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* lisp.h: Redo flags and XSET slightly to avoid overflow diagnostics.

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These changes make compilation easier to follow with Sun cc.
(ARRAY_MARK_FLAG): Make it signed, so that it can be assigned to
EMACS_INT values without provoking overflow diagnostics.
(PSEUDOVECTOR_FLAG): Likewise, for consistency.
(XSET) [! USE_LSB_TAG]: Use unsigned left shift to avoid overflow
diagnostic with signed left shift.
This commit is contained in:
Paul Eggert 2011-01-16 23:16:08 -08:00
parent 410ed5c357
commit 6df4097e92
2 changed files with 15 additions and 6 deletions
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8
src/ChangeLog
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@ -1,5 +1,13 @@
2011-01-17 Paul Eggert <eggert@cs.ucla.edu>
* lisp.h: Redo flags and XSET slightly to avoid overflow diagnostics.
These changes make compilation easier to follow with Sun cc.
(ARRAY_MARK_FLAG): Make it signed, so that it can be assigned to
EMACS_INT values without provoking overflow diagnostics.
(PSEUDOVECTOR_FLAG): Likewise, for consistency.
(XSET) [! USE_LSB_TAG]: Use unsigned left shift to avoid overflow
diagnostic with signed left shift.
* fileio.c (make_temp_name): Remove unreachable code.
* fontset.c (free_realized_fontset): Mark unreachable code with if (0).

13
src/lisp.h
View File

@ -327,13 +327,14 @@ typedef EMACS_INT Lisp_Object;
#define LISP_MAKE_RVALUE(o) (0+(o))
#endif /* USE_LISP_UNION_TYPE */
/* In the size word of a vector, this bit means the vector has been marked. */
/* In the size word of a vector, this bit means the vector has been marked.
(Shift -1 left, not 1, to avoid provoking overflow diagnostics.) */
#define ARRAY_MARK_FLAG ((EMACS_UINT) 1 << (BITS_PER_EMACS_INT - 1))
#define ARRAY_MARK_FLAG ((EMACS_INT) -1 << (BITS_PER_EMACS_INT - 1))
/* In the size word of a struct Lisp_Vector, this bit means it's really
some other vector-like object. */
#define PSEUDOVECTOR_FLAG ((ARRAY_MARK_FLAG >> 1))
#define PSEUDOVECTOR_FLAG ((EMACS_INT) 1 << (BITS_PER_EMACS_INT - 2))
/* In a pseudovector, the size field actually contains a word with one
PSEUDOVECTOR_FLAG bit set, and exactly one of the following bits to
@ -437,8 +438,9 @@ enum pvec_type
((((EMACS_INT) (N)) & VALMASK) | ((EMACS_INT) Lisp_Int) << VALBITS)
#endif
#define XSET(var, type, ptr) \
((var) = ((EMACS_INT)(type) << VALBITS) + ((EMACS_INT) (ptr) & VALMASK))
#define XSET(var, type, ptr) \
((var) = ((EMACS_INT) ((EMACS_UINT) (type) << VALBITS) \
+ ((EMACS_INT) (ptr) & VALMASK)))
#define XPNTR(a) ((EMACS_UINT) ((a) & VALMASK))
@ -3670,4 +3672,3 @@ extern Lisp_Object safe_alloca_unwind (Lisp_Object);
#endif /* EMACS_LISP_H */