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author | Paul Gilbert | 2019-09-22 22:37:10 -0700 |
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committer | Paul Gilbert | 2019-09-25 20:13:27 -0700 |
commit | 1e483ec0f50a430598f5f76f59338d74f67b20f5 (patch) | |
tree | 174f9dcb52bf50c47860e9b9336a71a283cec0c7 /engines/glk | |
parent | a401ccc61e5f70350152bccc05e45c68520d845d (diff) | |
download | scummvm-rg350-1e483ec0f50a430598f5f76f59338d74f67b20f5.tar.gz scummvm-rg350-1e483ec0f50a430598f5f76f59338d74f67b20f5.tar.bz2 scummvm-rg350-1e483ec0f50a430598f5f76f59338d74f67b20f5.zip |
GLK: ADRIFT: Refactor tokenizer to not use longjmp
Diffstat (limited to 'engines/glk')
-rw-r--r-- | engines/glk/adrift/scexpr.cpp | 272 |
1 files changed, 135 insertions, 137 deletions
diff --git a/engines/glk/adrift/scexpr.cpp b/engines/glk/adrift/scexpr.cpp index 2375b5e5a7..0f4c2be4ce 100644 --- a/engines/glk/adrift/scexpr.cpp +++ b/engines/glk/adrift/scexpr.cpp @@ -22,6 +22,7 @@ #include "glk/adrift/scare.h" #include "glk/adrift/scprotos.h" +#include "glk/jumps.h" namespace Glk { namespace Adrift { @@ -545,16 +546,12 @@ static sc_int expr_eval_abs(sc_int value) { return value < 0 ? -value : value; } - -/* Parse error jump buffer. */ -static jmp_buf expr_parse_error; - /* - * expr_eval_action() + * expr_eval_action * * Evaluate the effect of a token into the values stack. */ -static void expr_eval_action(sc_int token) { +static void expr_eval_action(CONTEXT, sc_int token) { sc_vartype_t token_value; switch (token) { @@ -577,7 +574,7 @@ static void expr_eval_action(sc_int token) { if (!var_get(expr_varset, token_value.string, &type, &vt_rvalue)) { sc_error("expr_eval_action:" " undefined variable, %s\n", token_value.string); - longjmp(expr_parse_error, 1); + LONG_JUMP; } switch (type) { case VAR_INTEGER: @@ -1044,23 +1041,23 @@ static void expr_eval_action(sc_int token) { static sc_int expr_parse_lookahead = TOK_NONE; /* Forward declaration of factor parsers and string expression parser. */ -static void expr_parse_numeric_factor(void); -static void expr_parse_string_factor(void); -static void expr_parse_string_expr(void); +static void expr_parse_numeric_factor(CONTEXT); +static void expr_parse_string_factor(CONTEXT); +static void expr_parse_string_expr(CONTEXT); /* - * expr_parse_match() + * expr_parse_match * * Match a token to the lookahead, then advance lookahead. */ -static void expr_parse_match(sc_int token) { +static void expr_parse_match(CONTEXT, sc_int token) { if (expr_parse_lookahead == token) expr_parse_lookahead = expr_next_token(); else { /* Syntax error. */ sc_error("expr_parse_match: syntax error," " expected %ld, got %ld\n", expr_parse_lookahead, token); - longjmp(expr_parse_error, 1); + LONG_JUMP; } } @@ -1143,14 +1140,14 @@ static int expr_parse_contains_token(const sc_precedence_entry_t *entry, sc_int * to match tokens, then decide whether, and how, to recurse into itself, or * whether to parse a highest-precedence factor. */ -static void expr_parse_numeric_element(sc_int precedence) { +static void expr_parse_numeric_element(CONTEXT, sc_int precedence) { const sc_precedence_entry_t *entry; /* See if the level passed in has listed tokens. */ entry = PRECEDENCE_TABLE + precedence; if (entry->token_count == 0) { /* Precedence levels that hit the table end are factors. */ - expr_parse_numeric_factor(); + CALL0(expr_parse_numeric_factor); return; } @@ -1158,27 +1155,27 @@ static void expr_parse_numeric_element(sc_int precedence) { * Parse initial higher-precedence factor, then others that associate * with the given level. */ - expr_parse_numeric_element(precedence + 1); + CALL1(expr_parse_numeric_element, precedence + 1); while (expr_parse_contains_token(entry, expr_parse_lookahead)) { sc_int token; /* Note token and match, parse next level, then action this token. */ token = expr_parse_lookahead; - expr_parse_match(token); - expr_parse_numeric_element(precedence + 1); - expr_eval_action(token); + CALL1(expr_parse_match, token); + CALL1(expr_parse_numeric_element, precedence + 1); + CALL1(expr_eval_action, token); } } /* - * expr_parse_numeric_expr() + * expr_parse_numeric_expr * * Parse a complete numeric (sub-)expression. */ -static void expr_parse_numeric_expr(void) { +static void expr_parse_numeric_expr(CONTEXT) { /* Call the parser of the lowest precedence operators. */ - expr_parse_numeric_element(0); + CALL1(expr_parse_numeric_element, 0); } @@ -1187,30 +1184,30 @@ static void expr_parse_numeric_expr(void) { * * Parse a numeric expression factor. */ -static void expr_parse_numeric_factor(void) { +static void expr_parse_numeric_factor(CONTEXT) { /* Handle factors based on lookahead token. */ switch (expr_parse_lookahead) { /* Handle straightforward factors first. */ case TOK_LPAREN: - expr_parse_match(TOK_LPAREN); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); break; case TOK_UMINUS: - expr_parse_match(TOK_UMINUS); - expr_parse_numeric_factor(); - expr_eval_action(TOK_UMINUS); + CALL1(expr_parse_match, TOK_UMINUS); + CALL0(expr_parse_numeric_factor); + CALL1(expr_eval_action, TOK_UMINUS); break; case TOK_UPLUS: - expr_parse_match(TOK_UPLUS); - expr_parse_numeric_factor(); + CALL1(expr_parse_match, TOK_UPLUS); + CALL0(expr_parse_numeric_factor); break; case TOK_INTEGER: - expr_eval_action(TOK_INTEGER); - expr_parse_match(TOK_INTEGER); + CALL1(expr_eval_action, TOK_INTEGER); + CALL1(expr_parse_match, TOK_INTEGER); break; case TOK_VARIABLE: { @@ -1221,51 +1218,51 @@ static void expr_parse_numeric_factor(void) { if (!var_get(expr_varset, token_value.string, &type, &vt_rvalue)) { sc_error("expr_parse_numeric_factor:" " undefined variable, %s\n", token_value.string); - longjmp(expr_parse_error, 1); + LONG_JUMP; } if (type != VAR_INTEGER) { sc_error("expr_parse_numeric_factor:" " string variable in numeric context, %s\n", token_value.string); - longjmp(expr_parse_error, 1); + LONG_JUMP; } - expr_eval_action(TOK_VARIABLE); - expr_parse_match(TOK_VARIABLE); + CALL1(expr_eval_action, TOK_VARIABLE); + CALL1(expr_parse_match, TOK_VARIABLE); break; } /* Handle functions as factors. */ case TOK_ABS: /* Parse as "abs (val)". */ - expr_parse_match(TOK_ABS); - expr_parse_match(TOK_LPAREN); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_ABS); + CALL1(expr_parse_match, TOK_ABS); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_ABS); break; case TOK_IF: /* Parse as "if (boolean, val1, val2)". */ - expr_parse_match(TOK_IF); - expr_parse_match(TOK_LPAREN); - expr_parse_numeric_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_IF); + CALL1(expr_parse_match, TOK_IF); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_IF); break; case TOK_RANDOM: /* Parse as "random (low, high)". */ - expr_parse_match(TOK_RANDOM); - expr_parse_match(TOK_LPAREN); - expr_parse_numeric_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_RANDOM); + CALL1(expr_parse_match, TOK_RANDOM); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_RANDOM); break; case TOK_MAX: @@ -1277,64 +1274,64 @@ static void expr_parse_numeric_factor(void) { /* Match up the function name and opening parenthesis. */ token = expr_parse_lookahead; - expr_parse_match(token); - expr_parse_match(TOK_LPAREN); + CALL1(expr_parse_match, token); + CALL1(expr_parse_match, TOK_LPAREN); /* Count variable number of arguments as they are stacked. */ - expr_parse_numeric_expr(); + CALL0(expr_parse_numeric_expr); argument_count = 1; while (expr_parse_lookahead == TOK_COMMA) { - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); argument_count++; } - expr_parse_match(TOK_RPAREN); + CALL1(expr_parse_match, TOK_RPAREN); /* Push additional value -- the count of arguments. */ expr_eval_push_integer(argument_count); - expr_eval_action(token); + CALL1(expr_eval_action, token); break; } case TOK_INSTR: /* Parse as "instr (val1, val2)". */ - expr_parse_match(TOK_INSTR); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_string_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_INSTR); + CALL1(expr_parse_match, TOK_INSTR); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_INSTR); break; case TOK_LEN: /* Parse as "len (val)". */ - expr_parse_match(TOK_LEN); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_LEN); + CALL1(expr_parse_match, TOK_LEN); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_LEN); break; case TOK_VAL: /* Parse as "val (val)". */ - expr_parse_match(TOK_VAL); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_VAL); + CALL1(expr_parse_match, TOK_VAL); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_VAL); break; case TOK_IDENT: /* Unrecognized function-type token. */ sc_error("expr_parse_numeric_factor: syntax error, unknown ident\n"); - longjmp(expr_parse_error, 1); + LONG_JUMP; default: /* Syntax error. */ sc_error("expr_parse_numeric_factor:" " syntax error, unexpected token, %ld\n", expr_parse_lookahead); - longjmp(expr_parse_error, 1); + LONG_JUMP; } } @@ -1344,17 +1341,17 @@ static void expr_parse_numeric_factor(void) { * * Parse a complete string (sub-)expression. */ -static void expr_parse_string_expr(void) { +static void expr_parse_string_expr(CONTEXT) { /* * Parse a string factor, then all repeated concatenations. Because the '+' * and '&' are context sensitive, we have to invent/translate them into the * otherwise unused TOK_CONCATENATE for evaluation. */ - expr_parse_string_factor(); + CALL0(expr_parse_string_factor); while (expr_parse_lookahead == TOK_AND || expr_parse_lookahead == TOK_ADD) { - expr_parse_match(expr_parse_lookahead); - expr_parse_string_factor(); - expr_eval_action(TOK_CONCATENATE); + CALL1(expr_parse_match, expr_parse_lookahead); + CALL0(expr_parse_string_factor); + CALL1(expr_eval_action, TOK_CONCATENATE); } } @@ -1364,19 +1361,19 @@ static void expr_parse_string_expr(void) { * * Parse a string expression factor. */ -static void expr_parse_string_factor(void) { +static void expr_parse_string_factor(CONTEXT) { /* Handle factors based on lookahead token. */ switch (expr_parse_lookahead) { /* Handle straightforward factors first. */ case TOK_LPAREN: - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_RPAREN); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_RPAREN); break; case TOK_STRING: - expr_eval_action(TOK_STRING); - expr_parse_match(TOK_STRING); + CALL1(expr_eval_action, TOK_STRING); + CALL1(expr_parse_match, TOK_STRING); break; case TOK_VARIABLE: { @@ -1387,16 +1384,16 @@ static void expr_parse_string_factor(void) { if (!var_get(expr_varset, token_value.string, &type, &vt_rvalue)) { sc_error("expr_parse_string_factor:" " undefined variable, %s\n", token_value.string); - longjmp(expr_parse_error, 1); + LONG_JUMP; } if (type != VAR_STRING) { sc_error("expr_parse_string_factor:" " numeric variable in string context, %s\n", token_value.string); - longjmp(expr_parse_error, 1); + LONG_JUMP; } - expr_eval_action(TOK_VARIABLE); - expr_parse_match(TOK_VARIABLE); + CALL1(expr_eval_action, TOK_VARIABLE); + CALL1(expr_parse_match, TOK_VARIABLE); break; } @@ -1409,11 +1406,11 @@ static void expr_parse_string_factor(void) { sc_int token; token = expr_parse_lookahead; - expr_parse_match(token); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(token); + CALL1(expr_parse_match, token); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, token); break; } @@ -1424,48 +1421,48 @@ static void expr_parse_string_factor(void) { sc_int token; token = expr_parse_lookahead; - expr_parse_match(token); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(token); + CALL1(expr_parse_match, token); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, token); break; } case TOK_MID: /* Parse as "mid (text,start,length)". */ - expr_parse_match(TOK_MID); - expr_parse_match(TOK_LPAREN); - expr_parse_string_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_COMMA); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_MID); + CALL1(expr_parse_match, TOK_MID); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_string_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_COMMA); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_MID); break; case TOK_STR: /* Parse as "str (val)". */ - expr_parse_match(TOK_STR); - expr_parse_match(TOK_LPAREN); - expr_parse_numeric_expr(); - expr_parse_match(TOK_RPAREN); - expr_eval_action(TOK_STR); + CALL1(expr_parse_match, TOK_STR); + CALL1(expr_parse_match, TOK_LPAREN); + CALL0(expr_parse_numeric_expr); + CALL1(expr_parse_match, TOK_RPAREN); + CALL1(expr_eval_action, TOK_STR); break; case TOK_IDENT: /* Unrecognized function-type token. */ sc_error("expr_parse_string_factor: syntax error, unknown ident\n"); - longjmp(expr_parse_error, 1); + LONG_JUMP; default: /* Syntax error. */ sc_error("expr_parse_string_factor:" " syntax error, unexpected token, %ld\n", expr_parse_lookahead); - longjmp(expr_parse_error, 1); + LONG_JUMP; } } @@ -1479,21 +1476,22 @@ static void expr_parse_string_factor(void) { static sc_bool expr_evaluate_expression(const sc_char *expression, sc_var_setref_t vars, sc_int assign_type, sc_vartype_t *vt_rvalue) { assert(assign_type == VAR_INTEGER || assign_type == VAR_STRING); + Context context; /* Reset values stack and start tokenizer. */ expr_eval_start(vars); expr_tokenize_start(expression); - /* Try parsing an expression, and catch errors. */ - if (setjmp(expr_parse_error) == 0) { - /* Parse an expression, and ensure it ends at string end. */ - expr_parse_lookahead = expr_next_token(); - if (assign_type == VAR_STRING) - expr_parse_string_expr(); - else - expr_parse_numeric_expr(); - expr_parse_match(TOK_EOS); - } else { + // Try parsing an expression, and ensure it ends at string end. */ + expr_parse_lookahead = expr_next_token(); + if (assign_type == VAR_STRING) + expr_parse_string_expr(context); + else + expr_parse_numeric_expr(context); + if (!context._break) + expr_parse_match(context, TOK_EOS); + + if (context._break) { /* Parse error -- clean up tokenizer, collect garbage, and fail. */ expr_tokenize_end(); expr_eval_garbage_collect(); |