Revert branch island experiments

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

@@ -26,7 +26,6 @@
 #include "lldb/Target/Thread.h"
 #include "lldb/Target/ThreadPlanCallFunction.h"
 #include "lldb/Target/ThreadPlanRunToAddress.h"
-#include "lldb/Target/ThreadPlanStepInstruction.h"
 #include "lldb/Utility/DataBuffer.h"
 #include "lldb/Utility/DataBufferHeap.h"
 #include "lldb/Utility/LLDBLog.h"
@@ -924,15 +923,15 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread,
   if (current_symbol != nullptr) {
     std::vector<Address> addresses;
 
-    ConstString current_name =
-        current_symbol->GetMangled().GetName(Mangled::ePreferMangled);
     if (current_symbol->IsTrampoline()) {
+      ConstString trampoline_name =
+          current_symbol->GetMangled().GetName(Mangled::ePreferMangled);
 
-      if (current_name) {
+      if (trampoline_name) {
         const ModuleList &images = target_sp->GetImages();
 
         SymbolContextList code_symbols;
-        images.FindSymbolsWithNameAndType(current_name, eSymbolTypeCode,
+        images.FindSymbolsWithNameAndType(trampoline_name, eSymbolTypeCode,
                                           code_symbols);
         for (const SymbolContext &context : code_symbols) {
           Address addr = context.GetFunctionOrSymbolAddress();
@@ -946,8 +945,8 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread,
         }
 
         SymbolContextList reexported_symbols;
-        images.FindSymbolsWithNameAndType(current_name, eSymbolTypeReExported,
-                                          reexported_symbols);
+        images.FindSymbolsWithNameAndType(
+            trampoline_name, eSymbolTypeReExported, reexported_symbols);
         for (const SymbolContext &context : reexported_symbols) {
           if (context.symbol) {
             Symbol *actual_symbol =
@@ -969,7 +968,7 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread,
         }
 
         SymbolContextList indirect_symbols;
-        images.FindSymbolsWithNameAndType(current_name, eSymbolTypeResolver,
+        images.FindSymbolsWithNameAndType(trampoline_name, eSymbolTypeResolver,
                                           indirect_symbols);
 
         for (const SymbolContext &context : indirect_symbols) {
@@ -1029,32 +1028,6 @@ DynamicLoaderDarwin::GetStepThroughTrampolinePlan(Thread &thread,
       thread_plan_sp = std::make_shared<ThreadPlanRunToAddress>(
           thread, load_addrs, stop_others);
     }
-    // One more case we have to consider is "branch islands".  These are regular
-    // TEXT symbols but their names end in .island plus maybe a .digit suffix.
-    // They are to allow arm64 code to branch further than the size of the
-    // address slot allows.  We just need to single-instruction step in that
-    // case.
-    static const char *g_branch_island_pattern = "\\.island\\.?[0-9]*$";
-    static RegularExpression g_branch_island_regex(g_branch_island_pattern);
-
-    bool is_branch_island = g_branch_island_regex.Execute(current_name);
-    // FIXME: this is extra logging so I can figure out why this test is failing
-    // on the bot but not locally with all the same tools, etc...
-    if (thread_plan_sp && is_branch_island) {
-      if (log) {
-        StreamString s;
-        thread_plan_sp->GetDescription(&s, eDescriptionLevelVerbose);
-        LLDB_LOGF(log, "Am at a branch island, but already had plan: \n\t%s", s.GetData());
-      }
-    }
-    if (!thread_plan_sp && is_branch_island) {
-      thread_plan_sp = std::make_shared<ThreadPlanStepInstruction>(
-          thread,
-          /* step_over= */ false, /* stop_others */ false, eVoteNoOpinion,
-          eVoteNoOpinion);
-      LLDB_LOG(log, "Stepping one instruction over branch island: '{0}'.",
-               current_name);
-    }
   } else {
     LLDB_LOGF(log, "Could not find symbol for step through.");
   }