utils/update_test_checks.py

#!/usr/bin/env python2.7

"""A test case update script.

This script is a utility to update LLVM opt or llc test cases with new
FileCheck patterns. It can either update all of the tests in the file or
a single test function.
"""

import argparse
import itertools
import os         # Used to advertise this file's name ("autogenerated_note").
import string
import subprocess
import sys
import tempfile
import re


# RegEx: this is where the magic happens.

SCRUB_WHITESPACE_RE = re.compile(r'(?!^(|  \w))[ \t]+', flags=re.M)
SCRUB_TRAILING_WHITESPACE_RE = re.compile(r'[ \t]+$', flags=re.M)
SCRUB_X86_SHUFFLES_RE = (
    re.compile(
        r'^(\s*\w+) [^#\n]+#+ ((?:[xyz]mm\d+|mem) = .*)$',
        flags=re.M))
SCRUB_X86_SP_RE = re.compile(r'\d+\(%(esp|rsp)\)')
SCRUB_X86_RIP_RE = re.compile(r'[.\w]+\(%rip\)')
SCRUB_KILL_COMMENT_RE = re.compile(r'^ *#+ +kill:.*\n')
SCRUB_IR_COMMENT_RE = re.compile(r'\s*;.*')

RUN_LINE_RE = re.compile('^\s*;\s*RUN:\s*(.*)$')
IR_FUNCTION_RE = re.compile('^\s*define\s+(?:internal\s+)?[^@]*@(\w+)\s*\(')
LLC_FUNCTION_RE = re.compile(
    r'^_?(?P<func>[^:]+):[ \t]*#+[ \t]*@(?P=func)\n[^:]*?'
    r'(?P<body>^##?[ \t]+[^:]+:.*?)\s*'
    r'^\s*(?:[^:\n]+?:\s*\n\s*\.size|\.cfi_endproc|\.globl|\.comm|\.(?:sub)?section)',
    flags=(re.M | re.S))
OPT_FUNCTION_RE = re.compile(
    r'^\s*define\s+(?:internal\s+)?[^@]*@(?P<func>\w+?)\s*\('
    r'(\s+)?[^{]*\{\n(?P<body>.*?)\}',
    flags=(re.M | re.S))
CHECK_PREFIX_RE = re.compile('--check-prefix=(\S+)')
CHECK_RE = re.compile(r'^\s*;\s*([^:]+?)(?:-NEXT|-NOT|-DAG|-LABEL)?:')
IR_VALUE_DEF_RE = re.compile(r'\s+%(.*) =')


# Invoke the tool that is being tested.
def invoke_tool(args, cmd_args, ir):
  with open(ir) as ir_file:
    stdout = subprocess.check_output(args.tool_binary + ' ' + cmd_args,
                                     shell=True, stdin=ir_file)
  # Fix line endings to unix CR style.
  stdout = stdout.replace('\r\n', '\n')
  return stdout


# FIXME: Separate the x86-specific scrubbers, so this can be used for other targets.
def scrub_asm(asm):
  # Detect shuffle asm comments and hide the operands in favor of the comments.
  asm = SCRUB_X86_SHUFFLES_RE.sub(r'\1 {{.*#+}} \2', asm)
  # Generically match the stack offset of a memory operand.
  asm = SCRUB_X86_SP_RE.sub(r'{{[0-9]+}}(%\1)', asm)
  # Generically match a RIP-relative memory operand.
  asm = SCRUB_X86_RIP_RE.sub(r'{{.*}}(%rip)', asm)
  # Strip kill operands inserted into the asm.
  asm = SCRUB_KILL_COMMENT_RE.sub('', asm)
  return asm


def scrub_body(body, tool_basename):
  # Scrub runs of whitespace out of the assembly, but leave the leading
  # whitespace in place.
  body = SCRUB_WHITESPACE_RE.sub(r' ', body)
  # Expand the tabs used for indentation.
  body = string.expandtabs(body, 2)
  # Strip trailing whitespace.
  body = SCRUB_TRAILING_WHITESPACE_RE.sub(r'', body)
  if tool_basename == "llc":
    body = scrub_asm(body)
  return body


# Build up a dictionary of all the function bodies.
def build_function_body_dictionary(raw_tool_output, prefixes, func_dict, verbose, tool_basename):
  if tool_basename == "llc":
    func_regex = LLC_FUNCTION_RE
  else:
    func_regex = OPT_FUNCTION_RE
  for m in func_regex.finditer(raw_tool_output):
    if not m:
      continue
    func = m.group('func')
    scrubbed_body = scrub_body(m.group('body'), tool_basename)
    if func.startswith('stress'):
      # We only use the last line of the function body for stress tests.
      scrubbed_body = '\n'.join(scrubbed_body.splitlines()[-1:])
    if verbose:
      print >>sys.stderr, 'Processing function: ' + func
      for l in scrubbed_body.splitlines():
        print >>sys.stderr, '  ' + l
    for prefix in prefixes:
      if func in func_dict[prefix] and func_dict[prefix][func] != scrubbed_body:
        if prefix == prefixes[-1]:
          print >>sys.stderr, ('WARNING: Found conflicting asm under the '
                               'same prefix: %r!' % (prefix,))
        else:
          func_dict[prefix][func] = None
          continue

      func_dict[prefix][func] = scrubbed_body


# Create a FileCheck variable name based on an IR name.
def get_value_name(var):
  if var.isdigit():
    var = 'TMP' + var
  var = var.replace('.', '_')
  return var.upper()


# Create a FileCheck variable from regex.
def get_value_definition(var):
  return '[[' + get_value_name(var) + ':%.*]]'


# Use a FileCheck variable.
def get_value_use(var):
  return '[[' + get_value_name(var) + ']]'


# Replace IR value defs and uses with FileCheck variables.
def genericize_check_lines(lines):
  lines_with_def = []
  vars_seen = []
  for line in lines:
    m = IR_VALUE_DEF_RE.match(line)
    if m:
      vars_seen.append(m.group(1))
      line = line.replace('%' + m.group(1), get_value_definition(m.group(1)))

    lines_with_def.append(line)

  # A single def isn't worth replacing?
  #if len(vars_seen) < 2:
  #  return lines

  output_lines = []
  vars_seen.sort(key=len, reverse=True)
  for line in lines_with_def:
    for var in vars_seen:
      line = line.replace('%' + var, get_value_use(var))
    output_lines.append(line)

  return output_lines


def add_checks(output_lines, prefix_list, func_dict, func_name, tool_basename):
  # Select a label format based on the whether we're checking asm or IR.
  if tool_basename == "llc":
    check_label_format = "; %s-LABEL: %s:"
  else:
    check_label_format = "; %s-LABEL: @%s("

  printed_prefixes = []
  for checkprefixes, _ in prefix_list:
    for checkprefix in checkprefixes:
      if checkprefix in printed_prefixes:
        break
      if not func_dict[checkprefix][func_name]:
        continue
      # Add some space between different check prefixes, but not after the last
      # check line (before the test code).
      #if len(printed_prefixes) != 0:
      #  output_lines.append(';')
      printed_prefixes.append(checkprefix)
      output_lines.append(check_label_format % (checkprefix, func_name))
      func_body = func_dict[checkprefix][func_name].splitlines()

      # For IR output, change all defs to FileCheck variables, so we're immune
      # to variable naming fashions.
      if tool_basename == "opt":
        func_body = genericize_check_lines(func_body)

      # Handle the first line of the function body as a special case because
      # it's often just noise (a useless asm comment or entry label).
      if func_body[0].startswith("#") or func_body[0].startswith("entry:"):
        is_blank_line = True
      else:
        output_lines.append('; %s:       %s' % (checkprefix, func_body[0]))
        is_blank_line = False

      for func_line in func_body[1:]:
        if func_line.strip() == '':
          is_blank_line = True
          continue
        # Do not waste time checking IR comments.
        if tool_basename == "opt":
          func_line = SCRUB_IR_COMMENT_RE.sub(r'', func_line)

        # Skip blank lines instead of checking them.
        if is_blank_line == True:
          output_lines.append('; %s:       %s' % (checkprefix, func_line))
        else:
          output_lines.append('; %s-NEXT:  %s' % (checkprefix, func_line))
        is_blank_line = False

      # Add space between different check prefixes and also before the first
      # line of code in the test function.
      output_lines.append(';')
      break
  return output_lines


def should_add_line_to_output(input_line, prefix_set):
  # Skip any blank comment lines in the IR.
  if input_line.strip() == ';':
    return False
  # Skip any blank lines in the IR.
  #if input_line.strip() == '':
  #  return False
  # And skip any CHECK lines. We're building our own.
  m = CHECK_RE.match(input_line)
  if m and m.group(1) in prefix_set:
    return False

  return True


def main():
  parser = argparse.ArgumentParser(description=__doc__)
  parser.add_argument('-v', '--verbose', action='store_true',
                      help='Show verbose output')
  parser.add_argument('--tool-binary', default='llc',
                      help='The tool used to generate the test case')
  parser.add_argument(
      '--function', help='The function in the test file to update')
  parser.add_argument('tests', nargs='+')
  args = parser.parse_args()

  autogenerated_note = ('; NOTE: Assertions have been autogenerated by '
                        + os.path.basename(__file__))

  tool_basename = os.path.basename(args.tool_binary)
  if (tool_basename != "llc" and tool_basename != "opt"):
    print >>sys.stderr, 'ERROR: Unexpected tool name: ' + tool_basename
    sys.exit(1)

  for test in args.tests:
    if args.verbose:
      print >>sys.stderr, 'Scanning for RUN lines in test file: %s' % (test,)
    with open(test) as f:
      input_lines = [l.rstrip() for l in f]

    run_lines = [m.group(1)
                 for m in [RUN_LINE_RE.match(l) for l in input_lines] if m]
    if args.verbose:
      print >>sys.stderr, 'Found %d RUN lines:' % (len(run_lines),)
      for l in run_lines:
        print >>sys.stderr, '  RUN: ' + l

    prefix_list = []
    for l in run_lines:
      (tool_cmd, filecheck_cmd) = tuple([cmd.strip() for cmd in l.split('|', 1)])

      if not tool_cmd.startswith(tool_basename + ' '):
        print >>sys.stderr, 'WARNING: Skipping non-%s RUN line: %s' % (tool_basename, l)
        continue

      if not filecheck_cmd.startswith('FileCheck '):
        print >>sys.stderr, 'WARNING: Skipping non-FileChecked RUN line: ' + l
        continue

      tool_cmd_args = tool_cmd[len(tool_basename):].strip()
      tool_cmd_args = tool_cmd_args.replace('< %s', '').replace('%s', '').strip()

      check_prefixes = [m.group(1)
                        for m in CHECK_PREFIX_RE.finditer(filecheck_cmd)]
      if not check_prefixes:
        check_prefixes = ['CHECK']

      # FIXME: We should use multiple check prefixes to common check lines. For
      # now, we just ignore all but the last.
      prefix_list.append((check_prefixes, tool_cmd_args))

    func_dict = {}
    for prefixes, _ in prefix_list:
      for prefix in prefixes:
        func_dict.update({prefix: dict()})
    for prefixes, tool_args in prefix_list:
      if args.verbose:
        print >>sys.stderr, 'Extracted tool cmd: ' + tool_basename + ' ' + tool_args
        print >>sys.stderr, 'Extracted FileCheck prefixes: ' + str(prefixes)

      raw_tool_output = invoke_tool(args, tool_args, test)
      build_function_body_dictionary(raw_tool_output, prefixes, func_dict, args.verbose, tool_basename)

    is_in_function = False
    is_in_function_start = False
    prefix_set = set([prefix for prefixes, _ in prefix_list for prefix in prefixes])
    if args.verbose:
      print >>sys.stderr, 'Rewriting FileCheck prefixes: %s' % (prefix_set,)
    output_lines = []
    output_lines.append(autogenerated_note)

    for input_line in input_lines:
      if is_in_function_start:
        if input_line == '':
          continue
        if input_line.lstrip().startswith(';'):
          m = CHECK_RE.match(input_line)
          if not m or m.group(1) not in prefix_set:
            output_lines.append(input_line)
            continue

        # Print out the various check lines here.
        output_lines = add_checks(output_lines, prefix_list, func_dict, name, tool_basename)
        is_in_function_start = False

      if is_in_function:
        if should_add_line_to_output(input_line, prefix_set) == True:
          # This input line of the function body will go as-is into the output.
          output_lines.append(input_line)
        else:
          continue
        if input_line.strip() == '}':
          is_in_function = False
        continue

      if input_line == autogenerated_note:
        continue

      # If it's outside a function, it just gets copied to the output.
      output_lines.append(input_line)

      m = IR_FUNCTION_RE.match(input_line)
      if not m:
        continue
      name = m.group(1)
      if args.function is not None and name != args.function:
        # When filtering on a specific function, skip all others.
        continue
      is_in_function = is_in_function_start = True

    if args.verbose:
      print>>sys.stderr, 'Writing %d lines to %s...' % (len(output_lines), test)

    with open(test, 'wb') as f:
      f.writelines([l + '\n' for l in output_lines])


if __name__ == '__main__':
  main()