https://bugs.llvm.org/show_bug.cgi?id=39802
Bug ID: 39802
Summary: alpha.deadcode.UnreachableCode false positive when
asserting on a float
Product: clang
Version: 7.0
Hardware: PC
OS: Windows NT
Status: NEW
Severity: enhancement
Priority: P
Component: Static Analyzer
Assignee: dcough...@apple.com
Reporter: riku....@riksteri.eu
CC: dcough...@apple.com, llvm-bugs@lists.llvm.org
Created attachment 21164
--> https://bugs.llvm.org/attachment.cgi?id=21164&action=edit
unreachable-repro.cpp
The attached sample code produces an analyzer warning about unreachable code
inside the nested for-loops (sample also inlined below). The warning is clearly
a false positive, since I can see the output of the "unreachable" code when I
execute the original, non-minimal application that reproduces this warning.
Command:
clang --analyze -Xanalyzer -analyzer-checker=alpha.deadcode.UnreachableCode
unreachable-repro.cpp
Output:
unreachable-repro.cpp:11:4: warning: This statement is never executed
continue;
^~~~~~~~
The warning still occurs if the "continue" is replaced with actually useful
code. The "continue" was the simplest statement I could come up with here.
If the assert is removed or split into two like this:
assert(0.f <= input);
assert(input <= 1.f);
then the warning does not appear.
If one or both of the two loops are removed, the warning does not appear.
If the function argument is an integer instead of a floating point type, the
warning does not appear.
I am using the pre-built 64-bit Windows binaries. This occurs at least in
release build version 7.0.0 and snapshot builds 6.0.0-r320423 and
8.0.0-r346630.
============================================
#include <assert.h>
void unreachable_repro(float input)
{
assert(0.f <= input && input <= 1.f);
for(int i = 0; i < 1; ++i)
{
for(int k = 0; k < 1; ++k)
{
continue;
}
}
}
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
