Host: generalise `GetXcodeSDKPath`

This generalises the GetXcodeSDKPath hook to a GetSDKRoot path which
will be re-used for the Windows support to compute a language specific
SDK path on the platform. Because there may be other options that we
wish to use to compute the SDK path, sink the XcodeSDK parameter into
a structure which can pass a disaggregated set of options. Furthermore,
optionalise the parameter as Xcode is not available for all platforms.

Differential Revision: https://reviews.llvm.org/D149397
Reviewed By: JDevlieghere

2 files changed, 26 insertions, 5 deletions

diff --git a/lldb/include/lldb/Host/HostInfoBase.h b/lldb/include/lldb/Host/HostInfoBase.h
index 42f71d91f9bf..28f809398d5b 100644
--- a/lldb/include/lldb/Host/HostInfoBase.h
+++ b/lldb/include/lldb/Host/HostInfoBase.h
@@ -31,6 +31,23 @@ struct SharedCacheImageInfo {
   lldb::DataBufferSP data_sp;
 };
 
+namespace {
+struct HostInfoError : public llvm::ErrorInfo<HostInfoError> {
+  static char ID;
+  const std::string message_;
+
+  HostInfoError(const std::string message) : message_(std::move(message)) {}
+
+  void log(llvm::raw_ostream &OS) const override { OS << "HostInfoError"; }
+
+  std::error_code convertToErrorCode() const override {
+    return llvm::inconvertibleErrorCode();
+  }
+};
+
+char HostInfoError::ID = 0;
+} // namespace
+
 class HostInfoBase {
 private:
   // Static class, unconstructable.
@@ -108,10 +125,14 @@ public:
 
   static FileSpec GetXcodeContentsDirectory() { return {}; }
   static FileSpec GetXcodeDeveloperDirectory() { return {}; }
-  
-  /// Return the directory containing a specific Xcode SDK.
-  static llvm::Expected<llvm::StringRef> GetXcodeSDKPath(XcodeSDK sdk) {
-    return "";
+
+  struct SDKOptions {
+    std::optional<XcodeSDK> XcodeSDK;
+  };
+
+  /// Return the directory containing something like a SDK (reused for Swift).
+  static llvm::Expected<llvm::StringRef> GetSDKRoot(SDKOptions options) {
+    return llvm::make_error<HostInfoError>("cannot determine SDK root");
   }
 
   /// Return information about module \p image_name if it is loaded in
diff --git a/lldb/include/lldb/Host/macosx/HostInfoMacOSX.h b/lldb/include/lldb/Host/macosx/HostInfoMacOSX.h
index 0402509cfa26..74d979d965a7 100644
--- a/lldb/include/lldb/Host/macosx/HostInfoMacOSX.h
+++ b/lldb/include/lldb/Host/macosx/HostInfoMacOSX.h
@@ -31,7 +31,7 @@ public:
   static FileSpec GetXcodeDeveloperDirectory();
 
   /// Query xcrun to find an Xcode SDK directory.
-  static llvm::Expected<llvm::StringRef> GetXcodeSDKPath(XcodeSDK sdk);
+  static llvm::Expected<llvm::StringRef> GetSDKRoot(SDKOptions options);
 
   /// Shared cache utilities
   static SharedCacheImageInfo