# Test if compile errors are produced where necessary.
cmake_minimum_required(VERSION 3.1.0)
include(CheckCXXSourceCompiles)
include(CheckCXXCompilerFlag)
set(CMAKE_REQUIRED_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR}/../../include)
set(CMAKE_REQUIRED_FLAGS ${CXX_STANDARD_FLAG} ${PEDANTIC_COMPILE_FLAGS})
function (generate_source result fragment)
set(${result} "
#define FMT_HEADER_ONLY 1
#include \"fmt/format.h\"
int main() {
${fragment}
}
" PARENT_SCOPE)
endfunction ()
function (expect_compile code)
generate_source(source "${code}")
check_cxx_source_compiles("${source}" compiles)
if (NOT compiles)
set(error_msg "Compile error for: ${code}")
endif ()
# Unset the CMake cache variable compiles. Otherwise the compile test will
# just use cached information next time it runs.
unset(compiles CACHE)
if (error_msg)
message(FATAL_ERROR ${error_msg})
function (expect_compile_error code)
if (compiles)
set(error_msg "No compile error for: ${code}")
# check if the source file skeleton compiles
expect_compile("")
# Formatting a wide character with a narrow format string is forbidden.
expect_compile_error("fmt::format(\"{}\", L'a');")
# Formatting a wide string with a narrow format string is forbidden.
expect_compile_error("fmt::format(\"{}\", L\"foo\");")
# Formatting a narrow string with a wide format string is forbidden because
# mixing UTF-8 with UTF-16/32 can result in an invalid output.
expect_compile_error("fmt::format(L\"{}\", \"foo\");")
expect_compile_error("
struct S {
operator std::string() const { return std::string(); }
};
fmt::format(\"{}\", S());
")
# Make sure that compiler features detected in the header
# match the features detected in CMake.
if (SUPPORTS_USER_DEFINED_LITERALS)
set(supports_udl 1)
else ()
set(supports_udl 0)
expect_compile("#if FMT_USE_USER_DEFINED_LITERALS != ${supports_udl}
# error
#endif")