add build-stdlib-docs flag that generates stdlib symbol graphs

Author: QuietMisdreavus

CMakeLists.txt

@@ -463,6 +463,10 @@ option(SWIFT_STDLIB_ENABLE_SIB_TARGETS
        "Should we generate sib targets for the stdlib or not?"
        FALSE)
 
+option(SWIFT_STDLIB_BUILD_SYMBOL_GRAPHS
+       "Whether to build symbol graphs for the stdlib, for use in documentation."
+       FALSE)
+
 
 set(SWIFT_DARWIN_SUPPORTED_ARCHS "" CACHE STRING
   "Semicolon-separated list of architectures to configure on Darwin platforms. \

stdlib/cmake/modules/AddSwiftStdlib.cmake

@@ -937,6 +937,13 @@ function(add_swift_target_library_single target name)
     set(SWIFTLIB_SINGLE_SOURCES ${SWIFTLIB_SINGLE_SOURCES} ${SWIFTLIB_SINGLE_HEADERS} ${SWIFTLIB_SINGLE_TDS})
   endif()
 
+  # FIXME: swiftDarwin currently trips an assertion in SymbolGraphGen
+  if (SWIFTLIB_IS_STDLIB AND SWIFT_STDLIB_BUILD_SYMBOL_GRAPHS AND NOT ${name} STREQUAL "swiftDarwin")
+    list(APPEND SWIFTLIB_SINGLE_SWIFT_COMPILE_FLAGS "-Xfrontend;-emit-symbol-graph")
+    list(APPEND SWIFTLIB_SINGLE_SWIFT_COMPILE_FLAGS
+         "-Xfrontend;-emit-symbol-graph-dir;-Xfrontend;${out_lib_dir}/symbol-graph/${VARIANT_NAME}")
+  endif()
+
   if(MODULE)
     set(libkind MODULE)
   elseif(SWIFTLIB_SINGLE_OBJECT_LIBRARY)
@@ -2233,7 +2240,6 @@ function(add_swift_target_library name)
       endif()
     endif()
 
-
     # Collect architecture agnostic SDK linker flags
     set(swiftlib_link_flags_all ${SWIFTLIB_LINK_FLAGS})
     if(sdk STREQUAL "IOS_SIMULATOR" AND name STREQUAL "swiftMediaPlayer")

utils/build_swift/build_swift/driver_arguments.py

@@ -1160,6 +1160,11 @@ def create_argument_parser():
            help='Include Unicode data in the standard library.'
                 'Note: required for full String functionality')
 
+    option('--build-stdlib-docs', toggle_true,
+           default=False,
+           help='Build documentation for the standard library.'
+                'Note: this builds SwiftDocC to perform the docs build.')
+
     option('--build-swift-clang-overlays', toggle_true,
            default=True,
            help='Build Swift overlays for the clang builtin modules')

utils/swift_build_support/swift_build_support/products/swift.py

@@ -89,6 +89,8 @@ def __init__(self, args, toolchain, source_dir, build_dir):
 
         self.cmake_options.extend(self._enable_embedded_stdlib_cross_compiling)
 
+        self.cmake_options.extend(self._enable_stdlib_symbol_graphs)
+
         self.cmake_options.extend(
             self._swift_tools_ld64_lto_codegen_only_for_supporting_targets)
 
@@ -271,6 +273,11 @@ def _enable_embedded_stdlib_cross_compiling(self):
         return [('SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB_CROSS_COMPILING',
                  self.args.build_embedded_stdlib_cross_compiling)]
 
+    @property
+    def _enable_stdlib_symbol_graphs(self):
+        return [('SWIFT_STDLIB_BUILD_SYMBOL_GRAPHS',
+                 self.args.build_stdlib_docs)]
+
     def _handle_swift_debuginfo_non_lto_args(self):
         if ('swift_debuginfo_non_lto_args' not in self.args
                 or self.args.swift_debuginfo_non_lto_args is None):