third_party/WebKit/Source/build/scripts/make_css_value_keywords.py

#!/usr/bin/env python

import os.path
import re
import subprocess
import sys

from in_file import InFile
from name_utilities import enum_for_css_keyword
from name_utilities import upper_first_letter
import in_generator
import license


HEADER_TEMPLATE = """
%(license)s

#ifndef %(class_name)s_h
#define %(class_name)s_h

#include "core/css/parser/CSSParserMode.h"
#include <string.h>

namespace blink {

enum CSSValueID {
%(value_keyword_enums)s
};

const int numCSSValueKeywords = %(value_keywords_count)d;
const size_t maxCSSValueKeywordLength = %(max_value_keyword_length)d;

const char* getValueName(CSSValueID);
bool isValueAllowedInMode(unsigned short id, CSSParserMode mode);

} // namespace blink

#endif // %(class_name)s_h
"""

GPERF_TEMPLATE = """
%%{
%(license)s

#include "%(class_name)s.h"
#include "core/css/HashTools.h"
#include <string.h>

#ifdef _MSC_VER
// Disable the warnings from casting a 64-bit pointer to 32-bit long
// warning C4302: 'type cast': truncation from 'char (*)[28]' to 'long'
// warning C4311: 'type cast': pointer truncation from 'char (*)[18]' to 'long'
#pragma warning(disable : 4302 4311)
#endif

namespace blink {
static const char valueListStringPool[] = {
%(value_keyword_strings)s
};

static const unsigned short valueListStringOffsets[] = {
%(value_keyword_offsets)s
};

%%}
%%struct-type
struct Value;
%%omit-struct-type
%%language=C++
%%readonly-tables
%%compare-strncmp
%%define class-name %(class_name)sHash
%%define lookup-function-name findValueImpl
%%define hash-function-name value_hash_function
%%define slot-name nameOffset
%%define word-array-name value_word_list
%%pic
%%enum
%%%%
%(value_keyword_to_enum_map)s
%%%%
const Value* findValue(register const char* str, register unsigned int len)
{
    return CSSValueKeywordsHash::findValueImpl(str, len);
}

const char* getValueName(CSSValueID id)
{
    ASSERT(id > 0 && id < numCSSValueKeywords);
    return valueListStringPool + valueListStringOffsets[id - 1];
}

bool isValueAllowedInMode(unsigned short id, CSSParserMode mode)
{
    switch (id) {
        %(ua_sheet_mode_values_keywords)s
            return isUASheetBehavior(mode);
        %(quirks_mode_or_ua_sheet_mode_values_keywords)s
            return isUASheetBehavior(mode) || isQuirksModeBehavior(mode);
        default:
            return true;
    }
}

} // namespace blink
"""


class CSSValueKeywordsWriter(in_generator.Writer):
    class_name = "CSSValueKeywords"
    defaults = {
        'mode': None,
    }

    def __init__(self, file_paths):
        in_generator.Writer.__init__(self, file_paths)
        self._outputs = {(self.class_name + ".h"): self.generate_header,
                         (self.class_name + ".cpp"): self.generate_implementation,
                        }

        self._value_keywords = self.in_file.name_dictionaries
        first_keyword_id = 1
        for offset, keyword in enumerate(self._value_keywords):
            keyword['lower_name'] = keyword['name'].lower()
            keyword['enum_name'] = enum_for_css_keyword(keyword['name'])
            keyword['enum_value'] = first_keyword_id + offset
            if keyword['name'].startswith('-internal-'):
                assert keyword['mode'] is None, 'Can\'t specify mode for value keywords with the prefix "-internal-".'
                keyword['mode'] = 'UASheet'
            else:
                assert keyword['mode'] != 'UASheet', 'UASheet mode only value keywords should have the prefix "-internal-".'

    def _enum_declaration(self, keyword):
        return "    %(enum_name)s = %(enum_value)s," % keyword

    def _case_value_keyword(self, keyword):
        return "case %(enum_name)s:" % keyword

    def generate_header(self):
        enum_enties = map(self._enum_declaration, [{'enum_name': 'CSSValueInvalid', 'enum_value': 0}] + self._value_keywords)
        return HEADER_TEMPLATE % {
            'license': license.license_for_generated_cpp(),
            'class_name': self.class_name,
            'value_keyword_enums': "\n".join(enum_enties),
            'value_keywords_count': len(enum_enties),
            'max_value_keyword_length': max(len(keyword['name']) for keyword in self._value_keywords),
        }

    def _value_keywords_with_mode(self, mode):
        return filter(lambda keyword: keyword['mode'] == mode, self._value_keywords)

    def generate_implementation(self):
        keyword_offsets = []
        current_offset = 0
        for keyword in self._value_keywords:
            keyword_offsets.append(current_offset)
            current_offset += len(keyword["name"]) + 1

        gperf_input = GPERF_TEMPLATE % {
            'license': license.license_for_generated_cpp(),
            'class_name': self.class_name,
            'value_keyword_strings': '\n'.join('    "%(name)s\\0"' % keyword for keyword in self._value_keywords),
            'value_keyword_offsets': '\n'.join('  %d,' % offset for offset in keyword_offsets),
            'value_keyword_to_enum_map': '\n'.join('%(lower_name)s, %(enum_name)s' % keyword for keyword in self._value_keywords),
            'ua_sheet_mode_values_keywords': '\n        '.join(map(self._case_value_keyword, self._value_keywords_with_mode('UASheet'))),
            'quirks_mode_or_ua_sheet_mode_values_keywords': '\n    '.join(map(self._case_value_keyword, self._value_keywords_with_mode('QuirksOrUASheet'))),
        }
        # FIXME: If we could depend on Python 2.7, we would use subprocess.check_output
        gperf_args = [self.gperf_path, '--key-positions=*', '-P', '-n']
        gperf_args.extend(['-m', '50'])  # Pick best of 50 attempts.
        gperf_args.append('-D')  # Allow duplicate hashes -> More compact code.
        gperf = subprocess.Popen(gperf_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, universal_newlines=True)
        return gperf.communicate(gperf_input)[0]


if __name__ == "__main__":
    in_generator.Maker(CSSValueKeywordsWriter).main(sys.argv)