forked from OSchip/llvm-project
341e825eae
Summary: This attribute specifies expectations about the initialization of static and thread local variables. Specifically that the variable has a [constant initializer](http://en.cppreference.com/w/cpp/language/constant_initialization) according to the rules of [basic.start.static]. Failure to meet this expectation will result in an error. Static objects with constant initializers avoid hard-to-find bugs caused by the indeterminate order of dynamic initialization. They can also be safely used by other static constructors across translation units. This attribute acts as a compile time assertion that the requirements for constant initialization have been met. Since these requirements change between dialects and have subtle pitfalls it's important to fail fast instead of silently falling back on dynamic initialization. ```c++ // -std=c++14 #define SAFE_STATIC __attribute__((require_constant_initialization)) static struct T { constexpr T(int) {} ~T(); }; SAFE_STATIC T x = {42}; // OK. SAFE_STATIC T y = 42; // error: variable does not have a constant initializer // copy initialization is not a constant expression on a non-literal type. ``` This attribute can only be applied to objects with static or thread-local storage duration. Reviewers: majnemer, rsmith, aaron.ballman Subscribers: jroelofs, cfe-commits Differential Revision: https://reviews.llvm.org/D23385 llvm-svn: 280525 |
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| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llgo | ||
| llvm | ||
| openmp | ||
| parallel-libs | ||
| polly | ||