unwind: Allow the building of libunwind for MIPS.
Summary:
Currently, libunwind doesn't support MIPS. However, with this patch
we do allow the library to build, and we warn the user about the lack of
support for MIPS. Also, the dummy unw_getcontext() implementation for MIPS just
traps on function entry in order to avoid any confusion with silent/weird
failures at runtime.
This allows us to test an LLVM-based toolchain without the dependency on a
GCC toolchain. Of course, C++ exception handling and other things that depend
on stack unwinding will not work until we add a proper implementation of the
stub functions.
Reviewers: compnerd, logan
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13160
git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@248673 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/UnwindRegistersSave.S b/src/UnwindRegistersSave.S
index 1275c2a..f84b711 100644
--- a/src/UnwindRegistersSave.S
+++ b/src/UnwindRegistersSave.S
@@ -87,6 +87,15 @@
xorl %eax, %eax # return UNW_ESUCCESS
ret
+# elif defined(__mips__)
+
+#
+# extern int unw_getcontext(unw_context_t* thread_state)
+#
+# Just trap for the time being.
+DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+ teq $0, $0
+
#elif defined(__ppc__)
;
diff --git a/src/config.h b/src/config.h
index 9b24634..ecc0a6b 100644
--- a/src/config.h
+++ b/src/config.h
@@ -41,7 +41,8 @@
#define _LIBUNWIND_BUILD_ZERO_COST_APIS (defined(__i386__) || \
defined(__x86_64__) || \
- defined(__arm64__))
+ defined(__arm64__) || \
+ defined(__mips__))
#define _LIBUNWIND_BUILD_SJLJ_APIS defined(__arm__)
#define _LIBUNWIND_SUPPORT_FRAME_APIS (defined(__i386__) || \
defined(__x86_64__))
diff --git a/src/libunwind.cpp b/src/libunwind.cpp
index a23dfcf..f9f32f0 100644
--- a/src/libunwind.cpp
+++ b/src/libunwind.cpp
@@ -64,6 +64,8 @@
#elif defined(__or1k__)
new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_or1k>(
context, LocalAddressSpace::sThisAddressSpace);
+#elif defined(__mips__)
+#warning The MIPS architecture is not supported.
#else
#error Architecture not supported
#endif
