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src/as/parser.c: check that numbers are in the allowed range.

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Henrik Hautakoski 2018-12-17 23:19:52 +01:00
parent 74ecdfc2ab
commit 2e66ffb9a5
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GPG key ID: 839F3A7EAFAEAFAA
1 changed files with 32 additions and 5 deletions
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37
src/as/parser.c
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@ -30,6 +30,12 @@
* Helper functions/macros for defining parser rules.
*/
enum number_size {
NUMBER_SIZE_U4,
NUMBER_SIZE_S4,
NUMBER_SIZE_S8,
};
// match the next token.
// returns 0 if the token was of the correct type. -1 otherwise
static int match_type(struct lexer* lex, enum token_type type) {
@ -38,6 +44,27 @@ static int match_type(struct lexer* lex, enum token_type type) {
return lex->token.type == type ? 0 : -1;
}
static int validate_number(struct lexer* lex, enum number_size size) {
int8_t n = lex->token.value.n;
switch(size) {
case NUMBER_SIZE_U4 :
if (!(n >= 0x0 && n <= 0xF))
return asm_error(lex->lineno, "Value out of range %u", (uint8_t) n);
break;
case NUMBER_SIZE_S4 :
if (!(n >= -8 && n < 8))
return asm_error(lex->lineno, "Value out of range %i", n);
break;
case NUMBER_SIZE_S8 :
if (!(n >= -128 && n< 128))
return asm_error(lex->lineno, "Value out of range %i", n);
break;
}
return 0;
}
// Same as match_type() but also generates a operand in the AST.
static int match_operand(struct lexer* lex, enum token_type type, struct ast *ast) {
@ -59,11 +86,11 @@ static int match_operand(struct lexer* lex, enum token_type type, struct ast *as
* Helper macros for matching tokens.
*/
#define match_reg(pos, ast) \
if (match_operand(lex, TOKEN_REG, ast) < 0) \
if (match_operand(lex, TOKEN_REG, ast) < 0 || validate_number(lex, NUMBER_SIZE_U4) < 0) \
return asm_error((lex)->lineno, "Expected number at argument %i", pos)
#define match_imm(pos, ast) \
if (match_operand(lex, TOKEN_NUMBER, ast) < 0) \
#define match_imm(pos, size, ast) \
if (match_operand(lex, TOKEN_NUMBER, ast) < 0 || validate_number(lex, size) < 0) \
return asm_error((lex)->lineno, "Expected number at argument %i", pos)
#define match_arg(pos) \
@ -94,7 +121,7 @@ static int match_typeRI(struct lexer* lex, struct ast *ast) {
match_reg(1, ast); match_arg(1);
match_reg(2, ast); match_arg(2);
match_imm(3, ast);
match_imm(3, NUMBER_SIZE_S4, ast);
match_end;
return 1;
@ -104,7 +131,7 @@ static int match_typeRI(struct lexer* lex, struct ast *ast) {
static int match_typeI(struct lexer* lex, struct ast *ast) {
match_reg(1, ast); match_arg(1);
match_imm(2, ast);
match_imm(2, NUMBER_SIZE_S8, ast);
match_end;
return 1;