[Lldb-commits] [lldb] 32dd5b2 - Work around a bug in the interaction between newer dyld's and older simulator dyld's (#78004)

[via lldb-commits]

Author: jimingham
Date: 2024-01-16T11:31:42-08:00
New Revision: 32dd5b20973bde1ef77fa3b84b9f85788a1a303a

URL: https://github.com/llvm/llvm-project/commit/32dd5b20973bde1ef77fa3b84b9f85788a1a303a
DIFF: https://github.com/llvm/llvm-project/commit/32dd5b20973bde1ef77fa3b84b9f85788a1a303a.diff

LOG: Work around a bug in the interaction between newer dyld's and older simulator dyld's (#78004)

There's a bad interaction between the macOS 14 dyld and the "dyld_sim"
shim that comes from older (iOS 15) simulator downloads that results in
dyld reporting some modules twice in the return from the dyld callback
to list modules. The records were identical, but lldb wasn't happy with
seeing the duplicates...

Since it's not possible to load two different modules at the same
address, this change just picks the first instance of any entries that
have the same load address.

There really isn't a good way to test this patch.

Added: 
    

Modified: 
    lldb/tools/debugserver/source/MacOSX/MachProcess.mm

Removed: 
    


################################################################################
diff  --git a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
index 29fabd087ecbe1..93b976127ba45c 100644
--- a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
+++ b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
@@ -33,6 +33,7 @@
 #include <algorithm>
 #include <chrono>
 #include <map>
+#include <unordered_set>
 
 #include <TargetConditionals.h>
 #import <Foundation/Foundation.h>
@@ -1053,9 +1054,16 @@ static bool mach_header_validity_test(uint32_t magic, uint32_t cputype) {
     dyld_process_info info =
         m_dyld_process_info_create(m_task.TaskPort(), 0, &kern_ret);
     if (info) {
+      // There's a bug in the interaction between dyld and older dyld_sim's
+      // (e.g. from the iOS 15 simulator) that causes dyld to report the same
+      // binary twice.  We use this set to eliminate the duplicates.
+      __block std::unordered_set<uint64_t> seen_header_addrs;
       m_dyld_process_info_for_each_image(
           info,
           ^(uint64_t mach_header_addr, const uuid_t uuid, const char *path) {
+            auto res_pair = seen_header_addrs.insert(mach_header_addr);
+            if (!res_pair.second)
+              return;
             struct binary_image_information image;
             image.filename = path;
             uuid_copy(image.macho_info.uuid, uuid);