nsObjCExceptions.h
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// Undo the damage that exception_defines.h does.
#undef try
#undef catch
#ifndef nsObjCExceptions_h_
#define nsObjCExceptions_h_
#import <Foundation/Foundation.h>
#ifdef DEBUG
#import <ExceptionHandling/NSExceptionHandler.h>
#endif
#if defined(MOZ_CRASHREPORTER) && defined(__cplusplus)
#include "nsICrashReporter.h"
#include "nsCOMPtr.h"
#include "nsServiceManagerUtils.h"
#endif
#include <unistd.h>
#include <signal.h>
#include "nsError.h"
// Undo the damage that exception_defines.h does.
#undef try
#undef catch
/* NOTE: Macros that claim to abort no longer abort, see bug 486574.
* If you actually want to log and abort, call "nsObjCExceptionLogAbort"
* from an exception handler. At some point we will fix this by replacing
* all macros in the tree with appropriately-named macros.
*/
// See Mozilla bug 163260.
// This file can only be included in an Objective-C context.
__attribute__((unused))
static void
nsObjCExceptionLog(NSException* aException)
{
NSLog(@"Mozilla has caught an Obj-C exception [%@: %@]",
[aException name], [aException reason]);
#if defined(MOZ_CRASHREPORTER) && defined(__cplusplus)
// Attach exception info to the crash report.
nsCOMPtr<nsICrashReporter> crashReporter =
do_GetService("@mozilla.org/toolkit/crash-reporter;1");
if (crashReporter) {
crashReporter->AppendObjCExceptionInfoToAppNotes(static_cast<void*>(aException));
}
#endif
#ifdef DEBUG
@try {
// Try to get stack information out of the exception. 10.5 returns the stack
// info with the callStackReturnAddresses selector.
NSArray* stackTrace = nil;
if ([aException respondsToSelector:@selector(callStackReturnAddresses)]) {
NSArray* addresses = (NSArray*)
[aException performSelector:@selector(callStackReturnAddresses)];
if ([addresses count]) {
stackTrace = addresses;
}
}
// 10.4 doesn't respond to callStackReturnAddresses so we'll try to pull the
// stack info out of the userInfo. It might not be there, sadly :(
if (!stackTrace) {
stackTrace = [[aException userInfo] objectForKey:NSStackTraceKey];
}
if (stackTrace) {
// The command line should look like this:
// /usr/bin/atos -p <pid> -printHeader <stack frame addresses>
NSMutableArray* args =
[NSMutableArray arrayWithCapacity:[stackTrace count] + 3];
[args addObject:@"-p"];
int pid = [[NSProcessInfo processInfo] processIdentifier];
[args addObject:[NSString stringWithFormat:@"%d", pid]];
[args addObject:@"-printHeader"];
unsigned int stackCount = [stackTrace count];
unsigned int stackIndex = 0;
for (; stackIndex < stackCount; stackIndex++) {
unsigned long address =
[[stackTrace objectAtIndex:stackIndex] unsignedLongValue];
[args addObject:[NSString stringWithFormat:@"0x%lx", address]];
}
NSPipe* outPipe = [NSPipe pipe];
NSTask* task = [[NSTask alloc] init];
[task setLaunchPath:@"/usr/bin/atos"];
[task setArguments:args];
[task setStandardOutput:outPipe];
[task setStandardError:outPipe];
NSLog(@"Generating stack trace for Obj-C exception...");
// This will throw an exception if the atos tool cannot be found, and in
// that case we'll just hit our @catch block below.
[task launch];
[task waitUntilExit];
[task release];
NSData* outData =
[[outPipe fileHandleForReading] readDataToEndOfFile];
NSString* outString =
[[NSString alloc] initWithData:outData encoding:NSUTF8StringEncoding];
NSLog(@"Stack trace:\n%@", outString);
[outString release];
} else {
NSLog(@"<No stack information available for Obj-C exception>");
}
}
@catch (NSException* exn) {
NSLog(@"Failed to generate stack trace for Obj-C exception [%@: %@]",
[exn name], [exn reason]);
}
#endif
}
__attribute__((unused))
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 = nullptr;
*foo = 1;
}
__attribute__((unused))
static void
nsObjCExceptionLogAbort(NSException* aException)
{
nsObjCExceptionLog(aException);
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) { \
nsObjCExceptionLog(_exn); \
}
#define NS_OBJC_TRY_EXPR_ABORT(_e) \
({ \
typeof(_e) _tmp; \
@try { _tmp = (_e); } \
@catch(NSException *_exn) { \
nsObjCExceptionLog(_exn); \
} \
_tmp; \
})
// For wrapping blocks of Obj-C calls. Does not actually terminate.
#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK } @catch(NSException *_exn) { \
nsObjCExceptionLog(_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) { \
nsObjCExceptionLog(_exn); \
} \
return nil;
#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSNULL @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_NSNULL } @catch(NSException *_exn) { \
nsObjCExceptionLog(_exn); \
} \
return nullptr;
#define NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT @try {
#define NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT } @catch(NSException *_exn) { \
nsObjCExceptionLog(_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) { \
nsObjCExceptionLog(_exn);\
} \
return _rv;
#define NS_OBJC_BEGIN_TRY_LOGONLY_BLOCK @try {
#define NS_OBJC_END_TRY_LOGONLY_BLOCK } @catch(NSException *_exn) { \
nsObjCExceptionLog(_exn); \
}
#define NS_OBJC_BEGIN_TRY_LOGONLY_BLOCK_RETURN @try {
#define NS_OBJC_END_TRY_LOGONLY_BLOCK_RETURN(_rv) } @catch(NSException *_exn) { \
nsObjCExceptionLog(_exn); \
} \
return _rv;
#endif // nsObjCExceptions_h_
