Add GCC compiler flag. (see #2094)

tests/SelfTest/UsageTests/Compilation.tests.cpp

@@ -12,6 +12,8 @@
 // in a different namespace.
 #include <ostream>
 
+#include <catch2/internal/catch_compiler_capabilities.hpp>
+
 namespace foo {
     struct helper_1403 {
         bool operator==(helper_1403) const { return true; }
@@ -23,7 +25,7 @@ namespace bar {
     struct TypeList {};
 }
 
-#ifdef __GNUC__
+#ifdef CATCH_COMPILER_GCC
 #pragma GCC diagnostic ignored "-Wmissing-declarations"
 #endif
 std::ostream& operator<<(std::ostream& out, foo::helper_1403 const&) {
@@ -79,7 +81,7 @@ struct B : private A {
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-function"
 #endif
-#ifdef __GNUC__
+#ifdef CATCH_COMPILER_GCC
 // Note that because -~GCC~-, this warning cannot be silenced temporarily, by pushing diagnostic stack...
 // Luckily it is firing in test files and thus can be silenced for the whole file, without losing much.
 #pragma GCC diagnostic ignored "-Wunused-function"

tests/SelfTest/UsageTests/Condition.tests.cpp

@@ -223,7 +223,7 @@ TEST_CASE( "Comparisons with int literals don't warn when mixing signed/ unsigne
 // Disable warnings about sign conversions for the next two tests
 // (as we are deliberately invoking them)
 // - Currently only disabled for GCC/ LLVM. Should add VC++ too
-#ifdef  __GNUC__
+#ifdef  CATCH_COMPILER_GCC
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wsign-compare"
 #pragma GCC diagnostic ignored "-Wsign-conversion"
@@ -277,7 +277,7 @@ TEST_CASE( "Comparisons between ints where one side is computed" )
      CHECK( 54 == 6*9 );
 }
 
-#ifdef  __GNUC__
+#ifdef  CATCH_COMPILER_GCC
 #pragma GCC diagnostic pop
 #endif
 

tests/SelfTest/UsageTests/Message.tests.cpp

@@ -216,7 +216,7 @@ TEST_CASE( "CAPTURE can deal with complex expressions", "[messages][capture]" )
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-value" // In (1, 2), the "1" is unused ...
 #endif
-#ifdef __GNUC__
+#ifdef CATCH_COMPILER_GCC
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-value" // All the comma operators are side-effect free
 #endif
@@ -243,7 +243,7 @@ std::ostream& operator<<(std::ostream& out, helper_1436<T1, T2> const& helper) {
 
 // Clang and gcc have different names for this warning, and clang also
 // warns about an unused value. This warning must be disabled for C++20.
-#if defined(__GNUG__) && !defined(__clang__)
+#if defined(CATCH_COMPILER_GCC) && __cplusplus
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wpragmas"
 #pragma GCC diagnostic ignored "-Wcomma-subscript"
@@ -265,7 +265,7 @@ TEST_CASE("CAPTURE can deal with complex expressions involving commas", "[messag
     SUCCEED();
 }
 
-#ifdef __GNUG__
+#ifdef CATCH_COMPILER_GCC
 #pragma GCC diagnostic pop
 #endif
 
@@ -279,7 +279,7 @@ TEST_CASE("CAPTURE parses string and character constants", "[messages][capture]"
 #ifdef __clang__
 #pragma clang diagnostic pop
 #endif
-#ifdef __GNUC__
+#ifdef CATCH_COMPILER_GCC
 #pragma GCC diagnostic pop
 #endif
 #ifdef _MSC_VER

tests/SelfTest/UsageTests/ToStringWhich.tests.cpp

@@ -8,9 +8,9 @@
 
 #include <catch2/catch_test_macros.hpp>
 
+#include <catch2/internal/catch_compiler_capabilities.hpp>
 
-
-#if defined(__GNUC__)
+#if defined(CATCH_COMPILER_GCC)
 // This has to be left enabled until end of the TU, because the GCC
 // frontend reports operator<<(std::ostream& os, const has_maker_and_operator&)
 // as unused anyway