[lldb] fix -print-script-interpreter-info on windows

Apparently "{sys.prefix}/bin/python3" isn't where you find the
python interpreter on windows, so the test I wrote for
-print-script-interpreter-info is failing.

We can't rely on sys.executable at runtime, because that will point
to lldb.exe not python.exe.

We can't just record sys.executable from build time, because python
could have been moved to a different location.

But it should be OK to apply relative path from sys.prefix to sys.executable
from build-time to the sys.prefix at runtime.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D113650

2 files changed, 26 insertions, 19 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt b/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
index f3c20a7..1dd6282 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
@@ -3,6 +3,12 @@ if(NOT LLDB_PYTHON_RELATIVE_PATH)
 endif()
 add_definitions(-DLLDB_PYTHON_RELATIVE_LIBDIR="${LLDB_PYTHON_RELATIVE_PATH}")
 
+if(NOT LLDB_PYTHON_EXE_RELATIVE_PATH)
+  message(FATAL_ERROR "LLDB_PYTHON_EXE_RELATIVE_PATH is not set.")
+endif()
+add_definitions(-DLLDB_PYTHON_EXE_RELATIVE_PATH="${LLDB_PYTHON_EXE_RELATIVE_PATH}")
+
+
 if (LLDB_ENABLE_LIBEDIT)
   list(APPEND LLDB_LIBEDIT_LIBS ${LibEdit_LIBRARIES})
 endif()
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 418e223..c1f4c2d 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -410,30 +410,31 @@ FileSpec ScriptInterpreterPython::GetPythonDir() {
   return g_spec;
 }
 
+static const char GetInterpreterInfoScript[] = R"(
+import os
+import sys
+
+def main(lldb_python_dir, python_exe_relative_path):
+  info = {
+    "lldb-pythonpath": lldb_python_dir,
+    "language": "python",
+    "prefix": sys.prefix,
+    "executable": os.path.join(sys.prefix, python_exe_relative_path)
+  }
+  return info
+)";
+
+static const char python_exe_relative_path[] = LLDB_PYTHON_EXE_RELATIVE_PATH;
+
 StructuredData::DictionarySP ScriptInterpreterPython::GetInterpreterInfo() {
   GIL gil;
   FileSpec python_dir_spec = GetPythonDir();
   if (!python_dir_spec)
     return nullptr;
-  PythonString python_dir(python_dir_spec.GetPath());
-  PythonDictionary info(PyInitialValue::Empty);
-  llvm::Error error = info.SetItem("lldb-pythonpath", python_dir);
-  if (error)
-    return nullptr;
-  static const char script[] = R"(
-def main(info):
-  import sys
-  import os
-  name = 'python' + str(sys.version_info.major)
-  info.update({
-    "language": "python",
-    "prefix": sys.prefix,
-    "executable": os.path.join(sys.prefix, "bin", name),
-  })
-  return info
-)";
-  PythonScript get_info(script);
-  auto info_json = unwrapIgnoringErrors(As<PythonDictionary>(get_info(info)));
+  PythonScript get_info(GetInterpreterInfoScript);
+  auto info_json = unwrapIgnoringErrors(
+      As<PythonDictionary>(get_info(PythonString(python_dir_spec.GetPath()),
+                                    PythonString(python_exe_relative_path))));
   if (!info_json)
     return nullptr;
   return info_json.CreateStructuredDictionary();