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1# This file is licensed under the Apache License v2.0 with LLVM Exceptions.2# See https://llvm.org/LICENSE.txt for license information.3# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception4 5"""A rule to expand LLVM target enumerations.6 7Replaces in a text file a single variable of the style `@LLVM_ENUM_FOOS@` with a8list of macro invocations, one for each target on its own line:9 10```11LLVM_FOO(TARGET1)12LLVM_FOO(TARGET2)13// ...14```15 16Example:17load(":enum_targets_gen.bzl", "enum_targets_gen")18 19enum_targets_gen(20 name = "disassemblers_def_gen",21 src = "include/llvm/Config/Disassemblers.def.in",22 out = "include/llvm/Config/Disassemblers.def",23 macro_name = "DISASSEMBLER",24 targets = llvm_target_disassemblers,25)26 27This rule provides a slightly more semantic API than template_rule, but the main28reason it exists is to permit a list with selects to be passed for `targets` as29a select is not allowed to be passed to a rule within another data structure. 30"""31 32def enum_targets_gen_impl(ctx):33 to_replace = ctx.attr.placeholder_name34 if not to_replace:35 to_replace = "@LLVM_ENUM_{}S@".format(ctx.attr.macro_name)36 replacement = "\n".join([37 "LLVM_{}({})\n".format(ctx.attr.macro_name, t)38 for t in ctx.attr.targets39 ])40 41 ctx.actions.expand_template(42 template = ctx.file.src,43 output = ctx.outputs.out,44 substitutions = {to_replace: replacement},45 )46 47enum_targets_gen = rule(48 attrs = {49 "src": attr.label(50 mandatory = True,51 allow_single_file = True,52 ),53 "out": attr.output(mandatory = True),54 "targets": attr.string_list(mandatory = True),55 "macro_name": attr.string(56 mandatory = True,57 doc = "The name of the enumeration. This is the suffix of the" +58 " placeholder being replaced `@LLVM_ENUM_{}S@` and of the" +59 " macro invocations generated `LLVM_{}(TARGET)`. Should be" +60 " all caps and singular, e.g. 'DISASSEMBLER'",61 ),62 "placeholder_name": attr.string(63 doc = "The name of the placeholder. If unset, this defaults to" +64 " `@LLVM_ENUM_{macro_name}S@`",65 ),66 },67 implementation = enum_targets_gen_impl,68)69