1 files changed, 79 insertions, 0 deletions
diff --git a/src/fmt/test/compile-error-test/CMakeLists.txt b/src/fmt/test/compile-error-test/CMakeLists.txt
new file mode 100644
index 000000000..75a0c5a5e
--- /dev/null
+++ b/src/fmt/test/compile-error-test/CMakeLists.txt
@@ -0,0 +1,79 @@
+# 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 ${error_msg})
+  endif ()
+endfunction ()
+
+function (expect_compile_error code)
+  generate_source(source "${code}")
+  check_cxx_source_compiles("${source}" compiles)
+  if (compiles)
+    set(error_msg "No 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})
+  endif ()
+endfunction ()
+
+# 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\");")
+
+# Formatting a wide string with a narrow format string is forbidden.
+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)
+endif ()
+expect_compile("#if FMT_USE_USER_DEFINED_LITERALS != ${supports_udl}
+                # error
+                #endif")