[Lldb-commits] [lldb] [lldb][NativePDB] Handle UEFI binaries without predetermined load addresses (PR #173499)

[Gary Beihl via lldb-commits]

https://github.com/garybeihl updated https://github.com/llvm/llvm-project/pull/173499

>From 5993787f8b3b17ea7de204bdb7df981dad00fece Mon Sep 17 00:00:00 2001
From: Gary Beihl <garybeihl at microsoft.com>
Date: Sun, 28 Dec 2025 18:03:36 -0500
Subject: [PATCH 1/3] [lldb][NativePDB] Handle UEFI binaries without
 predetermined load addresses

UEFI executables are relocatable PE/COFF images where GetFileAddress()
returns LLDB_INVALID_ADDRESS, causing symbol load failure from PDB files.

Use base address 0 when load address is invalid, allowing symbols to be
loaded with their RVAs. The module's actual runtime load address must be
provided using `target modules load --file <module> --slide <load_address>`.

Tested with Rust UEFI binaries, successfully loading 5,405 symbols with
full source and line information.

Fixes: #91060
---
 .../SymbolFile/NativePDB/SymbolFileNativePDB.cpp       | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index 3bf113a07d28c..40d45153b730f 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -422,6 +422,16 @@ void SymbolFileNativePDB::InitializeObject() {
                            ->GetObjectFile()
                            ->GetBaseAddress()
                            .GetFileAddress();
+
+  // For UEFI/PE binaries and other relocatable images lacking a predetermined
+  // load address, GetFileAddress() returns LLDB_INVALID_ADDRESS. Use base
+  // address 0 in this case to allow symbols to be loaded with RVA
+  // (Relative Virtual Address). To debug at runtime, the module's actual load
+  // address must be provided using 'target modules load --file <module> --slide <load_address>'.
+  if (m_obj_load_address == LLDB_INVALID_ADDRESS) {
+    m_obj_load_address = 0x0;
+  }
+
   m_index->SetLoadAddress(m_obj_load_address);
   m_index->ParseSectionContribs();
 

>From 863610ea4abb9fa6af31c3ee38735c3b0fed2faf Mon Sep 17 00:00:00 2001
From: Gary Beihl <garybeihl at microsoft.com>
Date: Fri, 30 Jan 2026 11:14:13 -0500
Subject: [PATCH 2/3] Fix coding style: remove braces for single-statement if
 body

---
 .../Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp       | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index 6d5645d589d0c..9f9ddff600876 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -428,9 +428,8 @@ void SymbolFileNativePDB::InitializeObject() {
   // address 0 in this case to allow symbols to be loaded with RVA
   // (Relative Virtual Address). To debug at runtime, the module's actual load
   // address must be provided using 'target modules load --file <module> --slide <load_address>'.
-  if (m_obj_load_address == LLDB_INVALID_ADDRESS) {
+  if (m_obj_load_address == LLDB_INVALID_ADDRESS)
     m_obj_load_address = 0x0;
-  }
 
   m_index->SetLoadAddress(m_obj_load_address);
   m_index->ParseSectionContribs();

>From 7411916e90526b080785692e0d103bf5f09e53b4 Mon Sep 17 00:00:00 2001
From: Gary Beihl <garybeihl at microsoft.com>
Date: Fri, 30 Jan 2026 13:26:32 -0500
Subject: [PATCH 3/3] Add test case for relocatable PE/COFF binaries with PDB
 symbols

Test that DLLs and other relocatable binaries can load PDB symbols correctly
when GetFileAddress() returns LLDB_INVALID_ADDRESS.
---
 .../Shell/SymbolFile/NativePDB/Inputs/relocatable.cpp |  6 ++++++
 .../SymbolFile/NativePDB/relocatable-binary.test      | 11 +++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 lldb/test/Shell/SymbolFile/NativePDB/Inputs/relocatable.cpp
 create mode 100644 lldb/test/Shell/SymbolFile/NativePDB/relocatable-binary.test

diff --git a/lldb/test/Shell/SymbolFile/NativePDB/Inputs/relocatable.cpp b/lldb/test/Shell/SymbolFile/NativePDB/Inputs/relocatable.cpp
new file mode 100644
index 0000000000000..98790dd7ece59
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/NativePDB/Inputs/relocatable.cpp
@@ -0,0 +1,6 @@
+// Test input for relocatable PE/COFF binary with PDB symbols.
+// This simulates a DLL or other position-independent code.
+
+extern "C" __declspec(dllexport) int relocatable_function(int x) {
+    return x * 2;
+}
\ No newline at end of file
diff --git a/lldb/test/Shell/SymbolFile/NativePDB/relocatable-binary.test b/lldb/test/Shell/SymbolFile/NativePDB/relocatable-binary.test
new file mode 100644
index 0000000000000..5c74c247f9e73
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/NativePDB/relocatable-binary.test
@@ -0,0 +1,11 @@
+# REQUIRES: lld, target-windows
+# RUN: %build --compiler=clang-cl --nodefaultlib -fuse-ld=lld -Wl,/dll -Wl,/noentry -o %t.dll %S/Inputs/relocatable.cpp
+# RUN: lldb-test symbols %t.dll | FileCheck %s
+
+# Test that relocatable PE/COFF binaries (like DLLs and UEFI drivers) with PDB
+# symbols can be loaded. These binaries return LLDB_INVALID_ADDRESS for
+# GetFileAddress() and should use 0x0 as the base to allow RVA-based symbol
+# loading.
+
+# CHECK: Module: {{.*}}.dll
+# CHECK: Function{{{.*}}}, extern "C" name = "relocatable_function"
\ No newline at end of file