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Diffstat (limited to 'src/backend/port/darwin/README')
| -rw-r--r-- | src/backend/port/darwin/README | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/backend/port/darwin/README b/src/backend/port/darwin/README new file mode 100644 index 00000000000..1a056bd5149 --- /dev/null +++ b/src/backend/port/darwin/README @@ -0,0 +1,38 @@ +The file system.c included herein is taken directly from Apple's Darwin +open-source CVS archives, and is redistributed under the BSD copyright +notice it bears. (According to Apple's CVS logs, their version is +identical to the FreeBSD original.) It provides our own implementation of +the system(3) function, which ought by all rights to be identical to the +one provided in libc on Darwin machines. Nonetheless, this version works, +whereas the one that actually ships with Mac OS X 10.1 doesn't. The +shipped version appears to disconnect the calling process from any shared +memory segments it is attached to. (The symptom seen in PostgreSQL is +that a backend attempting to execute CREATE DATABASE core-dumps.) I would +love to know why there is a discrepancy between the published source and +the actual behavior --- tgl 7-Nov-2001. + +Appropriate bug reports have been filed with Apple --- see +Radar Bug#s 2767956, 2683531, 2805147. One hopes we can retire this +kluge in the not too distant future. + + +As of PostgreSQL 7.2 and Mac OS X 10.1, one should expect warnings +like these while linking the backend: + +/usr/bin/ld: warning unused multiple definitions of symbol _system +port/SUBSYS.o definition of _system in section (__TEXT,__text) +/usr/lib/libm.dylib(system.o) unused definition of _system +/usr/bin/ld: warning unused multiple definitions of symbol _semctl +port/SUBSYS.o definition of _semctl in section (__TEXT,__text) +/usr/lib/libm.dylib(semctl.o) unused definition of _semctl +/usr/bin/ld: warning unused multiple definitions of symbol _semget +port/SUBSYS.o definition of _semget in section (__TEXT,__text) +/usr/lib/libm.dylib(semget.o) unused definition of _semget +/usr/bin/ld: warning unused multiple definitions of symbol _semop +port/SUBSYS.o definition of _semop in section (__TEXT,__text) +/usr/lib/libm.dylib(semop.o) unused definition of _semop + +The first of these shows us overriding system() per the above-described +hack. The rest show sem.c overriding the nonfunctional semaphore stubs +in libc. (Perhaps sem.c can also be retired someday, but semget support +is reportedly not high on Apple's to-do list.) |