Make options into BoolF types, remove added attribute

Author: SLTozer

clang/docs/ReleaseNotes.rst

@@ -417,11 +417,12 @@ New Compiler Flags
   will cause Clang to generate code that tries to preserve the lifetimes of
   source variables, meaning that variables will typically be visible in a
   debugger more often. The ``-fextend-this-ptr`` flag has the same behaviour,
-  but applies only to the ``this`` variable in C++ class member functions. Note
-  that this flag modifies the optimizations that Clang performs, which will
-  result in reduced performance in generated code; however, this feature will
-  not extend the lifetime of some variables in cases where doing so would have
-  too severe an impact on generated code performance.
+  but applies only to the ``this`` variable in C++ class member functions,
+  meaning its effect is a strict subset of ``-fextend-lifetimes``. Note that
+  this flag modifies the optimizations that Clang performs, which will result
+  in reduced performance in generated code; however, this feature will not
+  extend the lifetime of some variables in cases where doing so would have too
+  severe of an impact on generated code performance.
 
 Deprecated Compiler Flags
 -------------------------

clang/include/clang/Driver/Options.td

@@ -4298,15 +4298,18 @@ def stack_usage_file : Separate<["-"], "stack-usage-file">,
   Visibility<[CC1Option]>,
   HelpText<"Filename (or -) to write stack usage output to">,
   MarshallingInfoString<CodeGenOpts<"StackUsageOutput">>;
-def fextend_this_ptr : Flag <["-"], "fextend-this-ptr">, Group<f_Group>,
-  MarshallingInfoFlag<CodeGenOpts<"ExtendThisPtr">>,
-  HelpText<"Extend the lifetime of the 'this' pointer to improve visibility "
-           "in optimized debugging">, Visibility<[ClangOption, CC1Option]>;
-def fextend_lifetimes : Flag <["-"], "fextend-lifetimes">, Group<f_Group>,
-  MarshallingInfoFlag<CodeGenOpts<"ExtendLifetimes">>,
-  HelpText<"Extend the lifetimes of local variables and parameters to improve "
-           "visibility in optimized debugging">,
-           Visibility<[ClangOption, CC1Option]>;
+defm extend_this_ptr : BoolFOption<"extend-this-ptr",
+  CodeGenOpts<"ExtendThisPtr">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Extend the lifetime of the 'this' pointer to improve visibility "
+          "in optimized debugging">,
+  NegFlag<SetFalse>>;
+defm extend_lifetimes : BoolFOption<"extend-lifetimes",
+  CodeGenOpts<"ExtendLifetimes">, DefaultFalse,
+  PosFlag<SetTrue, [], [ClangOption, CC1Option],
+          "Extend the lifetimes of local variables and parameters to improve "
+          "visibility in optimized debugging">,
+  NegFlag<SetFalse>>;
 
 defm unique_basic_block_section_names : BoolFOption<"unique-basic-block-section-names",
   CodeGenOpts<"UniqueBasicBlockSectionNames">, DefaultFalse,

clang/lib/CodeGen/CGCall.cpp

@@ -2567,10 +2567,6 @@ void CodeGenModule::ConstructAttributeList(StringRef Name,
     if (shouldDisableTailCalls())
       FuncAttrs.addAttribute("disable-tail-calls", "true");
 
-    // Mark the function as having fake uses when -fextend-lifetimes is on.
-    if (CodeGenOpts.ExtendLifetimes || CodeGenOpts.ExtendThisPtr)
-      FuncAttrs.addAttribute(llvm::Attribute::HasFakeUses);
-
     // CPU/feature overrides.  addDefaultFunctionDefinitionAttributes
     // handles these separately to set them based on the global defaults.
     GetCPUAndFeaturesAttributes(CalleeInfo.getCalleeDecl(), FuncAttrs);

clang/lib/Driver/ToolChains/Clang.cpp

@@ -7654,10 +7654,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (Args.hasArg(options::OPT_fretain_comments_from_system_headers))
     CmdArgs.push_back("-fretain-comments-from-system-headers");
 
-  if (Args.hasArg(options::OPT_fextend_this_ptr))
-    CmdArgs.push_back("-fextend-this-ptr");
-  if (Args.hasArg(options::OPT_fextend_lifetimes))
-    CmdArgs.push_back("-fextend-lifetimes");
+  Args.addOptInFlag(CmdArgs, options::OPT_fextend_this_ptr,
+                    options::OPT_fno_extend_this_ptr);
+  Args.addOptInFlag(CmdArgs, options::OPT_fextend_lifetimes,
+                    options::OPT_fno_extend_lifetimes);
 
   // Forward -fcomment-block-commands to -cc1.
   Args.AddAllArgs(CmdArgs, options::OPT_fcomment_block_commands);

clang/lib/Frontend/CompilerInvocation.cpp

@@ -2245,11 +2245,6 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
                       Args.getAllArgValues(OPT_fsanitize_trap_EQ), Diags,
                       Opts.SanitizeTrap);
 
-  Opts.ExtendThisPtr =
-      Opts.OptimizationLevel > 0 && Args.hasArg(OPT_fextend_this_ptr);
-  Opts.ExtendLifetimes =
-      Opts.OptimizationLevel > 0 && Args.hasArg(OPT_fextend_lifetimes);
-
   Opts.EmitVersionIdentMetadata = Args.hasFlag(OPT_Qy, OPT_Qn, true);
 
   if (!LangOpts->CUDAIsDevice)