gecko/xpcom/base/nsObjCExceptions.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * Contributor(s):
 *  Josh Aas <josh@mozilla.com>
 *  Robert O'Callahan <robert@ocallahan.org>
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#ifndef nsObjCExceptions_h_
#define nsObjCExceptions_h_

#import <Foundation/NSException.h>
#import <Foundation/NSObjCRuntime.h>
#include <unistd.h>
#include <signal.h>
#include "nsError.h"

// See Mozilla bug 163260.
// This file can only be included in an Objective-C context.

static void nsObjCExceptionLog(NSException *e)
{
  NSLog(@"%@: %@", [e name], [e reason]);
}

static void nsObjCExceptionAbort()
{
  // We need to raise a mach-o signal here, the Mozilla crash reporter on
  // Mac OS X does not respond to POSIX signals. Raising mach-o signals directly
  // is tricky so we do it by just derefing a null pointer.
  int* foo = NULL;
  *foo = 1;
}

static void nsObjCExceptionLogAbort(NSException *e)
{
  nsObjCExceptionLog(e);
  nsObjCExceptionAbort();
}

#define NS_OBJC_TRY(_e, _fail)                     \
@try { _e; }                                       \
@catch(NSException *_exn) {                        \
  nsObjCExceptionLog(_exn);                        \
  _fail;                                           \
}

#define NS_OBJC_TRY_EXPR(_e, _fail)                \
({                                                 \
   typeof(_e) _tmp;                                \
   @try { _tmp = (_e); }                           \
   @catch(NSException *_exn) {                     \
     nsObjCExceptionLog(_exn);                     \
     _fail;                                        \
   }                                               \
   _tmp;                                           \
})

#define NS_OBJC_TRY_EXPR_NULL(_e)                  \
NS_OBJC_TRY_EXPR(_e, 0)

#define NS_OBJC_TRY_IGNORE(_e)                     \
NS_OBJC_TRY(_e, )

// To reduce code size the abort versions do not reuse above macros. This allows
// catch blocks to only contain one call.

#define NS_OBJC_TRY_ABORT(_e)                      \
@try { _e; }                                       \
@catch(NSException *_exn) {                        \
  nsObjCExceptionLogAbort(_exn);                   \
}

#define NS_OBJC_TRY_EXPR_ABORT(_e)                 \
({                                                 \
   typeof(_e) _tmp;                                \
   @try { _tmp = (_e); }                           \
   @catch(NSException *_exn) {                     \
     nsObjCExceptionLogAbort(_exn);                \
   }                                               \
   _tmp;                                           \
})

// For wrapping blocks of Obj-C calls. Terminates app after logging.
#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK   } @catch(NSException *_exn) {            \
                                        nsObjCExceptionLogAbort(_exn);         \
                                      }

// Same as above ABORT_BLOCK but returns a value after the try/catch block to
// suppress compiler warnings. This allows us to avoid having to refactor code
// to get scoping right when wrapping an entire method.

#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_NIL   } @catch(NSException *_exn) {        \
                                            nsObjCExceptionLogAbort(_exn);     \
                                          }                                    \
                                          return nil;

#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSNULL @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_NSNULL   } @catch(NSException *_exn) {     \
                                               nsObjCExceptionLogAbort(_exn);  \
                                             }                                 \
                                             return nsnull;

#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT   } @catch(NSException *_exn) {   \
                                                 nsObjCExceptionLogAbort(_exn);\
                                               }                               \
                                               return NS_ERROR_FAILURE;

#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_RETURN    @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_RETURN(_rv) } @catch(NSException *_exn) {   \
                                                  nsObjCExceptionLogAbort(_exn);\
                                                }                               \
                                                return _rv;

#endif // nsObjCExceptions_h_