Clang has traditionally allowed C programs to implicitly convert
integers to pointers and pointers to integers, despite it not being
valid to do so except under special circumstances (like converting the
integer 0, which is the null pointer constant, to a pointer). In C89,
this would result in undefined behavior per 3.3.4, and in C99 this rule
was strengthened to be a constraint violation instead. Constraint
violations are most often handled as an error.
This patch changes the warning to default to an error in all C modes
(it is already an error in C++). This gives us better security posture
by calling out potential programmer mistakes in code but still allows
users who need this behavior to use -Wno-error=int-conversion to retain
the warning behavior, or -Wno-int-conversion to silence the diagnostic
entirely.
Differential Revision: https://reviews.llvm.org/D129881
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the eighth batch of tests being updated (there are a
significant number of other tests left to be updated).
Summary:
I wanted to extend the diagnostics of the CStringChecker with taintedness.
This requires the CStringChecker to be refactored to support a more flexible
reporting mechanism.
This patch does only refactorings, such:
- eliminates always false parameters (like WarnAboutSize)
- reduces the number of parameters
- makes strong types differentiating *source* and *destination* buffers
(same with size expressions)
- binds the argument expression and the index, making diagnostics accurate
and easy to emit
- removes a bunch of default parameters to make it more readable
- remove random const char* warning message parameters, making clear where
and what is going to be emitted
Note that:
- CheckBufferAccess now checks *only* one buffer, this removed about 100 LOC
code duplication
- not every function was refactored to use the /new/ strongly typed API, since
the CString related functions are really closely coupled monolithic beasts,
I will refactor them separately
- all tests are preserved and passing; only the message changed at some places.
In my opinion, these messages are holding the same information.
I would also highlight that this refactoring caught a bug in
clang/test/Analysis/string.c:454 where the diagnostic did not reflect reality.
This catch backs my effort on simplifying this monolithic CStringChecker.
Reviewers: NoQ, baloghadamsoftware, Szelethus, rengolin, Charusso
Reviewed By: NoQ
Subscribers: whisperity, xazax.hun, szepet, rnkovacs, a.sidorin,
mikhail.ramalho, donat.nagy, dkrupp, Charusso, martong, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74806
- Fix false positive reports of strlcat.
- The return value of strlcat and strlcpy is now correctly calculated.
- The resulting string length of strlcat and strlcpy is now correctly
calculated.
Patch by Daniel Krupp!
Differential Revision: https://reviews.llvm.org/D66049
The last argument is expected to be the destination buffer size (or less).
Detects if it points to destination buffer size directly or via a variable.
Detects if it is an integral, try to detect if the destination buffer can receive the source length.
Updating bsd-string.c unit tests as it make it fails now.
Reviewers: george.karpenpov, NoQ
Reviewed By: george.karpenkov
Differential Revision: https://reviews.llvm.org/D48884
llvm-svn: 337499
Again, strlc* does not return a pointer so the zero size case doest not fit.
Reviewers: NoQ, george.karpenkov
Reviewed by: NoQ
Differential Revision: https://reviews.llvm.org/D47007
llvm-svn: 333060
