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