From b28fff6c371089223598b13f1276db224f085bc2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonathan=20M=C3=BCller?= <git@foonathan.net>
Date: Tue, 10 Oct 2017 21:13:29 +0200
Subject: [PATCH] Fix preprocessor line numbers if includes aren't supported

---
 src/libclang/libclang_parser.cpp | 26 ++++++++++++++------------
 src/libclang/preprocessor.cpp    | 20 ++++++++++++++++----
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/src/libclang/libclang_parser.cpp b/src/libclang/libclang_parser.cpp
index 996b8ec..12b602a 100644
--- a/src/libclang/libclang_parser.cpp
+++ b/src/libclang/libclang_parser.cpp
@@ -403,9 +403,8 @@ namespace
         auto args = get_arguments(config);
 
         CXTranslationUnit tu;
-        auto              flags = CXTranslationUnit_Incomplete | CXTranslationUnit_KeepGoing;
-        if (detail::libclang_compile_config_access::clang_version(config) >= 40000)
-            flags |= CXTranslationUnit_DetailedPreprocessingRecord;
+        auto              flags = CXTranslationUnit_Incomplete | CXTranslationUnit_KeepGoing
+                     | CXTranslationUnit_DetailedPreprocessingRecord;
 
         auto error =
             clang_parseTranslationUnit2(idx.get(), path, // index and path
@@ -479,17 +478,20 @@ std::unique_ptr<cpp_file> libclang_parser::do_parse(const cpp_entity_index& idx,
     detail::visit_tu(tu, path.c_str(), [&](const CXCursor& cur) {
         if (clang_getCursorKind(cur) == CXCursor_InclusionDirective)
         {
-            DEBUG_ASSERT(include_iter != preprocessed.includes.end()
-                             && get_line_no(cur) >= include_iter->line,
-                         detail::assert_handler{});
+            if (!preprocessed.includes.empty())
+            {
+                DEBUG_ASSERT(include_iter != preprocessed.includes.end()
+                                 && get_line_no(cur) >= include_iter->line,
+                             detail::assert_handler{});
 
-            auto include =
-                cpp_include_directive::build(std::move(include_iter->file), include_iter->kind,
-                                             detail::get_cursor_name(cur).c_str());
-            context.comments.match(*include, include_iter->line);
-            builder.add_child(std::move(include));
+                auto include =
+                    cpp_include_directive::build(std::move(include_iter->file), include_iter->kind,
+                                                 detail::get_cursor_name(cur).c_str());
+                context.comments.match(*include, include_iter->line);
+                builder.add_child(std::move(include));
 
-            ++include_iter;
+                ++include_iter;
+            }
         }
         else if (clang_getCursorKind(cur) != CXCursor_MacroDefinition)
         {
diff --git a/src/libclang/preprocessor.cpp b/src/libclang/preprocessor.cpp
index aa75277..c6802fd 100644
--- a/src/libclang/preprocessor.cpp
+++ b/src/libclang/preprocessor.cpp
@@ -30,6 +30,11 @@ namespace
         return '"' + std::move(str) + '"';
     }
 
+    bool support_include(const libclang_compile_config& c)
+    {
+        return detail::libclang_compile_config_access::clang_version(c) >= 40000;
+    }
+
     // build the command that runs the preprocessor
     std::string get_command(const libclang_compile_config& c, const char* full_path)
     {
@@ -39,7 +44,7 @@ namespace
         // -C: keep comments
         // -dD: print macro definitions as well
         auto flags = std::string("-x c++ -I. -E -C -dD");
-        if (detail::libclang_compile_config_access::clang_version(c) >= 40000)
+        if (support_include(c))
             // -Xclang -dI: print include directives as well (clang >= 4.0.0)
             flags += " -Xclang -dI";
         // -fno-caret-diagnostics: don't show the source extract in diagnostics
@@ -784,9 +789,16 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
                 if (file_depth == 0u)
                 {
                     DEBUG_ASSERT(lm.value().file == path, detail::assert_handler{});
-                    // difference is 1 if coming from an included file (because newline of include is already written)
-                    // difference is 0 if coming from a builtin file (because no include has been written)
-                    DEBUG_ASSERT(p.cur_line() - lm.value().line <= 1u, detail::assert_handler{});
+
+                    if (lm.value().line > p.cur_line())
+                        // might happen in weird cases
+                        p.write_str(std::string(lm.value().line - p.cur_line(), '\n'));
+                    else
+                        // difference is 1 if coming from an included file (because newline of include is already written)
+                        // difference is 0 if coming from a builtin file (because no include has been written)
+                        DEBUG_ASSERT(p.cur_line() - lm.value().line <= 1u,
+                                     detail::assert_handler{});
+
                     p.enable_write();
                 }
                 break;