Generalize the pass registration mechanism used by Polly to any third-party tool

There's quite a lot of references to Polly in the LLVM CMake codebase. However
the registration pattern used by Polly could be useful to other external
projects: thanks to that mechanism it would be possible to develop LLVM
extension without touching the LLVM code base.

This patch has two effects:

1. Remove all code specific to Polly in the llvm/clang codebase, replaicing it
   with a generic mechanism

2. Provide a generic mechanism to register compiler extensions.

A compiler extension is similar to a pass plugin, with the notable difference
that the compiler extension can be configured to be built dynamically (like
plugins) or statically (like regular passes).

As a result, people willing to add extra passes to clang/opt can do it using a
separate code repo, but still have their pass be linked in clang/opt as built-in
passes.

Differential Revision: https://reviews.llvm.org/D61446

CMakeLists.txt

@@ -465,29 +465,6 @@ set(LLVM_LIB_FUZZING_ENGINE "" CACHE PATH
 option(LLVM_USE_SPLIT_DWARF
   "Use -gsplit-dwarf when compiling llvm." OFF)
 
-option(LLVM_POLLY_LINK_INTO_TOOLS "Statically link Polly into tools (if available)" ON)
-option(LLVM_POLLY_BUILD "Build LLVM with Polly" ON)
-
-if (EXISTS ${LLVM_MAIN_SRC_DIR}/tools/polly/CMakeLists.txt)
-  set(POLLY_IN_TREE TRUE)
-elseif(LLVM_EXTERNAL_POLLY_SOURCE_DIR)
-  set(POLLY_IN_TREE TRUE)
-else()
-  set(POLLY_IN_TREE FALSE)
-endif()
-
-if (LLVM_POLLY_BUILD AND POLLY_IN_TREE)
-  set(WITH_POLLY ON)
-else()
-  set(WITH_POLLY OFF)
-endif()
-
-if (LLVM_POLLY_LINK_INTO_TOOLS AND WITH_POLLY)
-  set(LINK_POLLY_INTO_TOOLS ON)
-else()
-  set(LINK_POLLY_INTO_TOOLS OFF)
-endif()
-
 # Define an option controlling whether we should build for 32-bit on 64-bit
 # platforms, where supported.
 if( CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32 )
@@ -1112,3 +1089,5 @@ endif()
 if (LLVM_INCLUDE_UTILS AND LLVM_INCLUDE_TOOLS)
   add_subdirectory(utils/llvm-locstats)
 endif()
+
+process_llvm_pass_plugins()

cmake/modules/AddLLVM.cmake

@@ -404,7 +404,7 @@ endfunction(set_windows_version_resource_properties)
 #   )
 function(llvm_add_library name)
   cmake_parse_arguments(ARG
-    "MODULE;SHARED;STATIC;OBJECT;DISABLE_LLVM_LINK_LLVM_DYLIB;SONAME;NO_INSTALL_RPATH;COMPONENT_LIB"
+    "MODULE;SHARED;STATIC;OBJECT;DISABLE_LLVM_LINK_LLVM_DYLIB;SONAME;NO_INSTALL_RPATH;COMPONENT_LIB;ENABLE_PLUGINS"
     "OUTPUT_NAME;PLUGIN_TOOL;ENTITLEMENTS;BUNDLE_PATH"
     "ADDITIONAL_HEADERS;DEPENDS;LINK_COMPONENTS;LINK_LIBS;OBJLIBS"
     ${ARGN})
@@ -418,6 +418,9 @@ function(llvm_add_library name)
   else()
     llvm_process_sources(ALL_FILES ${ARG_UNPARSED_ARGUMENTS} ${ARG_ADDITIONAL_HEADERS})
   endif()
+  if(ARG_ENABLE_PLUGINS)
+    set_property(GLOBAL APPEND PROPERTY LLVM_PLUGIN_TARGETS ${name})
+  endif()
 
   if(ARG_MODULE)
     if(ARG_SHARED OR ARG_STATIC)
@@ -745,7 +748,7 @@ endmacro(add_llvm_library name)
 
 macro(add_llvm_executable name)
   cmake_parse_arguments(ARG
-    "DISABLE_LLVM_LINK_LLVM_DYLIB;IGNORE_EXTERNALIZE_DEBUGINFO;NO_INSTALL_RPATH;SUPPORT_PLUGINS"
+    "DISABLE_LLVM_LINK_LLVM_DYLIB;IGNORE_EXTERNALIZE_DEBUGINFO;NO_INSTALL_RPATH;SUPPORT_PLUGINS;ENABLE_PLUGINS"
     "ENTITLEMENTS;BUNDLE_PATH"
     "DEPENDS"
     ${ARGN})
@@ -832,10 +835,78 @@ macro(add_llvm_executable name)
     # API for all shared libaries loaded by this executable.
     target_link_libraries(${name} PRIVATE ${LLVM_PTHREAD_LIB})
   endif()
+  if(ARG_ENABLE_PLUGINS)
+    set_property(GLOBAL APPEND PROPERTY LLVM_PLUGIN_TARGETS ${name})
+  endif()
 
   llvm_codesign(${name} ENTITLEMENTS ${ARG_ENTITLEMENTS} BUNDLE_PATH ${ARG_BUNDLE_PATH})
 endmacro(add_llvm_executable name)
 
+# add_llvm_pass_plugin(name)
+#   Add ${name} as an llvm plugin.
+#   If option LLVM_${name_upper}_LINK_INTO_TOOLS is set to ON, the plugin is registered statically.
+#   Otherwise a pluggable shared library is registered.
+function(add_llvm_pass_plugin name)
+
+  string(TOUPPER ${name} name_upper)
+
+  option(LLVM_${name_upper}_LINK_INTO_TOOLS "Statically link ${name} into tools (if available)" OFF)
+
+  # process_llvm_pass_plugins takes care of the actual linking, just create an
+  # object library as of now
+  add_llvm_library(${name} OBJECT ${ARGN})
+
+  if(LLVM_${name_upper}_LINK_INTO_TOOLS)
+      target_compile_definitions(${name} PRIVATE LLVM_${name_upper}_LINK_INTO_TOOLS)
+      set_property(TARGET ${name} APPEND PROPERTY COMPILE_DEFINITIONS LLVM_LINK_INTO_TOOLS)
+      if (TARGET intrinsics_gen)
+        add_dependencies(obj.${name} intrinsics_gen)
+      endif()
+  endif()
+
+  message(STATUS "Registering ${name} as a pass plugin (static build: ${LLVM_${name_upper}_LINK_INTO_TOOLS})")
+  if(LLVM_${name_upper}_LINK_INTO_TOOLS)
+    set_property(GLOBAL APPEND PROPERTY LLVM_COMPILE_EXTENSIONS ${name})
+  endif()
+endfunction(add_llvm_pass_plugin)
+
+# Generate X Macro file for extension handling. It provides a
+# HANDLE_EXTENSION(extension_namespace, ExtensionProject) call for each extension
+# allowing client code to define HANDLE_EXTENSION to have a specific code be run for
+# each extension.
+#
+# Also correctly set lib dependencies between plugins and tools.
+function(process_llvm_pass_plugins)
+  get_property(LLVM_EXTENSIONS GLOBAL PROPERTY LLVM_COMPILE_EXTENSIONS)
+  file(WRITE "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def.tmp" "//extension handlers\n")
+  foreach(llvm_extension ${LLVM_EXTENSIONS})
+    string(TOLOWER ${llvm_extension} llvm_extension_lower)
+
+    string(TOUPPER ${llvm_extension} llvm_extension_upper)
+    string(SUBSTRING ${llvm_extension_upper} 0 1 llvm_extension_upper_first)
+    string(SUBSTRING ${llvm_extension_lower} 1 -1 llvm_extension_lower_tail)
+    string(CONCAT llvm_extension_project ${llvm_extension_upper_first} ${llvm_extension_lower_tail})
+
+    if(LLVM_${llvm_extension_upper}_LINK_INTO_TOOLS)
+        file(APPEND "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def.tmp" "HANDLE_EXTENSION(${llvm_extension_project})\n")
+
+        get_property(llvm_plugin_targets GLOBAL PROPERTY LLVM_PLUGIN_TARGETS)
+        foreach(llvm_plugin_target ${llvm_plugin_targets})
+          set_property(TARGET ${llvm_plugin_target} APPEND PROPERTY LINK_LIBRARIES ${llvm_extension})
+          set_property(TARGET ${llvm_plugin_target} APPEND PROPERTY INTERFACE_LINK_LIBRARIES ${llvm_extension})
+        endforeach()
+    else()
+      add_llvm_library(${llvm_extension_lower} MODULE obj.${llvm_extension_lower})
+    endif()
+
+  endforeach()
+  file(APPEND "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def.tmp" "#undef HANDLE_EXTENSION\n")
+
+  # only replace if there's an actual change
+  execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def.tmp" "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def")
+  file(REMOVE "${CMAKE_BINARY_DIR}/include/llvm/Support/Extension.def.tmp")
+endfunction()
+
 function(export_executable_symbols target)
   if (LLVM_EXPORTED_SYMBOL_FILE)
     # The symbol file should contain the symbols we want the executable to

docs/WritingAnLLVMPass.rst

@@ -1175,6 +1175,51 @@ implement ``releaseMemory`` to, well, release the memory allocated to maintain
 this internal state.  This method is called after the ``run*`` method for the
 class, before the next call of ``run*`` in your pass.
 
+Building pass plugins
+=====================
+
+As an alternative to using ``PLUGIN_TOOL``, LLVM provides a mechanism to
+automatically register pass plugins within ``clang``, ``opt`` and ``bugpoint``.
+One first needs to create an independent project and add it to either ``tools/``
+or, using the MonoRepo layout, at the root of the repo alongside other projects.
+This project must contain the following minimal ``CMakeLists.txt``:
+
+.. code-block:: cmake
+
+    add_llvm_pass_plugin(Name source0.cpp)
+
+The pass must provide two entry points for the new pass manager, one for static
+registration and one for dynamically loaded plugins:
+
+- ``llvm::PassPluginLibraryInfo get##Name##PluginInfo();``
+- ``extern "C" ::llvm::PassPluginLibraryInfo llvmGetPassPluginInfo() LLVM_ATTRIBUTE_WEAK;``
+
+Pass plugins are compiled and link dynamically by default, but it's
+possible to set the following variables to change this behavior:
+
+- ``LLVM_${NAME}_LINK_INTO_TOOLS``, when set to ``ON``, turns the project into
+  a statically linked extension
+
+
+When building a tool that uses the new pass manager, one can use the following snippet to
+include statically linked pass plugins:
+
+.. code-block:: c++
+
+    // fetch the declaration
+    #define HANDLE_EXTENSION(Ext) llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
+    #include "llvm/Support/Extension.def"
+
+    [...]
+
+    // use them, PB is an llvm::PassBuilder instance
+    #define HANDLE_EXTENSION(Ext) get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
+    #include "llvm/Support/Extension.def"
+
+
+
+
+
 Registering dynamically loaded passes
 =====================================
 

examples/Bye/Bye.cpp

@@ -0,0 +1,69 @@
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Pass.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/PassPlugin.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+
+using namespace llvm;
+
+static cl::opt<bool> Wave("wave-goodbye", cl::init(false),
+                          cl::desc("wave good bye"));
+
+namespace {
+
+bool runBye(Function &F) {
+  if (Wave) {
+    errs() << "Bye: ";
+    errs().write_escaped(F.getName()) << '\n';
+  }
+  return false;
+}
+
+struct LegacyBye : public FunctionPass {
+  static char ID;
+  LegacyBye() : FunctionPass(ID) {}
+  bool runOnFunction(Function &F) override { return runBye(F); }
+};
+
+struct Bye : PassInfoMixin<Bye> {
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &) {
+    if (!runBye(F))
+      return PreservedAnalyses::all();
+    return PreservedAnalyses::none();
+  }
+};
+
+} // namespace
+
+char LegacyBye::ID = 0;
+
+static RegisterPass<LegacyBye> X("goodbye", "Good Bye World Pass",
+                                 false /* Only looks at CFG */,
+                                 false /* Analysis Pass */);
+
+/* Legacy PM Registration */
+static llvm::RegisterStandardPasses RegisterBye(
+    llvm::PassManagerBuilder::EP_EarlyAsPossible,
+    [](const llvm::PassManagerBuilder &Builder,
+       llvm::legacy::PassManagerBase &PM) { PM.add(new LegacyBye()); });
+
+/* New PM Registration */
+llvm::PassPluginLibraryInfo getByePluginInfo() {
+  return {LLVM_PLUGIN_API_VERSION, "Bye", LLVM_VERSION_STRING,
+          [](PassBuilder &PB) {
+            PB.registerVectorizerStartEPCallback(
+                [](llvm::FunctionPassManager &PM,
+                   llvm::PassBuilder::OptimizationLevel Level) {
+                  PM.addPass(Bye());
+                });
+          }};
+}
+
+#ifndef LLVM_BYE_LINK_INTO_TOOLS
+extern "C" LLVM_ATTRIBUTE_WEAK ::llvm::PassPluginLibraryInfo
+llvmGetPassPluginInfo() {
+  return getByePluginInfo();
+}
+#endif

examples/Bye/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_llvm_pass_plugin(Bye Bye.cpp)
+if (LLVM_LINK_LLVM_DYLIB)
+  target_link_libraries(Bye PUBLIC LLVM)
+else()
+  target_link_libraries(Bye
+    PUBLIC
+    LLVMSupport
+    LLVMCore
+    LLVMipo
+    LLVMPasses
+    )
+endif()
+

examples/CMakeLists.txt

@@ -6,6 +6,7 @@ add_subdirectory(LLJITExamples)
 add_subdirectory(Kaleidoscope)
 add_subdirectory(ModuleMaker)
 add_subdirectory(SpeculativeJIT)
+add_subdirectory(Bye)
 
 if(LLVM_ENABLE_EH AND (NOT WIN32) AND (NOT "${LLVM_NATIVE_ARCH}" STREQUAL "ARM"))
     add_subdirectory(ExceptionDemo)

include/llvm/Config/llvm-config.h.cmake

@@ -17,9 +17,6 @@
 /* Define if LLVM_ENABLE_DUMP is enabled */
 #cmakedefine LLVM_ENABLE_DUMP
 
-/* Define if we link Polly to the tools */
-#cmakedefine LINK_POLLY_INTO_TOOLS
-
 /* Target triple LLVM will generate code for by default */
 #cmakedefine LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}"
 

test/Feature/load_extension.ll

@@ -0,0 +1,10 @@
+; RUN: opt %s %loadbye -goodbye -wave-goodbye -disable-output | FileCheck %s
+; REQUIRES: plugins, examples
+; CHECK: Bye
+
+@junk = global i32 0
+
+define i32* @somefunk() {
+  ret i32* @junk
+}
+

test/Other/new-pm-defaults.ll

@@ -9,72 +9,83 @@
 
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='default<O1>' -S %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O1
+; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O1 \
+; RUN:      --check-prefix=%llvmcheckext
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='default<O2>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O2 \
-; RUN:     --check-prefix=CHECK-O23SZ
+; RUN:      --check-prefix=CHECK-O23SZ --check-prefix=%llvmcheckext
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
-; RUN:     --check-prefix=CHECK-O23SZ
+; RUN:      --check-prefix=CHECK-O23SZ --check-prefix=%llvmcheckext
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='default<Os>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-Os \
-; RUN:     --check-prefix=CHECK-O23SZ
+; RUN:      --check-prefix=CHECK-O23SZ --check-prefix=%llvmcheckext
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='default<Oz>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-Oz \
-; RUN:     --check-prefix=CHECK-O23SZ
+; RUN:     --check-prefix=CHECK-O23SZ --check-prefix=%llvmcheckext
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='lto-pre-link<O2>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O2 \
-; RUN:     --check-prefix=CHECK-O2-LTO --check-prefix=CHECK-O23SZ
+; RUN:     --check-prefix=CHECK-O23SZ --check-prefix=%llvmcheckext \
+; RUN:     --check-prefix=CHECK-O2-LTO
 
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-peephole='no-op-function' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-PEEPHOLE --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-late-loop-optimizations='no-op-loop' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-LOOP-LATE --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-loop-optimizer-end='no-op-loop' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-LOOP-END --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-scalar-optimizer-late='no-op-function' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-SCALAR-LATE --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-cgscc-optimizer-late='no-op-cgscc' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-CGSCC-LATE --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-vectorizer-start='no-op-function' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-VECTORIZER-START --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-pipeline-start='no-op-module' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-PIPELINE-START --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-pipeline-start='no-op-module' \
 ; RUN:     -passes='lto-pre-link<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-PIPELINE-START --check-prefix=CHECK-O23SZ
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-optimizer-last='no-op-function' \
 ; RUN:     -passes='default<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
+; RUN:     --check-prefix=%llvmcheckext \
 ; RUN:     --check-prefix=CHECK-EP-OPTIMIZER-LAST --check-prefix=CHECK-O23SZ
 
 ; CHECK-O: Running analysis: PassInstrumentationAnalysis
@@ -226,6 +237,7 @@
 ; CHECK-O-NEXT: Running pass: Float2IntPass
 ; CHECK-O-NEXT: Running pass: LowerConstantIntrinsicsPass on foo
 ; CHECK-EP-VECTORIZER-START-NEXT: Running pass: NoOpFunctionPass
+; CHECK-EXT: Running pass: {{.*}}::Bye on foo
 ; CHECK-O-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}LoopRotatePass
 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass

test/Other/new-pm-thinlto-defaults.ll

@@ -30,22 +30,22 @@
 ; Postlink pipelines:
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='thinlto<O1>' -S %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O1,CHECK-POSTLINK-O,CHECK-POSTLINK-O1
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O1,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-O1
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='thinlto<O2>' -S  %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-O23SZ,CHECK-POSTLINK-O,CHECK-POSTLINK-O2
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-O23SZ,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-O2
 ; RUN: opt -disable-verify -debug-pass-manager -passes-ep-pipeline-start='no-op-module' \
 ; RUN:     -passes='thinlto<O3>' -S  %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O3,CHECK-O23SZ,CHECK-POSTLINK-O,CHECK-POSTLINK-O3
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O3,CHECK-O23SZ,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-O3
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='thinlto<Os>' -S %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Os,CHECK-O23SZ,CHECK-POSTLINK-O,CHECK-POSTLINK-Os
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Os,CHECK-O23SZ,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-Os
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='thinlto<Oz>' -S %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Oz,CHECK-O23SZ,CHECK-POSTLINK-O,CHECK-POSTLINK-Oz
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Oz,CHECK-O23SZ,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-Oz
 ; RUN: opt -disable-verify -debug-pass-manager -new-pm-debug-info-for-profiling \
 ; RUN:     -passes='thinlto<O2>' -S  %s 2>&1 \
-; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-O23SZ,CHECK-POSTLINK-O,CHECK-POSTLINK-O2
+; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-O23SZ,CHECK-POSTLINK-O,%llvmcheckext,CHECK-POSTLINK-O2
 ;
 ; CHECK-O: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
@@ -207,6 +207,7 @@
 ; CHECK-POSTLINK-O-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-POSTLINK-O-NEXT: Running pass: Float2IntPass
 ; CHECK-POSTLINK-O-NEXT: Running pass: LowerConstantIntrinsicsPass
+; CHECK-EXT: Running pass: {{.*}}::Bye
 ; CHECK-POSTLINK-O-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}LoopRotatePass
 ; CHECK-POSTLINK-O-NEXT: Starting llvm::Function pass manager run
 ; CHECK-POSTLINK-O-NEXT: Running pass: LoopSimplifyPass

test/Other/opt-O0-pipeline.ll

@@ -1,4 +1,4 @@
-; RUN: opt -mtriple=x86_64-- -O0 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: opt -mtriple=x86_64-- -O0 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s --check-prefixes=CHECK,%llvmcheckext
 
 ; REQUIRES: asserts
 
@@ -6,6 +6,7 @@
 ; CHECK-NEXT: Target Transform Information
 ; CHECK-NEXT:   FunctionPass Manager
 ; CHECK-NEXT:     Module Verifier
+; CHECK-EXT:     Good Bye World Pass
 ; CHECK-NEXT:     Instrument function entry/exit with calls to e.g. mcount() (pre inlining)
 ; CHECK-NEXT: Pass Arguments:
 ; CHECK-NEXT: Target Library Information

test/Other/opt-O2-pipeline.ll

@@ -1,4 +1,4 @@
-; RUN: opt -mtriple=x86_64-- -O2 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: opt -mtriple=x86_64-- -O2 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck --check-prefixes=CHECK-,%llvmcheckext %s 
 
 ; REQUIRES: asserts
 
@@ -10,6 +10,8 @@
 ; CHECK-NEXT: Target Library Information
 ; CHECK-NEXT:   FunctionPass Manager
 ; CHECK-NEXT:     Module Verifier
+; CHECK-EXT:      Good Bye World Pass
+; CHECK-NOEXT-NOT:      Good Bye World Pass
 ; CHECK-NEXT:     Instrument function entry/exit with calls to e.g. mcount() (pre inlining)
 ; CHECK-NEXT:     Simplify the CFG
 ; CHECK-NEXT:     Dominator Tree Construction

test/Other/opt-O3-pipeline.ll

@@ -1,4 +1,4 @@
-; RUN: opt -mtriple=x86_64-- -O3 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: opt -mtriple=x86_64-- -O3 -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck --check-prefixes=CHECK-,%llvmcheckext %s
 
 ; REQUIRES: asserts
 
@@ -10,6 +10,8 @@
 ; CHECK-NEXT: Target Library Information
 ; CHECK-NEXT:   FunctionPass Manager
 ; CHECK-NEXT:     Module Verifier
+; CHECK-EXT:      Good Bye World Pass
+; CHECK-NOEXT-NOT:      Good Bye World Pass
 ; CHECK-NEXT:     Instrument function entry/exit with calls to e.g. mcount() (pre inlining)
 ; CHECK-NEXT:     Simplify the CFG
 ; CHECK-NEXT:     Dominator Tree Construction

test/Other/opt-Os-pipeline.ll

@@ -1,4 +1,4 @@
-; RUN: opt -mtriple=x86_64-- -Os -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: opt -mtriple=x86_64-- -Os -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck --check-prefixes=CHECK-,%llvmcheckext %s
 
 ; REQUIRES: asserts
 
@@ -10,6 +10,8 @@
 ; CHECK-NEXT: Target Library Information
 ; CHECK-NEXT:   FunctionPass Manager
 ; CHECK-NEXT:     Module Verifier
+; CHECK-EXT:      Good Bye World Pass
+; CHECK-NOEXT-NOT:      Good Bye World Pass
 ; CHECK-NEXT:     Instrument function entry/exit with calls to e.g. mcount() (pre inlining)
 ; CHECK-NEXT:     Simplify the CFG
 ; CHECK-NEXT:     Dominator Tree Construction

test/lit.cfg.py

@@ -197,6 +197,18 @@ else:
 if config.has_plugins:
     config.available_features.add('plugins')
 
+if config.build_examples:
+    config.available_features.add('examples')
+
+if config.linked_bye_extension and config.build_examples:
+    config.substitutions.append(('%llvmcheckext', 'CHECK-EXT'))
+    config.substitutions.append(('%loadbye', ''))
+else:
+    config.substitutions.append(('%llvmcheckext', 'CHECK-NOEXT'))
+    config.substitutions.append(('%loadbye',
+                                 '-load={}/libBye{}'.format(config.llvm_shlib_dir,
+                                                                  config.llvm_shlib_ext)))
+
 # Static libraries are not built if BUILD_SHARED_LIBS is ON.
 if not config.build_shared_libs and not config.link_llvm_dylib:
     config.available_features.add('static-libs')

test/lit.site.cfg.py.in

@@ -2,6 +2,9 @@
 
 import sys
 
+def cmake_bool(val):
+    return val.lower() in (1, "on", "yes", "true", "y",)
+
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
@@ -47,6 +50,7 @@ config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
 config.libcxx_used = @LLVM_LIBCXX_USED@
 config.has_plugins = @LLVM_ENABLE_PLUGINS@
+config.linked_bye_extension = cmake_bool("@LLVM_BYE_LINK_INTO_TOOLS@")
 
 # Support substitution of the tools_dir with user parameters. This is
 # used when we can't determine the tool dir at configuration time.

tools/CMakeLists.txt

@@ -9,14 +9,6 @@
 # traversing each directory.
 create_llvm_tool_options()
 
-# Build polly before the tools: the tools link against polly when
-# LINK_POLLY_INTO_TOOLS is set.
-if(WITH_POLLY)
-  add_llvm_external_project(polly)
-else()
-  set(LLVM_TOOL_POLLY_BUILD Off)
-endif()
-
 if(NOT LLVM_BUILD_LLVM_DYLIB AND NOT LLVM_BUILD_LLVM_C_DYLIB)
   set(LLVM_TOOL_LLVM_SHLIB_BUILD Off)
 endif()
@@ -51,6 +43,8 @@ add_llvm_external_project(mlir)
 # file as external projects.
 add_llvm_implicit_projects()
 
+add_llvm_external_project(polly)
+
 # Add subprojects specified using LLVM_EXTERNAL_PROJECTS
 foreach(p ${LLVM_EXTERNAL_PROJECTS})
   add_llvm_external_project(${p})

tools/bugpoint/CMakeLists.txt

@@ -32,14 +32,10 @@ add_llvm_tool(bugpoint
   ToolRunner.cpp
   bugpoint.cpp
 
+  ENABLE_PLUGINS
+
   DEPENDS
   intrinsics_gen
   SUPPORT_PLUGINS
   )
 export_executable_symbols(bugpoint)
-
-if(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)
-  target_link_libraries(bugpoint PRIVATE Polly)
-  # Ensure LLVMTarget can resolve dependences in Polly.
-  target_link_libraries(bugpoint PRIVATE LLVMTarget)
-endif(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)

tools/bugpoint/bugpoint.cpp

@@ -21,6 +21,7 @@
 #include "llvm/InitializePasses.h"
 #include "llvm/LinkAllIR.h"
 #include "llvm/LinkAllPasses.h"
+#include "llvm/Passes/PassPlugin.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/ManagedStatic.h"
@@ -134,11 +135,9 @@ static void AddOptimizationPasses(legacy::FunctionPassManager &FPM,
   Builder.populateModulePassManager(FPM);
 }
 
-#ifdef LINK_POLLY_INTO_TOOLS
-namespace polly {
-void initializePollyPasses(llvm::PassRegistry &Registry);
-}
-#endif
+#define HANDLE_EXTENSION(Ext)                                                  \
+  llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
+#include "llvm/Support/Extension.def"
 
 int main(int argc, char **argv) {
 #ifndef DEBUG_BUGPOINT
@@ -159,10 +158,6 @@ int main(int argc, char **argv) {
   initializeInstrumentation(Registry);
   initializeTarget(Registry);
 
-#ifdef LINK_POLLY_INTO_TOOLS
-  polly::initializePollyPasses(Registry);
-#endif
-
   if (std::getenv("bar") == (char*) -1) {
     InitializeAllTargets();
     InitializeAllTargetMCs();
@@ -234,6 +229,13 @@ int main(int argc, char **argv) {
   sys::Process::PreventCoreFiles();
 #endif
 
+// Needed to pull in symbols from statically linked extensions, including static
+// registration. It is unused otherwise because bugpoint has no support for
+// NewPM.
+#define HANDLE_EXTENSION(Ext)                                                  \
+  (void)get##Ext##PluginInfo();
+#include "llvm/Support/Extension.def"
+
   if (Error E = D.run()) {
     errs() << toString(std::move(E));
     return 1;

tools/opt/CMakeLists.txt

@@ -33,12 +33,10 @@ add_llvm_tool(opt
   PrintSCC.cpp
   opt.cpp
 
+  ENABLE_PLUGINS
+
   DEPENDS
   intrinsics_gen
   SUPPORT_PLUGINS
   )
 export_executable_symbols(opt)
-
-if(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)
-  target_link_libraries(opt PRIVATE Polly)
-endif(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)

tools/opt/NewPMDriver.cpp

@@ -202,11 +202,9 @@ static void registerEPCallbacks(PassBuilder &PB, bool VerifyEachPass,
         });
 }
 
-#ifdef LINK_POLLY_INTO_TOOLS
-namespace polly {
-void RegisterPollyPasses(PassBuilder &);
-}
-#endif
+#define HANDLE_EXTENSION(Ext)                                                  \
+  llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
+#include "llvm/Support/Extension.def"
 
 bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
                            ToolOutputFile *Out, ToolOutputFile *ThinLTOLinkOut,
@@ -290,9 +288,9 @@ bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
         return false;
       });
 
-#ifdef LINK_POLLY_INTO_TOOLS
-  polly::RegisterPollyPasses(PB);
-#endif
+#define HANDLE_EXTENSION(Ext)                                                  \
+  get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
+#include "llvm/Support/Extension.def"
 
   // Specially handle the alias analysis manager so that we can register
   // a custom pipeline of AA passes with it.

tools/opt/opt.cpp

@@ -482,11 +482,6 @@ static TargetMachine* GetTargetMachine(Triple TheTriple, StringRef CPUStr,
                                         getCodeModel(), GetCodeGenOptLevel());
 }
 
-#ifdef LINK_POLLY_INTO_TOOLS
-namespace polly {
-void initializePollyPasses(llvm::PassRegistry &Registry);
-}
-#endif
 
 void exportDebugifyStats(llvm::StringRef Path, const DebugifyStatsMap &Map) {
   std::error_code EC;
@@ -564,10 +559,6 @@ int main(int argc, char **argv) {
   initializeHardwareLoopsPass(Registry);
   initializeTypePromotionPass(Registry);
 
-#ifdef LINK_POLLY_INTO_TOOLS
-  polly::initializePollyPasses(Registry);
-#endif
-
   cl::ParseCommandLineOptions(argc, argv,
     "llvm .bc -> .bc modular optimizer and analysis printer\n");
 

utils/gn/secondary/llvm/include/llvm/Config/BUILD.gn

@@ -319,7 +319,6 @@ write_cmake_config("llvm-config") {
   output = "$target_gen_dir/llvm-config.h"
   values = [
     "LLVM_ENABLE_DUMP=",
-    "LINK_POLLY_INTO_TOOLS=",
     "LLVM_DEFAULT_TARGET_TRIPLE=$llvm_target_triple",
     "LLVM_HAS_ATOMICS=1",
     "LLVM_HOST_TRIPLE=$llvm_current_triple",