diff options
Diffstat (limited to 'libbuild2/build/script/parser.cxx')
| -rw-r--r-- | libbuild2/build/script/parser.cxx | 141 |
1 files changed, 111 insertions, 30 deletions
diff --git a/libbuild2/build/script/parser.cxx b/libbuild2/build/script/parser.cxx index 0614f20..1a7f4e1 100644 --- a/libbuild2/build/script/parser.cxx +++ b/libbuild2/build/script/parser.cxx @@ -193,9 +193,22 @@ namespace build2 } } + // Parse a logical line, handling the flow control constructs + // recursively. + // + // If the flow control construct type is specified, then this line is + // assumed to belong to such a construct. + // void parser:: - pre_parse_line (token& t, type& tt, bool if_line) + pre_parse_line (token& t, type& tt, optional<line_type> fct) { + // enter: next token is peeked at (type in tt) + // leave: newline + + assert (!fct || + *fct == line_type::cmd_if || + *fct == line_type::cmd_while); + // Determine the line type/start token. // line_type lt ( @@ -235,19 +248,25 @@ namespace build2 case line_type::cmd_elif: case line_type::cmd_elifn: case line_type::cmd_else: - case line_type::cmd_end: { - if (!if_line) - { + if (!fct || *fct != line_type::cmd_if) fail (t) << lt << " without preceding 'if'"; - } + } + // Fall through. + case line_type::cmd_end: + { + if (!fct) + fail (t) << lt << " without preceding 'if', 'for', or 'while'"; } // Fall through. case line_type::cmd_if: case line_type::cmd_ifn: + case line_type::cmd_while: next (t, tt); // Skip to start of command. - if (lt == line_type::cmd_if || lt == line_type::cmd_ifn) + if (lt == line_type::cmd_if || + lt == line_type::cmd_ifn || + lt == line_type::cmd_while) ++level_; else if (lt == line_type::cmd_end) --level_; @@ -287,6 +306,50 @@ namespace build2 pre_parse_if_else (t, tt); } + else if (lt == line_type::cmd_while) + { + tt = peek (lexer_mode::first_token); + + pre_parse_while (t, tt); + } + } + + // Pre-parse the flow control construct block line. + // + void parser:: + pre_parse_block_line (token& t, type& tt, line_type bt) + { + // enter: peeked first token of the line (type in tt) + // leave: newline + + const location ll (get_location (peeked ())); + + if (tt == type::eos) + fail (ll) << "expected closing 'end'"; + + line_type fct; // Flow control type the block type relates to. + + switch (bt) + { + case line_type::cmd_if: + case line_type::cmd_ifn: + case line_type::cmd_elif: + case line_type::cmd_elifn: + case line_type::cmd_else: + { + fct = line_type::cmd_if; + break; + } + case line_type::cmd_while: + { + fct = line_type::cmd_while; + break; + } + default: assert(false); + } + + pre_parse_line (t, tt, fct); + assert (tt == type::newline); } void parser:: @@ -295,8 +358,7 @@ namespace build2 // enter: peeked first token of next line (type in tt) // leave: newline - // Parse lines until we see closing 'end'. Nested if-else blocks are - // handled recursively. + // Parse lines until we see closing 'end'. // for (line_type bt (line_type::cmd_if); // Current block. ; @@ -304,25 +366,21 @@ namespace build2 { const location ll (get_location (peeked ())); - if (tt == type::eos) - fail (ll) << "expected closing 'end'"; - // Parse one line. Note that this one line can still be multiple - // lines in case of if-else. In this case we want to view it as - // cmd_if, not cmd_end. Thus remember the start position of the - // next logical line. + // lines in case of a flow control construct. In this case we want + // to view it as cmd_if, not cmd_end. Thus remember the start + // position of the next logical line. // size_t i (script_->body.size ()); - pre_parse_line (t, tt, true /* if_line */); - assert (tt == type::newline); + pre_parse_block_line (t, tt, bt); line_type lt (script_->body[i].type); // First take care of 'end'. // if (lt == line_type::cmd_end) - return; + break; // Check if-else block sequencing. // @@ -346,6 +404,25 @@ namespace build2 } } + void parser:: + pre_parse_while (token& t, type& tt) + { + // enter: peeked first token of next line (type in tt) + // leave: newline + + // Parse lines until we see closing 'end'. + // + for (;; tt = peek (lexer_mode::first_token)) + { + size_t i (script_->body.size ()); + + pre_parse_block_line (t, tt, line_type::cmd_while); + + if (script_->body[i].type == line_type::cmd_end) + break; + } + } + command_expr parser:: parse_command_line (token& t, type& tt) { @@ -946,7 +1023,7 @@ namespace build2 // Note that we rely on "small function object" optimization here. // auto exec_cmd = [this] (token& t, build2::script::token_type& tt, - size_t li, + const iteration_index* ii, size_t li, bool single, const location& ll) { @@ -958,7 +1035,7 @@ namespace build2 command_expr ce ( parse_command_line (t, static_cast<token_type&> (tt))); - runner_->run (*environment_, ce, li, ll); + runner_->run (*environment_, ce, ii, li, ll); }; exec_lines (s.body, exec_cmd); @@ -1009,13 +1086,13 @@ namespace build2 auto exec_cmd = [this, &data] (token& t, build2::script::token_type& tt, - size_t li, + const iteration_index* ii, size_t li, bool /* single */, const location& ll) { // Note that we never reset the line index to zero (as we do in - // execute_body()) assuming that there are some script body - // commands to follow. + // execute_body()) assuming that there are some script body commands + // to follow. // if (tt == type::word && t.value == "depdb") { @@ -1128,7 +1205,7 @@ namespace build2 info (rt[0].location ()) << "depdb preamble ends here"; } - runner_->run (*environment_, ce, li, ll); + runner_->run (*environment_, ce, ii, li, ll); } }; @@ -1191,20 +1268,22 @@ namespace build2 apply_value_attributes (&var, lhs, move (rhs), kind); }; - auto exec_if = [this] (token& t, build2::script::token_type& tt, - size_t li, - const location& ll) + auto exec_cond = [this] (token& t, build2::script::token_type& tt, + const iteration_index* ii, size_t li, + const location& ll) { command_expr ce ( parse_command_line (t, static_cast<token_type&> (tt))); - // Assume if-else always involves multiple commands. + // Assume a flow control construct always involves multiple + // commands. // - return runner_->run_if (*environment_, ce, li, ll); + return runner_->run_cond (*environment_, ce, ii, li, ll); }; build2::script::parser::exec_lines (begin, end, - exec_set, exec_cmd, exec_if, + exec_set, exec_cmd, exec_cond, + nullptr /* iteration_index */, environment_->exec_line, &environment_->var_pool); } @@ -2145,10 +2224,12 @@ namespace build2 istringstream iss; if (prog) { + // Note: depdb is disallowed inside flow control constructs. + // string s; build2::script::run (*environment_, cmd, - li, + nullptr /* iteration_index */, li, ll, !file ? &s : nullptr); |