diff options
| author | Linus Torvalds <torvalds@home.transmeta.com> | 2003-04-04 22:09:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-07 21:00:13 -0700 |
| commit | 1ca3c2344cbb36e35cb7f1442f7f7601d686fe8d (patch) | |
| tree | 19fb2a9ed2b87c820b6d05c56861dbd3373ceece | |
| parent | 31ca6c598c12178f44a207a48a76c7c00cc07597 (diff) | |
| download | sparse-dev-1ca3c2344cbb36e35cb7f1442f7f7601d686fe8d.tar.gz | |
Allow pointers to differ in certain modifier bits. For example,
we don't care about 'const' vs 'volatile' in pointer differences.
And in assignments, it's ok if the target is more restricted than
the source.
| -rw-r--r-- | evaluate.c | 33 |
1 files changed, 23 insertions, 10 deletions
@@ -363,11 +363,12 @@ static struct symbol *evaluate_add(struct expression *expr) return evaluate_int_binop(expr); } -static int same_type(struct symbol *target, struct symbol *source) +static int same_type(struct symbol *target, struct symbol *source, + unsigned long target_mod_ignore, unsigned long source_mod_ignore) { int dropped_modifiers = 0; for (;;) { - unsigned long mod1, mod2; + unsigned long mod1, mod2, diff; unsigned long as1, as2; if (target == source) @@ -393,9 +394,14 @@ static int same_type(struct symbol *target, struct symbol *source) as2 |= source->ctype.as; } - /* Ignore differences in storage types */ - if ((mod1 ^ mod2) & ~MOD_STORAGE) - return 0; + /* Ignore differences in storage types or addressability */ + diff = (mod1 ^ mod2) & ~(MOD_STORAGE | MOD_ADDRESSABLE); + if (diff) { + mod1 &= diff & ~target_mod_ignore; + mod2 &= diff & ~source_mod_ignore; + if (mod1 | mod2) + return 0; + } /* Must be same address space to be comparable */ if (as1 != as2) @@ -430,6 +436,12 @@ static struct symbol *common_ptr_type(struct expression *l, struct expression *r return NULL; } +/* + * Ignore differences in "volatile" and "const"ness when + * subtracting pointers + */ +#define MOD_IGN (MOD_VOLATILE | MOD_CONST) + static struct symbol *evaluate_ptr_sub(struct expression *expr, struct expression *l, struct expression *r) { struct symbol *ctype; @@ -443,7 +455,7 @@ static struct symbol *evaluate_ptr_sub(struct expression *expr, struct expressio return evaluate_ptr_add(expr, l, r); ctype = ltype; - if (!same_type(ltype, rtype)) { + if (!same_type(ltype, rtype, MOD_IGN, MOD_IGN)) { ctype = common_ptr_type(l, r); if (!ctype) { warn(expr->pos, "subtraction of different types can't work"); @@ -644,7 +656,7 @@ static struct symbol * evaluate_conditional(struct expression *expr) rtype = false->ctype; ctype = ltype; - if (!same_type(ltype, rtype)) { + if (!same_type(ltype, rtype, MOD_IGN, MOD_IGN)) { ctype = compatible_integer_binop(expr, &true, &expr->cond_false); if (!ctype) { ctype = compatible_ptr_type(true, expr->cond_false); @@ -668,7 +680,8 @@ static struct symbol * evaluate_conditional(struct expression *expr) static int compatible_assignment_types(struct expression *expr, struct symbol *target, struct expression **rp, struct symbol *source) { - if (same_type(target, source)) + /* It's ok if the target is more volatile or const than the source */ + if (same_type(target, source, MOD_VOLATILE | MOD_CONST, 0)) return 1; if (compatible_integer_types(target, source)) { @@ -695,9 +708,9 @@ static int compatible_assignment_types(struct expression *expr, struct symbol *t target = target_base; target_base = target->ctype.base_type; } - if (source->type == SYM_ARRAY && same_type(target_base, source_base)) + if (source->type == SYM_ARRAY && same_type(target_base, source_base, MOD_IGN, MOD_IGN)) return 1; - if (source->type == SYM_FN && same_type(target_base, source)) + if (source->type == SYM_FN && same_type(target_base, source, MOD_IGN, MOD_IGN)) return 1; // NULL pointer? |