1 files changed, 82 insertions, 0 deletions
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/CppModuleConfiguration.cpp b/lldb/source/Plugins/ExpressionParser/Clang/CppModuleConfiguration.cpp
new file mode 100644
index 00000000000..47c0345d6a0
--- /dev/null
+++ b/lldb/source/Plugins/ExpressionParser/Clang/CppModuleConfiguration.cpp
@@ -0,0 +1,82 @@
+//===-- CppModuleConfiguration.cpp ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CppModuleConfiguration.h"
+
+#include "ClangHost.h"
+#include "lldb/Host/FileSystem.h"
+
+using namespace lldb_private;
+
+bool CppModuleConfiguration::SetOncePath::TrySet(llvm::StringRef path) {
+  // Setting for the first time always works.
+  if (m_first) {
+    m_path = path.str();
+    m_valid = true;
+    m_first = false;
+    return true;
+  }
+  // Changing the path to the same value is fine.
+  if (m_path == path)
+    return true;
+
+  // Changing the path after it was already set is not allowed.
+  m_valid = false;
+  return false;
+}
+
+bool CppModuleConfiguration::analyzeFile(const FileSpec &f) {
+  llvm::SmallString<256> dir_buffer = f.GetDirectory().GetStringRef();
+  // Convert to posix style so that we can use '/'.
+  llvm::sys::path::native(dir_buffer, llvm::sys::path::Style::posix);
+  llvm::StringRef posix_dir(dir_buffer);
+
+  // Check for /c++/vX/ that is used by libc++.
+  static llvm::Regex libcpp_regex(R"regex(/c[+][+]/v[0-9]/)regex");
+  if (libcpp_regex.match(f.GetPath())) {
+    // Strip away libc++'s /experimental directory if there is one.
+    posix_dir.consume_back("/experimental");
+    return m_std_inc.TrySet(posix_dir);
+  }
+
+  // Check for /usr/include. On Linux this might be /usr/include/bits, so
+  // we should remove that '/bits' suffix to get the actual include directory.
+  if (posix_dir.endswith("/usr/include/bits"))
+    posix_dir.consume_back("/bits");
+  if (posix_dir.endswith("/usr/include"))
+    return m_c_inc.TrySet(posix_dir);
+
+  // File wasn't interesting, continue analyzing.
+  return true;
+}
+
+bool CppModuleConfiguration::hasValidConfig() {
+  // We all these include directories to have a valid usable configuration.
+  return m_c_inc.Valid() && m_std_inc.Valid();
+}
+
+CppModuleConfiguration::CppModuleConfiguration(
+    const FileSpecList &support_files) {
+  // Analyze all files we were given to build the configuration.
+  bool error = !std::all_of(support_files.begin(), support_files.end(),
+                            std::bind(&CppModuleConfiguration::analyzeFile,
+                                      this, std::placeholders::_1));
+  // If we have a valid configuration at this point, set the
+  // include directories and module list that should be used.
+  if (!error && hasValidConfig()) {
+    // Calculate the resource directory for LLDB.
+    llvm::SmallString<256> resource_dir;
+    llvm::sys::path::append(resource_dir, GetClangResourceDir().GetPath(),
+                            "include");
+    m_resource_inc = resource_dir.str();
+
+    // This order matches the way Clang orders these directories.
+    m_include_dirs = {m_std_inc.Get(), m_resource_inc, m_c_inc.Get()};
+    m_imported_modules = {"std"};
+  }
+}