[compiler-rt][builtins] Better Fuchsia support

[phosek]

Summary

Add Fuchsia support to some builtins and avoid building builtins that are not and will never be used on Fuchsia.

[compnerd]

lib/builtins/CMakeLists.txt

226

eprintf is a darwin specific thing, not to be added everywhere. Is this still being filtered out?

lib/builtins/int_util.c

50

Please use the reserved spellings of the attributes.

[jroelofs]

lib/builtins/CMakeLists.txt

226

Feel free to stick eprintf.c in the "not on baremetal section", too.

[phosek]

lib/builtins/CMakeLists.txt

226

Should it be that one or the APPLE one?

[jroelofs]

compiler-rt/trunk/lib/builtins/int_util.c

50 ↗

(On Diff #106281)

Can __Fuscia__ && defined(_WIN32) ever be true?

lib/builtins/CMakeLists.txt

set(GENERIC_SOURCES
   addvti3.c
   apple_versioning.c
   ashldi3.c
   ashlti3.c
   ashrdi3.c
   ashrti3.c
   bswapdi2.c
   bswapsi2.c
-  clear_cache.c
   clzdi2.c
   clzsi2.c
   clzti2.c
   cmpdi2.c
   cmpti2.c
   comparedf2.c
   comparesf2.c
   cpu_model.c
   ctzdi2.c
   ctzsi2.c
   ctzti2.c
   divdc3.c
   divdf3.c
   divdi3.c
   divmoddi4.c
   divmodsi4.c
   divsc3.c
   divsf3.c
   divsi3.c
   divtc3.c
   divti3.c
   divtf3.c
   divxc3.c
-  eprintf.c
   extendsfdf2.c
   extendhfsf2.c
   ffsdi2.c
   ffssi2.c
   ffsti2.c
   fixdfdi.c
   fixdfsi.c
   fixdfti.c
set(GENERIC_TF_SOURCES
   multc3.c
   trunctfdf2.c
   trunctfsf2.c)
 
 option(COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN
   "Skip the atomic builtin (this may be needed if system headers are unavailable)"
   Off)
 
-if(NOT COMPILER_RT_BAREMETAL_BUILD)
+if(NOT FUCHSIA AND NOT COMPILER_RT_BAREMETAL_BUILD)
   set(GENERIC_SOURCES
     ${GENERIC_SOURCES}
     emutls.c 
     enable_execute_stack.c)
 endif()
 
 if(COMPILER_RT_HAS_ATOMIC_KEYWORD AND NOT COMPILER_RT_EXCLUDE_ATOMIC_BUILTIN)
   set(GENERIC_SOURCES

 endif()
 
 if (HAVE_UNWIND_H)
   set(GENERIC_SOURCES
       ${GENERIC_SOURCES}
       gcc_personality_v0.c)
 endif ()
 
+if (NOT FUCHSIA)
+  set(GENERIC_SOURCES
+    ${GENERIC_SOURCES}
+    clear_cache.c
+    eprintf.c)
+endif()
+
 if (NOT MSVC)
   set(x86_64_SOURCES
       x86_64/chkstk.S
       x86_64/chkstk2.S
       x86_64/floatdidf.c
       x86_64/floatdisf.c
       x86_64/floatdixf.c
       x86_64/floatundidf.S

lib/builtins/int_util.c

 #ifndef _WIN32
 __attribute__((weak))
 __attribute__((visibility("hidden")))
 #endif
 void compilerrt_abort_impl(const char *file, int line, const char *function) {
   __assert_rtn(function, file, line, "libcompiler_rt abort");
 }
 
+#elif __Fuchsia__
+
+__attribute__((weak)) __attribute__((visibility("hidden")))
+void compilerrt_abort_impl(const char *file, int line, const char *function) {
+  __builtin_trap();
+}
+
 #else
 
 /* Get the system definition of abort() */
 #include <stdlib.h>
 
 #ifndef _WIN32
 __attribute__((weak))
 __attribute__((visibility("hidden")))
 #endif
 void compilerrt_abort_impl(const char *file, int line, const char *function) {
   abort();
 }
 
 #endif