From ca2fae08a2c50c9759433b5abb1345fc78dcfc55 Mon Sep 17 00:00:00 2001
From: Zsolt Erhardt <chibidev@users.noreply.github.com>
Date: Mon, 22 Jan 2018 11:18:38 +0100
Subject: [PATCH] Bugfix/escaped character parsing (#32)

So as it turns out there's a nasty little piece of code in rapidjson's
source which breaks the preprocessor and will leave things a little bit
weird.

The test "preprocessor_parses_escaped_character" should prove
its validity.
---
 src/libclang/preprocessor.cpp | 10 +++++-----
 test/CMakeLists.txt           |  2 ++
 test/preprocessor.cpp         | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 test/preprocessor.cpp

diff --git a/src/libclang/preprocessor.cpp b/src/libclang/preprocessor.cpp
index e3036f3..d05c739 100644
--- a/src/libclang/preprocessor.cpp
+++ b/src/libclang/preprocessor.cpp
@@ -740,11 +740,7 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
         if (next && next > p.ptr())
             p.bump(std::size_t(next - p.ptr() - 1)); // subtract one to get before that character
 
-        if (starts_with(p, "\\\"")) // starts with \"
-            p.bump(2u);
-        else if (starts_with(p, "\\'")) // starts with \'
-            p.bump(2u);
-        else if (in_char == false && starts_with(p, "\"")) // starts with "
+        if (in_char == false && starts_with(p, "\"")) // starts with "
         {
             p.bump();
             in_string.toggle();
@@ -756,6 +752,10 @@ detail::preprocessor_output detail::preprocess(const libclang_compile_config& co
         }
         else if (in_string == true || in_char == true)
             p.bump();
+        else if (starts_with(p, "\\\"")) // starts with \"
+            p.bump(2u);
+        else if (starts_with(p, "\\'")) // starts with \'
+            p.bump(2u);
         else if (auto macro = parse_macro(p, result, file_depth == 0u))
         {
             if (logger.is_verbose())
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 281a4b1..9858f97 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -31,10 +31,12 @@ set(tests
         integration.cpp
         libclang_parser.cpp
         parser.cpp
+        preprocessor.cpp
         visitor.cpp)
 
 add_executable(cppast_test test.cpp test_parser.hpp ${tests})
 target_include_directories(cppast_test PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
+target_include_directories(cppast_test PRIVATE ${CMAKE_CURRENT_LIST_DIR}/../src)
 target_link_libraries(cppast_test PUBLIC cppast)
 set_target_properties(cppast_test PROPERTIES CXX_STANDARD 11)
 
diff --git a/test/preprocessor.cpp b/test/preprocessor.cpp
new file mode 100644
index 0000000..28b870f
--- /dev/null
+++ b/test/preprocessor.cpp
@@ -0,0 +1,34 @@
+#include <catch.hpp>
+#include <fstream>
+
+#include "libclang/preprocessor.hpp"
+#include "test_parser.hpp"
+
+using namespace cppast;
+
+TEST_CASE("preprocessor_parses_escaped_character", "[!hide][clang4]")
+{
+    write_file("ppec.hpp", R"(
+)");
+    // This is an actual macro from the rapidjson source (reader.h)
+    write_file("ppec.cpp", R"(
+#define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+ static const char escape[256] = {
+            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0, 0,'\"', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'/',
+            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0,
+            0, 0,'\b', 0, 0, 0,'\f', 0, 0, 0, 0, 0, 0, 0,'\n', 0,
+            0, 0,'\r', 0,'\t', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+        };
+#undef Z16
+
+#include "ppec.hpp"
+)");
+
+    libclang_compile_config config;
+    config.set_flags(cpp_standard::cpp_latest);
+
+    auto&& preprocessed = detail::preprocess(config, "ppec.cpp", default_logger().get());
+    REQUIRE(preprocessed.includes.size() == 1);
+    REQUIRE(preprocessed.includes[0].file_name == "ppec.hpp");
+}