This script takes configuration fragments and generates full Bison grammar

from them.
This commit is contained in:
Martin Mares 1998-11-27 19:33:53 +00:00
parent 882c588a40
commit ce6ca80926

63
conf/gen_parser.m4 Normal file
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m4_divert(-1)m4_dnl
#
# BIRD -- Generator of Configuration Grammar
#
# (c) 1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
#
# Can be freely distributed and used under the terms of the GNU GPL.
#
# Diversions used:
# 1 includes
# 2 types etc.
# 3 rules
# 4 C code
# Common aliases
m4_define(DNL, `m4_dnl')
# Define macros for defining sections
m4_define(CF_ZONE, `m4_divert($1)/* $2 from m4___file__ */')
m4_define(CF_HDR, `CF_ZONE(1, Headers)')
m4_define(CF_DECLS, `CF_ZONE(2, Declarations)')
m4_define(CF_GRAMMAR, `CF_ZONE(3, Grammar)')
m4_define(CF_CODE, `CF_ZONE(4, C Code)')
m4_define(CF_END, `m4_divert(-1)')
# Simple iterator
m4_define(CF_itera, `m4_ifelse($#, 1, [[CF_iter($1)]], [[CF_iter($1)[[]]CF_itera(m4_shift($@))]])')
m4_define(CF_iterate, `m4_define([[CF_iter]], m4_defn([[$1]]))CF_itera($2)')
# Keywords act as untyped %token
m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)m4_define([[CF_toks]],CF_toks $1)]])')
m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
)DNL')
# Dynamic syntax rules
m4_define(CF_dyn_rules,)
m4_define(CF_ADDTO, `m4_define([[CF_rule_$1]],m4_ifdef([[CF_rule_$1]],CF_rule_$1 | ,[[m4_define([[CF_dyn_rules]],CF_dyn_rules[[CF_RULE($1)
]])]])$2)DNL')
m4_define(CF_RULE, `$1: CF_rule_$1')
# After all configuration templates end, we finally generate the grammar file.
m4_m4wrap(`
m4_divert(0)DNL
%{
m4_undivert(1)DNL
%}
m4_undivert(2)DNL
%%
m4_undivert(3)DNL
/* Dynamic rules */
CF_dyn_rules
%%
m4_undivert(4)DNL
')
# As we are processing C source, we must access all M4 primitives via
# m4_* and also set different quoting convention: `[[' and ']]'
m4_changequote([[,]])