cb054b6341
A recent libffi upgrade caused the reflect test to fail on 386. The problem case is a function that returns an empty struct--a struct with no fields. The libffi library does not recognize the existence of empty structs, presumably since they can't happen in C. To work around this, the Go interface to the libffi library changes an empty struct to void. This normally works fine, but with the new libffi upgrade it fails for a function that returns an empty struct. On 386 a function that returns a struct is expected to pop the hidden pointer when it returns. So when we convert an empty struct to void, libffi is calling a function that pops the hidden pointer but does not expect that to happen. In the older version of libffi, this didn't matter, because the libffi code for 386 used a frame pointer, so the fact that the stack pointer was wonky when the function returned was ignored as the stack pointer was immediately replaced by the saved frame pointer. In the newer version of libffi, the 386 code is more efficient and does not use a frame pointer, and therefore it matters whether libffi expects the function to pop the hidden pointer or not. This patch changes libgo to convert an empty to a struct with a single field of type void. This seems to be enough to get the test cases working again. Of course the real fix would be to change libffi to handle empty types, but as libffi uses size == 0 as a marker for an uninitialized type, that would be a non-trivial change. From-SVN: r219701 |
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| .. | ||
| config | ||
| go | ||
| runtime | ||
| testsuite | ||
| LICENSE | ||
| MERGE | ||
| Makefile.am | ||
| Makefile.in | ||
| PATENTS | ||
| README | ||
| README.gcc | ||
| aclocal.m4 | ||
| config.h.in | ||
| configure | ||
| configure.ac | ||
| godeps.sh | ||
| merge.sh | ||
| mksysinfo.sh | ||
| mvifdiff.sh | ||
README
See ../README. This is the runtime support library for the Go programming language. This library is intended for use with the Go frontend. The library has only been tested on GNU/Linux using glibc. It should not be difficult to port to other operating systems. The library has only been tested on x86/x86_64 systems. It should not be difficult to port to other architectures. Directories: go A copy of the Go library from http://golang.org/, with a few changes for gccgo. Notably, the reflection interface is different. runtime Runtime functions, written in C, which are called directly by the compiler or by the library. syscalls System call support. Contributing ============ To contribute patches to the files in this directory, please see http://golang.org/doc/gccgo_contribute.html . The master copy of these files is hosted at http://code.google.com/p/gofrontend . Changes to these files require signing a Google contributor license agreement. If you are the copyright holder, you will need to agree to the individual contributor license agreement at http://code.google.com/legal/individual-cla-v1.0.html. This agreement can be completed online. If your organization is the copyright holder, the organization will need to agree to the corporate contributor license agreement at http://code.google.com/legal/corporate-cla-v1.0.html. If the copyright holder for your code has already completed the agreement in connection with another Google open source project, it does not need to be completed again.