JuliaLang/julia — pull request #1094 by vtjnash (2012-07-28 23:32:14+00:00)
Title: attempting to make switch_stack more reliable across compilers

the current implementation of switch_stack doesn't reserve quite enough stack space with clang -g (the entire function may need to be outside of the range of the stack being replaced, not just the return frame pointer), and can requires an unknown number of recursive calls. Using alloca and a single recursive call, it is possible to more quickly allocate the necessary space, still without allowing the compiler to optimize away the stack allocation request or the necessary function calls