Simplify conditional branching in diag-control.h.

Since diagnostic macros do not depend on each other, use the same
approach as in tcpslice: make one or more attempts to define a
diagnostic macro depending on conditions of varying complexity; if after
all the busy branching the macro is not yet defined, define it to an
empty string once.  This way the branches are simpler to rearrange when
required, and the file has a manifest of the macro names it defines.

1 files changed, 43 insertions, 43 deletions

diff --git a/diag-control.h b/diag-control.h
index ae2641b4..523872fb 100644
--- a/diag-control.h
+++ b/diag-control.h
@@ -62,9 +62,6 @@
     __pragma(warning(disable:4061))
   #define DIAG_ON_ENUM_SWITCH \
     __pragma(warning(pop))
-#else
-  #define DIAG_OFF_ENUM_SWITCH
-  #define DIAG_ON_ENUM_SWITCH
 #endif
 
 /*
@@ -78,9 +75,6 @@
     __pragma(warning(disable:4065))
   #define DIAG_ON_DEFAULT_ONLY_SWITCH \
     __pragma(warning(pop))
-#else
-  #define DIAG_OFF_DEFAULT_ONLY_SWITCH
-  #define DIAG_ON_DEFAULT_ONLY_SWITCH
 #endif
 
 /*
@@ -128,8 +122,6 @@
     PCAP_DO_PRAGMA(clang diagnostic ignored "-Wdeprecated-declarations")
   #define DIAG_ON_DEPRECATION \
     PCAP_DO_PRAGMA(clang diagnostic pop)
-  #define DIAG_OFF_FORMAT_TRUNCATION
-  #define DIAG_ON_FORMAT_TRUNCATION
 #elif defined(_MSC_VER)
   /*
    * This is Microsoft Visual Studio; we can use __pragma(warning(disable:XXXX))
@@ -165,8 +157,6 @@
     __pragma(warning(disable:4996))
   #define DIAG_ON_DEPRECATION \
     __pragma(warning(pop))
-  #define DIAG_OFF_FORMAT_TRUNCATION
-  #define DIAG_ON_FORMAT_TRUNCATION
 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(4,6)
   /*
    * This is GCC 4.6 or later, or a compiler claiming to be that.
@@ -184,8 +174,6 @@
   /*
    * GCC currently doesn't issue any narrowing warnings.
    */
-  #define DIAG_OFF_NARROWING
-  #define DIAG_ON_NARROWING
 
   /*
    * Suppress deprecation warnings.
@@ -207,24 +195,7 @@
       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wformat-truncation=")
     #define DIAG_ON_FORMAT_TRUNCATION \
       PCAP_DO_PRAGMA(GCC diagnostic pop)
-  #else
-   #define DIAG_OFF_FORMAT_TRUNCATION
-   #define DIAG_ON_FORMAT_TRUNCATION
   #endif
-#else
-  /*
-   * Neither Visual Studio, nor Clang 2.8 or later, nor GCC 4.6 or later
-   * or a compiler claiming to be that; there's nothing we know of that
-   * we can do.
-   */
-  #define DIAG_OFF_FLEX
-  #define DIAG_ON_FLEX
-  #define DIAG_OFF_NARROWING
-  #define DIAG_ON_NARROWING
-  #define DIAG_OFF_DEPRECATION
-  #define DIAG_ON_DEPRECATION
-  #define DIAG_OFF_FORMAT_TRUNCATION
-  #define DIAG_ON_FORMAT_TRUNCATION
 #endif
 
 #ifdef YYBYACC
@@ -268,12 +239,6 @@
     #define DIAG_OFF_BISON_BYACC \
       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wshadow") \
       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunreachable-code")
-  #else
-    /*
-     * Neither Clang 2.8 or later nor GCC 4.6 or later or a compiler
-     * claiming to be that; there's nothing we know of that we can do.
-     */
-    #define DIAG_OFF_BISON_BYACC
   #endif
 #else
   /*
@@ -310,12 +275,6 @@
      */
     #define DIAG_OFF_BISON_BYACC \
       PCAP_DO_PRAGMA(GCC diagnostic ignored "-Wunreachable-code")
-  #else
-    /*
-     * Neither Clang 2.8 or later nor GCC 4.6 or later or a compiler
-     * claiming to be that; there's nothing we know of that we can do.
-     */
-    #define DIAG_OFF_BISON_BYACC
   #endif
 #endif
 
@@ -331,8 +290,49 @@
    * So please remember to use this very carefully.
    */
   #define PCAP_UNREACHABLE __builtin_unreachable();
-#else
-  #define PCAP_UNREACHABLE
+#endif
+
+#ifndef DIAG_OFF_ENUM_SWITCH
+#define DIAG_OFF_ENUM_SWITCH
+#endif
+#ifndef DIAG_ON_ENUM_SWITCH
+#define DIAG_ON_ENUM_SWITCH
+#endif
+#ifndef DIAG_OFF_DEFAULT_ONLY_SWITCH
+#define DIAG_OFF_DEFAULT_ONLY_SWITCH
+#endif
+#ifndef DIAG_ON_DEFAULT_ONLY_SWITCH
+#define DIAG_ON_DEFAULT_ONLY_SWITCH
+#endif
+#ifndef DIAG_OFF_FLEX
+#define DIAG_OFF_FLEX
+#endif
+#ifndef DIAG_ON_FLEX
+#define DIAG_ON_FLEX
+#endif
+#ifndef DIAG_OFF_NARROWING
+#define DIAG_OFF_NARROWING
+#endif
+#ifndef DIAG_ON_NARROWING
+#define DIAG_ON_NARROWING
+#endif
+#ifndef DIAG_OFF_DEPRECATION
+#define DIAG_OFF_DEPRECATION
+#endif
+#ifndef DIAG_ON_DEPRECATION
+#define DIAG_ON_DEPRECATION
+#endif
+#ifndef DIAG_OFF_FORMAT_TRUNCATION
+#define DIAG_OFF_FORMAT_TRUNCATION
+#endif
+#ifndef DIAG_ON_FORMAT_TRUNCATION
+#define DIAG_ON_FORMAT_TRUNCATION
+#endif
+#ifndef DIAG_OFF_BISON_BYACC
+#define DIAG_OFF_BISON_BYACC
+#endif
+#ifndef PCAP_UNREACHABLE
+#define PCAP_UNREACHABLE
 #endif
 
 #endif /* _diag_control_h */