diff options
Diffstat (limited to 'parse.cxx')
| -rw-r--r-- | parse.cxx | 149 |
1 files changed, 111 insertions, 38 deletions
@@ -1,6 +1,10 @@ // recursive descent parser for systemtap scripts -// Copyright 2005 Red Hat Inc. -// GPL +// Copyright (C) 2005 Red Hat Inc. +// +// This file is part of systemtap, and is free software. You can +// redistribute it and/or modify it under the terms of the GNU General +// Public License (GPL); either version 2, or (at your option) any +// later version. #include "config.h" #include "staptree.h" @@ -109,8 +113,6 @@ parser::next () if (! next_t) throw parse_error ("unexpected end-of-file"); - // cerr << "[" << next_t->content << "]" << endl; - last_t = next_t; // advance by zeroing next_t next_t = 0; @@ -411,7 +413,6 @@ parser::parse_stmt_block () { try { - // handle empty blocks t = peek (); if (t && t->type == tok_operator && t->content == "}") { @@ -420,24 +421,6 @@ parser::parse_stmt_block () } pb->statements.push_back (parse_statement ()); - - // ';' is a statement separator in awk, not a terminator. - // Note that ';' is also a possible null statement. - t = peek (); - if (t && t->type == tok_operator && t->content == "}") - { - next (); - break; - } - else if (t && t->type == tok_operator && t->content == ";") - { - next (); - continue; - // this also accepts semicolon as a terminator: - // { a=1; } - } - else - throw parse_error ("expected ';' or '}'"); } catch (parse_error& pe) { @@ -466,29 +449,31 @@ parser::parse_statement () const token* t = peek (); if (t && t->type == tok_operator && t->content == ";") { - next (); - return new null_statement (); + null_statement* n = new null_statement (); + n->tok = next (); + return n; } else if (t && t->type == tok_operator && t->content == "{") return parse_stmt_block (); else if (t && t->type == tok_identifier && t->content == "if") return parse_if_statement (); + /* + else if (t && t->type == tok_identifier && t->content == "for") + return parse_for_loop (); + */ + else if (t && t->type == tok_identifier && t->content == "foreach") + return parse_foreach_loop (); else if (t && t->type == tok_identifier && t->content == "return") return parse_return_statement (); else if (t && t->type == tok_identifier && t->content == "delete") return parse_delete_statement (); - // XXX: other control constructs ("for", "delete", "while", "do", - // "break", "continue", "exit", "return") + // XXX: other control constructs ("delete", "while", "do", + // "break", "continue", "exit") else if (t && (t->type == tok_operator || // expressions are flexible t->type == tok_identifier || t->type == tok_number || t->type == tok_string)) - { - expr_statement *es = new expr_statement; - es->tok = t; - es->value = parse_expression (); - return es; - } + return parse_expr_statement (); else throw parse_error ("expected statement"); } @@ -695,6 +680,17 @@ parser::parse_if_statement () } +expr_statement* +parser::parse_expr_statement () +{ + expr_statement *es = new expr_statement; + const token* t = peek (); + es->tok = t; + es->value = parse_expression (); + return es; +} + + return_statement* parser::parse_return_statement () { @@ -721,6 +717,84 @@ parser::parse_delete_statement () } +for_loop* +parser::parse_for_loop () +{ + throw parse_error ("not yet implemented"); +} + + +foreach_loop* +parser::parse_foreach_loop () +{ + const token* t = next (); + if (! (t->type == tok_identifier && t->content == "foreach")) + throw parse_error ("expected 'foreach'"); + foreach_loop* s = new foreach_loop; + s->tok = t; + + t = next (); + if (! (t->type == tok_operator && t->content == "(")) + throw parse_error ("expected '('"); + + // see also parse_array_in + + bool parenthesized = false; + t = peek (); + if (t && t->type == tok_operator && t->content == "[") + { + next (); + parenthesized = true; + } + + while (1) + { + t = next (); + if (! (t->type == tok_identifier)) + throw parse_error ("expected identifier"); + symbol* sym = new symbol; + sym->tok = t; + sym->name = t->content; + s->indexes.push_back (sym); + + if (parenthesized) + { + const token* t = peek (); + if (t && t->type == tok_operator && t->content == ",") + { + next (); + continue; + } + else if (t && t->type == tok_operator && t->content == "]") + { + next (); + break; + } + else + throw parse_error ("expected ',' or ']'"); + } + else + break; // expecting only one expression + } + + t = next (); + if (! (t->type == tok_identifier && t->content == "in")) + throw parse_error ("expected 'in'"); + + t = next (); + if (t->type != tok_identifier) + throw parse_error ("expected identifier"); + s->base = t->content; + + t = next (); + if (! (t->type == tok_operator && t->content == ")")) + throw parse_error ("expected ')'"); + + s->block = parse_statement (); + return s; +} + + expression* parser::parse_expression () { @@ -831,12 +905,12 @@ expression* parser::parse_array_in () { // This is a very tricky case. All these are legit expressions: - // "a in b" "a+0 in b" "(a,b) in c" "(c,(d+0)) in b" + // "a in b" "a+0 in b" "[a,b] in c" "[c,(d+0)] in b" vector<expression*> indexes; bool parenthesized = false; const token* t = peek (); - if (t && t->type == tok_operator && t->content == "(") + if (t && t->type == tok_operator && t->content == "[") { next (); parenthesized = true; @@ -855,13 +929,13 @@ parser::parse_array_in () next (); continue; } - else if (t && t->type == tok_operator && t->content == ")") + else if (t && t->type == tok_operator && t->content == "]") { next (); break; } else - throw parse_error ("expected ',' or ')'"); + throw parse_error ("expected ',' or ']'"); } else break; // expecting only one expression @@ -871,7 +945,6 @@ parser::parse_array_in () if (t && t->type == tok_identifier && t->content == "in") { array_in *e = new array_in; - e->op = t->content; e->tok = t; next (); // swallow "in" |