Commit Graph

1 Commits

Author SHA1 Message Date
Henry Wong 7ee88a970e [Analyzer] More accurate modeling about the increment operator of the operand with type bool.
Summary:
There is a problem with analyzer that a wrong value is given when modeling the increment operator of the operand with type bool. After `rL307604` is applied, a unsigned overflow may occur.

Example:
```
void func() {
  bool b = true;
  // unsigned overflow occur, 2 -> 0 U1b
  b++;
}
``` 

The use of an operand of type bool with the ++ operators is deprecated but valid untill C++17. And if the operand of the increment operator is of type bool, it is set to true.

This patch includes two parts:

  - If the operand of the increment operator is of type bool or type _Bool, set to true.
  - Modify `BasicValueFactory::getTruthValue()`, use `getIntWidth()` instead `getTypeSize()` and use `unsigned` instead `signed`.

Reviewers: alexshap, NoQ, dcoughlin, george.karpenkov

Reviewed By: NoQ

Subscribers: xazax.hun, szepet, a.sidorin, cfe-commits, MTC

Differential Revision: https://reviews.llvm.org/D43741

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@326776 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-06 12:29:09 +00:00