[libunwind] Haiku: Initial support

[trungnt2910]

Summary

Adds build support for Haiku OS to libunwind.

libunwind can now be built on Haiku OS with clang 12. make check-unwind also passes.

[trungnt2910]

Ran the diff through git-clang-format, code looks a bit strange though.

[brad]

diffs need to have context, .e.g. git diff -U999999

[trungnt2910]

Added the full context.

Seems like git format-patch does not include it by default...

[brad]

libunwind/include/__libunwind_config.h

41

Fix the indentation.

libunwind/src/config.h

54

Fix the indentation.

[trungnt2910]

libunwind/include/__libunwind_config.h

41

The indentation is intended.

Using the indentation that looks correct would make the build fail due to clang-format: https://reviews.llvm.org/B252866

libunwind/src/config.h

54

Same as above.

[brad]

libunwind/include/__libunwind_config.h

41

The indentation is intended.

Using the indentation that looks correct would make the build fail due to clang-format: https://reviews.llvm.org/B252866

Don't worry about that. That's not an absolute requirement and matching the surrounding formatting is more important.

[brad]

The llvm-libunwind-shared.cfg.in chunk looks like it should probably be a separate commit, but make the sames changes for llvm-libunwind-merged.cfg.in and llvm-libunwind-static.cfg.in.

I don't know if the tests have ever been run on OpenBSD but this looks like it would help other OS's that do not have libdl.

[trungnt2910]

libunwind/include/__libunwind_config.h

41

Reverted the indentation changes.

[trungnt2910]

In D157866#4635779, @brad wrote:

The llvm-libunwind-shared.cfg.in chunk looks like it should probably be a separate commit, but make the sames changes for llvm-libunwind-merged.cfg.in and llvm-libunwind-static.cfg.in.

I don't know if the tests have ever been run on OpenBSD but this looks like it would help other OS's that do not have libdl.

Must it be in a different patch? The changes are relatively minor but required to test libunwind on Haiku (and therefore confirm that this patch is functional).

[brad]

I am not a libunwind developer, but it looks good to me and looking at the libraries mentioned they do check out (libroot / libbsd).

[MaskRay]

So, Haiku uses libroot instead of libc? The changes seem fine, but I hope that a Haiku contributor that is not the author can verify.

[waddlesplash]

In D157866#4636420, @MaskRay wrote:

So, Haiku uses libroot instead of libc? The changes seem fine, but I hope that a Haiku contributor that is not the author can verify.

This is correct. On Haiku, the C and POSIX functions are in libroot (excluding network-related ones, which are in a separate library.)

[brad]

@MaskRay Able to Ok this?

libunwind/cmake/config-ix.cmake

 # --unwindlib=none is supported, and use that if possible.
 llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
 
-check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB)
+if (HAIKU)
+  check_library_exists(root fopen "" LIBUNWIND_HAS_ROOT_LIB)
+else()
+  check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB)
+endif()
 
 if (NOT LIBUNWIND_USE_COMPILER_RT)
   if (ANDROID)

   if (LIBUNWIND_HAS_C_LIB)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
   endif ()
+  if (LIBUNWIND_HAS_ROOT_LIB)
+    list(APPEND CMAKE_REQUIRED_LIBRARIES root)
+  endif ()
   if (LIBUNWIND_USE_COMPILER_RT)
     include(HandleCompilerRT)
     find_compiler_rt_library(builtins LIBUNWIND_BUILTINS_LIBRARY

   check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB)
   check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB)
 endif()
+
+if(HAIKU)
+  check_library_exists(bsd dl_iterate_phdr "" LIBUNWIND_HAS_BSD_LIB)
+endif()

libunwind/include/__libunwind_config.h

 # if defined(__linux__)
 #  define _LIBUNWIND_TARGET_LINUX 1
 # endif
+# if defined(__HAIKU__)
+#  define _LIBUNWIND_TARGET_HAIKU 1
+# endif
 # if defined(__i386__)
 #  define _LIBUNWIND_TARGET_I386
 #  define _LIBUNWIND_CONTEXT_SIZE 8

libunwind/src/CMakeLists.txt

   endif ()
 endif ()
 
+if (HAIKU)
+  add_library_flags_if(LIBUNWIND_HAS_ROOT_LIB root)
+
+  add_library_flags_if(LIBUNWIND_HAS_BSD_LIB bsd)
+  add_compile_flags_if(LIBUNWIND_HAS_BSD_LIB -D_LIBUNWIND_USE_HAIKU_BSD_LIB=1)
+
+  add_compile_flags("-D_DEFAULT_SOURCE")
+  add_compile_flags("-DPT_GNU_EH_FRAME=PT_EH_FRAME")
+endif ()
+
 string(REPLACE ";" " " LIBUNWIND_COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}")
 string(REPLACE ";" " " LIBUNWIND_CXX_FLAGS "${LIBUNWIND_CXX_FLAGS}")
 string(REPLACE ";" " " LIBUNWIND_C_FLAGS "${LIBUNWIND_C_FLAGS}")

libunwind/src/config.h

 #elif defined(_AIX)
 // The traceback table at the end of each function is used for unwinding.
 #define _LIBUNWIND_SUPPORT_TBTAB_UNWIND 1
+#elif defined(__HAIKU__)
+  #if defined(_LIBUNWIND_USE_HAIKU_BSD_LIB)
+    #define _LIBUNWIND_USE_DL_ITERATE_PHDR 1
+  #endif
+  #define _LIBUNWIND_SUPPORT_DWARF_UNWIND 1
+  #define _LIBUNWIND_SUPPORT_DWARF_INDEX 1
 #else
   // Assume an ELF system with a dl_iterate_phdr function.
   #define _LIBUNWIND_USE_DL_ITERATE_PHDR 1

libunwind/test/configs/llvm-libunwind-shared.cfg.in

 if '@CMAKE_SYSTEM_NAME@' == 'Linux':
     link_flags.append('-Wl,--export-dynamic')
 
+if '@CMAKE_DL_LIBS@':
+    link_flags.append('-l@CMAKE_DL_LIBS@')
+
 # Stack unwinding tests need unwinding tables and these are not generated by default on all targets.
 compile_flags.append('-funwind-tables')
 

     '-nostdinc++ -I %{{include}} {}'.format(' '.join(compile_flags))
 ))
 config.substitutions.append(('%{link_flags}',
-    '-L %{{lib}} -Wl,-rpath,%{{lib}} -lunwind -ldl {}'.format(' '.join(link_flags))
+    '-L %{{lib}} -Wl,-rpath,%{{lib}} -lunwind {}'.format(' '.join(link_flags))
 ))
 config.substitutions.append(('%{exec}',
     '%{executor} --execdir %T -- '