On Darwin allow for sanitizer malloc implementations to provide a zone

enumerator.

This is done by defining `COMMON_MALLOC_HAS_ZONE_ENUMERATOR` to `1` and
then by providing an implementation of the `mi_enumerator(...)` function.
If a custom implementation isn't desired the macro is set to `0` which
causes a stub version (that fails) to be used.

Currently all Darwin sanitizers that have malloc implementations define
this to be `0` so there is no functionality change.

rdar://problem/45284065

llvm-svn: 351711

compiler-rt/lib/asan/asan_malloc_mac.cc

@@ -57,6 +57,7 @@ using namespace __asan;
   GET_STACK_TRACE_FREE; \
   ReportMacMzReallocUnknown((uptr)ptr, (uptr)zone_ptr, zone_name, &stack);
 #define COMMON_MALLOC_NAMESPACE __asan
+#define COMMON_MALLOC_HAS_ZONE_ENUMERATOR 0
 
 #include "sanitizer_common/sanitizer_malloc_mac.inc"
 

compiler-rt/lib/lsan/lsan_malloc_mac.cc

@@ -51,6 +51,7 @@ using namespace __lsan;
   (void)zone_name; \
   Report("mz_realloc(%p) -- attempting to realloc unallocated memory.\n", ptr);
 #define COMMON_MALLOC_NAMESPACE __lsan
+#define COMMON_MALLOC_HAS_ZONE_ENUMERATOR 0
 
 #include "sanitizer_common/sanitizer_malloc_mac.inc"
 

compiler-rt/lib/sanitizer_common/sanitizer_malloc_mac.inc

@@ -280,13 +280,28 @@ void __sanitizer_mz_free_definite_size(
 }
 #endif
 
-kern_return_t mi_enumerator(task_t task, void *,
-                            unsigned type_mask, vm_address_t zone_address,
-                            memory_reader_t reader,
+#ifndef COMMON_MALLOC_HAS_ZONE_ENUMERATOR
+#error "COMMON_MALLOC_HAS_ZONE_ENUMERATOR must be defined"
+#endif
+static_assert((COMMON_MALLOC_HAS_ZONE_ENUMERATOR) == 0 ||
+                  (COMMON_MALLOC_HAS_ZONE_ENUMERATOR) == 1,
+              "COMMON_MALLOC_HAS_ZONE_ENUMERATOR must be 0 or 1");
+
+#if COMMON_MALLOC_HAS_ZONE_ENUMERATOR
+// Forward declare and expect the implementation to provided by
+// includer.
+kern_return_t mi_enumerator(task_t task, void *, unsigned type_mask,
+                            vm_address_t zone_address, memory_reader_t reader,
+                            vm_range_recorder_t recorder);
+#else
+// Provide stub implementation that fails.
+kern_return_t mi_enumerator(task_t task, void *, unsigned type_mask,
+                            vm_address_t zone_address, memory_reader_t reader,
                             vm_range_recorder_t recorder) {
-  // Should enumerate all the pointers we have.  Seems like a lot of work.
+  // Not supported.
   return KERN_FAILURE;
 }
+#endif
 
 size_t mi_good_size(malloc_zone_t *zone, size_t size) {
   // I think it's always safe to return size, but we maybe could do better.

compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc

@@ -63,6 +63,7 @@ using namespace __tsan;
   (void)zone_name; \
   Report("mz_realloc(%p) -- attempting to realloc unallocated memory.\n", ptr);
 #define COMMON_MALLOC_NAMESPACE __tsan
+#define COMMON_MALLOC_HAS_ZONE_ENUMERATOR 0
 
 #include "sanitizer_common/sanitizer_malloc_mac.inc"