Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit6a02746

Browse files
committed
Change MemSet and StrNCpy to evaluate their arguments only once.
Fix inadequate parenthesization in several other macros.
1 parentfdd7f59 commit6a02746

File tree

1 file changed

+64
-65
lines changed

1 file changed

+64
-65
lines changed

‎src/include/c.h

Lines changed: 64 additions & 65 deletions
Original file line numberDiff line numberDiff line change
@@ -8,14 +8,14 @@
88
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
99
* Portions Copyright (c) 1994, Regents of the University of California
1010
*
11-
* $Id: c.h,v 1.64 2000/01/26 05:57:46 momjian Exp $
11+
* $Id: c.h,v 1.65 2000/03/19 22:08:51 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
1515
/*
1616
* TABLE OF CONTENTS
1717
*
18-
*When adding stuff to this file, please tryand put stuff
18+
*When adding stuff to this file, please tryto put stuff
1919
*into the relevant section, or add new sections as appropriate.
2020
*
2121
* sectiondescription
@@ -34,10 +34,6 @@
3434
*10)Berkeley-specific defs
3535
*11)system-specific hacks
3636
*
37-
* NOTES
38-
*
39-
*This file is MACHINE AND COMPILER dependent!!!(For now.)
40-
*
4137
* ----------------------------------------------------------------
4238
*/
4339
#ifndefC_H
@@ -279,8 +275,6 @@ typedef signed int Offset;
279275
*
280276
*If your machine meets these requirements, Datums should also be checked
281277
*to see if the positioning is correct.
282-
*
283-
*This file is MACHINE AND COMPILER dependent!!!
284278
*/
285279

286280
typedefunsigned longDatum;/* XXX sizeof(long) >= sizeof(void *) */
@@ -403,28 +397,28 @@ typedef Datum *DatumPtr;
403397
*Returns pointer value of a datum.
404398
*/
405399

406-
#defineDatumGetPointer(X) ((Pointer)X)
400+
#defineDatumGetPointer(X) ((Pointer)(X))
407401

408402
/*
409403
* PointerGetDatum
410404
*Returns datum representation for a pointer.
411405
*/
412406

413-
#definePointerGetDatum(X) ((Datum)X)
407+
#definePointerGetDatum(X) ((Datum)(X))
414408

415409
/*
416410
* DatumGetName
417411
*Returns name value of a datum.
418412
*/
419413

420-
#defineDatumGetName(X) ((Name) DatumGetPointer((Datum)X))
414+
#defineDatumGetName(X) ((Name) DatumGetPointer((Datum)(X)))
421415

422416
/*
423417
* NameGetDatum
424418
*Returns datum representation for a name.
425419
*/
426420

427-
#defineNameGetDatum(X) PointerGetDatum((Pointer)X)
421+
#defineNameGetDatum(X) PointerGetDatum((Pointer)(X))
428422

429423

430424
/*
@@ -433,15 +427,15 @@ typedef Datum *DatumPtr;
433427
*This is really a pointer, of course.
434428
*/
435429

436-
#defineDatumGetFloat32(X) ((float32) DatumGetPointer((Datum)X))
430+
#defineDatumGetFloat32(X) ((float32) DatumGetPointer(X))
437431

438432
/*
439433
* Float32GetDatum
440434
*Returns datum representation for a 32-bit floating point number.
441435
*This is really a pointer, of course.
442436
*/
443437

444-
#defineFloat32GetDatum(X) PointerGetDatum((Pointer)X)
438+
#defineFloat32GetDatum(X) PointerGetDatum((Pointer)(X))
445439

446440
/*
447441
* DatumGetFloat64
@@ -457,7 +451,7 @@ typedef Datum *DatumPtr;
457451
*This is really a pointer, of course.
458452
*/
459453

460-
#defineFloat64GetDatum(X) PointerGetDatum((Pointer)X)
454+
#defineFloat64GetDatum(X) PointerGetDatum((Pointer)(X))
461455

462456
/* ----------------------------------------------------------------
463457
*Section 5:IsValid macros for system types
@@ -473,18 +467,7 @@ typedef Datum *DatumPtr;
473467
* PointerIsValid
474468
*True iff pointer is valid.
475469
*/
476-
#definePointerIsValid(pointer) (bool)((void*)(pointer) != NULL)
477-
478-
/*
479-
* PointerIsInBounds
480-
*True iff pointer is within given bounds.
481-
*
482-
* Note:
483-
*Assumes the bounded interval to be [min,max),
484-
*i.e. closed on the left and open on the right.
485-
*/
486-
#definePointerIsInBounds(pointer,min,max) \
487-
((min) <= (pointer) && (pointer) < (max))
470+
#definePointerIsValid(pointer) ((void*)(pointer) != NULL)
488471

489472
/*
490473
* PointerIsAligned
@@ -560,14 +543,14 @@ typedef struct Exception
560543
*Isn't CPP fun?
561544
*/
562545
#defineTrapMacro(condition,exception) \
563-
((bool) ((! assert_enabled) ||(!condition) || \
546+
((bool) ((! assert_enabled) ||! (condition) || \
564547
(ExceptionalCondition(CppAsString(condition), \
565548
&(exception), \
566549
(char*) NULL, __FILE__, __LINE__))))
567550

568551
#ifndefUSE_ASSERT_CHECKING
569552
#defineAssert(condition)
570-
#defineAssertMacro(condition)(void)true
553+
#defineAssertMacro(condition)((void)true)
571554
#defineAssertArg(condition)
572555
#defineAssertState(condition)
573556
#defineassert_enabled 0
@@ -576,7 +559,7 @@ typedef struct Exception
576559
Trap(!(condition), FailedAssertion)
577560

578561
#defineAssertMacro(condition) \
579-
(void)TrapMacro(!(condition), FailedAssertion)
562+
((void)TrapMacro(!(condition), FailedAssertion))
580563

581564
#defineAssertArg(condition) \
582565
Trap(!(condition), BadArg)
@@ -604,7 +587,7 @@ extern intassert_enabled;
604587
*#define foo(x) (LogAssertMacro(x != 0, "yow!") && bar(x))
605588
*/
606589
#defineLogTrapMacro(condition,exception,printArgs) \
607-
((bool) ((! assert_enabled) ||(!condition) || \
590+
((bool) ((! assert_enabled) ||! (condition) || \
608591
(ExceptionalCondition(CppAsString(condition), \
609592
&(exception), \
610593
vararg_format printArgs, __FILE__, __LINE__))))
@@ -659,46 +642,62 @@ extern intassertTest(int val);
659642

660643
/*
661644
* StrNCpy
662-
*Does string copy, and forces terminating NULL
663-
*/
664-
/* we do this so if the macro is used in an if action, it will work */
665-
#defineStrNCpy(dst,src,len)\
666-
( \
667-
((len) > 0) ? \
668-
( \
669-
strncpy((dst),(src),(len)-1), \
670-
*((dst)+(len)-1)='\0' \
671-
) \
672-
: \
673-
(dummyret)NULL,(void)(dst) \
674-
)
645+
*Like standard library function strncpy(), except that result string
646+
*is guaranteed to be null-terminated --- that is, at most N-1 bytes
647+
*of the source string will be kept.
648+
*Also, the macro returns no result (too hard to do that without
649+
*evaluating the arguments multiple times, which seems worse).
650+
*/
651+
#defineStrNCpy(dst,src,len) \
652+
do \
653+
{ \
654+
char * _dst = (dst); \
655+
Size _len = (len); \
656+
\
657+
if (_len > 0) \
658+
{ \
659+
strncpy(_dst, (src), _len); \
660+
_dst[_len-1] = '\0'; \
661+
} \
662+
} while (0)
663+
675664

676665
/* Get a bit mask of the bits set in non-int32 aligned addresses */
677666
#defineINT_ALIGN_MASK (sizeof(int32) - 1)
678667

679668
/*
680-
*This function gets call too often, so we inline it if we can.
681-
*Are we aligned for int32?
682-
*We have to cast the pointer to int so we can do the AND
669+
* MemSet
670+
*Exactly the same as standard library function memset(), but considerably
671+
*faster for zeroing small word-aligned structures (such as parsetree nodes).
672+
*This has to be a macro because the main point is to avoid function-call
673+
*overhead.
674+
*
683675
*We got the 64 number by testing this against the stock memset() on
684-
*BSD/OS 3.0. Larger values were slower.
685-
*/
686-
#defineMemSet(start,val,len) do \
687-
{ \
688-
if (((long)(start) & INT_ALIGN_MASK) == 0 && \
689-
((len) & INT_ALIGN_MASK) == 0 && \
690-
(val) == 0 && \
691-
(len) <= 64) \
692-
{ \
693-
int32 *_i = (int32 *)(start); \
694-
int32 *_stop = (int32 *)((char *)(start) + (len)); \
695-
\
696-
while (_i < _stop) \
697-
*_i++ = 0; \
698-
} \
699-
else \
700-
memset((start), (val), (len)); \
701-
} while (0)
676+
*BSD/OS 3.0. Larger values were slower. (I think the crossover point
677+
*could be a good deal higher for most platforms, actually --- tgl)
678+
*/
679+
#defineMemSet(start,val,len) \
680+
do \
681+
{ \
682+
int32 * _start = (int32 *) (start); \
683+
int_val = (val); \
684+
Size_len = (len); \
685+
\
686+
if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
687+
(_len & INT_ALIGN_MASK) == 0 && \
688+
_val == 0 && \
689+
_len <= MEMSET_LOOP_LIMIT) \
690+
{ \
691+
int32 * _stop = (int32 *) ((char *) _start + _len); \
692+
while (_start < _stop) \
693+
*_start++ = 0; \
694+
} \
695+
else \
696+
memset((char *) _start, _val, _len); \
697+
} while (0)
698+
699+
#defineMEMSET_LOOP_LIMIT 64
700+
702701

703702
/* ----------------------------------------------------------------
704703
*Section 9: externs

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp