#!/usr/bin/env python3

"""A script to generate FileCheck statements for 'opt' regression tests.

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

Example usage:

# Default to using `opt` as found in your PATH.
$ update_test_checks.py test/foo.ll

# Override the path lookup.
$ update_test_checks.py --tool-binary=../bin/opt test/foo.ll

# Use a custom tool instead of `opt`.
$ update_test_checks.py --tool=yourtool test/foo.ll

Workflow:
1. Make a compiler patch that requires updating some number of FileCheck lines
   in regression test files.
2. Save the patch and revert it from your local work area.
3. Update the RUN-lines in the affected regression tests to look canonical.
   Example: "; RUN: opt < %s -instcombine -S | FileCheck %s"
4. Refresh the FileCheck lines for either the entire file or select functions by
   running this script.
5. Commit the fresh baseline of checks.
6. Apply your patch from step 1 and rebuild your local binaries.
7. Re-run this script on affected regression tests.
8. Check the diffs to ensure the script has done something reasonable.
9. Submit a patch including the regression test diffs for review.
"""

from __future__ import print_function

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

from UpdateTestChecks import common


def main():
    from argparse import RawTextHelpFormatter

    parser = argparse.ArgumentParser(
        description=__doc__, formatter_class=RawTextHelpFormatter
    )
    parser.add_argument(
        "--tool",
        default="opt",
        help='The name of the tool used to generate the test case (defaults to "opt")',
    )
    parser.add_argument(
        "--tool-binary",
        "--opt-binary",
        help="The tool binary used to generate the test case",
    )
    parser.add_argument("--function", help="The function in the test file to update")
    parser.add_argument(
        "-p", "--preserve-names", action="store_true", help="Do not scrub IR names"
    )
    parser.add_argument(
        "--function-signature",
        action="store_true",
        help="Keep function signature information around for the check line",
    )
    parser.add_argument(
        "--scrub-attributes",
        action="store_true",
        help="Remove attribute annotations (#0) from the end of check line",
    )
    parser.add_argument(
        "--check-attributes",
        action="store_true",
        help='Check "Function Attributes" for functions',
    )
    parser.add_argument(
        "--check-globals",
        nargs="?",
        const="all",
        default="default",
        choices=["none", "smart", "all"],
        help="Check global entries (global variables, metadata, attribute sets, ...) for functions",
    )
    parser.add_argument(
        "--reset-variable-names",
        action="store_true",
        help="Reset all variable names to correspond closely to the variable names in IR. "
        "This tends to result in larger diffs.",
    )
    parser.add_argument("tests", nargs="+")
    initial_args = common.parse_commandline_args(parser)

    script_name = os.path.basename(__file__)

    if initial_args.tool_binary:
        tool_basename = os.path.basename(initial_args.tool_binary)
        if not re.match(r"^%s(-\d+)?(\.exe)?$" % (initial_args.tool), tool_basename):
            common.error("Unexpected tool name: " + tool_basename)
            sys.exit(1)

    for ti in common.itertests(
        initial_args.tests, parser, script_name="utils/" + script_name
    ):
        # If requested we scrub trailing attribute annotations, e.g., '#0', together with whitespaces
        if ti.args.scrub_attributes:
            common.SCRUB_TRAILING_WHITESPACE_TEST_RE = (
                common.SCRUB_TRAILING_WHITESPACE_AND_ATTRIBUTES_RE
            )
        else:
            common.SCRUB_TRAILING_WHITESPACE_TEST_RE = (
                common.SCRUB_TRAILING_WHITESPACE_RE
            )

        tool_basename = ti.args.tool

        prefix_list = []
        for l in ti.run_lines:
            if "|" not in l:
                common.warn("Skipping unparsable RUN line: " + l)
                continue

            commands = [cmd.strip() for cmd in l.split("|")]
            assert len(commands) >= 2
            preprocess_cmd = None
            if len(commands) > 2:
                preprocess_cmd = " | ".join(commands[:-2])
            tool_cmd = commands[-2]
            filecheck_cmd = commands[-1]
            common.verify_filecheck_prefixes(filecheck_cmd)
            if not tool_cmd.startswith(tool_basename + " "):
                common.warn("Skipping non-%s RUN line: %s" % (tool_basename, l))
                continue

            if not filecheck_cmd.startswith("FileCheck "):
                common.warn("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 = common.get_check_prefixes(filecheck_cmd)

            # 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, preprocess_cmd))

        global_vars_seen_dict = {}
        builder = common.FunctionTestBuilder(
            run_list=prefix_list, flags=ti.args, scrubber_args=[], path=ti.path
        )

        tool_binary = ti.args.tool_binary
        if not tool_binary:
            tool_binary = tool_basename

        for prefixes, tool_args, preprocess_cmd in prefix_list:
            common.debug("Extracted tool cmd: " + tool_basename + " " + tool_args)
            common.debug("Extracted FileCheck prefixes: " + str(prefixes))

            raw_tool_output = common.invoke_tool(
                tool_binary,
                tool_args,
                ti.path,
                preprocess_cmd=preprocess_cmd,
                verbose=ti.args.verbose,
            )
            builder.process_run_line(
                common.OPT_FUNCTION_RE,
                common.scrub_body,
                raw_tool_output,
                prefixes,
                False,
            )
            builder.processed_prefixes(prefixes)

        prefix_set = set(
            [prefix for prefixes, _, _ in prefix_list for prefix in prefixes]
        )

        if not ti.args.reset_variable_names:
            original_check_lines = common.collect_original_check_lines(ti, prefix_set)
        else:
            original_check_lines = {}

        func_dict = builder.finish_and_get_func_dict()
        is_in_function = False
        is_in_function_start = False
        has_checked_pre_function_globals = False
        common.debug("Rewriting FileCheck prefixes:", str(prefix_set))
        output_lines = []

        include_generated_funcs = common.find_arg_in_test(
            ti,
            lambda args: ti.args.include_generated_funcs,
            "--include-generated-funcs",
            True,
        )
        generated_prefixes = []
        if include_generated_funcs:
            # Generate the appropriate checks for each function.  We need to emit
            # these in the order according to the generated output so that CHECK-LABEL
            # works properly.  func_order provides that.

            # We can't predict where various passes might insert functions so we can't
            # be sure the input function order is maintained.  Therefore, first spit
            # out all the source lines.
            common.dump_input_lines(output_lines, ti, prefix_set, ";")

            args = ti.args
            if args.check_globals != 'none':
                generated_prefixes.extend(
                    common.add_global_checks(
                        builder.global_var_dict(),
                        ";",
                        prefix_list,
                        output_lines,
                        global_vars_seen_dict,
                        args.preserve_names,
                        True,
                        args.check_globals,
                    )
                )

            # Now generate all the checks.
            generated_prefixes.extend(
                common.add_checks_at_end(
                    output_lines,
                    prefix_list,
                    builder.func_order(),
                    ";",
                    lambda my_output_lines, prefixes, func: common.add_ir_checks(
                        my_output_lines,
                        ";",
                        prefixes,
                        func_dict,
                        func,
                        False,
                        args.function_signature,
                        args.version,
                        global_vars_seen_dict,
                        is_filtered=builder.is_filtered(),
                        original_check_lines=original_check_lines.get(func, {}),
                    ),
                )
            )
        else:
            # "Normal" mode.
            dropped_previous_line = False
            for input_line_info in ti.iterlines(output_lines):
                input_line = input_line_info.line
                args = input_line_info.args
                if is_in_function_start:
                    if input_line == "":
                        continue
                    if input_line.lstrip().startswith(";"):
                        m = common.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.
                    generated_prefixes.extend(
                        common.add_ir_checks(
                            output_lines,
                            ";",
                            prefix_list,
                            func_dict,
                            func_name,
                            args.preserve_names,
                            args.function_signature,
                            args.version,
                            global_vars_seen_dict,
                            is_filtered=builder.is_filtered(),
                            original_check_lines=original_check_lines.get(
                                func_name, {}
                            ),
                        )
                    )
                    is_in_function_start = False

                m = common.IR_FUNCTION_RE.match(input_line)
                if m and not has_checked_pre_function_globals:
                    if args.check_globals:
                        generated_prefixes.extend(
                            common.add_global_checks(
                                builder.global_var_dict(),
                                ";",
                                prefix_list,
                                output_lines,
                                global_vars_seen_dict,
                                args.preserve_names,
                                True,
                                args.check_globals,
                            )
                        )
                    has_checked_pre_function_globals = True

                if common.should_add_line_to_output(
                    input_line,
                    prefix_set,
                    skip_global_checks=not is_in_function,
                    skip_same_checks=dropped_previous_line,
                ):
                    # This input line of the function body will go as-is into the output.
                    # Except make leading whitespace uniform: 2 spaces.
                    input_line = common.SCRUB_LEADING_WHITESPACE_RE.sub(
                        r"  ", input_line
                    )
                    output_lines.append(input_line)
                    dropped_previous_line = False
                    if input_line.strip() == "}":
                        is_in_function = False
                        continue
                else:
                    # If we are removing a check line, and the next line is CHECK-SAME, it MUST also be removed
                    dropped_previous_line = True

                if is_in_function:
                    continue

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

        if args.check_globals != 'none':
            generated_prefixes.extend(
                common.add_global_checks(
                    builder.global_var_dict(),
                    ";",
                    prefix_list,
                    output_lines,
                    global_vars_seen_dict,
                    args.preserve_names,
                    False,
                    args.check_globals,
                )
            )
        if ti.args.gen_unused_prefix_body:
            output_lines.extend(
                ti.get_checks_for_unused_prefixes(prefix_list, generated_prefixes)
            )
        common.debug("Writing %d lines to %s..." % (len(output_lines), ti.path))

        with open(ti.path, "wb") as f:
            f.writelines(["{}\n".format(l).encode("utf-8") for l in output_lines])


if __name__ == "__main__":
    main()