diff options
| author | Linus Torvalds <torvalds@home.transmeta.com> | 2003-03-25 22:42:26 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-07 20:59:48 -0700 |
| commit | 55e9b0efa2c45cdfa23c19402dfd3572b9ad2b59 (patch) | |
| tree | e35803ac5659c81fd721dadc067a436d182d916b | |
| parent | feb86da650d429a76b74db40bfd383f3dc1c1f08 (diff) | |
| download | sparse-dev-55e9b0efa2c45cdfa23c19402dfd3572b9ad2b59.tar.gz | |
Evaluate structure and union member dereferences (turn them into plain derefences
with a byte offset).
| -rw-r--r-- | evaluate.c | 81 |
1 files changed, 81 insertions, 0 deletions
@@ -188,6 +188,85 @@ static int evaluate_postop(struct expression *expr) return 0; } +struct symbol *find_identifier(struct ident *ident, struct symbol_list *_list, int *offset) +{ + struct ptr_list *head = (struct ptr_list *)_list; + struct ptr_list *list = head; + + if (!head) + return NULL; + do { + int i; + for (i = 0; i < list->nr; i++) { + struct symbol *sym = (struct symbol *) list->list[i]; + if (sym->ident) { + if (sym->ident->ident != ident) + continue; + *offset = sym->offset; + return sym; + } else { + struct symbol *ctype = sym->ctype.base_type; + struct symbol *sub; + if (!ctype) + continue; + if (ctype->type != SYM_UNION && ctype->type != SYM_STRUCT) + continue; + sub = find_identifier(ident, ctype->symbol_list, offset); + if (!sub) + continue; + *offset += sym->offset; + return sub; + } + } + } while ((list = list->next) != head); + return NULL; +} + +/* structure/union dereference */ +static int evaluate_dereference(struct expression *expr) +{ + int offset; + struct symbol *ctype, *member; + struct expression *deref = expr->deref, *add; + struct token *token = expr->member; + + if (!evaluate_expression(deref) || !token) + return 0; + + ctype = deref->ctype; + if (expr->op == SPECIAL_DEREFERENCE) { + if (ctype->type != SYM_PTR) { + warn(expr->token, "expected a pointer to a struct/union"); + return 0; + } + ctype = ctype->ctype.base_type; + } + if (!ctype || (ctype->type != SYM_STRUCT && ctype->type != SYM_UNION)) { + warn(expr->token, "expected structure or union"); + return 0; + } + offset = 0; + member = find_identifier(token->ident, ctype->symbol_list, &offset); + if (!member) { + warn(expr->token, "no such struct/union member"); + return 0; + } + + expr->type = EXPR_PREOP; + expr->op = '*'; + expr->ctype = member->ctype.base_type; + + add = alloc_expression(expr->token, EXPR_BINOP); + expr->unop = add; + add->op = '+'; + add->ctype = &ptr_ctype; + add->left = deref; + add->right = alloc_expression(expr->token, EXPR_VALUE); + add->right->ctype = &int_ctype; + add->right->value = offset; + return 1; +} + static int evaluate_sizeof(struct expression *expr) { int size; @@ -243,6 +322,8 @@ int evaluate_expression(struct expression *expr) return 1; case EXPR_SIZEOF: return evaluate_sizeof(expr); + case EXPR_DEREF: + return evaluate_dereference(expr); default: break; } |