[llvmbuild] --enable-optional-components should not be a substring match

[dsanders]

Summary

enabled_optional_components was a string so given something like
'AArch64AsmParser' it would also match components like 'AsmParser'.
There's nothing in tree where it matters. It came up while trying use
this feature to replace a downstream hack that removes unused subcomponents
from our dylib.

llvm/test/LLVMBuild/enable-optional-component/Input/LLVMBuild.txt

+;===- ./LLVMBuild.txt ------------------------------------------*- Conf -*--===;
+;
+; 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 is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[common]
+subdirectories = lib
+
+[component_0]
+type = LibraryGroup
+name = Engine
+parent = $ROOT
+
+[component_1]
+type = Library
+name = Interpreter
+parent = $ROOT
+
+[component_2]
+type = Group
+name = Miscellaneous
+parent = $ROOT
+
+[component_3]
+type = LibraryGroup
+name = Native
+parent = $ROOT
+
+[component_4]
+type = LibraryGroup
+name = NativeCodeGen
+parent = $ROOT
+
+[component_5]
+type = LibraryGroup
+name = all-targets
+parent = $ROOT

llvm/test/LLVMBuild/enable-optional-component/Input/lib/LLVMBuild.txt

+;===- ./LLVMBuild.txt ------------------------------------------*- Conf -*--===;
+;
+; 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 is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = OptionalLibrary
+name = Foo
+parent = $ROOT
+
+[component_1]
+type = OptionalLibrary
+name = FooBar
+parent = $ROOT
+
+[component_2]
+type = OptionalLibrary
+name = Z
+parent = $ROOT

llvm/test/LLVMBuild/enable-optional-component/enable-optional-component.test

+RUN: %llvmbuild --source-root=%S/Input --write-llvmbuild=%T \
+RUN:     --enable-optional-components=Foo --write-library-table=%T/table.inc
+RUN: FileCheck %s < %T/lib/LLVMBuild.txt
+RUN: FileCheck --check-prefix=TABLE %s < %T/table.inc
+
+CHECK:      [component_0]
+CHECK-NEXT: type = OptionalLibrary
+CHECK-NEXT: name = Foo
+CHECK-NEXT: parent = $ROOT
+CHECK-NEXT: enabled_component = 1
+
+CHECK:      [component_1]
+CHECK-NEXT: type = OptionalLibrary
+CHECK-NEXT: name = FooBar
+CHECK-NEXT: parent = $ROOT
+
+CHECK:      [component_2]
+CHECK-NEXT: type = OptionalLibrary
+CHECK-NEXT: name = Z
+CHECK-NEXT: parent = $ROOT
+
+TABLE-NOT: FooBar
+TABLE: { "foo", "LLVMFoo"
+TABLE-NOT: FooBar

llvm/utils/llvm-build/llvmbuild/main.py

 from __future__ import absolute_import
 import filecmp
 import os
 import sys
 
 import llvmbuild.componentinfo as componentinfo
 
 from llvmbuild.util import fatal, note
 
 ###
 
+def space_or_semicolon_list(x):
+    # We support both space separated and semi-colon separated lists.
+    if x == '':
+        return []
+    elif ' ' in x:
+        return x.split()
+    else:
+        return x.split(';')
+
 def cmake_quote_string(value):
     """
     cmake_quote_string(value) -> str
 
     Return a quoted form of the given value that is suitable for use in CMake
     language files.
     """
 
else:
         if native_target.type_name != 'TargetGroup':
             parser.error("invalid native target: %r (not a target)" % (
                     opts.native_target,))
 
     # Find the list of targets to enable.
     if opts.enable_targets is None:
         enable_targets = available_targets.values()
     else:
-        # We support both space separated and semi-colon separated lists.
-        if opts.enable_targets == '':
-            enable_target_names = []
-        elif ' ' in opts.enable_targets:
-            enable_target_names = opts.enable_targets.split()
-        else:
-            enable_target_names = opts.enable_targets.split(';')
+        enable_target_names = space_or_semicolon_list(opts.enable_targets)
 
         enable_targets = []
         for name in enable_target_names:
             target = available_targets.get(name)
             if target is None:
                 parser.error("invalid target to enable: %r (not in project)" % (
                         name,))
             if target.type_name != 'TargetGroup':
def main():
     group.add_option("", "--disable-optional-components",
                       dest="disable_optional_components", metavar="NAMES",
                       help=("Disable the given space or semi-colon separated "
                             "list of optional components"),
                       action="store", default="")
     parser.add_option_group(group)
 
     (opts, args) = parser.parse_args()
+    opts.enable_optional_components = \
+        space_or_semicolon_list(opts.enable_optional_components)
+    opts.disable_optional_components = \
+        space_or_semicolon_list(opts.disable_optional_components)
 
     # Determine the LLVM source path, if not given.
     source_root = opts.source_root
     if source_root:
         if not os.path.exists(os.path.join(source_root, 'lib', 'IR',
                                            'Function.cpp')):
             parser.error('invalid LLVM source root: %r' % source_root)
     else: