forked from OSchip/llvm-project
9d3ca9a5ae
Using ARC, strong, weak, and autoreleasing stack variables are implicitly
initialized with nil. This includes variable-length arrays of Objective-C object
pointers. However, in the analyzer we don't zero-initialize them. We used to,
but it accidentally regressed after r289618.
Under ARC, the array variable's initializer within DeclStmt is an
ImplicitValueInitExpr. Environment doesn't maintain any bindings for this
expression kind - instead it always knows that it's a known constant
(0 in our case), so it just returns the known value by calling
SValBuilder::makeZeroVal() (see EnvironmentManager::getSVal().
Commit r289618 had introduced reasonable behavior of SValBuilder::makeZeroVal()
for the arrays, which produces a zero-length compoundVal{}. When such value
is bound to arrays, in RegionStoreManager::bindArray() "remaining" items in the
array are default-initialized with zero, as in
RegionStoreManager::setImplicitDefaultValue(). The similar mechanism works when
an array is initialized by an initializer list that is too short, eg.
int a[3] = { 1, 2 };
would result in a[2] initialized with 0. However, in case of variable-length
arrays it didn't know if any more items need to be added,
because, well, the length is variable.
Add the default binding anyway, regardless of how many actually need
to be added. We don't really care how many, because the default binding covers
the whole array anyway.
Differential Revision: https://reviews.llvm.org/D41478
rdar://problem/35477763
llvm-svn: 321290
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| INPUTS | ||
| bindings | ||
| cmake | ||
| docs | ||
| examples | ||
| include | ||
| lib | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| www | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| INSTALL.txt | ||
| LICENSE.TXT | ||
| ModuleInfo.txt | ||
| NOTES.txt | ||
| README.txt | ||
README.txt
//===----------------------------------------------------------------------===// // C Language Family Front-end //===----------------------------------------------------------------------===// Welcome to Clang. This is a compiler front-end for the C family of languages (C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM compiler infrastructure project. Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer. If you're interested in more (including how to build Clang) it is best to read the relevant web sites. Here are some pointers: Information on Clang: http://clang.llvm.org/ Building and using Clang: http://clang.llvm.org/get_started.html Clang Static Analyzer: http://clang-analyzer.llvm.org/ Information on the LLVM project: http://llvm.org/ If you have questions or comments about Clang, a great place to discuss them is on the Clang development mailing list: http://lists.llvm.org/mailman/listinfo/cfe-dev If you find a bug in Clang, please file it in the LLVM bug tracker: http://llvm.org/bugs/