SafeStack: Disable Darwin support

[vlad.tsyrklevich]

Summary

Darwin support does not appear to be used as evidenced by the fact that
the pthread interceptors have never worked and there is no support for
other common threading mechanisms like GCD.

[pcc]

LGTM

(@kubamracek FYI)

[kubamracek]

Yes, this looks good, SafeStack has never worked on non-trivial programs on Darwin. Does the Clang driver also need a patch?

[vlad.tsyrklevich]

In D50718#1199324, @kubamracek wrote:

Yes, this looks good, SafeStack has never worked on non-trivial programs on Darwin. Does the Clang driver also need a patch?

It does! Thanks for reminding me, that change is https://reviews.llvm.org/D50724

[kubamracek]

Cool, LGTM.

lib/safestack/CMakeLists.txt

 add_compiler_rt_component(safestack)
 
 set(SAFESTACK_SOURCES safestack.cc)
 
 include_directories(..)
 
 set(SAFESTACK_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 
-if(APPLE)
-  # Build universal binary on APPLE.
-  add_compiler_rt_runtime(clang_rt.safestack
-    STATIC
-    OS osx
-    ARCHS ${SAFESTACK_SUPPORTED_ARCH}
-    SOURCES ${SAFESTACK_SOURCES}
-            $<TARGET_OBJECTS:RTInterception.osx>
-            $<TARGET_OBJECTS:RTSanitizerCommon.osx>
-            $<TARGET_OBJECTS:RTSanitizerCommonNoLibc.osx>
-    CFLAGS ${SAFESTACK_CFLAGS}
-    PARENT_TARGET safestack)
-else()
-  # Otherwise, build separate libraries for each target.
-  foreach(arch ${SAFESTACK_SUPPORTED_ARCH})
-    add_compiler_rt_runtime(clang_rt.safestack
-      STATIC
-      ARCHS ${arch}
-      SOURCES ${SAFESTACK_SOURCES}
-              $<TARGET_OBJECTS:RTInterception.${arch}>
-              $<TARGET_OBJECTS:RTSanitizerCommon.${arch}>
-              $<TARGET_OBJECTS:RTSanitizerCommonNoLibc.${arch}>
-      CFLAGS ${SAFESTACK_CFLAGS}
-      PARENT_TARGET safestack)
-  endforeach()
-endif()

test/safestack/lit.cfg

 
 # Add clang substitutions.
 config.substitutions.append( ("%clang_nosafestack ", config.clang + " -O0 -fno-sanitize=safe-stack ") )
 config.substitutions.append( ("%clang_safestack ", config.clang + " -O0 -fsanitize=safe-stack ") )
 
 if config.lto_supported:
   config.substitutions.append((r"%clang_lto_safestack ", ' '.join(config.lto_launch + [config.clang] + config.lto_flags + ['-fsanitize=safe-stack '])))
 
-if config.host_os not in ['Linux', 'FreeBSD', 'Darwin', 'NetBSD']:
+if config.host_os not in ['Linux', 'FreeBSD', 'NetBSD']:
    config.unsupported = True

test/safestack/pthread.c

 // RUN: %clang_safestack %s -pthread -o %t
 // RUN: %run %t
 
-// XFAIL: darwin
-
 // Test that pthreads receive their own unsafe stack.
 
 #include <stdlib.h>
 #include <string.h>
 #include <pthread.h>
 #include "utils.h"
 
 static int ptr_test = 42;