Enable [[noreturn]] some.

include/fmt/chrono.h

@@ -348,32 +348,32 @@ FMT_CONSTEXPR const Char* parse_chrono_format(const Char* begin,
 }
 
 struct chrono_format_checker {
-  void report_no_date() { FMT_THROW(format_error("no date")); }
+  FMT_NORETURN void report_no_date() { FMT_THROW(format_error("no date")); }
 
   template <typename Char> void on_text(const Char*, const Char*) {}
-  void on_abbr_weekday() { report_no_date(); }
-  void on_full_weekday() { report_no_date(); }
-  void on_dec0_weekday(numeric_system) { report_no_date(); }
-  void on_dec1_weekday(numeric_system) { report_no_date(); }
-  void on_abbr_month() { report_no_date(); }
-  void on_full_month() { report_no_date(); }
+  FMT_NORETURN void on_abbr_weekday() { report_no_date(); }
+  FMT_NORETURN void on_full_weekday() { report_no_date(); }
+  FMT_NORETURN void on_dec0_weekday(numeric_system) { report_no_date(); }
+  FMT_NORETURN void on_dec1_weekday(numeric_system) { report_no_date(); }
+  FMT_NORETURN void on_abbr_month() { report_no_date(); }
+  FMT_NORETURN void on_full_month() { report_no_date(); }
   void on_24_hour(numeric_system) {}
   void on_12_hour(numeric_system) {}
   void on_minute(numeric_system) {}
   void on_second(numeric_system) {}
-  void on_datetime(numeric_system) { report_no_date(); }
-  void on_loc_date(numeric_system) { report_no_date(); }
-  void on_loc_time(numeric_system) { report_no_date(); }
-  void on_us_date() { report_no_date(); }
-  void on_iso_date() { report_no_date(); }
+  FMT_NORETURN void on_datetime(numeric_system) { report_no_date(); }
+  FMT_NORETURN void on_loc_date(numeric_system) { report_no_date(); }
+  FMT_NORETURN void on_loc_time(numeric_system) { report_no_date(); }
+  FMT_NORETURN void on_us_date() { report_no_date(); }
+  FMT_NORETURN void on_iso_date() { report_no_date(); }
   void on_12_hour_time() {}
   void on_24_hour_time() {}
   void on_iso_time() {}
   void on_am_pm() {}
   void on_duration_value() {}
   void on_duration_unit() {}
-  void on_utc_offset() { report_no_date(); }
-  void on_tz_name() { report_no_date(); }
+  FMT_NORETURN void on_utc_offset() { report_no_date(); }
+  FMT_NORETURN void on_tz_name() { report_no_date(); }
 };
 
 template <typename Int> inline int to_int(Int value) {

include/fmt/core.h

@@ -143,6 +143,12 @@
 #  endif
 #endif
 
+#if FMT_EXCEPTIONS && FMT_HAS_CPP_ATTRIBUTE(noreturn)
+#  define FMT_NORETURN [[noreturn]]
+#else
+#  define FMT_NORETURN
+#endif
+
 #ifndef FMT_DEPRECATED
 #  if (FMT_HAS_CPP_ATTRIBUTE(deprecated) && __cplusplus >= 201402L) || \
       FMT_MSC_VER >= 1900
@@ -350,7 +356,7 @@ struct error_handler {
   FMT_CONSTEXPR error_handler(const error_handler&) {}
 
   // This function is intentionally not constexpr to give a compile-time error.
-  FMT_API void on_error(const char* message);
+  FMT_API FMT_NORETURN void on_error(const char* message);
 };
 
 // GCC 4.6.x cannot expand `T...`.

include/fmt/format.h

@@ -2621,7 +2621,7 @@ template <typename Range> class basic_writer {
                        num_writer{abs_value, size, sep});
     }
 
-    void on_error() { FMT_THROW(format_error("invalid type specifier")); }
+    FMT_NORETURN void on_error() { FMT_THROW(format_error("invalid type specifier")); }
   };
 
   // Writes a formatted integer.
@@ -2858,7 +2858,7 @@ struct float_spec_handler {
     if (type == 'A') upper = true;
   }
 
-  void on_error() { FMT_THROW(format_error("invalid type specifier")); }
+  FMT_NORETURN void on_error() { FMT_THROW(format_error("invalid type specifier")); }
 };
 
 template <typename Range>

test/format-impl-test.cc

@@ -22,12 +22,6 @@
 
 #undef max
 
-#if FMT_HAS_CPP_ATTRIBUTE(noreturn)
-#  define FMT_NORETURN [[noreturn]]
-#else
-#  define FMT_NORETURN
-#endif
-
 using fmt::internal::fp;
 
 template <bool is_iec559> void test_construct_from_double() {

test/gtest-extra-test.cc

@@ -52,9 +52,9 @@ int SingleEvaluationTest::b_;
 
 void do_nothing() {}
 
-void throw_exception() { throw std::runtime_error("test"); }
+FMT_NORETURN void throw_exception() { throw std::runtime_error("test"); }
 
-void throw_system_error() { throw fmt::system_error(EDOM, "test"); }
+FMT_NORETURN void throw_system_error() { throw fmt::system_error(EDOM, "test"); }
 
 // Tests that when EXPECT_THROW_MSG fails, it evaluates its message argument
 // exactly once.