Source/DebuggerBackEnd.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2011, Blue Static <http://www.bluestatic.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
   6  * General Public License as published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
  10  * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with this program; if not,
  14  * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 #import "DebuggerBackEnd.h"
  18
  19 #import "AppDelegate.h"
  20 #import "DebuggerModel.h"
  21 #import "modp_b64.h"
  22 #import "NSXMLElementAdditions.h"
  23
  24 @interface DebuggerBackEnd ()
  25 @property(readwrite, copy, nonatomic) NSString* status;
  26 @end
  27
  28 @implementation DebuggerBackEnd {
  29   // The connection to the debugger engine.
  30   NSUInteger _port;
  31   ProtocolClient* _client;
  32
  33   // Whether or not a debugging session is currently active.
  34   BOOL _active;
  35 }
  36
  37 @synthesize status = _status;
  38 @synthesize autoAttach = _autoAttach;
  39 @synthesize model = _model;
  40 @synthesize delegate = _delegate;
  41
  42 - (id)initWithPort:(NSUInteger)aPort
  43 {
  44   if (self = [super init]) {
  45     [[BreakpointManager sharedManager] setConnection:self];
  46     _port = aPort;
  47     _client = [[ProtocolClient alloc] initWithDelegate:self];
  48
  49     _autoAttach = [[NSUserDefaults standardUserDefaults] boolForKey:@"DebuggerAttached"];
  50
  51     if (self.autoAttach)
  52       [_client connectOnPort:_port];
  53   }
  54   return self;
  55 }
  56
  57 - (void)dealloc {
  58   [_client release];
  59   [super dealloc];
  60 }
  61
  62 // Getters /////////////////////////////////////////////////////////////////////
  63 #pragma mark Getters
  64
  65 /**
  66  * Gets the port number
  67  */
  68 - (NSUInteger)port {
  69   return _port;
  70 }
  71
  72 /**
  73  * Returns whether or not we have an active connection
  74  */
  75 - (BOOL)isConnected {
  76   return _active;
  77 }
  78
  79 /**
  80  * Sets the attached state of the debugger. This will open and close the
  81  * connection as appropriate.
  82  */
  83 - (void)setAutoAttach:(BOOL)flag {
  84   if (flag == _autoAttach)
  85     return;
  86
  87   if (_autoAttach)
  88     [_client disconnect];
  89   else
  90     [_client connectOnPort:_port];
  91
  92   _autoAttach = flag;
  93 }
  94
  95 // Commands ////////////////////////////////////////////////////////////////////
  96 #pragma mark Commands
  97
  98 /**
  99  * Tells the debugger to continue running the script. Returns the current stack frame.
 100  */
 101 - (void)run {
 102   [_client sendCommandWithFormat:@"run" handler:^(NSXMLDocument* message) {
 103     [self debuggerStep:message];
 104   }];
 105 }
 106
 107 /**
 108  * Tells the debugger to step into the current command.
 109  */
 110 - (void)stepIn {
 111   [_client sendCommandWithFormat:@"step_into" handler:^(NSXMLDocument* message) {
 112     [self debuggerStep:message];
 113   }];
 114 }
 115
 116 /**
 117  * Tells the debugger to step out of the current context
 118  */
 119 - (void)stepOut {
 120   [_client sendCommandWithFormat:@"step_out" handler:^(NSXMLDocument* message) {
 121     [self debuggerStep:message];
 122   }];
 123 }
 124
 125 /**
 126  * Tells the debugger to step over the current function
 127  */
 128 - (void)stepOver {
 129   [_client sendCommandWithFormat:@"step_over" handler:^(NSXMLDocument* message) {
 130     [self debuggerStep:message];
 131   }];
 132 }
 133
 134 /**
 135  * Halts execution of the script.
 136  */
 137 - (void)stop {
 138   [_client disconnect];
 139   _active = NO;
 140   self.status = @"Stopped";
 141 }
 142
 143 /**
 144  * Ends the current debugging session.
 145  */
 146 - (void)detach {
 147   [_client sendCommandWithFormat:@"detach"];
 148   _active = NO;
 149   self.status = @"Stopped";
 150 }
 151
 152 /**
 153  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 154  * that requested it so that the child can be attached.
 155  */
 156 - (void)getChildrenOfProperty:(VariableNode*)property
 157                       atDepth:(NSInteger)depth
 158                      callback:(void (^)(NSArray*))callback {
 159   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 160     /*
 161      <response>
 162        <property> <!-- this is the one we requested -->
 163          <property ... /> <!-- these are what we want -->
 164        </property>
 165      </repsonse>
 166      */
 167
 168     // Detach all the children so we can insert them into another document.
 169     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 170     NSArray* children = [parent children];
 171     [parent setChildren:nil];
 172
 173     callback(children);
 174   };
 175   [_client sendCommandWithFormat:@"property_get -d %d -n %@" handler:handler, depth, [property fullName]];
 176 }
 177
 178 - (void)loadStackFrame:(StackFrame*)frame {
 179   if (frame.loaded)
 180     return;
 181
 182   // Get the source code of the file. Escape % in URL chars.
 183   if ([frame.filename length]) {
 184     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 185       frame.source = [[message rootElement] base64DecodedValue];
 186       if ([self.delegate respondsToSelector:@selector(sourceUpdated:)])
 187         [self.delegate sourceUpdated:frame];
 188     };
 189     [_client sendCommandWithFormat:@"source -f %@" handler:handler, frame.filename];
 190   }
 191
 192   // Get the names of all the contexts.
 193   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 194     [self loadContexts:message forFrame:frame];
 195   };
 196   [_client sendCommandWithFormat:@"context_names -d %d" handler:handler, frame.index];
 197
 198   // This frame will be fully loaded.
 199   frame.loaded = YES;
 200 }
 201
 202 // Breakpoint Management ///////////////////////////////////////////////////////
 203 #pragma mark Breakpoints
 204
 205 /**
 206  * Send an add breakpoint command
 207  */
 208 - (void)addBreakpoint:(Breakpoint*)bp {
 209   if (!_active)
 210     return;
 211
 212   NSString* file = [ProtocolClient escapedFilePathURI:[bp transformedPath]];
 213   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 214     [bp setDebuggerId:[[[[message rootElement] attributeForName:@"id"] stringValue] intValue]];
 215   };
 216   [_client sendCommandWithFormat:@"breakpoint_set -t line -f %@ -n %i" handler:handler, file, [bp line]];
 217 }
 218
 219 /**
 220  * Removes a breakpoint
 221  */
 222 - (void)removeBreakpoint:(Breakpoint*)bp {
 223   if (!_active)
 224     return;
 225
 226   [_client sendCommandWithFormat:@"breakpoint_remove -d %i", [bp debuggerId]];
 227 }
 228
 229 /**
 230  * Sends a string to be evaluated by the engine.
 231  */
 232 - (void)evalScript:(NSString*)str callback:(void (^)(NSString*))callback {
 233   if (!_active)
 234     return;
 235
 236   char* encodedString = malloc(modp_b64_encode_len([str length]));
 237   modp_b64_encode(encodedString, [str UTF8String], [str length]);
 238   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 239     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 240     NSString* value = [parent base64DecodedValue];
 241     callback(value);
 242   };
 243   [_client sendCustomCommandWithFormat:@"eval -i {txn} -- %s" handler:handler, encodedString];
 244   free(encodedString);
 245 }
 246
 247 // Protocol Client Delegate ////////////////////////////////////////////////////
 248 #pragma mark Protocol Client Delegate
 249
 250 - (void)debuggerEngineConnected:(ProtocolClient*)client {
 251   _active = YES;
 252   [_model onNewConnection];
 253 }
 254
 255 /**
 256  * Called when the connection is finally closed. This will reopen the listening
 257  * socket if the debugger remains attached.
 258  */
 259 - (void)debuggerEngineDisconnected:(ProtocolClient*)client {
 260   _active = NO;
 261
 262   if ([self.delegate respondsToSelector:@selector(debuggerDisconnected)])
 263     [self.delegate debuggerDisconnected];
 264
 265   if (self.autoAttach)
 266     [_client connectOnPort:_port];
 267 }
 268
 269 - (void)protocolClient:(ProtocolClient*)client receivedInitialMessage:(NSXMLDocument*)message {
 270   [self handleInitialResponse:message];
 271 }
 272
 273 - (void)protocolClient:(ProtocolClient*)client receivedErrorMessage:(NSXMLDocument*)message {
 274   NSArray* error = [[message rootElement] elementsForName:@"error"];
 275   if ([error count] > 0) {
 276     NSLog(@"Xdebug error: %@", error);
 277     NSString* errorMessage = [[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue];
 278     [self errorEncountered:errorMessage];
 279   }
 280 }
 281
 282 // Specific Response Handlers //////////////////////////////////////////////////
 283 #pragma mark Response Handlers
 284
 285 - (void)errorEncountered:(NSString*)error {
 286   [self.delegate errorEncountered:error];
 287 }
 288
 289 /**
 290  * Initial packet received. We've started a brand-new connection to the engine.
 291  */
 292 - (void)handleInitialResponse:(NSXMLDocument*)response {
 293   if (!self.autoAttach) {
 294     [_client sendCommandWithFormat:@"detach"];
 295     return;
 296   }
 297
 298   _active = YES;
 299
 300   // Register any breakpoints that exist offline.
 301   for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 302     [self addBreakpoint:bp];
 303
 304   // Load the debugger to make it look active.
 305   [self.delegate debuggerConnected];
 306
 307   // TODO: update the status.
 308 }
 309
 310 /**
 311  * Receiver for status updates. This just freshens up the UI.
 312  */
 313 - (void)updateStatus:(NSXMLDocument*)response {
 314   self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 315   _active = YES;
 316   if (!_status || [_status isEqualToString:@"Stopped"]) {
 317     [_delegate debuggerDisconnected];
 318     _active = NO;
 319   } else if ([_status isEqualToString:@"Stopping"]) {
 320     [_client sendCommandWithFormat:@"stop"];
 321     _active = NO;
 322   }
 323   self.model.status = self.status;
 324 }
 325
 326 /**
 327  * Step in/out/over and run all take this path. We first get the status of the
 328  * debugger and then request fresh stack information.
 329  */
 330 - (void)debuggerStep:(NSXMLDocument*)response {
 331   [self updateStatus:response];
 332   if (![self isConnected])
 333     return;
 334
 335   [_client sendCommandWithFormat:@"stack_depth" handler:^(NSXMLDocument* message) {
 336     [self rebuildStack:message];
 337   }];
 338 }
 339
 340 /**
 341  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 342  * it.
 343  */
 344 - (void)rebuildStack:(NSXMLDocument*)response {
 345   NSUInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 346
 347   // Start with frame 0. If this is a shifted frame, then only it needs to be
 348   // re-loaded. If it is not shifted, see if another frame on the stack is equal
 349   // to it; if so, then the frames up to that must be discarded. If not, this is
 350   // a new stack frame that should be inserted at the top of the stack. Finally,
 351   // the sice of the stack is trimmed to |depth| from the bottom.
 352
 353   __block NSMutableArray* tempStack = [[NSMutableArray alloc] init];
 354
 355   for (NSUInteger i = 0; i < depth; ++i) {
 356     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 357       [tempStack addObject:[self transformXMLToStackFrame:message]];
 358       if (i == depth - 1) {
 359         [self.model updateStack:[tempStack autorelease]];
 360       }
 361     };
 362     [_client sendCommandWithFormat:@"stack_get -d %d" handler:handler, i];
 363   }
 364 }
 365
 366 /**
 367  * Creates a StackFrame object from an NSXMLDocument response from the "stack_get"
 368  * command.
 369  */
 370 - (StackFrame*)transformXMLToStackFrame:(NSXMLDocument*)response {
 371   NSXMLElement* xmlframe = (NSXMLElement*)[[[response rootElement] children] objectAtIndex:0];
 372   StackFrame* frame = [[[StackFrame alloc] init] autorelease];
 373   frame.index = [[[xmlframe attributeForName:@"level"] stringValue] intValue];
 374   frame.filename = [[xmlframe attributeForName:@"filename"] stringValue];
 375   frame.lineNumber = [[[xmlframe attributeForName:@"lineno"] stringValue] intValue];
 376   frame.function = [[xmlframe attributeForName:@"where"] stringValue];
 377   return frame;
 378 }
 379
 380 /**
 381  * Enumerates all the contexts of a given stack frame. We then in turn get the
 382  * contents of each one of these contexts.
 383  */
 384 - (void)loadContexts:(NSXMLDocument*)response forFrame:(StackFrame*)frame {
 385   NSXMLElement* contextNames = [response rootElement];
 386   for (NSXMLElement* context in [contextNames children]) {
 387     NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 388
 389     // Fetch each context's variables.
 390     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 391       NSMutableArray* variables = [NSMutableArray array];
 392
 393       // Merge the frame's existing variables.
 394       if (frame.variables)
 395         [variables addObjectsFromArray:frame.variables];
 396
 397       // Add these new variables.
 398       NSArray* addVariables = [[message rootElement] children];
 399       if (addVariables) {
 400         for (NSXMLElement* elm in addVariables) {
 401           VariableNode* node = [[VariableNode alloc] initWithXMLNode:elm];
 402           [variables addObject:[node autorelease]];
 403         }
 404       }
 405
 406       frame.variables = variables;
 407     };
 408     [_client sendCommandWithFormat:@"context_get -d %d -c %d" handler:handler, frame.index, cid];
 409   }
 410 }
 411
 412 @end