Commit Graph

7 Commits

Author SHA1 Message Date
Denys Petrov f0bc7d2488 [analyzer] Fix region cast between the same types with different qualifiers.
Summary: Specifically, this fixes the case when we get an access to array element through the pointer to element. This covers several FIXME's. in https://reviews.llvm.org/D111654.
Example:
  const int arr[4][2];
  const int *ptr = arr[1]; // Fixes this.
The issue is that `arr[1]` is `int*` (&Element{Element{glob_arr5,1 S64b,int[2]},0 S64b,int}), and `ptr` is `const int*`. We don't take qualifiers into account. Consequently, we doesn't match the types as the same ones.

Differential Revision: https://reviews.llvm.org/D113480
2021-11-15 19:23:00 +02:00
Denys Petrov a12bfac292 [analyzer] Retrieve a value from list initialization of multi-dimensional array declaration.
Summary: Add support of multi-dimensional arrays in `RegionStoreManager::getBindingForElement`. Handle nested ElementRegion's getting offsets and checking for being in bounds. Get values from the nested initialization lists using obtained offsets.

Differential Revision: https://reviews.llvm.org/D111654
2021-11-08 16:17:55 +02:00
Denys Petrov 1deccd05ba [analyzer] Retrieve a character from StringLiteral as an initializer for constant arrays.
Summary: Assuming that values of constant arrays never change, we can retrieve values for specific position(index) right from the initializer, if presented. Retrieve a character code by index from StringLiteral which is an initializer of constant arrays in global scope.

This patch has a known issue of getting access to characters past the end of the literal. The declaration, in which the literal is used, is an implicit cast of kind `array-to-pointer`. The offset should be in literal length's bounds. This should be distinguished from the states in the Standard C++20 [dcl.init.string] 9.4.2.3. Example:
  const char arr[42] = "123";
  char c = arr[41]; // OK
  const char * const str = "123";
  char c = str[41]; // NOK

Differential Revision: https://reviews.llvm.org/D107339
2021-10-29 19:44:37 +03:00
Denys Petrov 44e803ef6d [analyzer][NFCI] Move a block from `getBindingForElement` to separate functions
Summary:
1. Improve readability by moving deeply nested block of code from RegionStoreManager::getBindingForElement to new separate functions:
- getConstantValFromConstArrayInitializer;
- getSValFromInitListExpr.
2. Handle the case when index is a symbolic value. Write specific test cases.
3. Add test cases when there is no initialization expression presented.
This patch implies to make next patches clearer and easier for review process.

Differential Revision: https://reviews.llvm.org/D106681
2021-10-25 15:14:10 +03:00
Denys Petrov 98a95d4844 [analyzer] Retrieve a value from list initialization of constant array declaration in a global scope.
Summary: Fix the point that we didn't take into account array's dimension. Retrieve a value of global constant array by iterating through its initializer list.

Differential Revision: https://reviews.llvm.org/D104285

Fixes: https://bugs.llvm.org/show_bug.cgi?id=50604
2021-09-24 12:37:58 +03:00
Artem Dergachev b0914e7276 [analyzer] Specify the C++ standard in more tests.
Makes life easier for downstream developers with different default standard.

llvm-svn: 375308
2019-10-19 00:08:17 +00:00
Rafael Stahl 0137aa8679 [analyzer] const init: handle non-explicit cases more accurately
Summary: If the access is out of bounds, return UndefinedVal. If it is missing an explicit init, return the implicit zero value it must have.

Reviewers: NoQ, xazax.hun, george.karpenkov

Reviewed By: NoQ

Subscribers: szepet, rnkovacs, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D46823

llvm-svn: 333417
2018-05-29 14:14:22 +00:00