[tarantool-patches] [PATCH] Fix Debug build on GCC 8

[Alexander Turenko <alexander.turenko@tarantool.org>]

Fixed false positive -Wimplicit-fallthrough in http_parser.c by adding a
break. The code jumps anyway, so the execution flow is not changed.

Fixed false positive -Wparenthesis in reflection.h by removing the
parentheses. The argument 'method' of the macro 'type_foreach_method' is
just name of the loop variable and is passed to the macro for
readability reasons.

Fixed false positive -Wcast-function-type triggered by reflection.h by
adding -Wno-cast-function-type for sources and unit tests. We cast a
pointer to a member function to an another pointer to member function to
store it in a structure, but we cast it back before made a call. It is
legal and does not lead to an undefined behaviour.

Fixes #3685.
---

issue: https://github.com/tarantool/tarantool/issues/3685
branch: https://github.com/tarantool/tarantool/tree/Totktonada/gh-3685-fix-debug-build-gcc-8
travis-ci: https://travis-ci.org/tarantool/tarantool/builds/428903995

Please, push it to 1.9 as Kostya O. suggests.

 src/CMakeLists.txt       | 8 ++++++++
 src/http_parser.c        | 1 +
 src/reflection.h         | 6 +++---
 test/unit/CMakeLists.txt | 8 ++++++++
 4 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index b1c4cd711..2e7e1c436 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,6 +3,14 @@
 #
 enable_tnt_compile_flags()
 
+# Suppress noise GCC 8 warnings.
+#
+# reflection.h casts a pointer to a member function to an another pointer to a
+# member function to store it in a structure, but cast it back before a call.
+# It is legal and does not lead to an undefined behaviour.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-cast-function-type")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-cast-function-type")
+
 include_directories(${LIBEV_INCLUDE_DIR})
 include_directories(${LIBEIO_INCLUDE_DIR})
 include_directories(${LIBCORO_INCLUDE_DIR})
diff --git a/src/http_parser.c b/src/http_parser.c
index 94d7bc04f..d485f5b44 100644
--- a/src/http_parser.c
+++ b/src/http_parser.c
@@ -292,6 +292,7 @@ http_parse_header_line(struct http_parser *prsr, char **bufp,
 			default:
 				return HTTP_PARSE_INVALID;
 			}
+			break;
 		/* http_header name */
 		case sw_name:
 			c = lowcase[ch];
diff --git a/src/reflection.h b/src/reflection.h
index 40818c13f..45921c4ea 100644
--- a/src/reflection.h
+++ b/src/reflection.h
@@ -106,10 +106,10 @@ struct method_info {
 	};
 };
 
-#define type_foreach_method(m, method)					\
+#define type_foreach_method(m, method)						\
 	for(const struct type_info *_m = (m); _m != NULL; _m = _m->parent)	\
-		for (const struct method_info *(method) = _m->methods;	\
-		     (method)->name != NULL; (method)++)
+		for (const struct method_info *method = _m->methods;		\
+		     method->name != NULL; method++)
 
 inline const struct method_info *
 type_method_by_name(const struct type_info *type, const char *name)
diff --git a/test/unit/CMakeLists.txt b/test/unit/CMakeLists.txt
index 943788b94..b6ffe1cfa 100644
--- a/test/unit/CMakeLists.txt
+++ b/test/unit/CMakeLists.txt
@@ -5,6 +5,14 @@ endif()
 file(GLOB all_sources *.c *.cc)
 set_source_files_compile_flags(${all_sources})
 
+# Suppress noise GCC 8 warnings.
+#
+# reflection.h casts a pointer to a member function to an another pointer to a
+# member function to store it in a structure, but cast it back before a call.
+# It is legal and does not lead to an undefined behaviour.
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-cast-function-type")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-cast-function-type")
+
 include_directories(${PROJECT_SOURCE_DIR}/src)
 include_directories(${PROJECT_BINARY_DIR}/src)
 include_directories(${PROJECT_SOURCE_DIR}/src/box)
-- 
2.19.0