| # This file is licensed 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 |
| |
| """A rule to expand LLVM target enumerations. |
| |
| Replaces in a text file a single variable of the style `@LLVM_ENUM_FOOS@` with a |
| list of macro invocations, one for each target on its own line: |
| |
| ``` |
| LLVM_FOO(TARGET1) |
| LLVM_FOO(TARGET2) |
| // ... |
| ``` |
| |
| Example: |
| load(":enum_targets_gen.bzl", "enum_targets_gen") |
| |
| enum_targets_gen( |
| name = "disassemblers_def_gen", |
| src = "include/llvm/Config/Disassemblers.def.in", |
| out = "include/llvm/Config/Disassemblers.def", |
| macro_name = "DISASSEMBLER", |
| targets = llvm_target_disassemblers, |
| ) |
| |
| This rule provides a slightly more semantic API than template_rule, but the main |
| reason it exists is to permit a list with selects to be passed for `targets` as |
| a select is not allowed to be passed to a rule within another data structure. |
| """ |
| |
| def enum_targets_gen_impl(ctx): |
| to_replace = "@LLVM_ENUM_{}S@".format(ctx.attr.macro_name) |
| replacement = "\n".join([ |
| "LLVM_{}({})\n".format(ctx.attr.macro_name, t) |
| for t in ctx.attr.targets |
| ]) |
| |
| ctx.actions.expand_template( |
| template = ctx.file.src, |
| output = ctx.outputs.out, |
| substitutions = {to_replace: replacement}, |
| ) |
| |
| enum_targets_gen = rule( |
| attrs = { |
| "src": attr.label( |
| mandatory = True, |
| allow_single_file = True, |
| ), |
| "out": attr.output(mandatory = True), |
| "targets": attr.string_list(mandatory = True), |
| "macro_name": attr.string( |
| mandatory = True, |
| doc = "The name of the enumeration. This is the suffix of the" + |
| " placeholder being replaced `@LLVM_ENUM_{}S@` and of the" + |
| " macro invocations generated `LLVM_{}(TARGET)`. Should be" + |
| " all caps and singular, e.g. 'DISASSEMBLER'", |
| ), |
| }, |
| # output_to_genfiles is required for header files. |
| output_to_genfiles = True, |
| implementation = enum_targets_gen_impl, |
| ) |