[flang][nfc] Simplify option forwarding

[awarzynski]

Summary

Use AddAllArgs to keep the implementation succinct. Also adds missing
'-flang-experimental-hlfir` in "frontend-forwarding.f90"

[kiranchandramohan]

LG.

clang/lib/Driver/ToolChains/Flang.cpp

146–147

Is the order changing in the tests below (poly before hlfir) expected?

[awarzynski]

Thanks for taking a look!

clang/lib/Driver/ToolChains/Flang.cpp

146–147

Yes. AddAllArgs will consume -flang-experimental-polymorphism first because:

• it satisfies the condition specified here (i.e. either -flang-experimental-hlfir or -flang-experimental-polymorphism ), and
• that's the first option it encounters (i.e. it is specified before -flang-experimental-hlfir in the test file).

clang/lib/Driver/ToolChains/Flang.cpp

void Flang::addCodegenOptions(const ArgList &Args,
                               ArgStringList &CmdArgs) const {
   Arg *stackArrays =
       Args.getLastArg(options::OPT_Ofast, options::OPT_fstack_arrays,
                       options::OPT_fno_stack_arrays);
   if (stackArrays &&
       !stackArrays->getOption().matches(options::OPT_fno_stack_arrays))
     CmdArgs.push_back("-fstack-arrays");
 
-  if (Args.hasArg(options::OPT_flang_experimental_hlfir))
-    CmdArgs.push_back("-flang-experimental-hlfir");
-  if (Args.hasArg(options::OPT_flang_experimental_polymorphism))
-    CmdArgs.push_back("-flang-experimental-polymorphism");
   if (shouldLoopVersion(Args))
     CmdArgs.push_back("-fversion-loops-for-stride");
+
+  Args.AddAllArgs(CmdArgs, {options::OPT_flang_experimental_hlfir,
+                            options::OPT_flang_experimental_polymorphism});
 }
 
 void Flang::addPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
   // ParsePICArgs parses -fPIC/-fPIE and their variants and returns a tuple of
   // (RelocationModel, PICLevel, IsPIE).
   llvm::Reloc::Model RelocationModel;
   unsigned PICLevel;
   bool IsPIE;

flang/test/Driver/frontend-forwarding.f90

 ! RUN:     -fno-honor-nans \
 ! RUN:     -fapprox-func \
 ! RUN:     -fno-signed-zeros \
 ! RUN:     -fassociative-math \
 ! RUN:     -freciprocal-math \
 ! RUN:     -fpass-plugin=Bye%pluginext \
 ! RUN:     -fversion-loops-for-stride \
 ! RUN:     -flang-experimental-polymorphism \
+! RUN:     -flang-experimental-hlfir \
 ! RUN:     -mllvm -print-before-all \
 ! RUN:     -save-temps=obj \
 ! RUN:     -P \
 ! RUN:   | FileCheck %s
 
 ! CHECK: "-P"
 ! CHECK: "-finput-charset=utf-8"
 ! CHECK: "-fdefault-double-8"
 ! CHECK: "-fdefault-integer-8"
 ! CHECK: "-fdefault-real-8"
 ! CHECK: "-flarge-sizes"
 ! CHECK: "-ffp-contract=fast"
 ! CHECK: "-menable-no-nans"
 ! CHECK: "-fapprox-func"
 ! CHECK: "-fno-signed-zeros"
 ! CHECK: "-mreassociate"
 ! CHECK: "-freciprocal-math"
 ! CHECK: "-fconvert=little-endian"
 ! CHECK: "-fpass-plugin=Bye
-! CHECK: "-flang-experimental-polymorphism"
 ! CHECK: "-fversion-loops-for-stride"
+! CHECK: "-flang-experimental-polymorphism"
+! CHECK: "-flang-experimental-hlfir"
 ! CHECK: "-mllvm" "-print-before-all"
 ! CHECK: "-save-temps=obj"