[Lldb-commits] [lldb] [LLDB, FreeBSD, x86] Fix empty register set when trying to get size of register (PR #162890)

[via lldb-commits]

https://github.com/aokblast updated https://github.com/llvm/llvm-project/pull/162890

>From 60d267acf1967f894530f1fbb7ae7c28b433e5cd Mon Sep 17 00:00:00 2001
From: ShengYi Hung <aokblast at FreeBSD.org>
Date: Sat, 11 Oct 2025 01:07:36 +0800
Subject: [PATCH] [LLDB, FreeBSD, x86] Fix empty register set when trying to
 get size of register info

The register set information is stored as a singleton in
GetRegisterInfo_i386. However, it is later use by other function which
assume it stores in GetSharedRegisterInfoVector. Therefore, we copy the
data to GetSharedRegisterInfoVector directly so that LLDB won't get
panic.

Also, reorder the header order and provide a test for debugging 32bit
binary on 64bit platform. This test is just a copy paste from
dummy-target.test but change the target as -m32.
---
 lldb/source/Host/freebsd/Host.cpp             |  3 +--
 .../Utility/RegisterContextFreeBSD_x86_64.cpp |  6 +++--
 .../Breakpoint/debug_x86_over_amd64.test      | 26 +++++++++++++++++++
 3 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 lldb/test/Shell/Breakpoint/debug_x86_over_amd64.test

diff --git a/lldb/source/Host/freebsd/Host.cpp b/lldb/source/Host/freebsd/Host.cpp
index fa7efad466bad..dfdbfea0c3c0a 100644
--- a/lldb/source/Host/freebsd/Host.cpp
+++ b/lldb/source/Host/freebsd/Host.cpp
@@ -18,8 +18,6 @@
 #include <dlfcn.h>
 #include <execinfo.h>
 
-#include "llvm/Object/ELF.h"
-
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostInfo.h"
@@ -32,6 +30,7 @@
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/StreamString.h"
 
+#include "llvm/Object/ELF.h"
 #include "llvm/TargetParser/Host.h"
 
 namespace lldb_private {
diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextFreeBSD_x86_64.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextFreeBSD_x86_64.cpp
index e0f3971c6e272..b55a5c595d3ca 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextFreeBSD_x86_64.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextFreeBSD_x86_64.cpp
@@ -76,8 +76,7 @@ static std::vector<lldb_private::RegisterInfo> &GetSharedRegisterInfoVector() {
 
 static const RegisterInfo *
 GetRegisterInfo_i386(const lldb_private::ArchSpec &arch) {
-  static std::vector<lldb_private::RegisterInfo> g_register_infos(
-      GetSharedRegisterInfoVector());
+  static std::vector<lldb_private::RegisterInfo> g_register_infos;
 
   // Allocate RegisterInfo only once
   if (g_register_infos.empty()) {
@@ -93,6 +92,9 @@ GetRegisterInfo_i386(const lldb_private::ArchSpec &arch) {
 #define UPDATE_REGISTER_INFOS_I386_STRUCT_WITH_X86_64_OFFSETS
 #include "RegisterInfos_x86_64.h"
 #undef UPDATE_REGISTER_INFOS_I386_STRUCT_WITH_X86_64_OFFSETS
+    std::vector<lldb_private::RegisterInfo> &shared_regs =
+        GetSharedRegisterInfoVector();
+    shared_regs = g_register_infos;
   }
 
   return &g_register_infos[0];
diff --git a/lldb/test/Shell/Breakpoint/debug_x86_over_amd64.test b/lldb/test/Shell/Breakpoint/debug_x86_over_amd64.test
new file mode 100644
index 0000000000000..90d4748e5fa51
--- /dev/null
+++ b/lldb/test/Shell/Breakpoint/debug_x86_over_amd64.test
@@ -0,0 +1,26 @@
+# REQUIRES: target-x86_64
+# XFAIL: system-windows
+
+# RUN: mkdir -p %t
+# RUN: cd %t
+# RUN: %clang_host -m32 %p/Inputs/dummy-target.c -o dummy.out
+# RUN: %lldb -b -s %s dummy.out | FileCheck %s
+
+breakpoint set -D -n main
+# CHECK: Breakpoint {{[0-9]}}: no locations (pending).
+# CHECK: Breakpoint set in dummy target
+
+breakpoint list
+# CHECK: No breakpoints currently set
+
+breakpoint list -D
+# CHECK: name = 'main', locations = 0 (pending)
+
+target delete
+# CHECK: 1 targets deleted
+
+target create dummy.out
+# CHECK: Current executable set to {{.*}}dummy.out
+
+breakpoint list
+# CHECK: name = 'main', locations = {{[1-9]}}