diff options
Diffstat (limited to 'src/lisp.h')
| -rw-r--r-- | src/lisp.h | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/src/lisp.h b/src/lisp.h index 015346858b5..1d6fd5a4fe2 100644 --- a/src/lisp.h +++ b/src/lisp.h @@ -796,11 +796,11 @@ struct Lisp_Symbol /* Header of vector-like objects. This documents the layout constraints on vectors and pseudovectors (objects of PVEC_xxx subtype). It also prevents compilers from being fooled by Emacs's type punning: XSETPSEUDOVECTOR - and PSEUDOVECTORP cast their pointers to struct vectorlike_header *, + and PSEUDOVECTORP cast their pointers to union vectorlike_header *, because when two such pointers potentially alias, a compiler won't incorrectly reorder loads and stores to their size fields. See Bug#8546. */ -struct vectorlike_header +union vectorlike_header { /* The only field contains various pieces of information: - The MSB (ARRAY_MARK_FLAG) holds the gcmarkbit. @@ -1094,10 +1094,10 @@ INLINE bool | ((restsize) << PSEUDOVECTOR_SIZE_BITS) \ | (lispsize))) -/* The cast to struct vectorlike_header * avoids aliasing issues. */ +/* The cast to union vectorlike_header * avoids aliasing issues. */ #define XSETPSEUDOVECTOR(a, b, code) \ XSETTYPED_PSEUDOVECTOR (a, b, \ - (((struct vectorlike_header *) \ + (((union vectorlike_header *) \ XUNTAG (a, Lisp_Vectorlike)) \ ->size), \ code) @@ -1399,7 +1399,7 @@ STRING_SET_CHARS (Lisp_Object string, ptrdiff_t newsize) struct Lisp_Vector { - struct vectorlike_header header; + union vectorlike_header header; Lisp_Object contents[FLEXIBLE_ARRAY_MEMBER]; }; @@ -1456,7 +1456,7 @@ PSEUDOVECTOR_TYPE (struct Lisp_Vector *v) /* Can't be used with PVEC_NORMAL_VECTOR. */ INLINE bool -PSEUDOVECTOR_TYPEP (struct vectorlike_header *a, enum pvec_type code) +PSEUDOVECTOR_TYPEP (union vectorlike_header *a, enum pvec_type code) { /* We don't use PSEUDOVECTOR_TYPE here so as to avoid a shift * operation when `code' is known. */ @@ -1472,8 +1472,8 @@ PSEUDOVECTORP (Lisp_Object a, int code) return false; else { - /* Converting to struct vectorlike_header * avoids aliasing issues. */ - struct vectorlike_header *h = XUNTAG (a, Lisp_Vectorlike); + /* Converting to union vectorlike_header * avoids aliasing issues. */ + union vectorlike_header *h = XUNTAG (a, Lisp_Vectorlike); return PSEUDOVECTOR_TYPEP (h, code); } } @@ -1484,7 +1484,7 @@ struct Lisp_Bool_Vector { /* HEADER.SIZE is the vector's size field. It doesn't have the real size, just the subtype information. */ - struct vectorlike_header header; + union vectorlike_header header; /* This is the size in bits. */ EMACS_INT size; /* The actual bits, packed into bytes. @@ -1697,7 +1697,7 @@ struct Lisp_Char_Table pseudovector type information. It holds the size, too. The size counts the defalt, parent, purpose, ascii, contents, and extras slots. */ - struct vectorlike_header header; + union vectorlike_header header; /* This holds a default value, which is used whenever the value for a specific character is nil. */ @@ -1739,7 +1739,7 @@ struct Lisp_Sub_Char_Table { /* HEADER.SIZE is the vector's size field, which also holds the pseudovector type information. It holds the size, too. */ - struct vectorlike_header header; + union vectorlike_header header; /* Depth of this sub char-table. It should be 1, 2, or 3. A sub char-table of depth 1 contains 16 elements, and each element @@ -1814,7 +1814,7 @@ CHAR_TABLE_SET (Lisp_Object ct, int idx, Lisp_Object val) struct Lisp_Subr { - struct vectorlike_header header; + union vectorlike_header header; union { Lisp_Object (*a0) (void); Lisp_Object (*a1) (Lisp_Object); @@ -2026,7 +2026,7 @@ struct hash_table_test struct Lisp_Hash_Table { /* This is for Lisp; the hash table code does not refer to it. */ - struct vectorlike_header header; + union vectorlike_header header; /* Nil if table is non-weak. Otherwise a symbol describing the weakness of the table. */ @@ -3929,7 +3929,7 @@ typedef emacs_value (*emacs_subr) (emacs_env *, ptrdiff_t, struct Lisp_Module_Function { - struct vectorlike_header header; + union vectorlike_header header; /* Fields traced by GC; these must come first. */ Lisp_Object documentation; |