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Direktori : /proc/self/root/usr/share/doc/mawk/examples/ |
Current File : //proc/self/root/usr/share/doc/mawk/examples/gdecl.awk |
#!/usr/bin/mawk -f # parse a C declaration by recursive descent # # decl.awk with extra escapes \ ################################################ ############################################ # lexical scanner -- gobble() # input : string s -- treated as a regular expression # gobble eats SPACE, then eats longest match of s off front # of global variable line. # Cuts the matched part off of line # function gobble(s, x) { sub( /^ /, "", line) # eat SPACE if any # surround s with parenthesis to make sure ^ acts on the # whole thing match(line, "^" "(" s ")") x = substr(line, 1, RLENGTH) line = substr(line, RLENGTH+1) return x } function ptr_to(n, x) # print "pointer to" , n times { n = int(n) if ( n <= 0 ) return "" x = "pointer to" ; n-- while ( n-- ) x = x " pointer to" return x } #recursively get a decl # returns an english description of the declaration or # "" if not a C declaration. function decl( x, t, ptr_part) { x = gobble("[* ]+") # get list of *** ... gsub(/ /, "", x) # remove all SPACES ptr_part = ptr_to( length(x) ) # We expect to see either an identifier or '(' # if ( gobble("\\(") ) { # this is the recursive descent part # we expect to match a declaration and closing ')' # If not return "" to indicate failure if ( (x = decl()) == "" || gobble( "\\)" ) == "" ) return "" } else # expecting an identifier { if ( (x = gobble(id)) == "" ) return "" x = x ":" } # finally look for () # or [ opt_size ] while ( 1 ) if ( gobble( funct_mark ) ) x = x " function returning" else if ( t = gobble( array_mark ) ) { gsub(/ /, "", t) x = x " array" t " of" } else break x = x " " ptr_part return x } BEGIN { id = "[_A-Za-z][_A-Za-z0-9]*" funct_mark = "\\([ \t]*\\)" array_mark = "\\[[ \t]*[_A-Za-z0-9]*[ \t]*\\]" # I've assumed types are keywords or all CAPS or end in _t # Other conventions could be added. type0 = "int|char|short|long|double|float|void" type1 = "[_A-Z][_A-Z0-9]*" # types are CAPS type2 = "[_A-Za-z][_A-Za-z0-9]*_t" # end in _t types = "(" type0 "|" type1 "|" type2 ")" } { gsub( /\/\*([^*]|\*[^\/])*(\*\/|$)/ , " ") # remove comments gsub( /[ \t]+/, " ") # squeeze white space to a single space line = $0 scope = gobble( "extern|static" ) if ( type = gobble("(struct|union|enum) ") ) type = type gobble(id) # get the tag else { type = gobble("(un)?signed ") gobble( types ) } if ( ! type ) next if ( (x = decl()) && gobble( ";") ) { x = x " " type if ( scope ) x = x " (" scope ")" gsub( / +/, " ", x) # print x } }