Adds a Bazel BUILD for LLVM.

Change: 139938302

tensorflow/workspace.bzl

@@ -193,6 +193,16 @@ def tf_workspace(path_prefix = "", tf_repo_name = ""):
     build_file = str(Label("//:linenoise.BUILD")),
   )
 
+  # TODO(phawkins): currently, this rule uses an unofficial LLVM mirror.
+  # Switch to an official source of snapshots if/when possible.
+  native.new_http_archive(
+    name = "llvm",
+    url = "http://github.com/llvm-mirror/llvm/archive/ad27fdae895df1b9ad11a93102de6622f63e1220.tar.gz",
+    sha256 = "ce7abf076586f2ef13dcd1c4e7ba13604a0826a0f44fe0a6faceeb9bdffc8544",
+    strip_prefix = "llvm-ad27fdae895df1b9ad11a93102de6622f63e1220",
+    build_file = str(Label("//third_party/llvm:llvm.BUILD")),
+  )
+
   native.new_http_archive(
     name = "jsoncpp_git",
     url = "http://github.com/open-source-parsers/jsoncpp/archive/11086dd6a7eba04289944367ca82cea71299ed70.tar.gz",

third_party/llvm/BUILD

@@ -0,0 +1,7 @@
+licenses(["notice"])
+
+py_binary(
+    name = "expand_cmake_vars",
+    srcs = ["expand_cmake_vars.py"],
+    visibility = ["@llvm//:__subpackages__"],
+)

third_party/llvm/expand_cmake_vars.py"

@@ -0,0 +1,88 @@
+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Expands CMake variables in a text file."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import re
+import sys
+
+_CMAKE_DEFINE_REGEX = re.compile(r"\s*#cmakedefine\s+([A-Za-z_0-9]*)(\s.*)?$")
+_CMAKE_DEFINE01_REGEX = re.compile(r"\s*#cmakedefine01\s+([A-Za-z_0-9]*)")
+_CMAKE_VAR_REGEX = re.compile(r"\${([A-Za-z_0-9]*)}")
+
+
+def _parse_args(argv):
+  """Parses arguments with the form KEY=VALUE into a dictionary."""
+  result = {}
+  for arg in argv:
+    k, v = arg.split("=")
+    result[k] = v
+  return result
+
+
+def _expand_variables(input_str, cmake_vars):
+  """Expands ${VARIABLE}s in 'input_str', using dictionary 'cmake_vars'.
+
+  Args:
+    input_str: the string containing ${VARIABLE} expressions to expand.
+    cmake_vars: a dictionary mapping variable names to their values.
+
+  Returns:
+    The expanded string.
+  """
+  def replace(match):
+    if cmake_vars.has_key(match.group(1)):
+      return cmake_vars[match.group(1)]
+    return ""
+  return _CMAKE_VAR_REGEX.sub(replace, input_str)
+
+
+def _expand_cmakedefines(line, cmake_vars):
+  """Expands #cmakedefine declarations, using a dictionary 'cmake_vars'."""
+
+  # Handles #cmakedefine lines
+  match = _CMAKE_DEFINE_REGEX.match(line)
+  if match:
+    name = match.group(1)
+    suffix = match.group(2) or ""
+    if name in cmake_vars:
+      return "#define {}{}\n".format(name,
+                                     _expand_variables(suffix, cmake_vars))
+    else:
+      return "/* #undef {} */\n".format(name)
+
+  # Handles #cmakedefine01 lines
+  match = _CMAKE_DEFINE01_REGEX.match(line)
+  if match:
+    name = match.group(1)
+    value = cmake_vars.get(name, "0")
+    return "#define {} {}\n".format(name, value)
+
+  # Otherwise return the line unchanged.
+  return _expand_variables(line, cmake_vars)
+
+
+def main():
+  cmake_vars = _parse_args(sys.argv[1:])
+  for line in sys.stdin:
+    sys.stdout.write(_expand_cmakedefines(line, cmake_vars))
+
+
+if __name__ == "__main__":
+  main()

third_party/llvm/llvm.bzl

@@ -0,0 +1,149 @@
+"""This file contains BUILD extensions for generating source code from LLVM's table definition files using the TableGen tool.
+
+See http://llvm.org/cmds/tblgen.html for more information on the TableGen
+tool.
+TODO(chandlerc): Currently this expresses include-based dependencies as
+"sources", and has no transitive understanding due to these files not being
+correctly understood by the build system.
+"""
+
+def gentbl(name, tblgen, td_file, td_srcs, tbl_outs, library = True, **kwargs):
+  """gentbl() generates tabular code from a table definition file.
+
+  Args:
+    name: The name of the build rule for use in dependencies.
+    tblgen: The binary used to produce the output.
+    td_file: The primary table definitions file.
+    td_srcs: A list of table definition files included transitively.
+    tbl_outs: A list of tuples (opts, out), where each opts is a string of
+      options passed to tblgen, and the out is the corresponding output file
+      produced.
+    library: Whether to bundle the generated files into a library.
+    **kwargs: Keyword arguments to pass to subsidiary cc_library() rule.
+  """
+  if td_file not in td_srcs:
+    td_srcs += [td_file]
+  includes = []
+  for (opts, out) in tbl_outs:
+    outdir = out[:out.rindex("/")]
+    if outdir not in includes:
+      includes.append(outdir)
+    rule_suffix = "_".join(opts.replace("-", "_").replace("=", "_").split(" "))
+    native.genrule(
+        name="%s_%s_genrule" % (name, rule_suffix),
+        srcs=td_srcs,
+        outs=[out],
+        tools=[tblgen],
+        message="Generating code from table: %s" % td_file,
+        cmd=(("$(location %s) " + "-I external/llvm/include " +
+              "-I external/llvm/tools/clang/include " +
+              "-I $$(dirname $(location %s)) " + "%s $(location %s) -o $@") % (
+                  tblgen, td_file, opts, td_file)))
+  # For now, all generated files can be assumed to comprise public interfaces.
+  # If this is not true, you should specify library = False
+  # and list the generated '.inc' files in "srcs".
+  if library:
+    native.cc_library(name=name, textual_hdrs=[f for (_, f) in tbl_outs],
+                      includes=includes,  **kwargs)
+
+
+# Rule for simple expansion of template files. This performs a simple
+# search over the template file for the keys in substitutions,
+# and replaces them with the corresponding values.
+#
+# Typical usage:
+#   load("/tools/build_rules/expand_header_template", "expand_header_template")
+#   expand_header_template(
+#       name = "ExpandMyTemplate",
+#       template = "my.template",
+#       out = "my.txt",
+#       substitutions = {
+#         "$VAR1": "foo",
+#         "$VAR2": "bar",
+#       }
+#   )
+#
+# Args:
+#   name: The name of the rule.
+#   template: The template file to expand
+#   out: The destination of the expanded file
+#   substitutions: A dictionary mapping strings to their substitutions
+
+def expand_header_template_impl(ctx):
+  ctx.template_action(
+      template = ctx.file.template,
+      output = ctx.outputs.out,
+      substitutions = ctx.attr.substitutions,
+  )
+
+expand_header_template = rule(
+    implementation = expand_header_template_impl,
+    attrs = {
+        "template": attr.label(mandatory=True, allow_files=True, single_file=True),
+        "substitutions": attr.string_dict(mandatory=True),
+        "out": attr.output(mandatory=True),
+    },
+    # output_to_genfiles is required for header files.
+    output_to_genfiles = True,
+)
+
+
+def llvm_target_cmake_vars(native_arch, target_triple):
+  return {
+      "LLVM_HOST_TRIPLE": target_triple,
+      "LLVM_DEFAULT_TARGET_TRIPLE": target_triple,
+      "LLVM_NATIVE_ARCH": native_arch,
+  }
+
+def _quote(s):
+  """Quotes the given string for use in a shell command.
+
+  This function double-quotes the given string (in case it contains spaces or
+  other special characters) and escapes any special characters (dollar signs,
+  double-quotes, and backslashes) that may be present.
+
+  Args:
+    s: The string to quote.
+  Returns:
+    An escaped and quoted version of the string that can be passed to a shell
+    command.
+  """
+  return ('"' +
+          s.replace("\\", "\\\\").replace("$", "\\$").replace('"', '\\"') +
+          '"')
+
+def cmake_var_string(cmake_vars):
+  """Converts a dictionary to an input suitable for expand_cmake_vars.
+
+  Ideally we would jist stringify in the expand_cmake_vars() rule, but select()
+  interacts badly with genrules.
+
+  TODO(phawkins): replace the genrule() with native rule and delete this rule.
+
+  Args:
+    cmake_vars: a dictionary with string keys and values that are convertable to
+      strings.
+  """
+  return " ".join([_quote("{}={}".format(k, str(v)))
+                   for (k, v) in cmake_vars.items()])
+
+def expand_cmake_vars(name, src, dst, cmake_vars):
+  """Expands #cmakedefine, #cmakedefine01, and CMake variables in a text file.
+
+  Args:
+    name: the name of the rule
+    src: the input of the rule
+    dst: the output of the rule
+    cmake_vars: a string containing the CMake variables, as generated by
+      cmake_var_string.
+  """
+  expand_cmake_vars_tool = "@//third_party/llvm:expand_cmake_vars"
+  native.genrule(
+      name = name,
+      srcs = [src],
+      tools = [expand_cmake_vars_tool],
+      outs = [dst],
+      cmd = ("$(location {}) ".format(expand_cmake_vars_tool) + cmake_vars +
+             "< $< > $@")
+  )
+