[clang][NFC] Consolidating usage of "FinalPhase" in Driver::BuildActions

[plotfi]

Summary

I am working to remove this concept of the "FinalPhase" in the clang driver, but it is used in a lot of different places to do argument handling for different combinatios of phase pipelines and arguments. I am trying to consolidate most of the uses of "FinalPhase" into its own separate scope.

[plotfi]

adding context

[compnerd]

Seems like it should be equivalent.

clang/lib/Driver/Driver.cpp

void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
                           const InputList &Inputs, ActionList &Actions) const {
   llvm::PrettyStackTraceString CrashInfo("Building compilation actions");
 
   if (!SuppressMissingInputWarning && Inputs.empty()) {
     Diag(clang::diag::err_drv_no_input_files);
     return;
   }
 
-  Arg *FinalPhaseArg;
-  phases::ID FinalPhase = getFinalPhase(Args, &FinalPhaseArg);
-
-  if (FinalPhase == phases::Link) {
-    if (Args.hasArg(options::OPT_emit_llvm))
-      Diag(clang::diag::err_drv_emit_llvm_link);
-    if (IsCLMode() && LTOMode != LTOK_None &&
-        !Args.getLastArgValue(options::OPT_fuse_ld_EQ).equals_lower("lld"))
-      Diag(clang::diag::err_drv_lto_without_lld);
-  }
-
   // Reject -Z* at the top level, these options should never have been exposed
   // by gcc.
   if (Arg *A = Args.getLastArg(options::OPT_Z_Joined))
     Diag(clang::diag::err_drv_use_of_Z_option) << A->getAsString(Args);
 
   // Diagnose misuse of /Fo.
   if (Arg *A = Args.getLastArg(options::OPT__SLASH_Fo)) {
     StringRef V = A->getValue();
if (YcArg && YuArg && strcmp(YcArg->getValue(), YuArg->getValue()) != 0) {
     Args.eraseArg(options::OPT__SLASH_Yu);
     YcArg = YuArg = nullptr;
   }
   if (YcArg && Inputs.size() > 1) {
     Diag(clang::diag::warn_drv_yc_multiple_inputs_clang_cl);
     Args.eraseArg(options::OPT__SLASH_Yc);
     YcArg = nullptr;
   }
-  if (FinalPhase == phases::Preprocess || Args.hasArg(options::OPT__SLASH_Y_)) {
+
+  // Builder to be used to build offloading actions.
+  OffloadingActionBuilder OffloadBuilder(C, Args, Inputs);
+
+  // Construct the actions to perform.
+  HeaderModulePrecompileJobAction *HeaderModuleAction = nullptr;
+  ActionList LinkerInputs;
+
+  phases::ID FinalPhase;
+  {
+    Arg *FinalPhaseArg;
+    FinalPhase = getFinalPhase(Args, &FinalPhaseArg);
+
+    if (FinalPhase == phases::Link) {
+      if (Args.hasArg(options::OPT_emit_llvm))
+        Diag(clang::diag::err_drv_emit_llvm_link);
+      if (IsCLMode() && LTOMode != LTOK_None &&
+          !Args.getLastArgValue(options::OPT_fuse_ld_EQ).equals_lower("lld"))
+        Diag(clang::diag::err_drv_lto_without_lld);
+    }
+
+    if (FinalPhase == phases::Preprocess ||
+        Args.hasArg(options::OPT__SLASH_Y_)) {
       // If only preprocessing or /Y- is used, all pch handling is disabled.
       // Rather than check for it everywhere, just remove clang-cl pch-related
       // flags here.
       Args.eraseArg(options::OPT__SLASH_Fp);
       Args.eraseArg(options::OPT__SLASH_Yc);
       Args.eraseArg(options::OPT__SLASH_Yu);
       YcArg = YuArg = nullptr;
     }
 
-  // Builder to be used to build offloading actions.
-  OffloadingActionBuilder OffloadBuilder(C, Args, Inputs);
-
-  // Construct the actions to perform.
-  HeaderModulePrecompileJobAction *HeaderModuleAction = nullptr;
-  ActionList LinkerInputs;
-
     unsigned LastPLSize = 0;
     for (auto &I : Inputs) {
       types::ID InputType = I.first;
       const Arg *InputArg = I.second;
 
       llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases> PL;
       types::getCompilationPhases(InputType, PL);
       LastPLSize = PL.size();
for (auto &I : Inputs) {
         // Special case when final phase determined by binary name, rather than
         // by a command-line argument with a corresponding Arg.
         if (CCCIsCPP())
           Diag(clang::diag::warn_drv_input_file_unused_by_cpp)
               << InputArg->getAsString(Args) << getPhaseName(InitialPhase);
         // Special case '-E' warning on a previously preprocessed file to make
         // more sense.
         else if (InitialPhase == phases::Compile &&
-               FinalPhase == phases::Preprocess &&
+                 (Args.getLastArg(options::OPT__SLASH_EP,
+                                  options::OPT__SLASH_P) ||
+                  Args.getLastArg(options::OPT_E) ||
+                  Args.getLastArg(options::OPT_M, options::OPT_MM)) &&
                  getPreprocessedType(InputType) == types::TY_INVALID)
           Diag(clang::diag::warn_drv_preprocessed_input_file_unused)
               << InputArg->getAsString(Args) << !!FinalPhaseArg
               << (FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "");
         else
           Diag(clang::diag::warn_drv_input_file_unused)
               << InputArg->getAsString(Args) << getPhaseName(InitialPhase)
               << !!FinalPhaseArg
               << (FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "");
         continue;
       }
 
       if (YcArg) {
         // Add a separate precompile phase for the compile phase.
         if (FinalPhase >= phases::Compile) {
           const types::ID HeaderType = lookupHeaderTypeForSourceType(InputType);
           llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases> PCHPL;
           types::getCompilationPhases(HeaderType, PCHPL);
           // Build the pipeline for the pch file.
-        Action *ClangClPch =
-            C.MakeAction<InputAction>(*InputArg, HeaderType);
+          Action *ClangClPch = C.MakeAction<InputAction>(*InputArg, HeaderType);
           for (phases::ID Phase : PCHPL)
             ClangClPch = ConstructPhaseAction(C, Args, Phase, ClangClPch);
           assert(ClangClPch);
           Actions.push_back(ClangClPch);
           // The driver currently exits after the first failed command.  This
           // relies on that behavior, to make sure if the pch generation fails,
           // the main compilation won't run.
           // FIXME: If the main compilation fails, the PCH generation should
           // probably not be considered successful either.
         }
       }
+    }
+
+    // If we are linking, claim any options which are obviously only used for
+    // compilation.
+    // FIXME: Understand why the last Phase List length is used here.
+    if (FinalPhase == phases::Link && LastPLSize == 1) {
+      Args.ClaimAllArgs(options::OPT_CompileOnly_Group);
+      Args.ClaimAllArgs(options::OPT_cl_compile_Group);
+    }
+  }
+
+  for (auto &I : Inputs) {
+    types::ID InputType = I.first;
+    const Arg *InputArg = I.second;
+
+    llvm::SmallVector<phases::ID, phases::MaxNumberOfPhases> PL;
+    types::getCompilationPhases(InputType, PL);
+    if (PL[0] > FinalPhase)
+      continue;
 
     // Build the pipeline for this file.
     Action *Current = C.MakeAction<InputAction>(*InputArg, InputType);
 
     // Use the current host action in any of the offloading actions, if
     // required.
     if (OffloadBuilder.addHostDependenceToDeviceActions(Current, InputArg))
       break;
void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
 
   // Add a link action if necessary.
   if (!LinkerInputs.empty()) {
     Action *LA = C.MakeAction<LinkJobAction>(LinkerInputs, types::TY_Image);
     LA = OffloadBuilder.processHostLinkAction(LA);
     Actions.push_back(LA);
   }
 
-  // If we are linking, claim any options which are obviously only used for
-  // compilation.
-  // FIXME: Understand why the last Phase List length is used here.
-  if (FinalPhase == phases::Link && LastPLSize == 1) {
-    Args.ClaimAllArgs(options::OPT_CompileOnly_Group);
-    Args.ClaimAllArgs(options::OPT_cl_compile_Group);
-  }
-
   // If --print-supported-cpus, -mcpu=? or -mtune=? is specified, build a custom
   // Compile phase that prints out supported cpu models and quits.
   if (Arg *A = Args.getLastArg(options::OPT_print_supported_cpus)) {
     // Use the -mcpu=? flag as the dummy input to cc1.
     Actions.clear();
     Action *InputAc = C.MakeAction<InputAction>(*A, types::TY_C);
     Actions.push_back(
         C.MakeAction<PrecompileJobAction>(InputAc, types::TY_Nothing));