Index: clang/CMakeLists.txt
===================================================================
--- clang/CMakeLists.txt
+++ clang/CMakeLists.txt
@@ -681,7 +681,7 @@
         -DDYLD_LIBRARY_PATH=${LLVM_LIBRARY_OUTPUT_INTDIR})
     elseif(NOT WIN32)
       add_dependencies(clang-bootstrap-deps llvm-ar llvm-ranlib)
-      if(NOT BOOTSTRAP_LLVM_ENABLE_LLD AND LLVM_BINUTILS_INCDIR)
+      if(NOT BOOTSTRAP_LLVM_ENABLE_LLD)
         add_dependencies(clang-bootstrap-deps LLVMgold)
       endif()
       set(${CLANG_STAGE}_AR -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
@@ -721,7 +721,6 @@
     CLANG_VERSION_PATCHLEVEL
     CLANG_VENDOR
     LLVM_VERSION_SUFFIX
-    LLVM_BINUTILS_INCDIR
     CLANG_REPOSITORY_STRING
     CMAKE_C_COMPILER_LAUNCHER
     CMAKE_CXX_COMPILER_LAUNCHER
Index: clang/docs/ThinLTO.rst
===================================================================
--- clang/docs/ThinLTO.rst
+++ clang/docs/ThinLTO.rst
@@ -94,11 +94,9 @@
 
 .. code-block:: console
 
-  /usr/bin/ld: error: /path/to/clang/bin/../lib/LLVMgold.so: could not load plugin library: /path/to/clang/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory
+  /usr/bin/ld: fatal error: cannot use --plugin: /usr/bin/ld was compiled without plugin support
 
-Then either gold was not configured with plugins enabled, or clang
-was not built with ``-DLLVM_BINUTILS_INCDIR`` set properly. See
-the instructions for the
+Then gold was not configured with plugins enabled. See the instructions for the
 `LLVM gold plugin <https://llvm.org/docs/GoldPlugin.html#how-to-build-it>`_.
 
 Controlling Backend Parallelism
Index: compiler-rt/test/cfi/CMakeLists.txt
===================================================================
--- compiler-rt/test/cfi/CMakeLists.txt
+++ compiler-rt/test/cfi/CMakeLists.txt
@@ -69,11 +69,7 @@
     sanstats
   )
   if(LLVM_ENABLE_PIC)
-    if(LLVM_BINUTILS_INCDIR)
-      list(APPEND CFI_TEST_DEPS
-        LLVMgold
-      )
-    endif()
+    list(APPEND CFI_TEST_DEPS LLVMgold)
     if(APPLE)
       list(APPEND CFI_TEST_DEPS
         LTO
Index: compiler-rt/test/safestack/CMakeLists.txt
===================================================================
--- compiler-rt/test/safestack/CMakeLists.txt
+++ compiler-rt/test/safestack/CMakeLists.txt
@@ -7,10 +7,7 @@
 
   # Some tests require LTO, so add a dependency on the relevant LTO plugin.
   if(LLVM_ENABLE_PIC)
-    if(LLVM_BINUTILS_INCDIR)
-      list(APPEND SAFESTACK_TEST_DEPS
-        LLVMgold
-      )
+    list(APPEND SAFESTACK_TEST_DEPS LLVMgold)
     endif()
     if(APPLE)
       list(APPEND SAFESTACK_TEST_DEPS
Index: llvm/cmake/config-ix.cmake
===================================================================
--- llvm/cmake/config-ix.cmake
+++ llvm/cmake/config-ix.cmake
@@ -597,8 +597,6 @@
 endif()
 
 find_program(GOLD_EXECUTABLE NAMES ${LLVM_DEFAULT_TARGET_TRIPLE}-ld.gold ld.gold ${LLVM_DEFAULT_TARGET_TRIPLE}-ld ld DOC "The gold linker")
-set(LLVM_BINUTILS_INCDIR "" CACHE PATH
-    "PATH to binutils/include containing plugin-api.h for gold plugin.")
 
 if(CMAKE_GENERATOR MATCHES "Ninja")
   execute_process(COMMAND ${CMAKE_MAKE_PROGRAM} --version
Index: llvm/docs/GoldPlugin.rst
===================================================================
--- llvm/docs/GoldPlugin.rst
+++ llvm/docs/GoldPlugin.rst
@@ -64,10 +64,6 @@
   to automatically install the newly built gold as the default linker with
   ``make install``.
 
-* Build the LLVMgold plugin. Run CMake with
-  ``-DLLVM_BINUTILS_INCDIR=/path/to/binutils/include``.  The correct include
-  path will contain the file ``plugin-api.h``.
-
 Usage
 =====
 
@@ -175,11 +171,3 @@
 
 The environment variable settings may work for non-autotooled projects too,
 but you may need to set the ``LD`` environment variable as well.
-
-Licensing
-=========
-
-Gold is licensed under the GPLv3. LLVMgold uses the interface file
-``plugin-api.h`` from gold which means that the resulting ``LLVMgold.so``
-binary is also GPLv3. This can still be used to link non-GPLv3 programs
-just as much as gold could without the plugin.
Index: llvm/include/llvm/LTO/Plugin.h
===================================================================
--- /dev/null
+++ llvm/include/llvm/LTO/Plugin.h
@@ -0,0 +1,272 @@
+//===-Plugin.h - LLVM LTO Plugin API -------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares data types and functions used to support LLVMgold plugin.
+// These definitions must be in sync with GNU binutils' plugin-api.h header.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LTO_PLUGIN_H
+#define LLVM_LTO_PLUGIN_H
+
+namespace llvm {
+namespace lto {
+
+enum ld_plugin_status {
+  LDPS_OK,
+  LDPS_NO_SYMS,
+  LDPS_BAD_HANDLE,
+  LDPS_ERR,
+};
+
+enum ld_plugin_api_version {
+  LD_PLUGIN_API_VERSION = 1,
+};
+
+enum ld_plugin_output_file_type {
+  LDPO_REL,
+  LDPO_EXEC,
+  LDPO_DYN,
+  LDPO_PIE,
+};
+
+struct ld_plugin_input_file {
+  const char *name;
+  int fd;
+  uint64_t offset;
+  uint64_t filesize;
+  void *handle;
+};
+
+struct ld_plugin_symbol {
+  char *name;
+  char *version;
+#if __BIG_ENDIAN__
+  char unused;
+  char section_kind;
+  char symbol_type;
+  char def;
+#else
+  char def;
+  char symbol_type;
+  char section_kind;
+  char unused;
+#endif
+  int visibility;
+  uint64_t size;
+  char *comdat_key;
+  int resolution;
+};
+
+struct ld_plugin_section {
+  const void *handle;
+  unsigned int shndx;
+};
+
+enum ld_plugin_symbol_kind {
+  LDPK_DEF,
+  LDPK_WEAKDEF,
+  LDPK_UNDEF,
+  LDPK_WEAKUNDEF,
+  LDPK_COMMON,
+};
+
+enum ld_plugin_symbol_visibility {
+  LDPV_DEFAULT,
+  LDPV_PROTECTED,
+  LDPV_INTERNAL,
+  LDPV_HIDDEN,
+};
+
+enum ld_plugin_symbol_type {
+  LDST_UNKNOWN,
+  LDST_FUNCTION,
+  LDST_VARIABLE,
+};
+
+enum ld_plugin_symbol_section_kind {
+  LDSSK_DEFAULT,
+  LDSSK_BSS,
+};
+
+enum ld_plugin_symbol_resolution {
+  LDPR_UNKNOWN,
+  LDPR_UNDEF,
+  LDPR_PREVAILING_DEF,
+  LDPR_PREVAILING_DEF_IRONLY,
+  LDPR_PREEMPTED_REG,
+  LDPR_PREEMPTED_IR,
+  LDPR_RESOLVED_IR,
+  LDPR_RESOLVED_EXEC,
+  LDPR_RESOLVED_DYN,
+  LDPR_PREVAILING_DEF_IRONLY_EXP,
+};
+
+typedef ld_plugin_status (*ld_plugin_claim_file_handler)(
+    const ld_plugin_input_file *file, int *claimed);
+
+typedef ld_plugin_status (*ld_plugin_all_symbols_read_handler)();
+
+typedef ld_plugin_status (*ld_plugin_cleanup_handler)();
+
+typedef ld_plugin_status (*ld_plugin_register_claim_file)(
+    ld_plugin_claim_file_handler handler);
+
+typedef ld_plugin_status (*ld_plugin_register_all_symbols_read)(
+    ld_plugin_all_symbols_read_handler handler);
+
+typedef ld_plugin_status (*ld_plugin_register_cleanup)(
+    ld_plugin_cleanup_handler handler);
+
+typedef ld_plugin_status (*ld_plugin_add_symbols)(void *handle, int nsyms,
+                                                  const ld_plugin_symbol *syms);
+
+typedef ld_plugin_status (*ld_plugin_get_input_file)(
+    const void *handle, ld_plugin_input_file *file);
+
+typedef ld_plugin_status (*ld_plugin_get_view)(const void *handle,
+                                               const void **viewp);
+
+typedef ld_plugin_status (*ld_plugin_release_input_file)(const void *handle);
+
+typedef ld_plugin_status (*ld_plugin_get_symbols)(const void *handle, int nsyms,
+                                                  ld_plugin_symbol *syms);
+
+typedef ld_plugin_status (*ld_plugin_add_input_file)(const char *pathname);
+
+typedef ld_plugin_status (*ld_plugin_add_input_library)(const char *libname);
+
+typedef ld_plugin_status (*ld_plugin_set_extra_library_path)(const char *path);
+
+typedef ld_plugin_status (*ld_plugin_message)(int level, const char *format,
+                                              ...);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_count)(
+    const void *handle, unsigned int *count);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_type)(
+    const ld_plugin_section section, unsigned int *type);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_name)(
+    const ld_plugin_section section, char **section_name_ptr);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_contents)(
+    const ld_plugin_section section, const unsigned char **section_contents,
+    size_t *len);
+
+typedef ld_plugin_status (*ld_plugin_update_section_order)(
+    const ld_plugin_section *section_list, unsigned int num_sections);
+
+typedef ld_plugin_status (*ld_plugin_allow_section_ordering)();
+
+typedef ld_plugin_status (*ld_plugin_allow_unique_segment_for_sections)();
+
+typedef ld_plugin_status (*ld_plugin_unique_segment_for_sections)(
+    const char *segment_name, uint64_t segment_flags,
+    uint64_t segment_alignment, const ld_plugin_section *section_list,
+    unsigned int num_sections);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_alignment)(
+    const ld_plugin_section section, unsigned int *addralign);
+
+typedef ld_plugin_status (*ld_plugin_get_input_section_size)(
+    const ld_plugin_section section, uint64_t *secsize);
+
+typedef ld_plugin_status (*ld_plugin_new_input_handler)(
+    const ld_plugin_input_file *file);
+
+typedef ld_plugin_status (*ld_plugin_register_new_input)(
+    ld_plugin_new_input_handler handler);
+
+typedef ld_plugin_status (*ld_plugin_get_wrap_symbols)(
+    uint64_t *num_symbols, const char ***wrap_symbol_list);
+
+enum ld_plugin_level {
+  LDPL_INFO,
+  LDPL_WARNING,
+  LDPL_ERROR,
+  LDPL_FATAL,
+};
+
+enum ld_plugin_tag {
+  LDPT_NULL,
+  LDPT_API_VERSION,
+  LDPT_GOLD_VERSION,
+  LDPT_LINKER_OUTPUT,
+  LDPT_OPTION,
+  LDPT_REGISTER_CLAIM_FILE_HOOK,
+  LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK,
+  LDPT_REGISTER_CLEANUP_HOOK,
+  LDPT_ADD_SYMBOLS,
+  LDPT_GET_SYMBOLS,
+  LDPT_ADD_INPUT_FILE,
+  LDPT_MESSAGE,
+  LDPT_GET_INPUT_FILE,
+  LDPT_RELEASE_INPUT_FILE,
+  LDPT_ADD_INPUT_LIBRARY,
+  LDPT_OUTPUT_NAME,
+  LDPT_SET_EXTRA_LIBRARY_PATH,
+  LDPT_GNU_LD_VERSION,
+  LDPT_GET_VIEW,
+  LDPT_GET_INPUT_SECTION_COUNT,
+  LDPT_GET_INPUT_SECTION_TYPE,
+  LDPT_GET_INPUT_SECTION_NAME,
+  LDPT_GET_INPUT_SECTION_CONTENTS,
+  LDPT_UPDATE_SECTION_ORDER,
+  LDPT_ALLOW_SECTION_ORDERING,
+  LDPT_GET_SYMBOLS_V2,
+  LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS,
+  LDPT_UNIQUE_SEGMENT_FOR_SECTIONS,
+  LDPT_GET_SYMBOLS_V3,
+  LDPT_GET_INPUT_SECTION_ALIGNMENT,
+  LDPT_GET_INPUT_SECTION_SIZE,
+  LDPT_REGISTER_NEW_INPUT_HOOK,
+  LDPT_GET_WRAP_SYMBOLS,
+  LDPT_ADD_SYMBOLS_V2,
+};
+
+struct ld_plugin_tv {
+  ld_plugin_tag tv_tag;
+
+  union {
+    int tv_val;
+    const char *tv_string;
+    ld_plugin_register_claim_file tv_register_claim_file;
+    ld_plugin_register_all_symbols_read tv_register_all_symbols_read;
+    ld_plugin_register_cleanup tv_register_cleanup;
+    ld_plugin_add_symbols tv_add_symbols;
+    ld_plugin_get_symbols tv_get_symbols;
+    ld_plugin_add_input_file tv_add_input_file;
+    ld_plugin_message tv_message;
+    ld_plugin_get_input_file tv_get_input_file;
+    ld_plugin_get_view tv_get_view;
+    ld_plugin_release_input_file tv_release_input_file;
+    ld_plugin_add_input_library tv_add_input_library;
+    ld_plugin_set_extra_library_path tv_set_extra_library_path;
+    ld_plugin_get_input_section_count tv_get_input_section_count;
+    ld_plugin_get_input_section_type tv_get_input_section_type;
+    ld_plugin_get_input_section_name tv_get_input_section_name;
+    ld_plugin_get_input_section_contents tv_get_input_section_contents;
+    ld_plugin_update_section_order tv_update_section_order;
+    ld_plugin_allow_section_ordering tv_allow_section_ordering;
+    ld_plugin_allow_unique_segment_for_sections
+        tv_allow_unique_segment_for_sections;
+    ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections;
+    ld_plugin_get_input_section_alignment tv_get_input_section_alignment;
+    ld_plugin_get_input_section_size tv_get_input_section_size;
+    ld_plugin_register_new_input tv_register_new_input;
+    ld_plugin_get_wrap_symbols tv_get_wrap_symbols;
+  } tv_u;
+};
+
+typedef ld_plugin_status (*ld_plugin_onload)(ld_plugin_tv *tv);
+
+} // namespace lto
+} // namespace llvm
+
+#endif
Index: llvm/tools/gold/CMakeLists.txt
===================================================================
--- llvm/tools/gold/CMakeLists.txt
+++ llvm/tools/gold/CMakeLists.txt
@@ -1,8 +1,6 @@
 set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/gold.exports)
 
-if( LLVM_ENABLE_PIC AND LLVM_BINUTILS_INCDIR )
-  include_directories( ${LLVM_BINUTILS_INCDIR} )
-
+if (LLVM_ENABLE_PIC)
   set(LLVM_LINK_COMPONENTS
      ${LLVM_TARGETS_TO_BUILD}
      Linker
Index: llvm/tools/gold/gold-plugin.cpp
===================================================================
--- llvm/tools/gold/gold-plugin.cpp
+++ llvm/tools/gold/gold-plugin.cpp
@@ -20,6 +20,7 @@
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/LTO/LTO.h"
+#include "llvm/LTO/Plugin.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Remarks/HotnessThresholdParser.h"
 #include "llvm/Support/CachePruning.h"
@@ -35,7 +36,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include <list>
 #include <map>
-#include <plugin-api.h>
 #include <string>
 #include <system_error>
 #include <utility>