Revert "[flang] Add -fpass-plugin option to Flang frontend"

This reverts commit 43fe6f7.

Reverting this as CI breaks.

To reproduce, run check-flang, and it will fail with an error saying
.../lib/Bye.so not found in pass-plugin.f90

clang/include/clang/Driver/Options.td

@@ -2710,7 +2710,7 @@ 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,FlangOption,FC1Option]>, MetaVarName<"<dsopath>">,
+  Group<f_Group>, Flags<[CC1Option]>, 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",

clang/lib/Driver/ToolChains/Flang.cpp

@@ -55,8 +55,7 @@ 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_fpass_plugin_EQ});
+                   options::OPT_std_EQ, options::OPT_W_Joined});
 }
 
 void Flang::AddPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const {

flang/docs/FlangDriver.md

@@ -507,28 +507,3 @@ 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

@@ -24,10 +24,6 @@ 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

flang/include/flang/Frontend/CodeGenOptions.h

@@ -46,9 +46,6 @@ class CodeGenOptionsBase {
 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)                             \

flang/lib/Frontend/CompilerInvocation.cpp

@@ -125,9 +125,6 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
                    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)) {

flang/lib/Frontend/FrontendActions.cpp

@@ -46,7 +46,6 @@
 #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"
@@ -661,7 +660,6 @@ static void generateMachineCodeOrAssemblyImpl(clang::DiagnosticsEngine &diags,
 
 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.
@@ -678,17 +676,6 @@ void CodeGenAction::runOptimizationPipeline(llvm::raw_pwrite_stream &os) {
   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);

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

@@ -44,7 +44,6 @@
 ! 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
@@ -72,3 +71,4 @@
 
 ! Frontend driver -help-hidden is not supported
 ! ERROR-FLANG-FC1: error: unknown argument: '{{.*}}'
+

flang/test/Driver/driver-help.f90

@@ -42,7 +42,6 @@
 ! 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
@@ -121,7 +120,6 @@
 ! 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

flang/test/Driver/frontend-forwarding.f90

@@ -7,7 +7,6 @@
 ! 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
@@ -18,5 +17,4 @@
 ! CHECK: "-fdefault-integer-8"
 ! CHECK: "-fdefault-real-8"
 ! CHECK: "-flarge-sizes"
-! CHECK: "-fpass-plugin=Bye
-! CHECK: "-mllvm" "-print-before-all"
+! CHECK:  "-mllvm" "-print-before-all"