SCons/Tool/yacc.py

   1 # MIT License
   2 #
   3 # Copyright The SCons Foundation
   4 #
   5 # Permission is hereby granted, free of charge, to any person obtaining
   6 # a copy of this software and associated documentation files (the
   7 # "Software"), to deal in the Software without restriction, including
   8 # without limitation the rights to use, copy, modify, merge, publish,
   9 # distribute, sublicense, and/or sell copies of the Software, and to
  10 # permit persons to whom the Software is furnished to do so, subject to
  11 # the following conditions:
  12 #
  13 # The above copyright notice and this permission notice shall be included
  14 # in all copies or substantial portions of the Software.
  15 #
  16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
  17 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  18 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  20 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23
  24 """Tool-specific initialization for yacc.
  25
  26 This tool should support multiple yacc implementations, but is in actuality
  27 biased towards GNU Bison. In particular, it forces the output file name (thus
  28 avoiding the default convention of y.tab.c or foo.tab.c), so the tool *must*
  29 support the -o option, which pure POSIX yacc does not.  byacc should be okay
  30 as an alternative to bison.
  31
  32 There normally shouldn't be any need to import this module directly.
  33 It will usually be imported through the generic SCons.Tool.Tool()
  34 selection method.
  35 """
  36
  37 import os.path
  38 import sys
  39 from typing import Optional
  40
  41 import SCons.Defaults
  42 import SCons.Tool
  43 import SCons.Warnings
  44 from SCons.Platform.mingw import MINGW_DEFAULT_PATHS
  45 from SCons.Platform.cygwin import CYGWIN_DEFAULT_PATHS
  46 from SCons.Platform.win32 import CHOCO_DEFAULT_PATH
  47 from SCons.Util import CLVar, to_String
  48
  49 DEFAULT_PATHS = CHOCO_DEFAULT_PATH + MINGW_DEFAULT_PATHS + CYGWIN_DEFAULT_PATHS
  50
  51 YaccAction = SCons.Action.Action("$YACCCOM", "$YACCCOMSTR")
  52
  53 if sys.platform == 'win32':
  54     BINS = ['bison', 'yacc', 'win_bison']
  55 else:
  56     BINS = ["bison", "yacc", "byacc"]  # for byacc, yacc is normally a link
  57
  58
  59 def _yaccEmitter(target, source, env, ysuf, hsuf) -> tuple:
  60     """Adds extra files generated by yacc program to target list."""
  61
  62     yaccflags = env.subst_list("$YACCFLAGS", target=target, source=source)
  63     flags = yaccflags[0]
  64     targetBase, targetExt = os.path.splitext(to_String(target[0]))
  65
  66     if '.ym' in ysuf:  # If using Objective-C
  67         target = [targetBase + ".m"]  # the extension is ".m".
  68
  69     # If -d is specified on the command line, yacc will emit a .h
  70     # or .hpp file with the same base name as the .c or .cpp output file.
  71     # if '-d' in flags:
  72     # or  bison options -H, --header, --defines (obsolete)
  73     if "-d" in flags or "-H" in flags or "--header" in flags or "--defines" in flags:
  74         target.append(targetBase + env.subst(hsuf, target=target, source=source))
  75
  76     # If -g is specified on the command line, yacc will emit a graph
  77     # file with the same base name as the .c or .cpp output file.
  78     # TODO: should this be handled like -v? i.e. a side effect, not target
  79     # if "-g" in flags:
  80     # or bison option --graph
  81     if "-g" in flags or "--graph" in flags:
  82         target.append(targetBase + env.subst("$YACC_GRAPH_FILE_SUFFIX"))
  83
  84     # If -v is specified yacc will create the output debug file
  85     # which is not really source for any process, but should
  86     # be noted and also be cleaned (issue #2558)
  87     if "-v" in flags:
  88         env.SideEffect(targetBase + '.output', target[0])
  89         env.Clean(target[0], targetBase + '.output')
  90
  91     # With --defines and --graph, the file to write is defined by the option
  92     # argument, if present (the no-option-argument cases were caught above).
  93     # Extract this and include in the list of targets.
  94     # NOTE: a filename passed to the command this way is not modified by
  95     # SCons, and so will be interpreted relative to the project top directory
  96     # at execution time, while the name added to the target list will be
  97     # interpreted relative to the SConscript directory - a possible mismatch.
  98     # Better to use YACC_HEADER_FILE and YACC_GRAPH_FILE to pass these.
  99     #
 100     # These are GNU bison-only options.
 101     # Since bison 3.8, --header is the preferred name over --defines
 102     fileGenOptions = ["--defines=", "--header=", "--graph="]
 103     for option in flags:
 104         for fileGenOption in fileGenOptions:
 105             l = len(fileGenOption)
 106             if option[:l] == fileGenOption:
 107                 fileName = option[l:].strip()
 108                 target.append(fileName)
 109
 110     yaccheaderfile = env.subst("$YACC_HEADER_FILE", target=target, source=source)
 111     if yaccheaderfile:
 112         target.append(yaccheaderfile)
 113         # rewrite user-supplied file string with a node, we need later
 114         env.Replace(YACC_HEADER_FILE=env.File(yaccheaderfile))
 115
 116     yaccgraphfile = env.subst("$YACC_GRAPH_FILE", target=target, source=source)
 117     if yaccgraphfile:
 118         target.append(yaccgraphfile)
 119         # rewrite user-supplied file string with a node, we need later
 120         env.Replace(YACC_GRAPH_FILE=env.File(yaccgraphfile))
 121
 122     return target, source
 123
 124
 125 def yEmitter(target, source, env) -> tuple:
 126     return _yaccEmitter(target, source, env, ['.y', '.yacc'], '$YACCHFILESUFFIX')
 127
 128
 129 def ymEmitter(target, source, env) -> tuple:
 130     return _yaccEmitter(target, source, env, ['.ym'], '$YACCHFILESUFFIX')
 131
 132
 133 def yyEmitter(target, source, env) -> tuple:
 134     return _yaccEmitter(target, source, env, ['.yy'], '$YACCHXXFILESUFFIX')
 135
 136
 137 def get_yacc_path(env, append_paths: bool=False) -> Optional[str]:
 138     """
 139     Returns the path to the yacc tool, searching several possible names.
 140
 141     Only called in the Windows case, so the `default_path` argument to
 142     :func:`find_program_path` can be Windows-specific.
 143
 144     Args:
 145         env: current construction environment
 146         append_paths: if true, add the path to the tool to PATH
 147     """
 148     for prog in BINS:
 149         bin_path = SCons.Tool.find_program_path(
 150             env,
 151             prog,
 152             default_paths=DEFAULT_PATHS,
 153             add_path=append_paths,
 154         )
 155         if bin_path:
 156             return bin_path
 157
 158     SCons.Warnings.warn(
 159         SCons.Warnings.SConsWarning,
 160         'yacc tool requested, but yacc or bison binary not found in ENV PATH'
 161     )
 162
 163
 164 def generate(env) -> None:
 165     """Add Builders and construction variables for yacc to an Environment."""
 166     c_file, cxx_file = SCons.Tool.createCFileBuilders(env)
 167
 168     # C
 169     c_file.add_action('.y', YaccAction)
 170     c_file.add_emitter('.y', yEmitter)
 171
 172     c_file.add_action('.yacc', YaccAction)
 173     c_file.add_emitter('.yacc', yEmitter)
 174
 175     # Objective-C
 176     c_file.add_action('.ym', YaccAction)
 177     c_file.add_emitter('.ym', ymEmitter)
 178
 179     # C++
 180     cxx_file.add_action('.yy', YaccAction)
 181     cxx_file.add_emitter('.yy', yyEmitter)
 182
 183     if sys.platform == 'win32':
 184         # ignore the return, all we need is for the path to be added
 185         _ = get_yacc_path(env, append_paths=True)
 186
 187     env.SetDefault(
 188         YACC=env.Detect(BINS),
 189         YACCFLAGS=CLVar(""),
 190         YACC_HEADER_FILE="",
 191         YACC_GRAPH_FILE="",
 192     )
 193
 194     env['YACCCOM'] = '$YACC $YACCFLAGS $_YACC_HEADER $_YACC_GRAPH -o $TARGET $SOURCES'
 195     env['YACCHFILESUFFIX'] = '.h'
 196     env['YACCHXXFILESUFFIX'] = '.hpp'
 197     env['YACCVCGFILESUFFIX'] = '.gv'
 198     env['YACC_GRAPH_FILE_SUFFIX'] = '$YACCVCGFILESUFFIX'
 199     env['_YACC_HEADER'] = '${YACC_HEADER_FILE and "--header=" + str(YACC_HEADER_FILE)}'
 200     env['_YACC_GRAPH'] = '${YACC_GRAPH_FILE and "--graph=" + str(YACC_GRAPH_FILE)}'
 201
 202
 203 def exists(env) -> Optional[str]:
 204     if 'YACC' in env:
 205         return env.Detect(env['YACC'])
 206
 207     if sys.platform == 'win32':
 208         return get_yacc_path(env)
 209     else:
 210         return env.Detect(BINS)
 211
 212 # Local Variables:
 213 # tab-width:4
 214 # indent-tabs-mode:nil
 215 # End:
 216 # vim: set expandtab tabstop=4 shiftwidth=4: