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 "modp_b64.h"
  21 #import "NSXMLElementAdditions.h"
  22
  23 // GDBpConnection (Private) ////////////////////////////////////////////////////
  24
  25 @interface DebuggerBackEnd ()
  26 @property (readwrite, copy) NSString* status;
  27
  28 - (void)recordCallback:(SEL)callback forTransaction:(NSNumber*)txn;
  29
  30 - (void)updateStatus:(NSXMLDocument*)response;
  31 - (void)debuggerStep:(NSXMLDocument*)response;
  32 - (void)rebuildStack:(NSXMLDocument*)response;
  33 - (void)getStackFrame:(NSXMLDocument*)response;
  34 - (void)setSource:(NSXMLDocument*)response;
  35 - (void)contextsReceived:(NSXMLDocument*)response;
  36 - (void)variablesReceived:(NSXMLDocument*)response;
  37 - (void)propertiesReceived:(NSXMLDocument*)response;
  38 - (void)evalScriptReceived:(NSXMLDocument*)response;
  39
  40 @end
  41
  42 // GDBpConnection //////////////////////////////////////////////////////////////
  43
  44 @implementation DebuggerBackEnd
  45
  46 @synthesize status;
  47 @synthesize attached = attached_;
  48 @synthesize delegate;
  49
  50 /**
  51  * Creates a new DebuggerBackEnd and initializes the socket from the given connection
  52  * paramters.
  53  */
  54 - (id)initWithPort:(NSUInteger)aPort
  55 {
  56   if (self = [super init])
  57   {
  58     stackFrames_ = [[NSMutableDictionary alloc] init];
  59     callbackContext_ = [NSMutableDictionary new];
  60     callTable_ = [NSMutableDictionary new];
  61
  62     [[BreakpointManager sharedManager] setConnection:self];
  63     connection_ = [[NetworkConnection alloc] initWithPort:aPort];
  64     connection_.delegate = self;
  65
  66     attached_ = [[NSUserDefaults standardUserDefaults] boolForKey:@"DebuggerAttached"];
  67
  68     if (self.attached)
  69       [connection_ connect];
  70   }
  71   return self;
  72 }
  73
  74 /**
  75  * Deallocates the object
  76  */
  77 - (void)dealloc
  78 {
  79   [connection_ close];
  80   [stackFrames_ release];
  81   [callTable_ release];
  82   [callbackContext_ release];
  83   [super dealloc];
  84 }
  85
  86
  87 // Getters /////////////////////////////////////////////////////////////////////
  88 #pragma mark Getters
  89
  90 /**
  91  * Gets the port number
  92  */
  93 - (NSUInteger)port
  94 {
  95   return [connection_ port];
  96 }
  97
  98 /**
  99  * Returns whether or not we have an active connection
 100  */
 101 - (BOOL)isConnected
 102 {
 103   return [connection_ connected] && active_;
 104 }
 105
 106 /**
 107  * Sets the attached state of the debugger. This will open and close the
 108  * connection as appropriate.
 109  */
 110 - (void)setAttached:(BOOL)attached {
 111   if (attached != attached_) {
 112     if (!attached)
 113       [connection_ close];
 114     else
 115       [connection_ connect];
 116   }
 117   attached_ = attached;
 118 }
 119
 120 // Commands ////////////////////////////////////////////////////////////////////
 121 #pragma mark Commands
 122
 123 /**
 124  * Tells the debugger to continue running the script. Returns the current stack frame.
 125  */
 126 - (void)run
 127 {
 128   NSNumber* tx = [connection_ sendCommandWithFormat:@"run"];
 129   [self recordCallback:@selector(debuggerStep:) forTransaction:tx];
 130 }
 131
 132 /**
 133  * Tells the debugger to step into the current command.
 134  */
 135 - (void)stepIn
 136 {
 137   NSNumber* tx = [connection_ sendCommandWithFormat:@"step_into"];
 138   [self recordCallback:@selector(debuggerStep:) forTransaction:tx];
 139 }
 140
 141 /**
 142  * Tells the debugger to step out of the current context
 143  */
 144 - (void)stepOut
 145 {
 146   NSNumber* tx = [connection_ sendCommandWithFormat:@"step_out"];
 147   [self recordCallback:@selector(debuggerStep:) forTransaction:tx];
 148 }
 149
 150 /**
 151  * Tells the debugger to step over the current function
 152  */
 153 - (void)stepOver
 154 {
 155   NSNumber* tx = [connection_ sendCommandWithFormat:@"step_over"];
 156   [self recordCallback:@selector(debuggerStep:) forTransaction:tx];
 157 }
 158
 159 /**
 160  * Halts execution of the script.
 161  */
 162 - (void)stop
 163 {
 164   [connection_ close];
 165   active_ = NO;
 166   self.status = @"Stopped";
 167 }
 168
 169 /**
 170  * Ends the current debugging session.
 171  */
 172 - (void)detach
 173 {
 174   [connection_ sendCommandWithFormat:@"detach"];
 175   active_ = NO;
 176   self.status = @"Stopped";
 177 }
 178
 179 /**
 180  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 181  * that requested it so that the child can be attached.
 182  */
 183 - (NSInteger)getChildrenOfProperty:(VariableNode*)property atDepth:(NSInteger)depth;
 184 {
 185   NSNumber* tx = [connection_ sendCommandWithFormat:@"property_get -d %d -n %@", depth, [property fullName]];
 186   [self recordCallback:@selector(propertiesReceived:) forTransaction:tx];
 187   return [tx intValue];
 188 }
 189
 190 - (void)loadStackFrame:(StackFrame*)frame
 191 {
 192   if (frame.loaded)
 193     return;
 194
 195   NSNumber* routingNumber = [NSNumber numberWithInt:frame.routingID];
 196   NSNumber* transaction = nil;
 197
 198   // Get the source code of the file. Escape % in URL chars.
 199   if ([frame.filename length]) {
 200     NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 201     transaction = [connection_ sendCommandWithFormat:@"source -f %@", escapedFilename];
 202     [self recordCallback:@selector(setSource:) forTransaction:transaction];
 203     [callbackContext_ setObject:routingNumber forKey:transaction];
 204   }
 205
 206   // Get the names of all the contexts.
 207   transaction = [connection_ sendCommandWithFormat:@"context_names -d %d", frame.index];
 208   [self recordCallback:@selector(contextsReceived:) forTransaction:transaction];
 209   [callbackContext_ setObject:routingNumber forKey:transaction];
 210
 211   // This frame will be fully loaded.
 212   frame.loaded = YES;
 213 }
 214
 215 // Breakpoint Management ///////////////////////////////////////////////////////
 216 #pragma mark Breakpoints
 217
 218 /**
 219  * Send an add breakpoint command
 220  */
 221 - (void)addBreakpoint:(Breakpoint*)bp
 222 {
 223   if (![connection_ connected])
 224     return;
 225
 226   NSString* file = [connection_ escapedURIPath:[bp transformedPath]];
 227   NSNumber* tx = [connection_ sendCommandWithFormat:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 228   [self recordCallback:@selector(breakpointReceived:) forTransaction:tx];
 229   [callbackContext_ setObject:bp forKey:tx];
 230 }
 231
 232 /**
 233  * Removes a breakpoint
 234  */
 235 - (void)removeBreakpoint:(Breakpoint*)bp
 236 {
 237   if (![connection_ connected])
 238     return;
 239
 240   [connection_ sendCommandWithFormat:@"breakpoint_remove -d %i", [bp debuggerId]];
 241 }
 242
 243 /**
 244  * Sends a string to be evaluated by the engine.
 245  */
 246 - (void)evalScript:(NSString*)str
 247 {
 248   if (![connection_ connected])
 249     return;
 250
 251   char* encodedString = malloc(modp_b64_encode_len([str length]));
 252   modp_b64_encode(encodedString, [str UTF8String], [str length]);
 253   NSNumber* tx = [connection_ sendCustomCommandWithFormat:@"eval -i {txn} -- %s", encodedString];
 254   free(encodedString);
 255
 256   [self recordCallback:@selector(evalScriptReceived:) forTransaction:tx];
 257 }
 258
 259 // Specific Response Handlers //////////////////////////////////////////////////
 260 #pragma mark Response Handlers
 261
 262 - (void)errorEncountered:(NSString*)error
 263 {
 264   [delegate errorEncountered:error];
 265 }
 266
 267 /**
 268  * Initial packet received. We've started a brand-new connection to the engine.
 269  */
 270 - (void)handleInitialResponse:(NSXMLDocument*)response
 271 {
 272   if (!self.attached) {
 273     [connection_ sendCommandWithFormat:@"detach"];
 274     return;
 275   }
 276
 277   active_ = YES;
 278
 279   // Register any breakpoints that exist offline.
 280   for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 281     [self addBreakpoint:bp];
 282
 283   // Load the debugger to make it look active.
 284   [delegate debuggerConnected];
 285
 286   // TODO: update the status.
 287 }
 288
 289 /**
 290  * Called when the connection is finally closed. This will reopen the listening
 291  * socket if the debugger remains attached.
 292  */
 293 - (void)connectionDidClose:(NetworkConnection*)connection
 294 {
 295   if ([delegate respondsToSelector:@selector(debuggerDisconnected)])
 296     [delegate debuggerDisconnected];
 297
 298   if (self.attached)
 299     [connection_ connect];
 300 }
 301
 302 - (void)handleResponse:(NSXMLDocument*)response
 303 {
 304   NSInteger transactionID = [connection_ transactionIDFromResponse:response];
 305   NSNumber* key = [NSNumber numberWithInt:transactionID];
 306   NSString* callbackStr = [callTable_ objectForKey:key];
 307   if (callbackStr)
 308   {
 309     SEL callback = NSSelectorFromString(callbackStr);
 310     [self performSelector:callback withObject:response];
 311   }
 312   [callTable_ removeObjectForKey:key];
 313 }
 314
 315 /**
 316  * Receiver for status updates. This just freshens up the UI.
 317  */
 318 - (void)updateStatus:(NSXMLDocument*)response
 319 {
 320   self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 321   active_ = YES;
 322   if (!status || [status isEqualToString:@"Stopped"]) {
 323     [delegate debuggerDisconnected];
 324     active_ = NO;
 325   } else if ([status isEqualToString:@"Stopping"]) {
 326     [connection_ sendCommandWithFormat:@"stop"];
 327     active_ = NO;
 328   }
 329 }
 330
 331 /**
 332  * Step in/out/over and run all take this path. We first get the status of the
 333  * debugger and then request fresh stack information.
 334  */
 335 - (void)debuggerStep:(NSXMLDocument*)response
 336 {
 337   [self updateStatus:response];
 338   if (![self isConnected])
 339     return;
 340
 341   // If this is the run command, tell the delegate that a bunch of updates
 342   // are coming. Also remove all existing stack routes and request a new stack.
 343   if ([delegate respondsToSelector:@selector(clobberStack)])
 344     [delegate clobberStack];
 345   [stackFrames_ removeAllObjects];
 346   NSNumber* tx = [connection_ sendCommandWithFormat:@"stack_depth"];
 347   [self recordCallback:@selector(rebuildStack:) forTransaction:tx];
 348   stackFirstTransactionID_ = [tx intValue];
 349 }
 350
 351 /**
 352  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 353  * it.
 354  */
 355 - (void)rebuildStack:(NSXMLDocument*)response
 356 {
 357   NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 358
 359   if (stackFirstTransactionID_ == [connection_ transactionIDFromResponse:response])
 360     stackDepth_ = depth;
 361
 362   // We now need to alloc a bunch of stack frames and get the basic information
 363   // for them.
 364   for (NSInteger i = 0; i < depth; i++)
 365   {
 366     // Use the transaction ID to create a routing path.
 367     NSNumber* routingID = [connection_ sendCommandWithFormat:@"stack_get -d %d", i];
 368     [self recordCallback:@selector(getStackFrame:) forTransaction:routingID];
 369     [stackFrames_ setObject:[[StackFrame new] autorelease] forKey:routingID];
 370   }
 371 }
 372
 373 /**
 374  * The initial rebuild of the stack frame. We now have enough to initialize
 375  * a StackFrame object.
 376  */
 377 - (void)getStackFrame:(NSXMLDocument*)response
 378 {
 379   // Get the routing information.
 380   NSInteger routingID = [connection_ transactionIDFromResponse:response];
 381   if (routingID < stackFirstTransactionID_)
 382     return;
 383   NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 384
 385   // Make sure we initialized this frame in our last |-rebuildStack:|.
 386   StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 387   if (!frame)
 388     return;
 389
 390   NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 391
 392   // Initialize the stack frame.
 393   frame.index = [[[xmlframe attributeForName:@"level"] stringValue] intValue];
 394   frame.filename = [[xmlframe attributeForName:@"filename"] stringValue];
 395   frame.lineNumber = [[[xmlframe attributeForName:@"lineno"] stringValue] intValue];
 396   frame.function = [[xmlframe attributeForName:@"where"] stringValue];
 397   frame.routingID = routingID;
 398
 399   // Only get the complete frame for the first level. The other frames will get
 400   // information loaded lazily when the user clicks on one.
 401   if (frame.index == 0) {
 402     [self loadStackFrame:frame];
 403   }
 404
 405   if ([delegate respondsToSelector:@selector(newStackFrame:)])
 406     [delegate newStackFrame:frame];
 407 }
 408
 409 /**
 410  * Callback for setting the source of a file while rebuilding a specific stack
 411  * frame.
 412  */
 413 - (void)setSource:(NSXMLDocument*)response
 414 {
 415   NSNumber* transaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 416   if ([transaction intValue] < stackFirstTransactionID_)
 417     return;
 418   NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 419   if (!routingNumber)
 420     return;
 421
 422   [callbackContext_ removeObjectForKey:transaction];
 423   StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 424   if (!frame)
 425     return;
 426
 427   frame.source = [[response rootElement] base64DecodedValue];
 428
 429   if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 430     [delegate sourceUpdated:frame];
 431 }
 432
 433 /**
 434  * Enumerates all the contexts of a given stack frame. We then in turn get the
 435  * contents of each one of these contexts.
 436  */
 437 - (void)contextsReceived:(NSXMLDocument*)response
 438 {
 439   // Get the stack frame's routing ID and use it again.
 440   NSNumber* receivedTransaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 441   if ([receivedTransaction intValue] < stackFirstTransactionID_)
 442     return;
 443   NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 444   if (!routingID)
 445     return;
 446
 447   // Get the stack frame by the |routingID|.
 448   StackFrame* frame = [stackFrames_ objectForKey:routingID];
 449
 450   NSXMLElement* contextNames = [response rootElement];
 451   for (NSXMLElement* context in [contextNames children])
 452   {
 453     NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 454
 455     // Fetch each context's variables.
 456     NSNumber* tx = [connection_ sendCommandWithFormat:@"context_get -d %d -c %d", frame.index, cid];
 457     [self recordCallback:@selector(variablesReceived:) forTransaction:tx];
 458     [callbackContext_ setObject:routingID forKey:tx];
 459   }
 460 }
 461
 462 /**
 463  * Receives the variables from the context and attaches them to the stack frame.
 464  */
 465 - (void)variablesReceived:(NSXMLDocument*)response
 466 {
 467   // Get the stack frame's routing ID and use it again.
 468   NSInteger transaction = [connection_ transactionIDFromResponse:response];
 469   if (transaction < stackFirstTransactionID_)
 470     return;
 471   NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 472   NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 473   if (!routingID)
 474     return;
 475
 476   // Get the stack frame by the |routingID|.
 477   StackFrame* frame = [stackFrames_ objectForKey:routingID];
 478
 479   NSMutableArray* variables = [NSMutableArray array];
 480
 481   // Merge the frame's existing variables.
 482   if (frame.variables)
 483     [variables addObjectsFromArray:frame.variables];
 484
 485   // Add these new variables.
 486   NSArray* addVariables = [[response rootElement] children];
 487   if (addVariables) {
 488     for (NSXMLElement* elm in addVariables) {
 489       VariableNode* node = [[VariableNode alloc] initWithXMLNode:elm];
 490       [variables addObject:[node autorelease]];
 491     }
 492   }
 493
 494   frame.variables = variables;
 495 }
 496
 497 /**
 498  * Callback from a |-getProperty:| request.
 499  */
 500 - (void)propertiesReceived:(NSXMLDocument*)response
 501 {
 502   NSInteger transaction = [connection_ transactionIDFromResponse:response];
 503
 504   /*
 505    <response>
 506      <property> <!-- this is the one we requested -->
 507        <property ... /> <!-- these are what we want -->
 508      </property>
 509    </repsonse>
 510    */
 511
 512   // Detach all the children so we can insert them into another document.
 513   NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 514   NSArray* children = [parent children];
 515   [parent setChildren:nil];
 516
 517   [delegate receivedProperties:children forTransaction:transaction];
 518 }
 519
 520 /**
 521  * Callback from a |-evalScript:| request.
 522  */
 523 - (void)evalScriptReceived:(NSXMLDocument*)response
 524 {
 525   NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 526   NSString* value = [parent base64DecodedValue];
 527   [delegate scriptWasEvaluatedWithResult:value];
 528 }
 529
 530 /**
 531  * Callback for setting a breakpoint.
 532  */
 533 - (void)breakpointReceived:(NSXMLDocument*)response
 534 {
 535   NSNumber* transaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 536   Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 537   if (!bp)
 538     return;
 539
 540   [callbackContext_ removeObjectForKey:callbackContext_];
 541   [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 542 }
 543
 544 // Private /////////////////////////////////////////////////////////////////////
 545
 546 - (void)recordCallback:(SEL)callback forTransaction:(NSNumber*)txn
 547 {
 548   [callTable_ setObject:NSStringFromSelector(callback) forKey:txn];
 549 }
 550
 551 @end