X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/127b079813952d5f2d5a186ec02b22ba12ad669b..09b51d326c38ea8e10ce4da09c09d50e08c5aeb8:/pcap/funcattrs.h

diff --git a/pcap/funcattrs.h b/pcap/funcattrs.h
index 9b6427fb..37409499 100644
--- a/pcap/funcattrs.h
+++ b/pcap/funcattrs.h
@@ -35,6 +35,8 @@
 #ifndef lib_pcap_funcattrs_h
 #define lib_pcap_funcattrs_h
 
+#include <pcap/compiler-tests.h>
+
 /*
  * Attributes to apply to functions and their arguments, using various
  * compiler-specific extensions.
@@ -50,115 +52,80 @@
  * exported from libpcap; PCAP_API_DEF won't work on all platforms.
  */
 
-/*
- * This was introduced by Clang:
- *
- *     http://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
- *
- * in some version (which version?); it has been picked up by GCC 5.0.
- */
-#ifndef __has_attribute
+#if defined(_WIN32)
   /*
-   * It's a macro, so you can check whether it's defined to check
-   * whether it's supported.
+   * For Windows:
+   *
+   *    when building libpcap:
+   *
+   *       if we're building it as a DLL, we have to declare API
+   *       functions with __declspec(dllexport);
+   *
+   *       if we're building it as a static library, we don't want
+   *       to do so.
+   *
+   *    when using libpcap:
+   *
+   *       if we're using the DLL, calls to its functions are a
+   *       little more efficient if they're declared with
+   *       __declspec(dllimport);
+   *
+   *       if we're not using the dll, we don't want to declare
+   *       them that way.
+   *
+   * So:
+   *
+   *    if pcap_EXPORTS is defined, we define PCAP_API_DEF as
+   *     __declspec(dllexport);
+   *
+   *    if PCAP_DLL is defined, we define PCAP_API_DEF as
+   *    __declspec(dllimport);
    *
-   * If it's not, define it to always return 0, so that we move on to
-   * the fallback checks.
+   *    otherwise, we define PCAP_API_DEF as nothing.
    */
-  #define __has_attribute(x) 0
-#endif
-
-/*
- * Check whether this is GCC major.minor or a later release, or some
- * compiler that claims to be "just like GCC" of that version or a
- * later release.
- */
-#define PCAP_IS_AT_LEAST_GNUC_VERSION(major, minor) \
-	(defined(__GNUC__) && \
-	    (__GNUC__ > (major) || \
-	     (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))))
-
-/*
- * Check wehether this is Sun C/SunPro C/Oracle Studio major.minor
- * or a later release.
- *
- * The version number in __SUNPRO_C is encoded in hex BCD, with the
- * uppermost hex digit being the major version number, the next
- * one or two hex digits being the minor version number, and
- * the last digit being the patch version.
- *
- * It represents the *compiler* version, not the product version;
- * see
- *
- *    https://sourceforge.net/p/predef/wiki/Compilers/
- *
- * for a partial mapping, which we assume continues for later
- * 12.x product releases.
- */
-#define PCAP_SUNPRO_VERSION_TO_BCD(major, minor) \
-	(((minor) >= 10) ? \
-	    (((major) << 12) | (((minor)/10) << 8) | (((minor)%10) << 4)) : \
-	    (((major) << 8) | ((minor) << 4)))
-#define PCAP_IS_AT_LEAST_SUNC_VERSION(major, minor) \
-	(defined(__SUNPRO_C) && \
-	    (__SUNPRO_C >= PCAP_SUNPRO_VERSION_TO_BCD((major), (minor))))
-
-/*
- * Check wehether this is IBM XL C major.minor or a later release.
- *
- * The version number in __xlC__ has the major version in the
- * upper 8 bits and the minor version in the lower 8 bits.
- */
-#define PCAP_IS_AT_LEAST_XL_C_VERSION(major, minor) \
-	(defined(__xlC__) && __xlC__ >= (((major) << 8) | (minor)))
-
-/*
- * Check wehether this is Sun C/SunPro C/Oracle Studio major.minor
- * or a later release.
- *
- * The version number in __HP_aCC is encoded in zero-padded decimal BCD,
- * with the "A." stripped off, the uppermost two decimal digits being
- * the major version number, the next two decimal digits being the minor
- * version number, and the last two decimal digits being the patch version.
- * (Strip off the A., remove the . between the major and minor version
- * number, and add two digits of patch.)
- */
-#define PCAP_IS_AT_LEAST_HP_C_VERSION(major, minor) \
-	(defined(__HP_aCC) && \
-	    (__HP_aCC >= ((major)*10000 + (minor)*100)))
-
-#if defined(_WIN32)
-  #ifdef BUILDING_PCAP
+  #if defined(pcap_EXPORTS)
     /*
-     * We're compiling libpcap, so we should export functions in our
-     * API.
+     * We're compiling libpcap as a DLL, so we should export functions
+     * in our API.
      */
     #define PCAP_API_DEF	__declspec(dllexport)
-  #else
+  #elif defined(PCAP_DLL)
+    /*
+     * We're using libpcap as a DLL, so the calls will be a little more
+     * efficient if we explicitly import the functions.
+     */
     #define PCAP_API_DEF	__declspec(dllimport)
+  #else
+    /*
+     * Either we're building libpcap as a static library, or we're using
+     * it as a static library, or we don't know for certain that we're
+     * using it as a dynamic library, so neither import nor export the
+     * functions explicitly.
+     */
+    #define PCAP_API_DEF
   #endif
 #elif defined(MSDOS)
   /* XXX - does this need special treatment? */
   #define PCAP_API_DEF
 #else /* UN*X */
-  #ifdef BUILDING_PCAP
+  #ifdef pcap_EXPORTS
     /*
-     * We're compiling libpcap, so we should export functions in our API.
-     * The compiler might be configured not to export functions from a
-     * shared library by default, so we might have to explicitly mark
-     * functions as exported.
+     * We're compiling libpcap as a (dynamic) shared library, so we should
+     * export functions in our API.  The compiler might be configured not
+     * to export functions from a shared library by default, so we might
+     * have to explicitly mark functions as exported.
      */
-    #if PCAP_IS_AT_LEAST_GNUC_VERSION(3, 4) \
-        || PCAP_IS_AT_LEAST_XL_C_VERSION(12, 0)
+    #if PCAP_IS_AT_LEAST_GNUC_VERSION(3,4) \
+        || PCAP_IS_AT_LEAST_XL_C_VERSION(12,0)
       /*
-       * GCC 3.4 or later, or some compiler asserting compatibility with
-       * GCC 3.4 or later, or XL C 13.0 or later, so we have
+       * GCC 3.4 and later, or some compiler asserting compatibility with
+       * GCC 3.4 and later, or XL C 13.0 and later, so we have
        * __attribute__((visibility()).
        */
       #define PCAP_API_DEF	__attribute__((visibility("default")))
-    #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5, 5)
+    #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5,5)
       /*
-       * Sun C 5.5 or later, so we have __global.
+       * Sun C 5.5 and later, so we have __global.
        * (Sun C 5.9 and later also have __attribute__((visibility()),
        * but there's no reason to prefer it with Sun C.)
        */
@@ -179,31 +146,123 @@
 
 #define PCAP_API	PCAP_API_DEF extern
 
+/*
+ * Definitions to 1) indicate what version of libpcap first had a given
+ * API and 2) allow upstream providers whose build environments allow
+ * APIs to be designated as "first available in this release" to do so
+ * by appropriately defining them.
+ *
+ * Yes, that's you, Apple. :-)  Please define PCAP_AVAILABLE_MACOS()
+ * as necessary to make various APIs "weak exports" to make it easier
+ * for software that's distributed in binary form and that uses libpcap
+ * to run on multiple macOS versions and use new APIs when available.
+ * (Yes, such third-party software exists - Wireshark provides binary
+ * packages for macOS, for example.  tcpdump doesn't count, as that's
+ * provided by Apple, so each release can come with a version compiled
+ * to use the APIs present in that release.)
+ *
+ * The non-macOS versioning is based on
+ *
+ *    https://en.wikipedia.org/wiki/Darwin_(operating_system)#Release_history
+ *
+ * If there are any corrections, please submit it upstream to the
+ * libpcap maintainers, preferably as a pull request on
+ *
+ *    https://github.com/the-tcpdump-group/libpcap
+ *
+ * We don't define it ourselves because, if you're building and
+ * installing libpcap on macOS yourself, the APIs will be available
+ * no matter what OS version you're installing it on.
+ *
+ * For other platforms, we don't define them, leaving it up to
+ * others to do so based on their OS versions, if appropriate.
+ *
+ * We start with libpcap 0.4, as that was the last LBL release, and
+ * I've never seen earlier releases.
+ */
+#ifdef __APPLE__
+#include <Availability.h>
+/*
+ * When building as part of macOS, define this as __API_AVAILABLE(__VA_ARGS__).
+ *
+ * XXX - if there's some #define to indicate that this is being built
+ * as part of the macOS build process, we could make that Just Work.
+ */
+#define PCAP_AVAILABLE(...)
+#define PCAP_AVAILABLE_0_4	PCAP_AVAILABLE(macos(10.0)) /* Did any version of Mac OS X ship with this? */
+#define PCAP_AVAILABLE_0_5	PCAP_AVAILABLE(macos(10.0)) /* Did any version of Mac OS X ship with this? */
+#define PCAP_AVAILABLE_0_6	PCAP_AVAILABLE(macos(10.1))
+#define PCAP_AVAILABLE_0_7	PCAP_AVAILABLE(macos(10.4))
+#define PCAP_AVAILABLE_0_8	PCAP_AVAILABLE(macos(10.4))
+#define PCAP_AVAILABLE_0_9	PCAP_AVAILABLE(macos(10.5), ios(1.0))
+#define PCAP_AVAILABLE_1_0	PCAP_AVAILABLE(macos(10.6), ios(4.0))
+/* #define PCAP_AVAILABLE_1_1	no routines added to the API */
+#define PCAP_AVAILABLE_1_2	PCAP_AVAILABLE(macos(10.9), ios(6.0))
+/* #define PCAP_AVAILABLE_1_3	no routines added to the API */
+/* #define PCAP_AVAILABLE_1_4	no routines added to the API */
+#define PCAP_AVAILABLE_1_5	PCAP_AVAILABLE(macos(10.10), ios(7.0), watchos(1.0))
+/* #define PCAP_AVAILABLE_1_6	no routines added to the API */
+#define PCAP_AVAILABLE_1_7	PCAP_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0))
+#define PCAP_AVAILABLE_1_8	PCAP_AVAILABLE(macos(10.13), ios(11.0), tvos(11.0), watchos(4.0)) /* only Windows adds routines to the API; XXX - what version first had it? */
+#define PCAP_AVAILABLE_1_9	PCAP_AVAILABLE(macos(10.13), ios(11.0), tvos(11.0), watchos(4.0))
+#define PCAP_AVAILABLE_1_10	/* not in macOS yet */
+#define PCAP_AVAILABLE_1_11	/* not released yet, so not in macOS yet */
+#else /* __APPLE__ */
+#define PCAP_AVAILABLE_0_4
+#define PCAP_AVAILABLE_0_5
+#define PCAP_AVAILABLE_0_6
+#define PCAP_AVAILABLE_0_7
+#define PCAP_AVAILABLE_0_8
+#define PCAP_AVAILABLE_0_9
+#define PCAP_AVAILABLE_1_0
+/* #define PCAP_AVAILABLE_1_1	no routines added to the API */
+#define PCAP_AVAILABLE_1_2
+/* #define PCAP_AVAILABLE_1_3	no routines added to the API */
+/* #define PCAP_AVAILABLE_1_4	no routines added to the API */
+#define PCAP_AVAILABLE_1_5
+/* #define PCAP_AVAILABLE_1_6	no routines added to the API */
+#define PCAP_AVAILABLE_1_7
+#define PCAP_AVAILABLE_1_8
+#define PCAP_AVAILABLE_1_9
+#define PCAP_AVAILABLE_1_10
+#define PCAP_AVAILABLE_1_11
+#endif /* __APPLE__ */
+
 /*
  * PCAP_NORETURN, before a function declaration, means "this function
  * never returns".  (It must go before the function declaration, e.g.
  * "extern PCAP_NORETURN func(...)" rather than after the function
  * declaration, as the MSVC version has to go before the declaration.)
+ *
+ * PCAP_NORETURN_DEF, before a function *definition*, means "this
+ * function never returns"; it would be used only for static functions
+ * that are defined before any use, and thus have no declaration.
+ * (MSVC doesn't support that; I guess the "decl" in "__declspec"
+ * means "declaration", and __declspec doesn't work with definitions.)
  */
 #if __has_attribute(noreturn) \
-    || PCAP_IS_AT_LEAST_GNUC_VERSION(2, 5) \
-    || PCAP_IS_AT_LEAST_SUNC_VERSION(5, 9) \
-    || PCAP_IS_AT_LEAST_XL_C_VERSION(10, 1) \
-    || PCAP_IS_AT_LEAST_HP_C_VERSION(6, 10)
+    || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
+    || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
+    || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
+    || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
   /*
    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
+   * later, or some compiler asserting compatibility with GCC 2.5 and
    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
-   * and later (do any earlier versions of XL C support this?), or
-   * HP aCC A.06.10 and later.
+   * and later (do any earlier versions of XL C support this?), or HP aCC
+   * A.06.10 and later.
    */
   #define PCAP_NORETURN __attribute((noreturn))
+  #define PCAP_NORETURN_DEF __attribute((noreturn))
 #elif defined(_MSC_VER)
   /*
    * MSVC.
    */
   #define PCAP_NORETURN __declspec(noreturn)
+  #define PCAP_NORETURN_DEF
 #else
   #define PCAP_NORETURN
+  #define PCAP_NORETURN_DEF
 #endif
 
 /*
@@ -213,11 +272,12 @@
  * string".
  */
 #if __has_attribute(__format__) \
-    || PCAP_IS_AT_LEAST_GNUC_VERSION(2, 3) \
-    || PCAP_IS_AT_LEAST_XL_C_VERSION(10, 1) \
-    || PCAP_IS_AT_LEAST_HP_C_VERSION(6, 10)
+    || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
+    || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1) \
+    || PCAP_IS_AT_LEAST_HP_C_VERSION(6,10)
   /*
-   * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1
+   * Compiler with support for it, or GCC 2.3 and later, or some compiler
+   * asserting compatibility with GCC 2.3 and later, or IBM XL C 10.1
    * and later (do any earlier versions of XL C support this?),
    * or HP aCC A.06.10 and later.
    */
@@ -230,50 +290,48 @@
  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
  * function as deprecated.
  *
- * The first argument is the name of the function; the second argument is
- * a string giving the warning message to use if the compiler supports that.
- *
- * (Thank you, Microsoft, for requiring the function name.)
+ * The argument is a string giving the warning message to use if the
+ * compiler supports that.
  */
 #if __has_attribute(deprecated) \
-    || PCAP_IS_AT_LEAST_GNUC_VERSION(4, 5) \
-    || PCAP_IS_AT_LEAST_SUNC_VERSION(5, 13)
+    || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
+    || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
   /*
    * Compiler that supports __has_attribute and __attribute__((deprecated)),
-   * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) or later.
+   * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) and later.
    *
    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
    * incorrectly, that anything that supports __has_attribute() is
    * recent enough to support __attribute__((deprecated(msg)))).
    */
-  #define PCAP_DEPRECATED(func, msg)	__attribute__((deprecated(msg)))
-#elif PCAP_IS_AT_LEAST_GNUC_VERSION(3, 1)
+  #define PCAP_DEPRECATED(msg)	__attribute__((deprecated(msg)))
+#elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
   /*
    * GCC 3.1 through 4.4.
    *
    * Those support __attribute__((deprecated)) but not
    * __attribute__((deprecated(msg))).
    */
-  #define PCAP_DEPRECATED(func, msg)	__attribute__((deprecated))
-#elif (defined(_MSC_VER) && (_MSC_VER >= 1500))
+  #define PCAP_DEPRECATED(msg)	__attribute__((deprecated))
+#elif defined(_MSC_VER) && !defined(BUILDING_PCAP)
   /*
-   * MSVC from Visual Studio 2008 or later.
+   * MSVC, and we're not building libpcap itself; it's VS 2015
+   * and later, so we have __declspec(deprecated(...)).
+   *
+   * If we *are* building libpcap, we don't want this, as it'll warn
+   * us even if we *define* the function.
    */
-  #define PCAP_DEPRECATED(func, msg)	__pragma(deprecated(func))
+  #define PCAP_DEPRECATED(msg)	_declspec(deprecated(msg))
 #else
-  #define PCAP_DEPRECATED(func, msg)
+  #define PCAP_DEPRECATED(msg)
 #endif
 
 /*
  * For flagging arguments as format strings in MSVC.
  */
-#if _MSC_VER >= 1400
+#ifdef _MSC_VER
  #include <sal.h>
- #if _MSC_VER > 1400
-  #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
- #else
-  #define PCAP_FORMAT_STRING(p) __format_string p
- #endif
+ #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 #else
  #define PCAP_FORMAT_STRING(p) p
 #endif