--- /dev/null
+/* ------------------------------------------------------------------------- */
+/* "syntax" : Syntax analyser and compiler */
+/* */
+/* Copyright (c) Graham Nelson 1993 - 2018 */
+/* */
+/* This file is part of Inform. */
+/* */
+/* Inform is free software: you can redistribute it and/or modify */
+/* it under the terms of the GNU General Public License as published by */
+/* the Free Software Foundation, either version 3 of the License, or */
+/* (at your option) any later version. */
+/* */
+/* Inform is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU General Public License for more details. */
+/* */
+/* You should have received a copy of the GNU General Public License */
+/* along with Inform. If not, see https://gnu.org/licenses/ */
+/* */
+/* ------------------------------------------------------------------------- */
+
+#include "header.h"
+
+static char *lexical_source;
+
+int no_syntax_lines; /* Syntax line count */
+
+static void begin_syntax_line(int statement_mode)
+{ no_syntax_lines++;
+ next_token_begins_syntax_line = TRUE;
+
+ clear_expression_space();
+ if (statement_mode)
+ { statements.enabled = TRUE;
+ conditions.enabled = TRUE;
+ local_variables.enabled = TRUE;
+ system_functions.enabled = TRUE;
+
+ misc_keywords.enabled = FALSE;
+ directive_keywords.enabled = FALSE;
+ directives.enabled = FALSE;
+ segment_markers.enabled = FALSE;
+ opcode_names.enabled = FALSE;
+ }
+ else
+ { directives.enabled = TRUE;
+ segment_markers.enabled = TRUE;
+
+ statements.enabled = FALSE;
+ misc_keywords.enabled = FALSE;
+ directive_keywords.enabled = FALSE;
+ local_variables.enabled = FALSE;
+ system_functions.enabled = FALSE;
+ conditions.enabled = FALSE;
+ opcode_names.enabled = FALSE;
+ }
+
+ sequence_point_follows = TRUE;
+
+ if (debugfile_switch)
+ { get_next_token();
+ statement_debug_location = get_token_location();
+ put_token_back();
+ }
+}
+
+extern void panic_mode_error_recovery(void)
+{
+ /* Consume tokens until the next semicolon (or end of file).
+ This is typically called after a syntax error, in hopes of
+ getting parsing back on track. */
+
+ while ((token_type != EOF_TT)
+ && ((token_type != SEP_TT)||(token_value != SEMICOLON_SEP)))
+
+ get_next_token();
+}
+
+extern void get_next_token_with_directives(void)
+{
+ /* A higher-level version of get_next_token(), which detects and
+ obeys directives such as #ifdef/#ifnot/#endif. (The # sign is
+ required in this case.)
+
+ This is called while parsing a long construct, such as Class or
+ Object, where we want to support internal #ifdefs. (Although
+ function-parsing predates this and doesn't make use of it.)
+
+ (Technically this permits *any* #-directive, which means you
+ can define global variables or properties or what-have-you in
+ the middle of an object. You can do that in the middle of an
+ object, too. Don't. It's about as well-supported as Wile E.
+ Coyote one beat before the plummet-lines kick in.) */
+
+ int directives_save, segment_markers_save, statements_save;
+
+ while (TRUE)
+ {
+ get_next_token();
+
+ /* If the first token is not a '#', return it directly. */
+ if ((token_type != SEP_TT) || (token_value != HASH_SEP))
+ return;
+
+ /* Save the lexer flags, and set up for directive parsing. */
+ directives_save = directives.enabled;
+ segment_markers_save = segment_markers.enabled;
+ statements_save = statements.enabled;
+
+ directives.enabled = TRUE;
+ segment_markers.enabled = FALSE;
+ statements.enabled = FALSE;
+ conditions.enabled = FALSE;
+ local_variables.enabled = FALSE;
+ misc_keywords.enabled = FALSE;
+ system_functions.enabled = FALSE;
+
+ get_next_token();
+
+ if ((token_type == SEP_TT) && (token_value == OPEN_SQUARE_SEP))
+ { error("It is illegal to nest a routine inside an object using '#['");
+ return;
+ }
+
+ if (token_type == DIRECTIVE_TT)
+ parse_given_directive(TRUE);
+ else
+ { ebf_error("directive", token_text);
+ return;
+ }
+
+ /* Restore all the lexer flags. (We are squashing several of them
+ into a single save variable, which I think is safe because that's
+ what CKnight did.)
+ */
+ directive_keywords.enabled = FALSE;
+ directives.enabled = directives_save;
+ segment_markers.enabled = segment_markers_save;
+ statements.enabled =
+ conditions.enabled =
+ local_variables.enabled =
+ misc_keywords.enabled =
+ system_functions.enabled = statements_save;
+ }
+}
+
+extern void parse_program(char *source)
+{
+ lexical_source = source;
+ while (parse_directive(FALSE)) ;
+}
+
+extern int parse_directive(int internal_flag)
+{
+ /* Internal_flag is FALSE if the directive is encountered normally,
+ TRUE if encountered with a # prefix inside a routine or object
+ definition.
+
+ Returns: TRUE if program continues, FALSE if end of file reached. */
+
+ int routine_symbol, rep_symbol;
+ int is_renamed;
+
+ begin_syntax_line(FALSE);
+ get_next_token();
+
+ if (token_type == EOF_TT) return(FALSE);
+
+ if ((token_type == SEP_TT) && (token_value == HASH_SEP))
+ get_next_token();
+
+ if ((token_type == SEP_TT) && (token_value == OPEN_SQUARE_SEP))
+ { if (internal_flag)
+ { error("It is illegal to nest routines using '#['");
+ return(TRUE);
+ }
+
+ directives.enabled = FALSE;
+ directive_keywords.enabled = FALSE;
+ segment_markers.enabled = FALSE;
+
+ /* The upcoming symbol is a definition; don't count it as a
+ top-level reference *to* the function. */
+ df_dont_note_global_symbols = TRUE;
+ get_next_token();
+ df_dont_note_global_symbols = FALSE;
+ if ((token_type != SYMBOL_TT)
+ || ((!(sflags[token_value] & UNKNOWN_SFLAG))
+ && (!(sflags[token_value] & REPLACE_SFLAG))))
+ { ebf_error("routine name", token_text);
+ return(FALSE);
+ }
+
+ routine_symbol = token_value;
+
+ rep_symbol = routine_symbol;
+ is_renamed = find_symbol_replacement(&rep_symbol);
+
+ if ((sflags[routine_symbol] & REPLACE_SFLAG)
+ && !is_renamed && (is_systemfile()))
+ { /* The function is definitely being replaced (system_file
+ always loses priority in a replacement) but is not
+ being renamed to something else. Skip its definition
+ entirely. */
+ dont_enter_into_symbol_table = TRUE;
+ do
+ { get_next_token();
+ } while (!((token_type == EOF_TT)
+ || ((token_type==SEP_TT)
+ && (token_value==CLOSE_SQUARE_SEP))));
+ dont_enter_into_symbol_table = FALSE;
+ if (token_type == EOF_TT) return FALSE;
+ }
+ else
+ { /* Parse the function definition and assign its symbol. */
+ assign_symbol(routine_symbol,
+ parse_routine(lexical_source, FALSE,
+ (char *) symbs[routine_symbol], FALSE, routine_symbol),
+ ROUTINE_T);
+ slines[routine_symbol] = routine_starts_line;
+ }
+
+ if (is_renamed) {
+ /* This function was subject to a "Replace X Y" directive.
+ The first time we see a definition for symbol X, we
+ copy it to Y -- that's the "original" form of the
+ function. */
+ if (svals[rep_symbol] == 0) {
+ assign_symbol(rep_symbol, svals[routine_symbol], ROUTINE_T);
+ }
+ }
+
+ get_next_token();
+ if ((token_type != SEP_TT) || (token_value != SEMICOLON_SEP))
+ { ebf_error("';' after ']'", token_text);
+ put_token_back();
+ }
+ return TRUE;
+ }
+
+ if ((token_type == SYMBOL_TT) && (stypes[token_value] == CLASS_T))
+ { if (internal_flag)
+ { error("It is illegal to nest an object in a routine using '#classname'");
+ return(TRUE);
+ }
+ sflags[token_value] |= USED_SFLAG;
+ make_object(FALSE, NULL, -1, -1, svals[token_value]);
+ return TRUE;
+ }
+
+ if (token_type != DIRECTIVE_TT)
+ { /* If we're internal, we expect only a directive here. If
+ we're top-level, the possibilities are broader. */
+ if (internal_flag)
+ ebf_error("directive", token_text);
+ else
+ ebf_error("directive, '[' or class name", token_text);
+ panic_mode_error_recovery();
+ return TRUE;
+ }
+
+ return !(parse_given_directive(internal_flag));
+}
+
+static int switch_sign(void)
+{
+ if ((token_type == SEP_TT)&&(token_value == COLON_SEP)) return 1;
+ if ((token_type == SEP_TT)&&(token_value == COMMA_SEP)) return 2;
+ if ((token_type==MISC_KEYWORD_TT)&&(token_value==TO_MK)) return 3;
+ return 0;
+}
+
+static assembly_operand spec_stack[32];
+static int spec_type[32];
+
+static void compile_alternatives_z(assembly_operand switch_value, int n,
+ int stack_level, int label, int flag)
+{ switch(n)
+ { case 1:
+ assemblez_2_branch(je_zc, switch_value,
+ spec_stack[stack_level],
+ label, flag); return;
+ case 2:
+ assemblez_3_branch(je_zc, switch_value,
+ spec_stack[stack_level], spec_stack[stack_level+1],
+ label, flag); return;
+ case 3:
+ assemblez_4_branch(je_zc, switch_value,
+ spec_stack[stack_level], spec_stack[stack_level+1],
+ spec_stack[stack_level+2],
+ label, flag); return;
+ }
+}
+
+static void compile_alternatives_g(assembly_operand switch_value, int n,
+ int stack_level, int label, int flag)
+{
+ int the_zc = (flag) ? jeq_gc : jne_gc;
+
+ if (n == 1) {
+ assembleg_2_branch(the_zc, switch_value,
+ spec_stack[stack_level],
+ label);
+ }
+ else {
+ error("*** Cannot generate multi-equality tests in Glulx ***");
+ }
+}
+
+static void compile_alternatives(assembly_operand switch_value, int n,
+ int stack_level, int label, int flag)
+{
+ if (!glulx_mode)
+ compile_alternatives_z(switch_value, n, stack_level, label, flag);
+ else
+ compile_alternatives_g(switch_value, n, stack_level, label, flag);
+}
+
+static void parse_switch_spec(assembly_operand switch_value, int label,
+ int action_switch)
+{
+ int i, j, label_after = -1, spec_sp = 0;
+ int max_equality_args = ((!glulx_mode) ? 3 : 1);
+
+ sequence_point_follows = FALSE;
+
+ do
+ { if (spec_sp == 32)
+ { error("At most 32 values can be given in a single 'switch' case");
+ panic_mode_error_recovery();
+ return;
+ }
+
+ if (action_switch)
+ { get_next_token();
+ if (token_type == SQ_TT || token_type == DQ_TT) {
+ ebf_error("action (or fake action) name", token_text);
+ continue;
+ }
+ spec_stack[spec_sp] = action_of_name(token_text);
+
+ if (spec_stack[spec_sp].value == -1)
+ { spec_stack[spec_sp].value = 0;
+ ebf_error("action (or fake action) name", token_text);
+ }
+ }
+ else
+ spec_stack[spec_sp] =
+ code_generate(parse_expression(CONSTANT_CONTEXT), CONSTANT_CONTEXT, -1);
+
+ misc_keywords.enabled = TRUE;
+ get_next_token();
+ misc_keywords.enabled = FALSE;
+
+ spec_type[spec_sp++] = switch_sign();
+ switch(spec_type[spec_sp-1])
+ { case 0:
+ if (action_switch)
+ ebf_error("',' or ':'", token_text);
+ else ebf_error("',', ':' or 'to'", token_text);
+ panic_mode_error_recovery();
+ return;
+ case 1: goto GenSpecCode;
+ case 3: if (label_after == -1) label_after = next_label++;
+ }
+ } while(TRUE);
+
+ GenSpecCode:
+
+ if ((spec_sp > max_equality_args) && (label_after == -1))
+ label_after = next_label++;
+
+ if (label_after == -1)
+ { compile_alternatives(switch_value, spec_sp, 0, label, FALSE); return;
+ }
+
+ for (i=0; i<spec_sp;)
+ {
+ j=i; while ((j<spec_sp) && (spec_type[j] != 3)) j++;
+
+ if (j > i)
+ { if (j-i > max_equality_args) j=i+max_equality_args;
+
+ if (j == spec_sp)
+ compile_alternatives(switch_value, j-i, i, label, FALSE);
+ else
+ compile_alternatives(switch_value, j-i, i, label_after, TRUE);
+
+ i=j;
+ }
+ else
+ {
+ if (!glulx_mode) {
+ if (i == spec_sp - 2)
+ { assemblez_2_branch(jl_zc, switch_value, spec_stack[i],
+ label, TRUE);
+ assemblez_2_branch(jg_zc, switch_value, spec_stack[i+1],
+ label, TRUE);
+ }
+ else
+ { assemblez_2_branch(jl_zc, switch_value, spec_stack[i],
+ next_label, TRUE);
+ assemblez_2_branch(jg_zc, switch_value, spec_stack[i+1],
+ label_after, FALSE);
+ assemble_label_no(next_label++);
+ }
+ }
+ else {
+ if (i == spec_sp - 2)
+ { assembleg_2_branch(jlt_gc, switch_value, spec_stack[i],
+ label);
+ assembleg_2_branch(jgt_gc, switch_value, spec_stack[i+1],
+ label);
+ }
+ else
+ { assembleg_2_branch(jlt_gc, switch_value, spec_stack[i],
+ next_label);
+ assembleg_2_branch(jle_gc, switch_value, spec_stack[i+1],
+ label_after);
+ assemble_label_no(next_label++);
+ }
+ }
+ i = i+2;
+ }
+ }
+
+ assemble_label_no(label_after);
+}
+
+extern int32 parse_routine(char *source, int embedded_flag, char *name,
+ int veneer_flag, int r_symbol)
+{ int32 packed_address; int i; int debug_flag = FALSE;
+ int switch_clause_made = FALSE, default_clause_made = FALSE,
+ switch_label = 0;
+ debug_location_beginning beginning_debug_location =
+ get_token_location_beginning();
+
+ /* (switch_label needs no initialisation here, but it prevents some
+ compilers from issuing warnings) */
+
+ if ((source != lexical_source) || (veneer_flag))
+ { lexical_source = source;
+ restart_lexer(lexical_source, name);
+ }
+
+ no_locals = 0;
+
+ for (i=0;i<MAX_LOCAL_VARIABLES-1;i++) local_variables.keywords[i] = "";
+
+ do
+ { statements.enabled = TRUE;
+ dont_enter_into_symbol_table = TRUE;
+ get_next_token();
+ dont_enter_into_symbol_table = FALSE;
+ if ((token_type == SEP_TT) && (token_value == TIMES_SEP)
+ && (no_locals == 0) && (!debug_flag))
+ { debug_flag = TRUE; continue;
+ }
+
+ if (token_type != DQ_TT)
+ { if ((token_type == SEP_TT)
+ && (token_value == SEMICOLON_SEP)) break;
+ ebf_error("local variable name or ';'", token_text);
+ panic_mode_error_recovery();
+ break;
+ }
+
+ if (strlen(token_text) > MAX_IDENTIFIER_LENGTH)
+ { error_named("Local variable identifier too long:", token_text);
+ panic_mode_error_recovery();
+ break;
+ }
+
+ if (no_locals == MAX_LOCAL_VARIABLES-1)
+ { error_numbered("Too many local variables for a routine; max is",
+ MAX_LOCAL_VARIABLES-1);
+ panic_mode_error_recovery();
+ break;
+ }
+
+ for (i=0;i<no_locals;i++)
+ if (strcmpcis(token_text, local_variables.keywords[i])==0)
+ error_named("Local variable defined twice:", token_text);
+ local_variables.keywords[no_locals++] = token_text;
+ } while(TRUE);
+
+ construct_local_variable_tables();
+
+ if ((trace_fns_setting==3)
+ || ((trace_fns_setting==2) && (veneer_mode==FALSE))
+ || ((trace_fns_setting==1) && (is_systemfile()==FALSE)))
+ debug_flag = TRUE;
+ if ((embedded_flag == FALSE) && (veneer_mode == FALSE) && debug_flag)
+ sflags[r_symbol] |= STAR_SFLAG;
+
+ packed_address = assemble_routine_header(no_locals, debug_flag,
+ name, embedded_flag, r_symbol);
+
+ do
+ { begin_syntax_line(TRUE);
+
+ get_next_token();
+
+ if (token_type == EOF_TT)
+ { ebf_error("']'", token_text);
+ assemble_routine_end
+ (embedded_flag,
+ get_token_location_end(beginning_debug_location));
+ put_token_back();
+ break;
+ }
+
+ if ((token_type == SEP_TT)
+ && (token_value == CLOSE_SQUARE_SEP))
+ { if (switch_clause_made && (!default_clause_made))
+ assemble_label_no(switch_label);
+ directives.enabled = TRUE;
+ sequence_point_follows = TRUE;
+ get_next_token();
+ assemble_routine_end
+ (embedded_flag,
+ get_token_location_end(beginning_debug_location));
+ put_token_back();
+ break;
+ }
+
+ if ((token_type == STATEMENT_TT) && (token_value == SDEFAULT_CODE))
+ { if (default_clause_made)
+ error("Multiple 'default' clauses defined in same 'switch'");
+ default_clause_made = TRUE;
+
+ if (switch_clause_made)
+ { if (!execution_never_reaches_here)
+ { sequence_point_follows = FALSE;
+ if (!glulx_mode)
+ assemblez_0((embedded_flag)?rfalse_zc:rtrue_zc);
+ else
+ assembleg_1(return_gc,
+ ((embedded_flag)?zero_operand:one_operand));
+ }
+ assemble_label_no(switch_label);
+ }
+ switch_clause_made = TRUE;
+
+ get_next_token();
+ if ((token_type == SEP_TT) &&
+ (token_value == COLON_SEP)) continue;
+ ebf_error("':' after 'default'", token_text);
+ panic_mode_error_recovery();
+ continue;
+ }
+
+ /* Only check for the form of a case switch if the initial token
+ isn't double-quoted text, as that would mean it was a print_ret
+ statement: this is a mild ambiguity in the grammar.
+ Action statements also cannot be cases. */
+
+ if ((token_type != DQ_TT) && (token_type != SEP_TT))
+ { get_next_token();
+ if (switch_sign() > 0)
+ { assembly_operand AO;
+ if (default_clause_made)
+ error("'default' must be the last 'switch' case");
+
+ if (switch_clause_made)
+ { if (!execution_never_reaches_here)
+ { sequence_point_follows = FALSE;
+ if (!glulx_mode)
+ assemblez_0((embedded_flag)?rfalse_zc:rtrue_zc);
+ else
+ assembleg_1(return_gc,
+ ((embedded_flag)?zero_operand:one_operand));
+ }
+ assemble_label_no(switch_label);
+ }
+
+ switch_label = next_label++;
+ switch_clause_made = TRUE;
+ put_token_back(); put_token_back();
+
+ if (!glulx_mode) {
+ INITAOTV(&AO, VARIABLE_OT, 249);
+ }
+ else {
+ INITAOTV(&AO, GLOBALVAR_OT, MAX_LOCAL_VARIABLES+6); /* sw__var */
+ }
+ parse_switch_spec(AO, switch_label, TRUE);
+
+ continue;
+ }
+ else
+ { put_token_back(); put_token_back(); get_next_token();
+ sequence_point_follows = TRUE;
+ }
+ }
+
+ parse_statement(-1, -1);
+
+ } while (TRUE);
+
+ return packed_address;
+}
+
+extern void parse_code_block(int break_label, int continue_label,
+ int switch_rule)
+{ int switch_clause_made = FALSE, default_clause_made = FALSE, switch_label = 0,
+ unary_minus_flag;
+
+ begin_syntax_line(TRUE);
+ get_next_token();
+
+ if (token_type == SEP_TT && token_value == OPEN_BRACE_SEP)
+ { do
+ { begin_syntax_line(TRUE);
+ get_next_token();
+ if (token_type == SEP_TT && token_value == CLOSE_BRACE_SEP)
+ { if (switch_clause_made && (!default_clause_made))
+ assemble_label_no(switch_label);
+ return;
+ }
+ if (token_type == EOF_TT)
+ { ebf_error("'}'", token_text); return; }
+
+ if (switch_rule != 0)
+ {
+ /* Within a 'switch' block */
+
+ if ((token_type==STATEMENT_TT)&&(token_value==SDEFAULT_CODE))
+ { if (default_clause_made)
+ error("Multiple 'default' clauses defined in same 'switch'");
+ default_clause_made = TRUE;
+
+ if (switch_clause_made)
+ { if (!execution_never_reaches_here)
+ { sequence_point_follows = FALSE;
+ assemble_jump(break_label);
+ }
+ assemble_label_no(switch_label);
+ }
+ switch_clause_made = TRUE;
+
+ get_next_token();
+ if ((token_type == SEP_TT) &&
+ (token_value == COLON_SEP)) continue;
+ ebf_error("':' after 'default'", token_text);
+ panic_mode_error_recovery();
+ continue;
+ }
+
+ /* Decide: is this an ordinary statement, or the start
+ of a new case? */
+
+ if (token_type == DQ_TT) goto NotASwitchCase;
+
+ unary_minus_flag
+ = ((token_type == SEP_TT)&&(token_value == MINUS_SEP));
+ if (unary_minus_flag) get_next_token();
+
+ /* Now read the token _after_ any possible constant:
+ if that's a 'to', ',' or ':' then we have a case */
+
+ misc_keywords.enabled = TRUE;
+ get_next_token();
+ misc_keywords.enabled = FALSE;
+
+ if (switch_sign() > 0)
+ { assembly_operand AO;
+
+ if (default_clause_made)
+ error("'default' must be the last 'switch' case");
+
+ if (switch_clause_made)
+ { if (!execution_never_reaches_here)
+ { sequence_point_follows = FALSE;
+ assemble_jump(break_label);
+ }
+ assemble_label_no(switch_label);
+ }
+
+ switch_label = next_label++;
+ switch_clause_made = TRUE;
+ put_token_back(); put_token_back();
+ if (unary_minus_flag) put_token_back();
+
+ AO = temp_var1;
+ parse_switch_spec(AO, switch_label, FALSE);
+ continue;
+ }
+ else
+ { put_token_back(); put_token_back();
+ if (unary_minus_flag) put_token_back();
+ get_next_token();
+ }
+ }
+
+ if ((switch_rule != 0) && (!switch_clause_made))
+ ebf_error("switch value", token_text);
+
+ NotASwitchCase:
+ sequence_point_follows = TRUE;
+ parse_statement(break_label, continue_label);
+ }
+ while(TRUE);
+ }
+
+ if (switch_rule != 0)
+ ebf_error("braced code block after 'switch'", token_text);
+
+ parse_statement(break_label, continue_label);
+ return;
+}
+
+/* ========================================================================= */
+/* Data structure management routines */
+/* ------------------------------------------------------------------------- */
+
+extern void init_syntax_vars(void)
+{
+}
+
+extern void syntax_begin_pass(void)
+{ no_syntax_lines = 0;
+}
+
+extern void syntax_allocate_arrays(void)
+{
+}
+
+extern void syntax_free_arrays(void)
+{
+}
+
+/* ========================================================================= */
projects / inform.git / blobdiff