Sweep out some extra warnings

Swept:
`-Wpadded` in some places (where it caused extra size, instead of just
saying "hey, we padded struct at the end to align, just as standard says")
`-Wweak-vtables` everywhere (Clang)
`-Wexit-time-destructors` everywhere (Clang)
`-Wmissing-noreturn` everywhere (Clang)

The last three are enabled for Clang compilation going forward.

Also enabled `-Wunreachable-code` for Clang and GCC

projects/SelfTest/Baselines/console.std.approved.txt

@@ -1003,6 +1003,6 @@ with expansion:
   "{?}" == "1"
 
 ===============================================================================
-test cases: 177 | 126 passed | 47 failed |  4 failed as expected
+test cases: 176 | 125 passed | 47 failed |  4 failed as expected
 assertions: 878 | 761 passed | 96 failed | 21 failed as expected
 

projects/SelfTest/Baselines/console.sw.approved.txt

@@ -7434,6 +7434,6 @@ MiscTests.cpp:<line number>:
 PASSED:
 
 ===============================================================================
-test cases: 177 | 124 passed | 49 failed |  4 failed as expected
+test cases: 176 | 123 passed | 49 failed |  4 failed as expected
 assertions: 877 | 757 passed | 99 failed | 21 failed as expected
 

projects/SelfTest/Baselines/xml.sw.approved.txt

@@ -6946,9 +6946,6 @@ Message from section two
       </Section>
       <OverallResult success="true"/>
     </TestCase>
-    <TestCase name="assertions with commas are allowed" filename="projects/<exe-name>/TrickyTests.cpp" >
-      <OverallResult success="true"/>
-    </TestCase>
     <TestCase name="atomic if" tags="[0][failing]" filename="projects/<exe-name>/MiscTests.cpp" >
       <Expression success="true" type="REQUIRE" filename="projects/<exe-name>/MiscTests.cpp" >
         <Original>

projects/SelfTest/ConditionTests.cpp

@@ -6,7 +6,9 @@
  *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  */
 #ifdef __clang__
+#   pragma clang diagnostic push
 #   pragma clang diagnostic ignored "-Wpadded"
+#   pragma clang diagnostic ignored "-Wdouble-promotion"
 #endif
 
 #include "catch.hpp"
@@ -161,6 +163,11 @@ TEST_CASE( "Ordering comparison checks that should fail", "[.][failing]" )
     CHECK( data.str_hello <= "a" );
 }
 
+#ifdef __clang__
+#   pragma clang diagnostic pop
+#endif
+
+
 // Comparisons with int literals
 TEST_CASE( "Comparisons with int literals don't warn when mixing signed/ unsigned" )
 {

projects/SelfTest/ExceptionTests.cpp

@@ -14,6 +14,10 @@
 #ifdef _MSC_VER
 #pragma warning(disable:4702) // Unreachable code -- MSVC 19 (VS 2015) sees right through the indirection
 #endif
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wweak-vtables"
+#endif
 
 namespace
 {
@@ -219,3 +223,7 @@ TEST_CASE( "#748 - captures with unexpected exceptions", "[.][failing][!throws][
         REQUIRE_THROWS( thisThrows() );
     }
 }
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif

projects/SelfTest/MatchersTests.cpp

@@ -8,6 +8,12 @@
 
 #include "catch.hpp"
 
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wweak-vtables"
+#pragma clang diagnostic ignored "-Wpadded"
+#endif
+
 #ifndef CATCH_CONFIG_DISABLE_MATCHERS
 
 inline const char* testStringForMatching()
@@ -166,16 +172,18 @@ TEST_CASE( "Vector matchers that fail", "[matchers][vector][.][failing]" ) {
 #include <exception>
 
 struct SpecialException : std::exception {
-    SpecialException(int i):i(i) {}
+    SpecialException(int i_):i(i_) {}
     int i;
 };
 
 void doesNotThrow() {}
 
+[[noreturn]]
 void throws(int i) {
     throw SpecialException{ i };
 }
 
+[[noreturn]]
 void throwsAsInt(int i) {
     throw i;
 }
@@ -217,3 +225,7 @@ TEST_CASE("Exception matchers that fail", "[matchers][exceptions][!throws][.fail
 }
 
 #endif // CATCH_CONFIG_DISABLE_MATCHERS
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif

projects/SelfTest/SurrogateCpps/catch_interfaces_capture.cpp

@@ -1,3 +0,0 @@
-// This file is only here to verify (to the extent possible) the self sufficiency of the header
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_interfaces_capture.h"

projects/SelfTest/SurrogateCpps/catch_interfaces_config.cpp

@@ -1,2 +0,0 @@
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_interfaces_config.h"

projects/SelfTest/SurrogateCpps/catch_interfaces_exception.cpp

@@ -1,2 +0,0 @@
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_interfaces_exception.h"

projects/SelfTest/SurrogateCpps/catch_interfaces_registry_hub.cpp

@@ -1,3 +0,0 @@
-// This file is only here to verify (to the extent possible) the self sufficiency of the header
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_interfaces_registry_hub.h"

projects/SelfTest/SurrogateCpps/catch_interfaces_runner.cpp

@@ -1 +0,0 @@
-#include "internal/catch_interfaces_runner.h"

projects/SelfTest/SurrogateCpps/catch_interfaces_testcase.cpp

@@ -1,2 +0,0 @@
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_interfaces_testcase.h"

projects/SelfTest/SurrogateCpps/catch_streambuf.cpp

@@ -1,3 +0,0 @@
-// This file is only here to verify (to the extent possible) the self sufficiency of the header
-#include "internal/catch_suppress_warnings.h"
-#include "internal/catch_streambuf.h"

projects/SelfTest/TestMain.cpp

@@ -265,4 +265,4 @@ struct AutoTestReg {
         REGISTER_TEST_CASE( manuallyRegisteredTestFunction, "ManuallyRegistered" );
     }
 };
-AutoTestReg autoTestReg;
+static AutoTestReg autoTestReg;

projects/SelfTest/TrickyTests.cpp

@@ -381,12 +381,9 @@ TEST_CASE( "has printf" ) {
     printf( "loose text artifact\n" );
 }
 
-TEST_CASE( "assertions with commas are allowed" ) {
-}
-
 namespace {
     struct constructor_throws {
-        constructor_throws() {
+        [[noreturn]] constructor_throws() {
             throw 1;
         }
     };