diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0a24e8..8d574ce 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,15 +7,16 @@ cmake_minimum_required(VERSION 2.8)
 
 option(USE_LZMA "Build lzma decompression support." ON)
 option(DEBUG_EXTRA "Expensive debug options" OFF)
+option(SET_WARNING_FLAGS "Adjust compiler warning flags" ON)
+option(SET_OPTIMIZATION_FLAGS "Adjust compiler optimization flags" ON)
 
-set(MAN_DIR "share/man" CACHE STRING "Install location for man pages (relative to prefix).")
+set(MAN_DIR "share/man" CACHE STRING "Install path for man pages (relative to prefix).")
 mark_as_advanced(MAN_DIR)
 
 
 # Helper scrips
 
-# For custom cmake modules.
-set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
+set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake") # For custom cmake modules
 include(CompileCheck)
 include(VersionString)
 include(CheckSymbolExists)
@@ -27,14 +28,16 @@ include(TestBigEndian)
 
 # Find required libraries
 
-# Force re-checking libraries if the compiler or compiler flags change.
+# Force re-checking libraries if the compiler or compiler flags change
 if((NOT LAST_CMAKE_CXX_FLAGS STREQUAL CMAKE_CXX_FLAGS)
    OR (NOT LAST_CMAKE_CXX_COMPILER STREQUAL CMAKE_CXX_COMPILER))
 	force_recheck_library(LZMA)
 	force_recheck_library(Boost)
 	unset(Boost_INCLUDE_DIR CACHE)
-	set(LAST_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" CACHE INTERNAL "The last C++ compiler flags.")
-	set(LAST_CMAKE_CXX_COMPILER "${CMAKE_CXX_COMPILER}" CACHE INTERNAL "The last C++ compiler.")
+	set(LAST_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" CACHE INTERNAL
+	    "The last C++ compiler flags")
+	set(LAST_CMAKE_CXX_COMPILER "${CMAKE_CXX_COMPILER}" CACHE INTERNAL
+	    "The last C++ compiler")
 endif()
 
 unset(LIBRARIES)
@@ -73,44 +76,53 @@ check_link_library(iconv iconv_LIBRARIES)
 
 if(${Boost_VERSION} LESS 104800)
 	# Older Boost versions don't work with C++11
+	add_cxxflag("-std=c++03")
 else()
 	add_cxxflag("-std=c++11")
 endif()
 
-add_cxxflag("-Wall")
-add_cxxflag("-Wextra")
-add_cxxflag("-Wformat=2")
-add_cxxflag("-Wundef")
-add_cxxflag("-Wpointer-arith")
-add_cxxflag("-Wcast-qual")
-add_cxxflag("-Woverloaded-virtual")
-add_cxxflag("-Wlogical-op")
-add_cxxflag("-Wliteral-conversion")
-add_cxxflag("-Wshift-overflow")
-add_cxxflag("-Woverflow")
-add_cxxflag("-Wbool-conversions")
-add_cxxflag("-Wconversion")
-add_cxxflag("-Wsign-conversion")
-add_cxxflag("-Wmissing-declarations")
-add_cxxflag("-Wredundant-decls")
+if(SET_WARNING_FLAGS)
+	
+	# GCC (and compatible)
+	add_cxxflag("-Wall")
+	add_cxxflag("-Wextra")
+	add_cxxflag("-Wformat=2")
+	add_cxxflag("-Wundef")
+	add_cxxflag("-Wpointer-arith")
+	add_cxxflag("-Wcast-qual")
+	add_cxxflag("-Woverloaded-virtual")
+	add_cxxflag("-Wlogical-op")
+	add_cxxflag("-Woverflow")
+	add_cxxflag("-Wconversion")
+	add_cxxflag("-Wsign-conversion")
+	add_cxxflag("-Wmissing-declarations")
+	add_cxxflag("-Wredundant-decls")
+	
+	# clang
+	add_cxxflag("-Wliteral-conversion")
+	add_cxxflag("-Wshift-overflow")
+	add_cxxflag("-Wbool-conversions")
+	
+	# icc
+	if(NOT DEBUG_EXTRA)
+		add_cxxflag("-wd1418") # 'external function definition with no prior declaration'
+	endif()
+	
+endif()
 
 if(DEBUG_EXTRA)
 	add_cxxflag("-ftrapv") # to add checks for (undefined) signed integer overflow
 	add_cxxflag("-fbounds-checking")
 	add_cxxflag("-fcatch-undefined-behavior")
 	add_cxxflag("-Wstrict-aliasing=1")
-else()
-	# -Wuninitialized causes too many false positives - thanks very much, gcc
-	add_cxxflag("-Wno-uninitialized")
-	# (clang only) Conflicts with using const variables for configuration.
-	add_cxxflag("-Wno-constant-logical-operand")
-	add_cxxflag("-Wno-unneeded-internal-declaration")
-	add_cxxflag("-Wno-unused-function")
 endif()
 
-# Link as few libraries as possible
-# This is much easier than trying to decide which libraries are needed for each system
-add_ldflag("-Wl,--as-needed")
+if(SET_OPTIMIZATION_FLAGS)
+	# Link as few libraries as possible
+	# This is much easier than trying to decide which libraries are needed for each system
+	# Specifically, then need for libboost_system depends on the Boost version
+	add_ldflag("-Wl,--as-needed")
+endif()
 
 
 # Check for optional functionality and system configuration
diff --git a/README.md b/README.md
index b2aa314..035093a 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,9 @@ Build options:
 * `USE_LZMA` (default: `ON`): Use *liblzma* if available.
 * `CMAKE_BUILD_TYPE` (default: `Release`): Set to `Debug` to enable debug output.
 * `CMAKE_INSTALL_PREFIX` (default: `/usr/local` on UNIX): Where to install innoextract.
-* `DEBUG_EXTRA` (default: `OFF`): Expensive debug options
+* `SET_WARNING_FLAGS` (default: `ON`): Adjust compiler warning flags. This should not affect the produced binaries but is useful to catch potential problems.
+* `SET_OPTIMIZATION_FLAGS` (default: `ON`): Adjust compiler optimization flags. For non-debug builds the only thing this does is instruct the linker to only link against libraries that are actually needed.
+* `DEBUG_EXTRA` (default: `OFF`): Expensive debug options.
 * `MAN_DIR` (default: `share/man`): Install location for man pages (relative to prefix).
 
 Set options by passing `-D<option>=<value>` to cmake.
diff --git a/cmake/BuildType.cmake b/cmake/BuildType.cmake
index 871a249..dd04beb 100644
--- a/cmake/BuildType.cmake
+++ b/cmake/BuildType.cmake
@@ -10,14 +10,21 @@ if(CMAKE_BUILD_TYPE STREQUAL "Debug")
 	add_definitions(-DDEBUG)
 	set(DEBUG 1)
 	
-	check_compiler_flag(RESULT "-g3")
-	if(NOT RESULT STREQUAL "")
-		string(REGEX REPLACE "-g(|[0-9]|gdb)" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
+	if(SET_OPTIMIZATION_FLAGS)
+		
+		# set debug symbol level to -g3
+		check_compiler_flag(RESULT "-g3")
+		if(NOT RESULT STREQUAL "")
+			string(REGEX REPLACE "-g(|[0-9]|gdb)" "" CMAKE_CXX_FLAGS_DEBUG
+			       "${CMAKE_CXX_FLAGS_DEBUG}")
+			set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${RESULT}")
+		endif()
+		
+		# disable optimizations
+		check_compiler_flag(RESULT "-O0")
+		string(REGEX REPLACE "-O[0-9]" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
 		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${RESULT}")
+		
 	endif()
 	
-	check_compiler_flag(RESULT "-O0")
-	string(REGEX REPLACE "-O[0-9]" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
-	set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${RESULT}")
-	
 endif()
diff --git a/cmake/CompileCheck.cmake b/cmake/CompileCheck.cmake
index d4cd192..776f1f2 100644
--- a/cmake/CompileCheck.cmake
+++ b/cmake/CompileCheck.cmake
@@ -30,9 +30,11 @@ function(check_compiler_flag RESULT FLAG)
 	
 	set(compile_test_file "${CMAKE_CURRENT_BINARY_DIR}/compile_flag_test.cpp")
 	file(WRITE ${compile_test_file} "__attribute__((const)) int main(){ return 0; }\n")
-	try_compile(CHECK_COMPILER_FLAG ${CMAKE_BINARY_DIR} ${compile_test_file} COMPILE_DEFINITIONS "${FLAG}" OUTPUT_VARIABLE ERRORLOG)
+	try_compile(CHECK_COMPILER_FLAG ${CMAKE_BINARY_DIR} ${compile_test_file}
+	            COMPILE_DEFINITIONS "${FLAG}" OUTPUT_VARIABLE ERRORLOG)
 	
-	string(REGEX MATCH "warning:" HAS_WARNING "${ERRORLOG}")
+	string(REGEX MATCH "warning:|command line warning|unrecognized option"
+	       HAS_WARNING "${ERRORLOG}")
 	
 	if(NOT CHECK_COMPILER_FLAG)
 		message(STATUS "Checking compiler flag: ${FLAG} - unsupported")
@@ -69,18 +71,19 @@ function(add_ldflag FLAG)
 endfunction(add_ldflag)
 
 function(try_link_library LIBRARY_NAME LIBRARY_FILE ERROR_VAR)
-	# See if we can link a simple program with the library using the configured c++ compiler.
+	# See if we can link a simple program with the library using the configured c++ compiler
 	set(link_test_file "${CMAKE_CURRENT_BINARY_DIR}/link_test.cpp")
 	file(WRITE ${link_test_file} "int main(){}\n")
 	if(CMAKE_THREAD_LIBS_INIT)
 		list(APPEND LIBRARY_FILE "${CMAKE_THREAD_LIBS_INIT}")
 	endif()
-	try_compile(CHECK_${LIBRARY_NAME}_LINK "${CMAKE_BINARY_DIR}" "${link_test_file}" CMAKE_FLAGS "-DLINK_LIBRARIES=${LIBRARY_FILE}" OUTPUT_VARIABLE ERRORLOG)
+	try_compile(CHECK_${LIBRARY_NAME}_LINK "${CMAKE_BINARY_DIR}" "${link_test_file}"
+	            CMAKE_FLAGS "-DLINK_LIBRARIES=${LIBRARY_FILE}" OUTPUT_VARIABLE ERRORLOG)
 	set(${ERROR_VAR} "${ERRORLOG}" PARENT_SCOPE)
 endfunction(try_link_library)
 
 ##############################################################################
-# Check that a a library actually works for the current configuration.
+# Check that a a library actually works for the current configuration
 function(check_link_library LIBRARY_NAME LIBRARY_VARIABLE)
 	
 	set(lib_current "${${LIBRARY_VARIABLE}}")
@@ -102,7 +105,7 @@ function(check_link_library LIBRARY_NAME LIBRARY_VARIABLE)
 		message(STATUS "Checking ${LIBRARY_NAME}: ${lib_current}")
 	endif()
 	
-	# Check if we can link to the full path found by find_package.
+	# Check if we can link to the full path found by find_package
 	try_link_library(${LIBRARY_NAME} "${lib_current}" ERRORLOG1)
 	
 	if(CHECK_${LIBRARY_NAME}_LINK)
@@ -110,8 +113,9 @@ function(check_link_library LIBRARY_NAME LIBRARY_VARIABLE)
 		return()
 	endif()
 	
-	# Check if the linker is smarter than cmake and try to link with only the library name.
-	string(REGEX REPLACE "(^|;)[^;]*/lib([^;/]*)\\.so" "\\1-l\\2" LIBRARY_FILE "${lib_current}")
+	# Check if the linker is smarter than cmake and try to link with only the library name
+	string(REGEX REPLACE "(^|;)[^;]*/lib([^;/]*)\\.so" "\\1-l\\2"
+	       LIBRARY_FILE "${lib_current}")
 	
 	if(NOT LIBRARY_FILE STREQUAL lib_current)
 		
@@ -126,11 +130,15 @@ function(check_link_library LIBRARY_NAME LIBRARY_VARIABLE)
 		
 	endif()
 	
-	# Force cmake to search again, as the cached library doesn't work.
+	# Force cmake to search again, as the cached library doesn't work
 	unset(FIND_PACKAGE_MESSAGE_DETAILS_${ARGV2} CACHE)
 	unset(FIND_PACKAGE_MESSAGE_DETAILS_${LIBRARY_NAME} CACHE)
 	
-	message(FATAL_ERROR "\n${ERRORLOG1}\n\n${ERRORLOG2}\n\n!! No suitable version of ${LIBRARY_NAME} found.\n   Maybe you don't have the right (32 vs.64 bit) architecture installed?\n\n   Tried ${lib_current} and ${LIBRARY_FILE}\n   Using compiler ${CMAKE_CXX_COMPILER} ${CMAKE_CXX_FLAGS}\n\n\n")
+	message(FATAL_ERROR "\n${ERRORLOG1}\n\n${ERRORLOG2}\n\n"
+	        "!! No suitable version of ${LIBRARY_NAME} found.\n"
+	        "   Maybe you don't have the right (32 vs.64 bit) architecture installed?\n\n"
+	        "   Tried ${lib_current} and ${LIBRARY_FILE}\n"
+	        "   Using compiler ${CMAKE_CXX_COMPILER} ${CMAKE_CXX_FLAGS}\n\n\n")
 	
 endfunction(check_link_library)
 
diff --git a/src/cli/main.cpp b/src/cli/main.cpp
index 69768f0..7d0c19c 100644
--- a/src/cli/main.cpp
+++ b/src/cli/main.cpp
@@ -207,7 +207,7 @@ static void process_file(const fs::path & file, const options & o) {
 	
 	BOOST_FOREACH(const Chunks::value_type & chunk, chunks) {
 		
-		debug("[starting " << chunk.first.compression << " chunk @ " << chunk.first.first_slice
+		debug("[starting " << chunk.first.compression << " chunk @ slice " << chunk.first.first_slice
 		      << " + " << print_hex(offsets.data_offset) << " + " << print_hex(chunk.first.offset)
 		      << ']');
 		
diff --git a/src/setup/file.cpp b/src/setup/file.cpp
index 687299f..935c355 100644
--- a/src/setup/file.cpp
+++ b/src/setup/file.cpp
@@ -72,7 +72,7 @@ namespace setup {
 
 void file_entry::load(std::istream & is, const version & version) {
 	
-	(void)enum_names<file_copy_mode>::names;
+	USE_ENUM_NAMES(file_copy_mode)
 	
 	options = 0;
 	
diff --git a/src/setup/type.cpp b/src/setup/type.cpp
index 1b6eef4..30375d3 100644
--- a/src/setup/type.cpp
+++ b/src/setup/type.cpp
@@ -53,6 +53,8 @@ namespace setup {
 
 void type_entry::load(std::istream & is, const version & version) {
 	
+	USE_FLAG_NAMES(setup::type_flags)
+	
 	is >> encoded_string(name, version.codepage());
 	is >> encoded_string(description, version.codepage());
 	if(version >= INNO_VERSION(4, 0, 1)) {
diff --git a/src/stream/block.cpp b/src/stream/block.cpp
index 0f7b486..902d9aa 100644
--- a/src/stream/block.cpp
+++ b/src/stream/block.cpp
@@ -154,7 +154,7 @@ namespace stream {
 
 block_reader::pointer block_reader::get(std::istream & base, const setup::version & version) {
 	
-	(void)enum_names<block_compression>::name;
+	USE_ENUM_NAMES(block_compression)
 	
 	uint32_t expected_checksum = load_number<uint32_t>(base);
 	crypto::crc32 actual_checksum;
diff --git a/src/util/enum.hpp b/src/util/enum.hpp
index 14bd245..d7848e9 100644
--- a/src/util/enum.hpp
+++ b/src/util/enum.hpp
@@ -68,6 +68,15 @@ struct enum_names {
 	const size_t enum_names<get_enum<Enum>::type>::count \
 	 = ARRAY_SIZE(enum_names<get_enum<Enum>::type>::names);
 
+#define USE_ENUM_NAMES(Enum) \
+	(void)enum_names<get_enum<Enum>::type>::count; \
+	(void)enum_names<get_enum<Enum>::type>::name; \
+	(void)enum_names<get_enum<Enum>::type>::names;
+
+#define USE_FLAG_NAMES(Flags) \
+	USE_FLAGS_OVERLOADS(Flags) \
+	USE_ENUM_NAMES(Flags)
+
 template <class Enum>
 typename boost::enable_if_c<enum_names<Enum>::named, std::ostream &>::type
 operator<<(std::ostream & os, Enum value) {
diff --git a/src/util/flags.hpp b/src/util/flags.hpp
index b41ebea..fe0b266 100644
--- a/src/util/flags.hpp
+++ b/src/util/flags.hpp
@@ -148,6 +148,11 @@ public:
 	
 };
 
+template <typename Enum, size_t Bits>
+inline flags<Enum, Bits> operator|(Enum a, flags<Enum, Bits> b) {
+	return b | a;
+}
+
 #define DECLARE_ENUM_SIZE(Enum, Size) \
 	template <> \
 	struct enum_size<Enum> { \
@@ -165,9 +170,6 @@ public:
 	inline Flagname operator|(Flagname::enum_type a, Flagname::enum_type b) { \
 		return Flagname(a) | b; \
 	} \
-	inline Flagname operator|(Flagname::enum_type a, Flagname b) { \
-		return b | a; \
-	} \
 	inline Flagname operator~(Flagname::enum_type a) { \
 		return ~Flagname(a); \
 	}
@@ -197,4 +199,8 @@ public:
 	DECLARE_ENUM_SIZE(FLAGS_ENUM(Flagname), FLAGS_ENUM_END(Flagname)) \
 	DECLARE_FLAGS_OPERATORS(Flagname)
 
+#define USE_FLAGS_OVERLOADS(Flagname) \
+	(void)(~Flagname::enum_type(0)); \
+	(void)(Flagname::enum_type(0) | Flagname::enum_type(0));
+
 #endif // INNOEXTRACT_UTIL_FLAGS_HPP