group<g_Group>, Flags<[FrontendOption]>,
   HelpText<"Don't emit debug info">;
 def gline_tables_only : Flag<["-"], "gline-tables-only">,
   Group<g_Group>, Flags<[FrontendOption]>,
   HelpText<"Emit minimal debug info for backtraces only">;
+def gdwarf_types : Flag<["-"], "gdwarf-types">,
+  Group<g_Group>, Flags<[FrontendOption]>,
+  HelpText<"Emit full DWARF type info.">;
 
 // Assert configuration identifiers.
 def AssertConfig : Separate<["-"], "assert-config">,

lib/Driver/Driver.cpp

@@ -975,6 +975,8 @@ void Driver::buildOutputInfo(const ToolChain &TC, const DerivedArgList &Args,
       OI.DebugInfoKind = IRGenDebugInfoKind::Normal;
     else if (A->getOption().matches(options::OPT_gline_tables_only))
       OI.DebugInfoKind = IRGenDebugInfoKind::LineTables;
+    else if (A->getOption().matches(options::OPT_gdwarf_types))
+      OI.DebugInfoKind = IRGenDebugInfoKind::DwarfTypes;
     else
       assert(A->getOption().matches(options::OPT_gnone) &&
              "unknown -g<kind> option");
@@ -985,7 +987,7 @@ void Driver::buildOutputInfo(const ToolChain &TC, const DerivedArgList &Args,
     // top-level output.
     OI.ShouldGenerateModule = true;
     OI.ShouldTreatModuleAsTopLevelOutput = true;
-  } else if ((OI.DebugInfoKind == IRGenDebugInfoKind::Normal &&
+  } else if ((OI.DebugInfoKind > IRGenDebugInfoKind::LineTables &&
               OI.shouldLink()) ||
              Args.hasArg(options::OPT_emit_objc_header,
                          options::OPT_emit_objc_header_path)) {

lib/Driver/ToolChains.cpp

@@ -964,7 +964,7 @@ toolchains::Darwin::constructInvocation(const LinkJobAction &job,
 
   addInputsOfType(Arguments, context.InputActions, types::TY_Object);
 
-  if (context.OI.DebugInfoKind == IRGenDebugInfoKind::Normal) {
+  if (context.OI.DebugInfoKind > IRGenDebugInfoKind::LineTables) {
     size_t argCount = Arguments.size();
     if (context.OI.CompilerMode == OutputInfo::Mode::SingleCompile)
       addInputsOfType(Arguments, context.Inputs, types::TY_SwiftModuleFile);

lib/Frontend/CompilerInvocation.cpp

@@ -1143,11 +1143,13 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
       Opts.DebugInfoKind = IRGenDebugInfoKind::Normal;
     else if (A->getOption().matches(options::OPT_gline_tables_only))
       Opts.DebugInfoKind = IRGenDebugInfoKind::LineTables;
+    else if (A->getOption().matches(options::OPT_gdwarf_types))
+      Opts.DebugInfoKind = IRGenDebugInfoKind::DwarfTypes;
     else
       assert(A->getOption().matches(options::OPT_gnone) &&
              "unknown -g<kind> option");
 
-    if (Opts.DebugInfoKind == IRGenDebugInfoKind::Normal) {
+    if (Opts.DebugInfoKind > IRGenDebugInfoKind::LineTables) {
       ArgStringList RenderedArgs;
       for (auto A : Args)
         A->render(Args, RenderedArgs);