Fix for breaking -fpass-plugin patch

[tarunprabhu]

Summary

Try to fix the patch from https://reviews.llvm.org/D129156.

clang/include/clang/Driver/Options.td

defm rwpi : BoolFOption<"rwpi",
   PosFlag<SetTrue, [CC1Option], "Generate read-write position independent code (ARM only)">,
   NegFlag<SetFalse>>;
 def fplugin_EQ : Joined<["-"], "fplugin=">, Group<f_Group>, Flags<[NoXarchOption]>, MetaVarName<"<dsopath>">,
   HelpText<"Load the named plugin (dynamic shared object)">;
 def fplugin_arg : Joined<["-"], "fplugin-arg-">,
   MetaVarName<"<name>-<arg>">,
   HelpText<"Pass <arg> to plugin <name>">;
 def fpass_plugin_EQ : Joined<["-"], "fpass-plugin=">,
-  Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<dsopath>">,
+  Group<f_Group>, Flags<[CC1Option,FlangOption,FC1Option]>, MetaVarName<"<dsopath>">,
   HelpText<"Load pass plugin from a dynamic shared object file (only with new pass manager).">,
   MarshallingInfoStringVector<CodeGenOpts<"PassPlugins">>;
 defm preserve_as_comments : BoolFOption<"preserve-as-comments",
   CodeGenOpts<"PreserveAsmComments">, DefaultTrue,
   NegFlag<SetFalse, [CC1Option], "Do not preserve comments in inline assembly">,
   PosFlag<SetTrue>>;
 def framework : Separate<["-"], "framework">, Flags<[LinkerInput]>;
 def frandom_seed_EQ : Joined<["-"], "frandom-seed=">, Group<clang_ignored_f_Group>;

clang/lib/Driver/ToolChains/Flang.cpp

Args.AddAllArgs(CmdArgs,
                   {options::OPT_P, options::OPT_D, options::OPT_U,
                    options::OPT_I, options::OPT_cpp, options::OPT_nocpp});
 }
 
 void Flang::AddOtherOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
   Args.AddAllArgs(CmdArgs,
                   {options::OPT_module_dir, options::OPT_fdebug_module_writer,
                    options::OPT_fintrinsic_modules_path, options::OPT_pedantic,
-                   options::OPT_std_EQ, options::OPT_W_Joined});
+                   options::OPT_std_EQ, options::OPT_W_Joined,
+                   options::OPT_fpass_plugin_EQ});
 }
 
 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/docs/FlangDriver.md

 trivial. Please take this into consideration when designing your plugin. In
 particular, creating a transformation plugin will be noticeably harder than
 analysis plugins that just consume (rather than edit) `ParseTree`.
 
 Lastly, if `ParseTree` modifications are performed, then it might be necessary
 to re-analyze expressions and modify scope or symbols. You can check
 [Semantics.md](Semantics.md) for more details on how `ParseTree` is edited
 e.g. during the semantic checks.
+
+# LLVM Pass Plugins
+
+Pass plugins are dynamic shared objects that consist of one or more LLVM IR
+passes. The `-fpass-plugin` option enables these passes to be passed to the 
+middle-end where they are added to the optimization pass pipeline and run after
+lowering to LLVM IR.The exact position of the pass in the pipeline will depend 
+on how it has been registered with the `llvm::PassBuilder`. See the 
+documentation for 
+[`llvm::PassBuilder`](https://llvm.org/doxygen/classllvm_1_1PassBuilder.html)
+for details. 
+
+The framework to enable pass plugins in `flang-new` uses the exact same 
+machinery as that used by `clang` and thus has the same capabilities and
+limitations. 
+
+In order to use a pass plugin, the pass(es) must be compiled into a dynamic 
+shared object which is then loaded using the `-fpass-plugin` option. 
+
+```
+flang-new -fpass-plugin=/path/to/plugin.so <file.f90>
+```
+
+This option is available in both the compiler driver and the frontend driver. 
+Note that LLVM plugins are not officially supported on Windows.

flang/docs/ReleaseNotes.md

 
 Note that if you are reading this file from a Git checkout, this
 document applies to the *next* release, not the current one. To see the
 release notes for a specific release, please see the [releases
 page](https://llvm.org/releases/).
 
 ## Major New Features
 
+* Flang now supports loading LLVM pass plugins with the `-fpass-plugin` option
+  which is also available in clang. The option mimics the behavior of the
+  corresponding option in clang and has the same capabilities and limitations.
+
 ## Bug Fixes
 
 ## Non-comprehensive list of changes in this release
 * The bash wrapper script, `flang`, is renamed as `flang-to-external-fc`.
 * In contrast to Clang, Flang will not default to using `-fpie` when linking
   executables. This is only a temporary solution and the goal is to align with
   Clang in the near future. First, however, the frontend driver needs to be
   extended so that it can generate position independent code (that requires

flang/include/flang/Frontend/CodeGenOptions.h

 #include "flang/Frontend/CodeGenOptions.def"
 };
 
 /// Tracks various options which control how the code is optimized and passed
 /// to the LLVM backend.
 class CodeGenOptions : public CodeGenOptionsBase {
 
 public:
+  /// The paths to the pass plugins that were registered using -fpass-plugin.
+  std::vector<std::string> LLVMPassPlugins;
+
   // Define accessors/mutators for code generation options of enumeration type.
 #define CODEGENOPT(Name, Bits, Default)
 #define ENUM_CODEGENOPT(Name, Type, Bits, Default)                             \
   Type get##Name() const { return static_cast<Type>(Name); }                   \
   void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
 #include "flang/Frontend/CodeGenOptions.def"
 
   CodeGenOptions();
 };
 
 } // end namespace Fortran::frontend
 
 #endif

flang/lib/Frontend/CompilerInvocation.cpp

static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
                              llvm::opt::ArgList &args,
                              clang::DiagnosticsEngine &diags) {
   opts.OptimizationLevel = getOptimizationLevel(args, diags);
 
   if (args.hasFlag(clang::driver::options::OPT_fdebug_pass_manager,
                    clang::driver::options::OPT_fno_debug_pass_manager, false))
     opts.DebugPassManager = 1;
 
+  for (auto *a : args.filtered(clang::driver::options::OPT_fpass_plugin_EQ))
+    opts.LLVMPassPlugins.push_back(a->getValue());
+
   // -mrelocation-model option.
   if (const llvm::opt::Arg *A =
           args.getLastArg(clang::driver::options::OPT_mrelocation_model)) {
     llvm::StringRef ModelName = A->getValue();
     auto RM = llvm::StringSwitch<llvm::Optional<llvm::Reloc::Model>>(ModelName)
                   .Case("static", llvm::Reloc::Static)
                   .Case("pic", llvm::Reloc::PIC_)
                   .Case("dynamic-no-pic", llvm::Reloc::DynamicNoPIC)

flang/lib/Frontend/FrontendActions.cpp

 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/PassPlugin.h"
 #include "llvm/Passes/StandardInstrumentations.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Target/TargetMachine.h"
 #include <memory>
 
 using namespace Fortran::frontend;
 
static void generateMachineCodeOrAssemblyImpl(clang::DiagnosticsEngine &diags,
   }
 
   // Run the passes
   codeGenPasses.run(llvmModule);
 }
 
 void CodeGenAction::runOptimizationPipeline(llvm::raw_pwrite_stream &os) {
   auto opts = getInstance().getInvocation().getCodeGenOpts();
+  auto &diags = getInstance().getDiagnostics();
   llvm::OptimizationLevel level = mapToLevel(opts);
 
   // Create the analysis managers.
   llvm::LoopAnalysisManager lam;
   llvm::FunctionAnalysisManager fam;
   llvm::CGSCCAnalysisManager cgam;
   llvm::ModuleAnalysisManager mam;
 
   // Create the pass manager builder.
   llvm::PassInstrumentationCallbacks pic;
   llvm::PipelineTuningOptions pto;
   llvm::Optional<llvm::PGOOptions> pgoOpt;
   llvm::StandardInstrumentations si(opts.DebugPassManager);
   si.registerCallbacks(pic, &fam);
   llvm::PassBuilder pb(tm.get(), pto, pgoOpt, &pic);
 
+  // Attempt to load pass plugins and register their callbacks with PB.
+  for (auto &pluginFile : opts.LLVMPassPlugins) {
+    auto passPlugin = llvm::PassPlugin::Load(pluginFile);
+    if (passPlugin) {
+      passPlugin->registerPassBuilderCallbacks(pb);
+    } else {
+      diags.Report(clang::diag::err_fe_unable_to_load_plugin)
+          << pluginFile << passPlugin.takeError();
+    }
+  }
+
   // Register all the basic analyses with the managers.
   pb.registerModuleAnalyses(mam);
   pb.registerCGSCCAnalyses(cgam);
   pb.registerFunctionAnalyses(fam);
   pb.registerLoopAnalyses(lam);
   pb.crossRegisterProxies(lam, fam, cgam, mam);
 
   // Create the pass manager.

flang/test/Driver/driver-help-hidden.f90

 ! CHECK-NEXT:                        Enable support for generating executables (experimental)
 ! CHECK-NEXT: -flarge-sizes          Use INTEGER(KIND=8) for the result type in size-related intrinsics
 ! CHECK-NEXT: -flogical-abbreviations Enable logical abbreviations
 ! CHECK-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! CHECK-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! CHECK-NEXT: -fno-integrated-as     Disable the integrated assembler
 ! CHECK-NEXT: -fopenacc              Enable OpenACC
 ! CHECK-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
+! CHECK-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! CHECK-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages
 ! CHECK-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.
 ! CHECK-NEXT: -help     Display available options
 ! CHECK-NEXT: -I <dir>               Add directory to the end of the list of include search paths
 ! CHECK-NEXT: -mllvm <value>         Additional arguments to forward to LLVM's option processing
 ! CHECK-NEXT: -mmlir <value>         Additional arguments to forward to MLIR's option processing
 ! CHECK-NEXT: -module-dir <dir>      Put MODULE files in <dir>
 ! CHECK-NEXT: -nocpp                 Disable predefined and command line preprocessor macros

 ! CHECK-NEXT: --version Print version information
 ! CHECK-NEXT: -W<warning>            Enable the specified warning
 ! CHECK-NEXT: -Xflang <arg>          Pass <arg> to the flang compiler
 
 ! ERROR-FLANG: error: unknown argument '-help-hidden'; did you mean '--help-hidden'?
 
 ! Frontend driver -help-hidden is not supported
 ! ERROR-FLANG-FC1: error: unknown argument: '{{.*}}'
-

flang/test/Driver/driver-help.f90

 ! HELP-NEXT:                        Specify where to find the compiled intrinsic modules
 ! HELP-NEXT: -flarge-sizes          Use INTEGER(KIND=8) for the result type in size-related intrinsics
 ! HELP-NEXT: -flogical-abbreviations Enable logical abbreviations
 ! HELP-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! HELP-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! HELP-NEXT: -fno-integrated-as      Disable the integrated assembler
 ! HELP-NEXT: -fopenacc              Enable OpenACC
 ! HELP-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
+! HELP-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! HELP-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages
 ! HELP-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.
 ! HELP-NEXT: -help                  Display available options
 ! HELP-NEXT: -I <dir>               Add directory to the end of the list of include search paths
 ! HELP-NEXT: -mllvm <value>         Additional arguments to forward to LLVM's option processing
 ! HELP-NEXT: -mmlir <value>         Additional arguments to forward to MLIR's option processing
 ! HELP-NEXT: -module-dir <dir>      Put MODULE files in <dir>
 ! HELP-NEXT: -nocpp                 Disable predefined and command line preprocessor macros

 ! HELP-FC1-NEXT: -flogical-abbreviations Enable logical abbreviations
 ! HELP-FC1-NEXT: -fno-analyzed-objects-for-unparse
 ! HELP-FC1-NEXT:                        Do not use the analyzed objects when unparsing
 ! HELP-FC1-NEXT: -fno-automatic         Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE
 ! HELP-FC1-NEXT: -fno-debug-pass-manager Disables debug printing for the new pass manager
 ! HELP-FC1-NEXT: -fno-reformat          Dump the cooked character stream in -E mode
 ! HELP-FC1-NEXT: -fopenacc              Enable OpenACC
 ! HELP-FC1-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
+! HELP-FC1-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! HELP-FC1-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages
 ! HELP-FC1-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.
 ! HELP-FC1-NEXT: -help                  Display available options
 ! HELP-FC1-NEXT: -init-only             Only execute frontend initialization
 ! HELP-FC1-NEXT: -I <dir>               Add directory to the end of the list of include search paths
 ! HELP-FC1-NEXT: -load <dsopath>        Load the named plugin (dynamic shared object)
 ! HELP-FC1-NEXT: -mllvm <value>         Additional arguments to forward to LLVM's option processing
 ! HELP-FC1-NEXT: -mmlir <value>         Additional arguments to forward to MLIR's option processing

flang/test/Driver/frontend-forwarding.f90

 ! Test that flang-new forwards Flang frontend
 ! options to flang-new -fc1 as expected.
 
 ! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \
 ! RUN:     -finput-charset=utf-8 \
 ! RUN:     -fdefault-double-8 \
 ! RUN:     -fdefault-integer-8 \
 ! RUN:     -fdefault-real-8 \
 ! RUN:     -flarge-sizes \
+! RUN:     -fpass-plugin=Bye%pluginext \
 ! RUN:     -mllvm -print-before-all\
 ! 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:  "-mllvm" "-print-before-all"
+! CHECK: "-fpass-plugin=Bye
+! CHECK: "-mllvm" "-print-before-all"

flang/test/Driver/pass-plugin-not-found.f90

+! Check the correct error diagnostic is reported when a pass plugin shared object isn't found
+
+! REQUIRES: plugins, shell
+
+! RUN: not %flang -fpass-plugin=X.Y %s 2>&1 | FileCheck %s --check-prefix=ERROR
+! RUN: not %flang_fc1 -emit-llvm -o /dev/null -fpass-plugin=X.Y %s 2>&1 | FileCheck %s --check-prefix=ERROR
+
+! ERROR: error: unable to load plugin 'X.Y': 'Could not load library 'X.Y': X.Y: cannot open shared object file: No such file or directory'

flang/test/Driver/pass-plugin.f90

+! Verify that the plugin passed to -fpass-plugin is loaded and run
+
+! UNSUPPORTED: system-windows
+
+! REQUIRES: examples, plugins, shell
+
+! RUN: %flang -S %s -fpass-plugin=%llvmshlibdir/Bye%pluginext -Xflang -fdebug-pass-manager -o /dev/null 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -S %s -fpass-plugin=%llvmshlibdir/Bye%pluginext -fdebug-pass-manager -o /dev/null 2>&1 | FileCheck %s
+
+! CHECK: Running pass: {{.*}}Bye on empty_
+
+subroutine empty
+end subroutine empty