Add xmalloc()-like functionality.

xmalloc is a non-standard extension forcing malloc() to
abort should the memory allocation failed instead of returning a
null pointer. Such functionality is quite useful as it provides one
single point of error handling if the caller of malloc() does not
check the result (as it often does!) and segfault is ocurring somewhere
else. If more fine-grained control is necessary one could register a custom
error handler, however, this might not be an option while interposing.

CMakeLists.txt

@@ -15,6 +15,7 @@ option(MI_LOCAL_DYNAMIC_TLS "Use slightly slower, dlopen-compatible TLS mechanis
 option(MI_BUILD_TESTS       "Build test executables" ON)
 option(MI_CHECK_FULL        "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
 option(MI_PADDING           "Enable padding to detect heap block overflow (only in debug mode)" ON)
+option(MI_XMALLOC           "Enable abort() call on memory allocation failure by default" OFF)
 
 include("cmake/mimalloc-config-version.cmake")
 
@@ -105,6 +106,11 @@ if(MI_PADDING MATCHES "OFF")
   list(APPEND mi_defines MI_PADDING=0)
 endif()
 
+if(MI_XMALLOC MATCHES "ON")
+  message(STATUS "Enable abort() calls on memory allocation failure (MI_XMALLOC=ON)")
+  list(APPEND mi_defines MI_XMALLOC=1)
+endif()
+
 if(MI_USE_CXX MATCHES "ON")
   message(STATUS "Use the C++ compiler to compile (MI_USE_CXX=ON)")
   set_source_files_properties(${mi_sources} PROPERTIES LANGUAGE CXX )

include/mimalloc-types.h

@@ -61,7 +61,6 @@ terms of the MIT license. A copy of the license can be found in the file
 #define MI_ENCODE_FREELIST  1
 #endif
 
-
 // ------------------------------------------------------
 // Platform specific values
 // ------------------------------------------------------

src/options.c

@@ -348,6 +348,11 @@ static void mi_error_default(int err) {
     abort();
   }
 #endif
+#if defined(MI_XMALLOC)
+  if (err==ENOMEM || err==EOVERFLOW) { // abort on memory allocation fails in xmalloc mode
+    abort();
+  }
+#endif
 }
 
 void mi_register_error(mi_error_fun* fun, void* arg) {