Commit Graph

3 Commits

Author SHA1 Message Date
Gabor Horvath ec87e17c84 [clang-tidy] Misc redundant expressions checker updated for macros
Redundant Expression Checker is updated to be able to detect expressions that
contain macros. Also, other small details are modified to improve the current
implementation.

The improvements in detail are as follows:
* Binary and ternary operator expressions containing two constants, with at
least one of them from a macro, are detected and tested for redundancy.

Macro expressions are treated somewhat differently from other expressions,
because the particular values of macros can vary across builds.
They can be considered correct and intentional, even if macro values equal,
produce ranges that exclude each other or fully overlap, etc. 

* The code structure is slightly modified: typos are corrected,
comments are added and some functions are renamed to improve comprehensibility,
both in the checker and the test file. A few test cases are moved to another
function.

* The checker is now able to detect redundant CXXFunctionalCastExprs as well.
A corresponding test case is added.

Patch by: Lilla Barancsuk!

Differential Revision: https://reviews.llvm.org/D38688

llvm-svn: 317570
2017-11-07 13:17:58 +00:00
Etienne Bergeron 00639bc529 [clang-tidy] Enhance redundant-expression check
Summary: This patch is adding support to recognize more complex redundant expressions.

Reviewers: alexfh

Subscribers: aaron.ballman, cfe-commits, chrisha

Differential Revision: http://reviews.llvm.org/D21392

llvm-svn: 274731
2016-07-07 04:03:05 +00:00
Etienne Bergeron bda187decd [clang-tidy] New checker for redundant expressions.
Summary:
This checker finds redundant expression on both side of a binary operator.

The current implementation provide a function to check whether expressions
are equivalent. This implementation is able to recognize the common
subset encounter in C++ program. Side-effects like "x++" are not considered
to be equivalent.

There are many False Positives related to macros and to floating point
computations (detecting NaN). The checker is ignoring these cases.

Example:
```
    if( !dst || dst->depth != desired_depth ||
        dst->nChannels != desired_num_channels ||
        dst_size.width != src_size.width ||
        dst_size.height != dst_size.height )    <<--- bug
    {
```

Reviewers: alexfh

Subscribers: danielmarjamaki, fahlgren, jordan_rose, zaks.anna, Eugene.Zelenko, cfe-commits

Differential Revision: http://reviews.llvm.org/D19451

llvm-svn: 267574
2016-04-26 17:30:30 +00:00