Properly detect iconv features to compile

CMakeLists.txt

@@ -13,14 +13,16 @@ set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Og -fsanitize=address")
 #
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 find_package(Cryptopp REQUIRED)
+find_package(Iconv REQUIRED)
 include(FindEXPAT)
 find_package(EXPAT REQUIRED)
 
 include_directories("src/")
+include_directories(${EXPAT_INCLUDE_DIRS})
+include_directories(${ICONV_INCLUDE_DIR})
 # the SYSTEM flag tells the compiler that we don't care about warnings
 # coming from these headers.
 include_directories(SYSTEM ${CRYPTO++_INCLUDE_DIR})
-include_directories(SYSTEM ${EXPAT_INCLUDE_DIRS})
 
 #
 ## utils
@@ -28,6 +30,7 @@ include_directories(SYSTEM ${EXPAT_INCLUDE_DIRS})
 file(GLOB source_utils
   src/utils/*.[hc]pp)
 add_library(utils STATIC ${source_utils})
+target_link_libraries(utils ${ICONV_LIBRARIES})
 
 #
 ## network

cmake/Modules/FindIconv.cmake

+# - Try to find Iconv
+# Once done this will define
+#
+# ICONV_FOUND - system has Iconv
+# ICONV_INCLUDE_DIR - the Iconv include directory
+# ICONV_LIBRARIES - Link these to use Iconv
+# ICONV_SECOND_ARGUMENT_IS_CONST - the second argument for iconv() is const
+#
+include(CheckCXXSourceCompiles)
+
+IF (ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
+  # Already in cache, be silent
+  SET(ICONV_FIND_QUIETLY TRUE)
+ENDIF (ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
+
+FIND_PATH(ICONV_INCLUDE_DIR iconv.h)
+
+FIND_LIBRARY(ICONV_LIBRARIES NAMES iconv libiconv libiconv-2 c)
+
+IF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
+   SET(ICONV_FOUND TRUE)
+ENDIF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
+
+set(CMAKE_REQUIRED_INCLUDES ${ICONV_INCLUDE_DIR})
+set(CMAKE_REQUIRED_LIBRARIES ${ICONV_LIBRARIES})
+IF(ICONV_FOUND)
+  check_cxx_source_compiles("
+ #include <iconv.h>
+ int main(){
+ iconv_t conv = 0;
+ const char* in = 0;
+ size_t ilen = 0;
+ char* out = 0;
+ size_t olen = 0;
+ iconv(conv, &in, &ilen, &out, &olen);
+ return 0;
+ }
+" ICONV_SECOND_ARGUMENT_IS_CONST )
+ENDIF(ICONV_FOUND)
+set(CMAKE_REQUIRED_INCLUDES)
+set(CMAKE_REQUIRED_LIBRARIES)
+
+IF(ICONV_FOUND)
+  IF(NOT ICONV_FIND_QUIETLY)
+    MESSAGE(STATUS "Found Iconv: ${ICONV_LIBRARIES}")
+  ENDIF(NOT ICONV_FIND_QUIETLY)
+ELSE(ICONV_FOUND)
+  IF(Iconv_FIND_REQUIRED)
+    MESSAGE(FATAL_ERROR "Could not find Iconv")
+  ENDIF(Iconv_FIND_REQUIRED)
+ENDIF(ICONV_FOUND)
+
+MARK_AS_ADVANCED(
+  ICONV_INCLUDE_DIR
+  ICONV_LIBRARIES
+  ICONV_SECOND_ARGUMENT_IS_CONST
+)
\ No newline at end of file

src/utils/encoding.cpp

@@ -75,10 +75,15 @@ namespace utils
     // Make sure cd is always closed when we leave this function
     ScopeGuard sg([&]{ iconv_close(cd); });
 
-    // iconv will not attempt to modify this buffer, but it still requires
-    // a char**.
     size_t inbytesleft = str.size();
+
+    // iconv will not attempt to modify this buffer, but some plateform
+    // require a char** anyway
+#ifdef ICONV_SECOND_ARGUMENT_IS_CONST
+    const char* inbuf_ptr = str.c_str();
+#else
     char* inbuf_ptr = const_cast<char*>(str.c_str());
+#endif
 
     size_t outbytesleft = str.size() * 4;
     char* outbuf = new char[outbytesleft];