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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2017-01-05 04:22:19 +0100 |
|---|---|---|
| committer | Christopher Li <sparse@chrisli.org> | 2017-02-13 09:34:45 +0800 |
| commit | 0f89a2c57648682bb4c8c195feadcb750f10fd52 (patch) | |
| tree | d46a350fb1881848440a286b2c44e071e982c03b | |
| parent | cb172dce6555c0b1eb1771a374018721ddf8b8a5 (diff) | |
| download | sparse-dev-0f89a2c57648682bb4c8c195feadcb750f10fd52.tar.gz | |
C11: teach sparse about '_Alignas()'
This is quite similar to GCC's 'attribute(aligned(..))' but defined
as a new specifier and also accepting a typename as argument.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>
| -rw-r--r-- | parse.c | 43 | ||||
| -rw-r--r-- | validation/c11-alignas.c | 40 |
2 files changed, 83 insertions, 0 deletions
@@ -129,6 +129,12 @@ static struct symbol_op noreturn_op = { .declarator = noreturn_specifier, }; +static declarator_t alignas_specifier; +static struct symbol_op alignas_op = { + .type = KW_MODIFIER, + .declarator = alignas_specifier, +}; + static struct symbol_op auto_op = { .type = KW_MODIFIER, .declarator = auto_specifier, @@ -448,6 +454,8 @@ static struct init_keyword { { "_Noreturn", NS_TYPEDEF, .op = &noreturn_op }, + { "_Alignas", NS_TYPEDEF, .op = &alignas_op }, + /* Ignored for now.. */ { "restrict", NS_TYPEDEF, .op = &restrict_op}, { "__restrict", NS_TYPEDEF, .op = &restrict_op}, @@ -1391,6 +1399,41 @@ static struct token *noreturn_specifier(struct token *next, struct decl_state *c return next; } +static struct token *alignas_specifier(struct token *token, struct decl_state *ctx) +{ + int alignment = 0; + + if (!match_op(token, '(')) { + sparse_error(token->pos, "expected '(' after _Alignas"); + return token; + } + if (lookup_type(token->next)) { + struct symbol *sym = NULL; + token = typename(token->next, &sym, NULL); + sym = examine_symbol_type(sym); + alignment = sym->ctype.alignment; + token = expect(token, ')', "after _Alignas(..."); + } else { + struct expression *expr = NULL; + token = parens_expression(token, &expr, "after _Alignas"); + if (!expr) + return token; + alignment = const_expression_value(expr); + } + + if (alignment < 0) { + warning(token->pos, "non-positive alignment"); + return token; + } + if (alignment & (alignment-1)) { + warning(token->pos, "non-power-of-2 alignment"); + return token; + } + if (alignment > ctx->ctype.alignment) + ctx->ctype.alignment = alignment; + return token; +} + static struct token *const_qualifier(struct token *next, struct decl_state *ctx) { apply_qualifier(&next->pos, &ctx->ctype, MOD_CONST); diff --git a/validation/c11-alignas.c b/validation/c11-alignas.c new file mode 100644 index 00000000..4b264a5d --- /dev/null +++ b/validation/c11-alignas.c @@ -0,0 +1,40 @@ +static _Alignas(8) int v; +static _Alignas(long) int t; +static _Alignas(void *) int p; +static _Alignas(int[4]) int a; +static _Alignas(0) int z; +static _Alignas(3) int bnpow2; +static _Alignas(-1) int bneg; +static _Alignas(-2) int bnegpow2; +static _Alignas(v) int bnc; +static _Alignas(+) int bsyn; + +static int check(void) +{ + if (_Alignof(v) != 8) + return -1; + if (_Alignof(t) != _Alignof(long)) + return -1; + if (_Alignof(p) != _Alignof(void *)) + return -1; + if (_Alignof(a) != _Alignof(int)) + return -1; + + return 0; +} + +/* + * check-name: c11-alignas + * check-command: test-linearize -std=c11 $file + * + * check-error-start +c11-alignas.c:6:25: warning: non-power-of-2 alignment +c11-alignas.c:7:25: warning: non-positive alignment +c11-alignas.c:8:25: warning: non-positive alignment +c11-alignas.c:9:17: error: bad constant expression +c11-alignas.c:10:17: error: Syntax error in unary expression + * check-error-end + * + * check-output-ignore + * check-output-contains: ret\\.32 *\$0 + */ |