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KWSys: Avoid undefined behavior in Process crash tests 

Clang is smart enough to recognize that "*(int*)0=0" invokes undefined
behavior, warns, and produces an "undefined instruction".  The message
in commit "Avoid Clang optimizer bug in testProcess-[45]" (2010-07-02)
is incorrect; this is not a Clang bug.  It really is undefined
behavior.  Use "*(int*)1=0" to produce a crash instead.
This commit is contained in:
Brad King 2010-07-09 10:30:18 -04:00
parent a1a4a2cb6d
commit 70154efef8
1 changed files with 2 additions and 3 deletions
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5
Source/kwsys/testProcess.c
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@ -94,9 +94,8 @@ int test4(int argc, const char* argv[])
fprintf(stderr, "Output before crash on stderr from crash test.\n"); fprintf(stderr, "Output before crash on stderr from crash test.\n");
fflush(stdout); fflush(stdout);
fflush(stderr); fflush(stderr);
#if defined(__APPLE__) && defined(__x86_64__) && defined(__OPTIMIZE__) \ #if defined(__clang__)
&& defined(__clang__) *(int*)1 = 0; /* Clang warns about 0-ptr; undefined behavior. */
*(int*)1 = 0; /* Clang's optimizer produces bad code for 0-ptr. */
#else #else
*(int*)0 = 0; *(int*)0 = 0;
#endif #endif