[llvm-branch-commits] [lldb] release/23.x: [lldb] Fix crash on creating string error (#212503) (PR #212747)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/212747

Backport 29bc0749034c4f2bda0752360ecacd4e89d7439c

Requested by: @da-viper

>From da9fd5668dc70a9aed4191b45a81a0b2daf1e3eb Mon Sep 17 00:00:00 2001
From: Ebuka Ezike <e_ezike at apple.com>
Date: Wed, 29 Jul 2026 12:30:37 +0100
Subject: [PATCH] [lldb] Fix crash on creating string error (#212503)

It crashes because the `default` error string may not be a format string
compared to the `fallback` error string

(cherry picked from commit 29bc0749034c4f2bda0752360ecacd4e89d7439c)
---
 lldb/source/API/SBTarget.cpp  |  2 ++
 lldb/source/Target/Target.cpp | 12 +++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/lldb/source/API/SBTarget.cpp b/lldb/source/API/SBTarget.cpp
index cf2b1dc611df3..9eca813d8584b 100644
--- a/lldb/source/API/SBTarget.cpp
+++ b/lldb/source/API/SBTarget.cpp
@@ -2159,6 +2159,8 @@ lldb::SBInstructionList SBTarget::ReadInstructions(lldb::SBAddress base_addr,
       if (llvm::Expected<DisassemblerSP> disassembler =
               target_sp->ReadInstructions(*addr_ptr, count, flavor_string)) {
         sb_instructions.SetDisassembler(*disassembler);
+      } else {
+        LLDB_LOG_ERROR(GetLog(LLDBLog::API), disassembler.takeError(), "{0}");
       }
     }
   }
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index e851495a81f38..0638f29969d31 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -3120,11 +3120,13 @@ Target::ReadInstructions(const Address &start_addr, uint32_t count,
       ReadMemory(start_addr, data.GetBytes(), data.GetByteSize(), error,
                  force_live_memory, &load_addr);
 
-  if (error.Fail())
-    return llvm::createStringErrorV(
-        error.AsCString(
-            "Target::ReadInstructions failed to read memory at {:x}"),
-        start_addr.GetLoadAddress(this));
+  if (error.Fail()) {
+    return llvm::joinErrors(
+        llvm::createStringErrorV(
+            "Target::ReadInstructions failed to read memory at {:x}: ",
+            start_addr.GetLoadAddress(this)),
+        error.takeError());
+  }
 
   const bool data_from_file = load_addr == LLDB_INVALID_ADDRESS;
   if (!flavor_string || flavor_string[0] == '\0') {