# cmake-parser.awk: rudimentary CMake script parser # # Copyright (c) 2022, Přemysl Eric Janouch
# SPDX-License-Identifier: 0BSD # # Implemented roughly according to the grammar described in cmake-language(7), # which is self-conflicting, and not an accurate description. # # The result of parsing is stored in the case-normalized Command variable, # and the Args array. These can be used by subsequent scripts. function warning(message) { print FILENAME ":" FNR ": warning: " message > "/dev/stderr" } function fatal(message) { print FILENAME ":" FNR ": fatal error: " message > "/dev/stderr" exit 1 } function expect(v) { if (!v && v == 0) fatal("broken expectations at `" $0 "'") return v } function literal(v) { if (substr($0, 1, length(v)) != v) return 0 $0 = substr($0, length(v) + 1) return 1 } function regexp(re) { if (!match($0, "^" re)) return 0 $0 = substr($0, RLENGTH + 1) return 1 } function space() { return regexp("[ \t]+") } function unbracket(len, v) { do { if (match($0, "]={" len "}]")) { v = v substr($0, 1, RSTART - 1) $0 = substr($0, RSTART + RLENGTH) return v } v = v $0 RS } while (getline > 0) fatal("unterminated bracket") } function bracket_comment() { if (!match($0, /^#\[=*\[/)) return 0 $0 = substr($0, RSTART + RLENGTH) unbracket(RLENGTH - 3) return 1 } function line_ending() { while (space() || bracket_comment()) {} if (/^#/) $0 = "" return !$0 } # ------------------------------------------------------------------------------ # While elementary expansion of previously set variables is implementable, # it doesn't seem to be worth the effort. function expand(s, v) { v = s while (match(v, /\\*[$](|ENV|CACHE)[{]/)) { if (index(substr(v, RSTART), "$") % 2 != 0) { warning("variable expansion is not supported: " s) return s } v = substr(v, RSTART + RLENGTH) } return s } function escape_sequence( v) { if (!literal("\\")) return 0 if (literal("t")) return "\t" if (literal("r")) return "\r" if (literal("n")) return "\n" # escape_semicolon isn't treated any specially here. if (regexp("[A-Za-z0-9]")) fatal("unsupported escape sequence") if ($0) { v = substr($0, 1, 1) $0 = substr($0, 2) return v } if (getline > 0) return "" fatal("premature end of file") } function quoted_argument( v, unescaped) { if (!literal("\"")) return 0 v = "" while (!literal("\"")) { if (!$0) { if (getline <= 0) fatal("premature end of file") v = v RS } else if ((unescaped = escape_sequence())) { if (unescaped == "\\" || unescaped == "$") v = v "\\" else if (unescaped == ";") v = v "\\\\" v = v unescaped } else if (unescaped == "") { # quoted_continuation } else { v = v substr($0, 1, 1) $0 = substr($0, 2) } } return v } function finalize_quoted(expanded, v) { while (match(expanded, /\\./)) { v = v substr(expanded, 1, RSTART - 1) \ substr(expanded, RSTART + 1, 1) expanded = substr(expanded, RSTART + RLENGTH) } Args[++N] = v expanded } function unquoted_argument( v, unescaped) { while (1) { if (match($0, /^[^[:space:]()#"\\]+/)) { v = v substr($0, RSTART, RLENGTH) $0 = substr($0, RSTART + RLENGTH) } else if ((unescaped = escape_sequence())) { if (unescaped == "\\" || unescaped == "$" || unescaped == ";") v = v "\\" v = v unescaped } else if (unescaped == "") { fatal("unexpected backslash in an unquoted argument") } else { # unquoted_legacy is not supported. return v } } } function finalize_unquoted(expanded, v) { while (expanded) { if (expanded ~ /^;/) { if (v) Args[++N] = v v = "" expanded = substr(expanded, 2) } else if (expanded ~ /^\\./) { v = v substr(expanded, 2, 1) expanded = substr(expanded, 3) } else { v = v substr(expanded, 1, 1) expanded = substr(expanded, 2) } } if (v) Args[++N] = v } # We keep and reprocess some escape sequences in here. function argument( arg, expanded, v) { if (regexp("\\[=*\\[")) Args[++N] = unbracket(RLENGTH - 2) else if ((arg = quoted_argument()) || arg == "") finalize_quoted(expand(arg)) else if ((arg = unquoted_argument())) finalize_unquoted(expand(arg)) else return 0 return 1 } # ------------------------------------------------------------------------------ function identifier( v) { if (!match($0, /^[A-Za-z_][A-Za-z0-9_]*/)) return 0 v = substr($0, 1, RLENGTH) $0 = substr($0, RLENGTH + 1) return v } function separation() { if (space() || bracket_comment()) return 1 if (!line_ending()) return 0 if (getline > 0) return 1 fatal("premature end of file") } function command_invocation( level) { while (space()) {} Command = identifier() if (!Command) return 0 while (space()) {} Command = tolower(Command) for (N in Args) delete Args[N] N = 0 expect(literal("(")) while (1) { while (separation()) {} if (literal(")")) { if (!level--) break Args[++N] = ")" continue } if (literal("(")) { level++ Args[++N] = "(" continue } expect(argument()) if (!/^[()]/) expect(separation()) } return 1 } { command_invocation() expect(line_ending()) }