Incorrectly reports "The left operand of '!=' is a garbage value"

[llvmbot]

Bugzilla Link	9455
Resolution	FIXED
Resolved on	Mar 16, 2011 22:52
Version	2.9
OS	MacOS X
Attachments	A bare-bone c-file that shows the problem.
Reporter	LLVM Bugzilla Contributor
CC	@tkremenek

Extended Description

In the attached source, the analyzer incorrectly reports a potential garbage value.

It seems that the analyzer gets confused by the combination of static initialization of the char string:
char pattern[4] = "000";

and by the subsequent modification by the if statements:
if (fun(t-1)) {
pattern[0] = '1';
}
if (fun(t)) {
pattern[1] = '1';
}
if (fun(t+1)) {
pattern[2] = '1';
}

when the code reaches a loop that make simple checks over the string:

int i;
for( i=0; i<3; ++i ) {
	if(pattern[i]!=fun2(i))            
        return 0;
}

the analyzer incorrectly thinks that pattern[i] is gargbage value. This cannot be the case since all indices in 0..2 have been initialized to the character '0'.

[llvmbot]

assigned to @tkremenek

[tkremenek]

cloned to rdar://problem/9122947

[tkremenek]

Fixed: r127796