On Mon, Dec 21, 2015 at 4:10 PM, Ian Lance Taylor <i...@golang.org> wrote: > The GNU linker doesn't support a zero-sized global variable that is > dynamically exported, so gccgo generates those global variables with a > size of 1 byte. Unfortunately, that means that passing a global > variable to a function that takes an argument of a zero-sized type > will actually pass 1 byte, taking up an argument slot, rather than a > zero-sized argument that should be skipped. This patch fixes the > problem in the Go frontend -> GCC interface by adding a conversion to > the real type for any such global variables, and undoing the > conversion where necessary. Bootstrapped and ran Go testsuite on > x86_64-pc-linux-gnu. Committed to mainline and gccgo branch.
VIEW_CONVERT_EXPR on different size types is invalid for GCC's IR. So this patch cause other issues. Thanks, Andrew Pinski > > Ian > > 2015-12-21 Ian Lance Taylor <i...@google.com> > > * go-gcc.cc (Gcc_backend::global_variable): If type is zero-sized, > add a VIEW_CONVERT_EXPR to the tree. > (Gcc_backend::global_variable_set_init): Remove any > VIEW_CONVERT_EXPR. > (Gcc_backend::write_global_definitions): Likewise.
