Remove dependency from Host to python

Summary:
The only reason python was used in the Host module was to compute the
python path. I resolve this the same way as D47384 did for clang, by
moving the path computation into the python plugin and modifying
SBHostOS class to call into this module for ePathTypePythonDir.

Reviewers: zturner, jingham, davide

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D48215

llvm-svn: 335104

1 files changed, 66 insertions, 1 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 101e07b..9ae6317 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -347,6 +347,71 @@ const char *ScriptInterpreterPython::GetPluginDescriptionStatic() {
   return "Embedded Python interpreter";
 }
 
+void ScriptInterpreterPython::ComputePythonDirForApple(
+    llvm::SmallVectorImpl<char> &path) {
+  auto style = llvm::sys::path::Style::posix;
+
+  llvm::StringRef path_ref(path.begin(), path.size());
+  auto rbegin = llvm::sys::path::rbegin(path_ref, style);
+  auto rend = llvm::sys::path::rend(path_ref);
+  auto framework = std::find(rbegin, rend, "LLDB.framework");
+  if (framework == rend) {
+    ComputePythonDirForPosix(path);
+    return;
+  }
+  path.resize(framework - rend);
+  llvm::sys::path::append(path, style, "LLDB.framework", "Resources", "Python");
+}
+
+void ScriptInterpreterPython::ComputePythonDirForPosix(
+    llvm::SmallVectorImpl<char> &path) {
+  auto style = llvm::sys::path::Style::posix;
+#if defined(LLDB_PYTHON_RELATIVE_LIBDIR)
+  // Build the path by backing out of the lib dir, then building with whatever
+  // the real python interpreter uses.  (e.g. lib for most, lib64 on RHEL
+  // x86_64).
+  llvm::sys::path::remove_filename(path, style);
+  llvm::sys::path::append(path, style, LLDB_PYTHON_RELATIVE_LIBDIR);
+#else
+  llvm::sys::path::append(path, style,
+                          "python" + llvm::Twine(PY_MAJOR_VERSION) + "." +
+                              llvm::Twine(PY_MINOR_VERSION),
+                          "site-packages");
+#endif
+}
+
+void ScriptInterpreterPython::ComputePythonDirForWindows(
+    llvm::SmallVectorImpl<char> &path) {
+  auto style = llvm::sys::path::Style::windows;
+  llvm::sys::path::remove_filename(path, style);
+  llvm::sys::path::append(path, style, "lib", "site-packages");
+
+  // This will be injected directly through FileSpec.GetDirectory().SetString(),
+  // so we need to normalize manually.
+  std::replace(path.begin(), path.end(), '\\', '/');
+}
+
+FileSpec ScriptInterpreterPython::GetPythonDir() {
+  static FileSpec g_spec = []() {
+    FileSpec spec = HostInfo::GetShlibDir();
+    if (!spec)
+      return FileSpec();
+    llvm::SmallString<64> path;
+    spec.GetPath(path);
+
+#if defined(__APPLE__)
+    ComputePythonDirForApple(path);
+#elif defined(_WIN32)
+    ComputePythonDirForWindows(path);
+#else
+    ComputePythonDirForPosix(path);
+#endif
+    spec.GetDirectory().SetString(path);
+    return spec;
+  }();
+  return g_spec;
+}
+
 lldb_private::ConstString ScriptInterpreterPython::GetPluginName() {
   return GetPluginNameStatic();
 }
@@ -3098,7 +3163,7 @@ void ScriptInterpreterPython::InitializePrivate() {
   // that use a backslash as the path separator, this will result in executing
   // python code containing paths with unescaped backslashes.  But Python also
   // accepts forward slashes, so to make life easier we just use that.
-  if (FileSpec file_spec = HostInfo::GetPythonDir())
+  if (FileSpec file_spec = GetPythonDir())
     AddToSysPath(AddLocation::Beginning, file_spec.GetPath(false));
   if (FileSpec file_spec = HostInfo::GetShlibDir())
     AddToSysPath(AddLocation::Beginning, file_spec.GetPath(false));