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| author | Joseph Myers <jsm@polyomino.org.uk> | 2004-07-08 09:45:05 +0100 |
|---|---|---|
| committer | Joseph Myers <jsm28@gcc.gnu.org> | 2004-07-08 09:45:05 +0100 |
| commit | bc15d0efe4230e2f3636dc5255c331232211fb44 (patch) | |
| tree | 69763a66482d42b14599835106ea027f80e7499e /gcc/c-decl.c | |
| parent | 942e59391c7a8ff8d57439229877257eb62b2eb0 (diff) | |
| download | gcc-bc15d0efe4230e2f3636dc5255c331232211fb44.zip gcc-bc15d0efe4230e2f3636dc5255c331232211fb44.tar.gz gcc-bc15d0efe4230e2f3636dc5255c331232211fb44.tar.bz2 | |
re PR c/2511 (-pedantic not warning about bitfield overflow)
2004-07-08 Joseph S. Myers <jsm@polyomino.org.uk>
Neil Booth <neil@daikokuya.co.uk>
PR c/2511
PR c/3325
* c-decl.c (finish_struct): Ensure bit-fields are given the
correct type.
* c-common.c (c_common_signed_or_unsigned_type): For C, require
the precision to match as well as the mode.
* expr.c (reduce_to_bit_field_precision): New function.
(expand_expr_real_1): Reduce expressions of bit-field type to
proper precision.
* langhooks.h (reduce_bit_field_operations): New hook.
* langhooks-def.h (LANG_HOOKS_REDUCE_BIT_FIELD_OPERATIONS):
Define.
* c-lang.c, objc/objc-lang.c
(LANG_HOOKS_REDUCE_BIT_FIELD_OPERATIONS): Define.
* objc/objc-act.c (check_ivars): Convert types to bit-field types
before checking.
* tree.c (build_nonstandard_integer_type): New function.
* tree.h (build_nonstandard_integer_type): New prototype.
* tree-ssa.c (tree_ssa_useless_type_conversion_1): Don't treat
conversions between integer and boolean types as useless.
testsuite:
* gcc.c-torture/execute/bitfld-1.x: Remove.
* gcc.c-torture/execute/bitfld-3.c: New test.
* gcc.dg/bitfld-2.c: Remove XFAILs.
Co-Authored-By: Neil Booth <neil@daikokuya.co.uk>
From-SVN: r84279
Diffstat (limited to 'gcc/c-decl.c')
| -rw-r--r-- | gcc/c-decl.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/gcc/c-decl.c b/gcc/c-decl.c index 3f6be35..2a236aa 100644 --- a/gcc/c-decl.c +++ b/gcc/c-decl.c @@ -5162,9 +5162,11 @@ finish_struct (tree t, tree fieldlist, tree attributes) } /* Install struct as DECL_CONTEXT of each field decl. - Also process specified field sizes,m which is found in the DECL_INITIAL. - Store 0 there, except for ": 0" fields (so we can find them - and delete them, below). */ + Also process specified field sizes, found in the DECL_INITIAL, + storing 0 there after the type has been changed to precision equal + to its width, rather than the precision of the specified standard + type. (Correct layout requires the original type to have been preserved + until now.) */ saw_named_field = 0; for (x = fieldlist; x; x = TREE_CHAIN (x)) @@ -5208,8 +5210,6 @@ finish_struct (tree t, tree fieldlist, tree attributes) SET_DECL_C_BIT_FIELD (x); } - DECL_INITIAL (x) = 0; - /* Detect flexible array member in an invalid context. */ if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE @@ -5250,12 +5250,21 @@ finish_struct (tree t, tree fieldlist, tree attributes) layout_type (t); - /* Delete all zero-width bit-fields from the fieldlist. */ + /* Give bit-fields their proper types. */ { tree *fieldlistp = &fieldlist; while (*fieldlistp) - if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp)) - *fieldlistp = TREE_CHAIN (*fieldlistp); + if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) + && TREE_TYPE (*fieldlistp) != error_mark_node) + { + unsigned HOST_WIDE_INT width + = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); + tree type = TREE_TYPE (*fieldlistp); + if (width != TYPE_PRECISION (type)) + TREE_TYPE (*fieldlistp) + = build_nonstandard_integer_type (width, TYPE_UNSIGNED (type)); + DECL_INITIAL (*fieldlistp) = 0; + } else fieldlistp = &TREE_CHAIN (*fieldlistp); } |