[PATCH] D85799: [DebugInfo] Add -fuse-ctor-homing cc1 flag so we can turn on constructor homing only if limited debug info is already on.

[Amy Huang via Phabricator via cfe-commits]

akhuang created this revision.
akhuang added reviewers: dblaikie, aprantl, MaskRay.
Herald added subscribers: cfe-commits, dang.
Herald added a project: clang.
akhuang requested review of this revision.

This adds a cc1 flag to enable constructor homing but doesn't turn on debug
info if it wasn't enabled already (which is what using
-debug-info-kind=constructor does). This will be used for testing, and won't
be needed anymore once ctor homing is used as default / merged into =limited.

Bug to enable ctor homing: https://bugs.llvm.org/show_bug.cgi?id=46537


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D85799

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Frontend/CompilerInvocation.cpp


Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -775,6 +775,12 @@
     else
       Opts.setDebugInfo(static_cast<codegenoptions::DebugInfoKind>(Val));
   }
+  // If -fuse-ctor-homing is set and limited debug info is already on, then use
+  // constructor homing.
+  if (Arg *A = Args.getLastArg(OPT_fuse_ctor_homing))
+    if (Opts.getDebugInfo() == codegenoptions::LimitedDebugInfo)
+      Opts.setDebugInfo(codegenoptions::DebugInfoConstructor);
+
   if (Arg *A = Args.getLastArg(OPT_debugger_tuning_EQ)) {
     unsigned Val = llvm::StringSwitch<unsigned>(A->getValue())
                        .Case("gdb", unsigned(llvm::DebuggerKind::GDB))
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -3691,6 +3691,8 @@
   AutoNormalizeEnum;
 def fno_math_builtin : Flag<["-"], "fno-math-builtin">,
   HelpText<"Disable implicit builtin knowledge of math functions">;
+def fuse_ctor_homing: Flag<["-"], "fuse-ctor-homing">,
+    HelpText<"Use constructor homing if we are using limited debug info already">;
 }
 
 def disable_llvm_verifier : Flag<["-"], "disable-llvm-verifier">,


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