Implement GetIncludePaths (#311)

Fixes #69

Author: Vipul-Cariappa

include/clang/Interpreter/CppInterOp.h

@@ -507,6 +507,13 @@ namespace Cpp {
   /// GetResourceDir() function.
   CPPINTEROP_API void AddIncludePath(const char* dir);
 
+  // Gets the currently used include paths
+  ///\param[out] IncludePaths - the list of include paths
+  ///
+  CPPINTEROP_API void GetIncludePaths(std::vector<std::string>& IncludePaths,
+                                      bool withSystem = false,
+                                      bool withFlags = false);
+
   /// Only Declares a code snippet in \c code and does not execute it.
   ///\returns 0 on success
   CPPINTEROP_API int Declare(const char* code, bool silent = false);

lib/Interpreter/CppInterOp.cpp

@@ -2702,6 +2702,14 @@ namespace Cpp {
     getInterp().AddIncludePath(dir);
   }
 
+  void GetIncludePaths(std::vector<std::string>& IncludePaths, bool withSystem,
+                       bool withFlags) {
+    llvm::SmallVector<std::string> paths(1);
+    getInterp().GetIncludePaths(paths, withSystem, withFlags);
+    for (auto& i : paths)
+      IncludePaths.push_back(i);
+  }
+
   namespace {
 
   class clangSilent {

lib/Interpreter/CppInterOpInterpreter.h

@@ -381,6 +381,24 @@ class Interpreter {
     return AddIncludePaths(PathsStr, nullptr);
   }
 
+  ///\brief Get the current include paths that are used.
+  ///
+  ///\param[out] incpaths - Pass in a llvm::SmallVector<std::string, N> with
+  ///       sufficiently sized N, to hold the result of the call.
+  ///\param[in] withSystem - if true, incpaths will also contain system
+  ///       include paths (framework, STL etc).
+  ///\param[in] withFlags - if true, each element in incpaths will be prefixed
+  ///       with a "-I" or similar, and some entries of incpaths will signal
+  ///       a new include path region (e.g. "-cxx-isystem"). Also, flags
+  ///       defining header search behavior will be included in incpaths, e.g.
+  ///       "-nostdinc".
+  ///
+  void GetIncludePaths(llvm::SmallVectorImpl<std::string>& incpaths,
+                       bool withSystem, bool withFlags) const {
+    utils::CopyIncludePaths(getCI()->getHeaderSearchOpts(), incpaths,
+                            withSystem, withFlags);
+  }
+
   CompilationResult loadLibrary(const std::string& filename, bool lookup) {
     DynamicLibraryManager* DLM = getDynamicLibraryManager();
     std::string canonicalLib;

unittests/CppInterOp/InterpreterTest.cpp

@@ -113,6 +113,24 @@ TEST(InterpreterTest, DetectSystemCompilerIncludePaths) {
   EXPECT_FALSE(includes.empty());
 }
 
+TEST(InterpreterTest, GetIncludePaths) {
+  std::vector<std::string> includes;
+  Cpp::GetIncludePaths(includes);
+  EXPECT_FALSE(includes.empty());
+
+  size_t len = includes.size();
+  includes.clear();
+  Cpp::GetIncludePaths(includes, true, false);
+  EXPECT_FALSE(includes.empty());
+  EXPECT_TRUE(includes.size() >= len);
+
+  len = includes.size();
+  includes.clear();
+  Cpp::GetIncludePaths(includes, true, true);
+  EXPECT_FALSE(includes.empty());
+  EXPECT_TRUE(includes.size() >= len);
+}
+
 TEST(InterpreterTest, CodeCompletion) {
 #if CLANG_VERSION_MAJOR >= 18 || defined(USE_CLING)
   Cpp::CreateInterpreter();