Merge pull request #11897 from charles-zablit/charles-zablit/lldb/windows/test-if-python.dll-is-in-path-to-swift-release-6.2.2

🍒 [lldb][windows] print an error if python.dll is not in the DLL search path

Author: adrian-prantl

lldb/CMakeLists.txt

@@ -110,6 +110,12 @@ if (LLDB_ENABLE_PYTHON)
       set(LLDB_PYTHON_EXT_SUFFIX "_d${LLDB_PYTHON_EXT_SUFFIX}")
     endif()
   endif()
+  if(TARGET Python3::Python)
+    get_target_property(_Python3_LIB_PATH Python3::Python IMPORTED_LIBRARY_LOCATION)
+    if(_Python3_LIB_PATH)
+      get_filename_component(LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME "${_Python3_LIB_PATH}" NAME)
+    endif()
+  endif()
 endif ()
 
 if (LLDB_ENABLE_LUA)

lldb/tools/driver/CMakeLists.txt

@@ -31,6 +31,9 @@ add_dependencies(lldb
 if(DEFINED LLDB_PYTHON_DLL_RELATIVE_PATH)
   target_compile_definitions(lldb PRIVATE LLDB_PYTHON_DLL_RELATIVE_PATH="${LLDB_PYTHON_DLL_RELATIVE_PATH}")
 endif()
+if(DEFINED LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME)
+  target_compile_definitions(lldb PRIVATE LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME="${LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME}")
+endif()
 
 if(LLDB_BUILD_FRAMEWORK)
   # In the build-tree, we know the exact path to the framework directory.

lldb/tools/driver/Driver.cpp

@@ -430,7 +430,8 @@ SBError Driver::ProcessArgs(const opt::InputArgList &args, bool &exiting) {
   return error;
 }
 
-#if defined(_WIN32) && defined(LLDB_PYTHON_DLL_RELATIVE_PATH)
+#ifdef _WIN32
+#ifdef LLDB_PYTHON_DLL_RELATIVE_PATH
 /// Returns the full path to the lldb.exe executable.
 inline std::wstring GetPathToExecutableW() {
   // Iterate until we reach the Windows API maximum path length (32,767).
@@ -444,30 +445,72 @@ inline std::wstring GetPathToExecutableW() {
   return L"";
 }
 
-/// Resolve the full path of the directory defined by
+/// \brief Resolve the full path of the directory defined by
 /// LLDB_PYTHON_DLL_RELATIVE_PATH. If it exists, add it to the list of DLL
 /// search directories.
-void AddPythonDLLToSearchPath() {
+/// \return `true` if the library was added to the search path.
+/// `false` otherwise.
+bool AddPythonDLLToSearchPath() {
   std::wstring modulePath = GetPathToExecutableW();
-  if (modulePath.empty()) {
-    llvm::errs() << "error: unable to find python.dll." << '\n';
-    return;
-  }
+  if (modulePath.empty())
+    return false;
 
   SmallVector<char, MAX_PATH> utf8Path;
   if (sys::windows::UTF16ToUTF8(modulePath.c_str(), modulePath.length(),
                                 utf8Path))
-    return;
+    return false;
   sys::path::remove_filename(utf8Path);
   sys::path::append(utf8Path, LLDB_PYTHON_DLL_RELATIVE_PATH);
   sys::fs::make_absolute(utf8Path);
 
   SmallVector<wchar_t, 1> widePath;
   if (sys::windows::widenPath(utf8Path.data(), widePath))
-    return;
+    return false;
 
   if (sys::fs::exists(utf8Path))
-    SetDllDirectoryW(widePath.data());
+    return SetDllDirectoryW(widePath.data());
+  return false;
+}
+#endif
+
+#ifdef LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME
+/// Returns true if `python3x.dll` can be loaded.
+bool IsPythonDLLInPath() {
+#define WIDEN2(x) L##x
+#define WIDEN(x) WIDEN2(x)
+  HMODULE h = LoadLibraryW(WIDEN(LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME));
+  if (!h)
+    return false;
+  FreeLibrary(h);
+  return true;
+#undef WIDEN2
+#undef WIDEN
+}
+#endif
+
+/// Try to setup the DLL search path for the Python Runtime Library
+/// (python3xx.dll).
+///
+/// If `LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME` is set, we first check if
+/// python3xx.dll is in the search path. If it's not, we try to add it and
+/// check for it a second time.
+/// If only `LLDB_PYTHON_DLL_RELATIVE_PATH` is set, we try to add python3xx.dll
+/// to the search path python.dll is already in the search path or not.
+void SetupPythonRuntimeLibrary() {
+#ifdef LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME
+  if (IsPythonDLLInPath())
+    return;
+#ifdef LLDB_PYTHON_DLL_RELATIVE_PATH
+  if (AddPythonDLLToSearchPath() && IsPythonDLLInPath())
+    return;
+#endif
+  WithColor::error() << "unable to find '"
+                     << LLDB_PYTHON_RUNTIME_LIBRARY_FILENAME << "'.\n";
+  return;
+#elif defined(LLDB_PYTHON_DLL_RELATIVE_PATH)
+  if (!AddPythonDLLToSearchPath())
+    WithColor::error() << "unable to find the Python runtime library.\n";
+#endif
 }
 #endif
 
@@ -801,8 +844,8 @@ int main(int argc, char const *argv[]) {
                         "~/Library/Logs/DiagnosticReports/.\n");
 #endif
 
-#if defined(_WIN32) && defined(LLDB_PYTHON_DLL_RELATIVE_PATH)
-  AddPythonDLLToSearchPath();
+#ifdef _WIN32
+  SetupPythonRuntimeLibrary();
 #endif
 
   // Parse arguments.