[lldb] Objective-C runtime: Work around a bug in the shared cache builder (#130209)
where it can overflow a 2GB offset by just a little bit by applying a
heuristic.
rdar://145888306
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index ff17028..c91a29a 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -458,7 +458,14 @@
if (objc_opt->version == 16)
{
- const objc_clsopt_v16_t* clsopt = (const objc_clsopt_v16_t*)((uint8_t *)objc_opt + objc_opt_v16->largeSharedCachesClassOffset);
+ int32_t large_offset = objc_opt_v16->largeSharedCachesClassOffset;
+ const objc_clsopt_v16_t* clsopt = (const objc_clsopt_v16_t*)((uint8_t *)objc_opt + large_offset);
+ // Work around a bug in some version shared cache builder where the offset overflows 2GiB (rdar://146432183).
+ uint32_t unsigned_offset = (uint32_t)large_offset;
+ if (unsigned_offset > 0x7fffffff && unsigned_offset < 0x82000000) {
+ clsopt = (const objc_clsopt_v16_t*)((uint8_t *)objc_opt + unsigned_offset);
+ DEBUG_PRINTF("warning: applying largeSharedCachesClassOffset overflow workaround!\n");
+ }
const size_t max_class_infos = class_infos_byte_size/sizeof(ClassInfo);
DEBUG_PRINTF("max_class_infos = %llu\n", (uint64_t)max_class_infos);
