Introduce a native-only unwinder build.
Currently libunwind is built to support cross-unwinding [1] by default, which
requires the buffers unw_context_t and unw_cursor_t to be large enough to hold
the vritual register set (VRS) of any supported architecture. This is not
desirable for some platforms where the stack usage of the unwinder needs
to be kept to a minimum (e.g. bare-metal targets). The current patch introduces
a native-only (-DLIBUNWIND_ENABLE_CROSS_UNWINDING=OFF) unwinder variant that
adopts strict sizes for the buffers unw_context_t and unw_cursor_t depending
on the target architecture.
[1] http://www.nongnu.org/libunwind/man/libunwind(3).html#section_4
Change-Id: I380fff9a56c16a0fc520e3b1d8454a34b4a48373
git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@270692 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f45af84..628225b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -103,6 +103,7 @@
option(LIBUNWIND_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
option(LIBUNWIND_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
option(LIBUNWIND_ENABLE_SHARED "Build libunwind as a shared library." ON)
+option(LIBUNWIND_ENABLE_CROSS_UNWINDING "Enable cross-platform unwinding support." ON)
set(LIBUNWIND_GCC_TOOLCHAIN "" CACHE STRING "GCC toolchain for cross compiling.")
set(LIBUNWIND_SYSROOT "" CACHE STRING "Sysroot for cross compiling.")
@@ -202,6 +203,11 @@
endif ()
endif ()
+# Cross-unwinding
+if (NOT LIBUNWIND_ENABLE_CROSS_UNWINDING)
+ list(APPEND LIBUNWIND_COMPILE_FLAGS -D_LIBUNWIND_IS_NATIVE_ONLY)
+endif ()
+
# This is the _ONLY_ place where add_definitions is called.
if (MSVC)
add_definitions(-D_CRT_SECURE_NO_WARNINGS)