[clang] Remove duplication in types::getCompilationPhases()

[thakis]

Summary

Call Driver::getFinalPhase() instead of duplicating it.

https://reviews.llvm.org/D65993 added the duplication, then
02e35832c301e maded it more obviously a copy of getFinalPhase().

The only difference is that getCompilationPhases() used to use
LastPhase / IfsMerge where getFinalPhase() used Link. Adapt
getFinalPhase() to return IfsMerge when needed.

No intentional behavior change.

[hans]

clang/include/clang/Driver/Phases.h

25

Any reason not to keep the LastPhase alias?

[thakis]

clang/include/clang/Driver/Phases.h

25

I found it more confusing than helpful. Link and LastPhase both start with L and it took me a while to realize that the last return in getFinalPhase() was Link, but the last one in was getCompilationPhases(). For the call on line 3847, passing phases::IfsMerge is clearer. And then there's only one use of it left (the default arg), and it doesn't add a ton of clarity there imho. But maybe I subconsciously feel vengeful because I lost 10 minutes due to misreading it for Link :) If you want me to put it back, let me know and I'll do so.

[hans]

lgtm

clang/include/clang/Driver/Phases.h

25

No, that sounds reasonable, let's keep your patch as it is.

[thakis]

Thanks!

clang/include/clang/Driver/Driver.h

private:
   unsigned CheckInputsExist : 1;
 
 public:
   /// Force clang to emit reproducer for driver invocation. This is enabled
   /// indirectly by setting FORCE_CLANG_DIAGNOSTICS_CRASH environment variable
   /// or when using the -gen-reproducer driver flag.
   unsigned GenReproducer : 1;
 
+  // getFinalPhase - Determine which compilation mode we are in and record
+  // which option we used to determine the final phase.
+  // TODO: Much of what getFinalPhase returns are not actually true compiler
+  //       modes. Fold this functionality into Types::getCompilationPhases and
+  //       handleArguments.
+  phases::ID getFinalPhase(const llvm::opt::DerivedArgList &DAL,
+                           llvm::opt::Arg **FinalPhaseArg = nullptr) const;
+
 private:
   /// Certain options suppress the 'no input files' warning.
   unsigned SuppressMissingInputWarning : 1;
 
   /// Cache of all the ToolChains in use by the driver.
   ///
   /// This maps from the string representation of a triple to a ToolChain
   /// created targeting that triple. The driver owns all the ToolChain objects
   /// stored in it, and will clean them up when torn down.
   mutable llvm::StringMap<std::unique_ptr<ToolChain>> ToolChains;
 
 private:
   /// TranslateInputArgs - Create a new derived argument list from the input
   /// arguments, after applying the standard argument translations.
   llvm::opt::DerivedArgList *
   TranslateInputArgs(const llvm::opt::InputArgList &Args) const;
 
-  // getFinalPhase - Determine which compilation mode we are in and record
-  // which option we used to determine the final phase.
-  // TODO: Much of what getFinalPhase returns are not actually true compiler
-  //       modes. Fold this functionality into Types::getCompilationPhases and
-  //       handleArguments.
-  phases::ID getFinalPhase(const llvm::opt::DerivedArgList &DAL,
-                           llvm::opt::Arg **FinalPhaseArg = nullptr) const;
-
   // handleArguments - All code related to claiming and printing diagnostics
   // related to arguments to the driver are done here.
   void handleArguments(Compilation &C, llvm::opt::DerivedArgList &Args,
                        const InputList &Inputs, ActionList &Actions) const;
 
   // Before executing jobs, sets up response files for commands that need them.
   void setUpResponseFiles(Compilation &C, Command &Cmd);
 

clang/include/clang/Driver/Phases.h

namespace phases {
   enum ID {
     Preprocess,
     Precompile,
     Compile,
     Backend,
     Assemble,
     Link,
     IfsMerge,
-    LastPhase = IfsMerge,
   };
 
   enum {
-    MaxNumberOfPhases = LastPhase + 1
+    MaxNumberOfPhases = IfsMerge + 1
   };
 
   const char *getPhaseName(ID Id);
 
 } // end namespace phases
 } // end namespace driver
 } // end namespace clang
 
 #endif

clang/include/clang/Driver/Types.h

#undef TYPE
 
   /// lookupTypeForTypSpecifier - Lookup the type to use for a user
   /// specified type name.
   ID lookupTypeForTypeSpecifier(const char *Name);
 
   /// getCompilationPhases - Get the list of compilation phases ('Phases') to be
   /// done for type 'Id' up until including LastPhase.
   llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases>
-  getCompilationPhases(ID Id, phases::ID LastPhase = phases::LastPhase);
+  getCompilationPhases(ID Id, phases::ID LastPhase = phases::IfsMerge);
   llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases>
   getCompilationPhases(const clang::driver::Driver &Driver,
                        llvm::opt::DerivedArgList &DAL, ID Id);
 
   /// lookupCXXTypeForCType - Lookup CXX input type that corresponds to given
   /// C type (used for clang++ emulation of g++ behaviour)
   ID lookupCXXTypeForCType(ID Id);
 

clang/lib/Driver/Driver.cpp

phases::ID Driver::getFinalPhase(const DerivedArgList &DAL,
   // -S only runs up to the backend.
   } else if ((PhaseArg = DAL.getLastArg(options::OPT_S))) {
     FinalPhase = phases::Backend;
 
   // -c compilation only runs up to the assembler.
   } else if ((PhaseArg = DAL.getLastArg(options::OPT_c))) {
     FinalPhase = phases::Assemble;
 
+  } else if ((PhaseArg = DAL.getLastArg(options::OPT_emit_interface_stubs))) {
+    FinalPhase = phases::IfsMerge;
+
   // Otherwise do everything.
   } else
     FinalPhase = phases::Link;
 
   if (FinalPhaseArg)
     *FinalPhaseArg = PhaseArg;
 
   return FinalPhase;
void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
   // Add an interface stubs merge action if necessary.
   if (!MergerInputs.empty())
     Actions.push_back(
         C.MakeAction<IfsMergeJobAction>(MergerInputs, types::TY_Image));
 
   if (Args.hasArg(options::OPT_emit_interface_stubs)) {
     auto PhaseList = types::getCompilationPhases(
         types::TY_IFS_CPP,
-        Args.hasArg(options::OPT_c) ? phases::Compile : phases::LastPhase);
+        Args.hasArg(options::OPT_c) ? phases::Compile : phases::IfsMerge);
 
     ActionList MergerInputs;
 
     for (auto &I : Inputs) {
       types::ID InputType = I.first;
       const Arg *InputArg = I.second;
 
       // Currently clang and the llvm assembler do not support generating symbol

clang/lib/Driver/Types.cpp

if (Info.Phases.contains(static_cast<phases::ID>(I)))
       P.push_back(static_cast<phases::ID>(I));
   assert(P.size() <= phases::MaxNumberOfPhases && "Too many phases in list");
   return P;
 }
 
 llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases>
 types::getCompilationPhases(const clang::driver::Driver &Driver,
                             llvm::opt::DerivedArgList &DAL, ID Id) {
-  phases::ID LastPhase;
-
-  // Filter to compiler mode. When the compiler is run as a preprocessor then
-  // compilation is not an option.
-  // -S runs the compiler in Assembly listing mode.
-  if (Driver.CCCIsCPP() || DAL.getLastArg(options::OPT_E) ||
-      DAL.getLastArg(options::OPT__SLASH_EP) ||
-      DAL.getLastArg(options::OPT_M, options::OPT_MM) ||
-      DAL.getLastArg(options::OPT__SLASH_P))
-    LastPhase = phases::Preprocess;
-
-  // --precompile only runs up to precompilation.
-  // This is a clang extension and is not compatible with GCC.
-  else if (DAL.getLastArg(options::OPT__precompile))
-    LastPhase = phases::Precompile;
-
-  // -{fsyntax-only,-analyze,emit-ast} only run up to the compiler.
-  else if (DAL.getLastArg(options::OPT_fsyntax_only) ||
-           DAL.getLastArg(options::OPT_print_supported_cpus) ||
-           DAL.getLastArg(options::OPT_module_file_info) ||
-           DAL.getLastArg(options::OPT_verify_pch) ||
-           DAL.getLastArg(options::OPT_rewrite_objc) ||
-           DAL.getLastArg(options::OPT_rewrite_legacy_objc) ||
-           DAL.getLastArg(options::OPT__migrate) ||
-           DAL.getLastArg(options::OPT__analyze) ||
-           DAL.getLastArg(options::OPT_emit_ast))
-    LastPhase = phases::Compile;
-
-  else if (DAL.getLastArg(options::OPT_S) ||
-           DAL.getLastArg(options::OPT_emit_llvm))
-    LastPhase = phases::Backend;
-
-  else if (DAL.getLastArg(options::OPT_c))
-    LastPhase = phases::Assemble;
-
-  // Generally means, do every phase until Link.
-  else
-    LastPhase = phases::LastPhase;
-
-  return types::getCompilationPhases(Id, LastPhase);
+  return types::getCompilationPhases(Id, Driver.getFinalPhase(DAL));
 }
 
 ID types::lookupCXXTypeForCType(ID Id) {
   switch (Id) {
   default:
     return Id;
 
   case types::TY_C: