[PATCH] D124038: [clang] Prevent folding of non-const compound expr

[Eli Friedman via Phabricator via cfe-commits]

efriedma added a comment.

I think you're looking at old documentation?  Here's what the current page (https://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html) has to say:

  In C, a compound literal designates an unnamed object with static or automatic storage duration. In C++, a compound literal designates a temporary object that only lives until the end of its full-expression. As a result, well-defined C code that takes the address of a subobject of a compound literal can be undefined in C++, so G++ rejects the conversion of a temporary array to a pointer. For instance, if the array compound literal example above appeared inside a function, any subsequent use of foo in C++ would have undefined behavior because the lifetime of the array ends after the declaration of foo.
  
  As an optimization, G++ sometimes gives array compound literals longer lifetimes: when the array either appears outside a function or has a const-qualified type. If foo and its initializer had elements of type char *const rather than char *, or if foo were a global variable, the array would have static storage duration. But it is probably safest just to avoid the use of array compound literals in C++ code.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D124038/new/

https://reviews.llvm.org/D124038