[DebugInfo] Enable call site parameter debug info for ARM and AArch64

[NikolaPrica]

Summary

ARM and AArch64 SelectionDAG support for tacking parameter forwarding register is implemented so we can allow clang invocations for those two targets.
Beside that restrict debug entry value support to be emitted for LimitedDebugInfo info and FullDebugInfo. Other types of debug info do not have functions nor variables debug info.

[vsk]

Update test/CodeGen/debug-info-param-modification.c?

lib/Frontend/CompilerInvocation.cpp

784

This helper would be easier to read as an out-of-line function, imo.

[dstenb]

lib/Frontend/CompilerInvocation.cpp

784

Or perhaps something like this?

const llvm::Triple::ArchType DebugEntryValueArchs[] = {llvm::Triple::x86, [...]};

llvm::is_contained(DebugEntryValueArchs, Arch)

[NikolaPrica]

Addressing comments.
Thanks for suggestions!

[aprantl]

lib/Frontend/CompilerInvocation.cpp

784

I suppose this is fine, but it would be more elegant if we could query the target whether it supports entry values.

[NikolaPrica]

lib/Frontend/CompilerInvocation.cpp

784

At this point target has not been initialized yet. I considered adding such support to TargetMachine or LLVMTargetMachine but then we would need to reset this option later at some point when this object is initialized.

[NikolaPrica]

Ping.

[vsk]

Lgtm, sorry for the delay.

lib/CodeGen/CGDebugInfo.cpp

void CGDebugInfo::EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
   DBuilder.retainType(SP);
 }
 
 void CGDebugInfo::EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
                                           QualType CalleeType,
                                           const FunctionDecl *CalleeDecl) {
   auto &CGOpts = CGM.getCodeGenOpts();
   if (!CGOpts.EnableDebugEntryValues || !CGM.getLangOpts().Optimize ||
-      !CallOrInvoke ||
-      CGM.getCodeGenOpts().getDebugInfo() < codegenoptions::LimitedDebugInfo)
+      !CallOrInvoke)
     return;
 
   auto *Func = CallOrInvoke->getCalledFunction();
   if (!Func)
     return;
 
   // If there is no DISubprogram attached to the function being called,
   // create the one describing the function in order to have complete

lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   if (const Arg *A =
           Args.getLastArg(OPT_emit_llvm_uselists, OPT_no_emit_llvm_uselists))
     Opts.EmitLLVMUseLists = A->getOption().getID() == OPT_emit_llvm_uselists;
 
   Opts.DisableLLVMPasses = Args.hasArg(OPT_disable_llvm_passes);
   Opts.DisableLifetimeMarkers = Args.hasArg(OPT_disable_lifetimemarkers);
 
+  auto isDebugEntryValueSupportedByArch = [](llvm::Triple::ArchType Arch) {
+    return Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64 ||
+           Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::arm ||
+           Arch == llvm::Triple::armeb;
+  };
+
   llvm::Triple T(TargetOpts.Triple);
-  llvm::Triple::ArchType Arch = T.getArch();
   if (Opts.OptimizationLevel > 0 &&
-      (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64))
+      Opts.getDebugInfo() >= codegenoptions::LimitedDebugInfo &&
+      isDebugEntryValueSupportedByArch(T.getArch()))
     Opts.EnableDebugEntryValues = Args.hasArg(OPT_femit_debug_entry_values);
 
   Opts.DisableO0ImplyOptNone = Args.hasArg(OPT_disable_O0_optnone);
   Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone);
   Opts.IndirectTlsSegRefs = Args.hasArg(OPT_mno_tls_direct_seg_refs);
   Opts.ForbidGuardVariables = Args.hasArg(OPT_fforbid_guard_variables);
   Opts.UseRegisterSizedBitfieldAccess = Args.hasArg(
     OPT_fuse_register_sized_bitfield_access);