Move the compiler version tests to ws_compiler_tests.h and use them elsewhere.

While we're at it, sort some header file lists, and clean up white
space.

Change-Id: If737dda45334fedf1df7295d8719ad9381daf7a1
Reviewed-on: https://code.wireshark.org/review/24089
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 31 insertions, 27 deletions

diff --git a/ws_diag_control.h b/ws_diag_control.h
index b2a4561f6f..428091addd 100644
--- a/ws_diag_control.h
+++ b/ws_diag_control.h
@@ -24,6 +24,8 @@
 #ifndef __WS_DIAG_CONTROL_H__
 #define __WS_DIAG_CONTROL_H__
 
+#include "ws_compiler_tests.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -45,26 +47,35 @@ extern "C" {
    pragma clang diagnostic error/warning/ignored -Wxxx and
    pragma clang diagnostic push/pop were introduced in clang 2.8 */
 
-#if defined(__GNUC__) && !defined(__clang__)
-#  define gcc_version ((__GNUC__ * 1000) + (__GNUC_MINOR__ * 10))
-#  if gcc_version >= 4080
-     /*
-      * gcc version is >= 4.8.0. We can use "GCC diagnostic push/pop" *and*
-      * gcc supports "-Wpedantic".
-      */
-#    define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(GCC diagnostic x)
-#    define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
-#    define DIAG_ON(x) DIAG_PRAGMA(pop)
-#  endif
-#elif defined(__clang__)
-#  define clang_version ((__clang_major__ * 1000) + (__clang_minor__ * 10))
-#  if clang_version >= 2080
-     /* clang version is >= 2.8: we can use "clang diagnostic ignored -Wxxx"
-        and "clang diagnostic push/pop" */
-#    define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(clang diagnostic x)
-#    define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
-#    define DIAG_ON(x) DIAG_PRAGMA(pop)
-#  endif
+#if !defined(__clang__) && WS_IS_AT_LEAST_GNUC_VERSION(4,8)
+  /*
+   * This is GCC, or a compiler that 1) claims to be GCC and 2) does
+   * *not* claim to be Clang, and is claiming to be GCC version 4.8.0
+   * or later.
+   * We can use "GCC diagnostic push/pop" *and* gcc supports "-Wpedantic".
+   */
+  #define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(GCC diagnostic x)
+  #define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
+  #define DIAG_ON(x) DIAG_PRAGMA(pop)
+#elif WS_IS_AT_LEAST_CLANG_VERSION(2,8)
+  /*
+   * This is Clang 2.8 or later: we can use "clang diagnostic ignored -Wxxx"
+   * and "clang diagnostic push/pop".
+   */
+  #define DIAG_PRAGMA(x) DIAG_DO_PRAGMA(clang diagnostic x)
+  #define DIAG_OFF(x) DIAG_PRAGMA(push) DIAG_PRAGMA(ignored DIAG_JOINSTR(-W,x))
+  #define DIAG_ON(x) DIAG_PRAGMA(pop)
+#else
+  /*
+   * This is none of the above; we don't have any way to turn diagnostics
+   * on or off.
+   *
+   * XXX - you can do that in MSVC, but it's done differently; we'd
+   * have to have macros for *particular* diagnostics, using the
+   * warning flag for GCC and Clang and the error number for MSVC.
+   */
+  #define DIAG_OFF(x)
+  #define DIAG_ON(x)
 #endif
 
 /* Use for clang specific pragmas, so we can keep -Wpragmas enabled */
@@ -76,13 +87,6 @@ extern "C" {
 #  define DIAG_ON_CLANG(x)
 #endif
 
-#ifndef DIAG_OFF
-   /* no gcc or clang, or gcc version < 4.2.0, or clang version < 2.8:
-      we can't do anything */
-#  define DIAG_OFF(x)
-#  define DIAG_ON(x)
-#endif
-
 /*
  *	For dealing with APIs which are only deprecated in macOS (like the
  *	OpenSSL and MIT/Heimdal Kerberos APIs).