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   if ([delegate respondsToSelector:@selector(debuggerDisconnected)])
 168     [delegate debuggerDisconnected];
 169 }
 170
 171 /**
 172  * Ends the current debugging session.
 173  */
 174 - (void)detach
 175 {
 176   [connection_ sendCommandWithFormat:@"detach"];
 177   active_ = NO;
 178   self.status = @"Stopped";
 179   if ([delegate respondsToSelector:@selector(debuggerDisconnected)])
 180     [delegate debuggerDisconnected];
 181 }
 182
 183 /**
 184  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 185  * that requested it so that the child can be attached.
 186  */
 187 - (NSInteger)getChildrenOfProperty:(VariableNode*)property atDepth:(NSInteger)depth;
 188 {
 189   NSNumber* tx = [connection_ sendCommandWithFormat:@"property_get -d %d -n %@", depth, [property fullName]];
 190   [self recordCallback:@selector(propertiesReceived:) forTransaction:tx];
 191   return [tx intValue];
 192 }
 193
 194 - (void)loadStackFrame:(StackFrame*)frame
 195 {
 196   if (frame.loaded)
 197     return;
 198
 199   NSNumber* routingNumber = [NSNumber numberWithInt:frame.routingID];
 200   NSNumber* transaction = nil;
 201
 202   // Get the source code of the file. Escape % in URL chars.
 203   if ([frame.filename length]) {
 204     NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 205     transaction = [connection_ sendCommandWithFormat:@"source -f %@", escapedFilename];
 206     [self recordCallback:@selector(setSource:) forTransaction:transaction];
 207     [callbackContext_ setObject:routingNumber forKey:transaction];
 208   }
 209
 210   // Get the names of all the contexts.
 211   transaction = [connection_ sendCommandWithFormat:@"context_names -d %d", frame.index];
 212   [self recordCallback:@selector(contextsReceived:) forTransaction:transaction];
 213   [callbackContext_ setObject:routingNumber forKey:transaction];
 214
 215   // This frame will be fully loaded.
 216   frame.loaded = YES;
 217 }
 218
 219 // Breakpoint Management ///////////////////////////////////////////////////////
 220 #pragma mark Breakpoints
 221
 222 /**
 223  * Send an add breakpoint command
 224  */
 225 - (void)addBreakpoint:(Breakpoint*)bp
 226 {
 227   if (![connection_ connected])
 228     return;
 229
 230   NSString* file = [connection_ escapedURIPath:[bp transformedPath]];
 231   NSNumber* tx = [connection_ sendCommandWithFormat:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 232   [self recordCallback:@selector(breakpointReceived:) forTransaction:tx];
 233   [callbackContext_ setObject:bp forKey:tx];
 234 }
 235
 236 /**
 237  * Removes a breakpoint
 238  */
 239 - (void)removeBreakpoint:(Breakpoint*)bp
 240 {
 241   if (![connection_ connected])
 242     return;
 243
 244   [connection_ sendCommandWithFormat:@"breakpoint_remove -d %i", [bp debuggerId]];
 245 }
 246
 247 /**
 248  * Sends a string to be evaluated by the engine.
 249  */
 250 - (void)evalScript:(NSString*)str
 251 {
 252   if (![connection_ connected])
 253     return;
 254
 255   char* encodedString = malloc(modp_b64_encode_len([str length]));
 256   modp_b64_encode(encodedString, [str UTF8String], [str length]);
 257   NSNumber* tx = [connection_ sendCustomCommandWithFormat:@"eval -i {txn} -- %s", encodedString];
 258   free(encodedString);
 259
 260   [self recordCallback:@selector(evalScriptReceived:) forTransaction:tx];
 261 }
 262
 263 // Specific Response Handlers //////////////////////////////////////////////////
 264 #pragma mark Response Handlers
 265
 266 - (void)errorEncountered:(NSString*)error
 267 {
 268   [delegate errorEncountered:error];
 269 }
 270
 271 /**
 272  * Initial packet received. We've started a brand-new connection to the engine.
 273  */
 274 - (void)handleInitialResponse:(NSXMLDocument*)response
 275 {
 276   if (!self.attached) {
 277     [connection_ sendCommandWithFormat:@"detach"];
 278     return;
 279   }
 280
 281   active_ = YES;
 282
 283   // Register any breakpoints that exist offline.
 284   for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 285     [self addBreakpoint:bp];
 286
 287   // Load the debugger to make it look active.
 288   [delegate debuggerConnected];
 289
 290   // TODO: update the status.
 291 }
 292
 293 - (void)handleResponse:(NSXMLDocument*)response
 294 {
 295   NSInteger transactionID = [connection_ transactionIDFromResponse:response];
 296   NSNumber* key = [NSNumber numberWithInt:transactionID];
 297   NSString* callbackStr = [callTable_ objectForKey:key];
 298   if (callbackStr)
 299   {
 300     SEL callback = NSSelectorFromString(callbackStr);
 301     [self performSelector:callback withObject:response];
 302   }
 303   [callTable_ removeObjectForKey:key];
 304 }
 305
 306 /**
 307  * Receiver for status updates. This just freshens up the UI.
 308  */
 309 - (void)updateStatus:(NSXMLDocument*)response
 310 {
 311   self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 312   active_ = YES;
 313   if (!status || [status isEqualToString:@"Stopped"]) {
 314     [delegate debuggerDisconnected];
 315     active_ = NO;
 316   } else if ([status isEqualToString:@"Stopping"]) {
 317     [connection_ sendCommandWithFormat:@"stop"];
 318     active_ = NO;
 319   }
 320 }
 321
 322 /**
 323  * Step in/out/over and run all take this path. We first get the status of the
 324  * debugger and then request fresh stack information.
 325  */
 326 - (void)debuggerStep:(NSXMLDocument*)response
 327 {
 328   [self updateStatus:response];
 329   if (![self isConnected])
 330     return;
 331
 332   // If this is the run command, tell the delegate that a bunch of updates
 333   // are coming. Also remove all existing stack routes and request a new stack.
 334   if ([delegate respondsToSelector:@selector(clobberStack)])
 335     [delegate clobberStack];
 336   [stackFrames_ removeAllObjects];
 337   NSNumber* tx = [connection_ sendCommandWithFormat:@"stack_depth"];
 338   [self recordCallback:@selector(rebuildStack:) forTransaction:tx];
 339   stackFirstTransactionID_ = [tx intValue];
 340 }
 341
 342 /**
 343  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 344  * it.
 345  */
 346 - (void)rebuildStack:(NSXMLDocument*)response
 347 {
 348   NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 349
 350   if (stackFirstTransactionID_ == [connection_ transactionIDFromResponse:response])
 351     stackDepth_ = depth;
 352
 353   // We now need to alloc a bunch of stack frames and get the basic information
 354   // for them.
 355   for (NSInteger i = 0; i < depth; i++)
 356   {
 357     // Use the transaction ID to create a routing path.
 358     NSNumber* routingID = [connection_ sendCommandWithFormat:@"stack_get -d %d", i];
 359     [self recordCallback:@selector(getStackFrame:) forTransaction:routingID];
 360     [stackFrames_ setObject:[[StackFrame new] autorelease] forKey:routingID];
 361   }
 362 }
 363
 364 /**
 365  * The initial rebuild of the stack frame. We now have enough to initialize
 366  * a StackFrame object.
 367  */
 368 - (void)getStackFrame:(NSXMLDocument*)response
 369 {
 370   // Get the routing information.
 371   NSInteger routingID = [connection_ transactionIDFromResponse:response];
 372   if (routingID < stackFirstTransactionID_)
 373     return;
 374   NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 375
 376   // Make sure we initialized this frame in our last |-rebuildStack:|.
 377   StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 378   if (!frame)
 379     return;
 380
 381   NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 382
 383   // Initialize the stack frame.
 384   frame.index = [[[xmlframe attributeForName:@"level"] stringValue] intValue];
 385   frame.filename = [[xmlframe attributeForName:@"filename"] stringValue];
 386   frame.lineNumber = [[[xmlframe attributeForName:@"lineno"] stringValue] intValue];
 387   frame.function = [[xmlframe attributeForName:@"where"] stringValue];
 388   frame.routingID = routingID;
 389
 390   // Only get the complete frame for the first level. The other frames will get
 391   // information loaded lazily when the user clicks on one.
 392   if (frame.index == 0) {
 393     [self loadStackFrame:frame];
 394   }
 395
 396   if ([delegate respondsToSelector:@selector(newStackFrame:)])
 397     [delegate newStackFrame:frame];
 398 }
 399
 400 /**
 401  * Callback for setting the source of a file while rebuilding a specific stack
 402  * frame.
 403  */
 404 - (void)setSource:(NSXMLDocument*)response
 405 {
 406   NSNumber* transaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 407   if ([transaction intValue] < stackFirstTransactionID_)
 408     return;
 409   NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 410   if (!routingNumber)
 411     return;
 412
 413   [callbackContext_ removeObjectForKey:transaction];
 414   StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 415   if (!frame)
 416     return;
 417
 418   frame.source = [[response rootElement] base64DecodedValue];
 419
 420   if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 421     [delegate sourceUpdated:frame];
 422 }
 423
 424 /**
 425  * Enumerates all the contexts of a given stack frame. We then in turn get the
 426  * contents of each one of these contexts.
 427  */
 428 - (void)contextsReceived:(NSXMLDocument*)response
 429 {
 430   // Get the stack frame's routing ID and use it again.
 431   NSNumber* receivedTransaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 432   if ([receivedTransaction intValue] < stackFirstTransactionID_)
 433     return;
 434   NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 435   if (!routingID)
 436     return;
 437
 438   // Get the stack frame by the |routingID|.
 439   StackFrame* frame = [stackFrames_ objectForKey:routingID];
 440
 441   NSXMLElement* contextNames = [response rootElement];
 442   for (NSXMLElement* context in [contextNames children])
 443   {
 444     NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 445
 446     // Fetch each context's variables.
 447     NSNumber* tx = [connection_ sendCommandWithFormat:@"context_get -d %d -c %d", frame.index, cid];
 448     [self recordCallback:@selector(variablesReceived:) forTransaction:tx];
 449     [callbackContext_ setObject:routingID forKey:tx];
 450   }
 451 }
 452
 453 /**
 454  * Receives the variables from the context and attaches them to the stack frame.
 455  */
 456 - (void)variablesReceived:(NSXMLDocument*)response
 457 {
 458   // Get the stack frame's routing ID and use it again.
 459   NSInteger transaction = [connection_ transactionIDFromResponse:response];
 460   if (transaction < stackFirstTransactionID_)
 461     return;
 462   NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 463   NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 464   if (!routingID)
 465     return;
 466
 467   // Get the stack frame by the |routingID|.
 468   StackFrame* frame = [stackFrames_ objectForKey:routingID];
 469
 470   NSMutableArray* variables = [NSMutableArray array];
 471
 472   // Merge the frame's existing variables.
 473   if (frame.variables)
 474     [variables addObjectsFromArray:frame.variables];
 475
 476   // Add these new variables.
 477   NSArray* addVariables = [[response rootElement] children];
 478   if (addVariables) {
 479     for (NSXMLElement* elm in addVariables) {
 480       VariableNode* node = [[VariableNode alloc] initWithXMLNode:elm];
 481       [variables addObject:[node autorelease]];
 482     }
 483   }
 484
 485   frame.variables = variables;
 486 }
 487
 488 /**
 489  * Callback from a |-getProperty:| request.
 490  */
 491 - (void)propertiesReceived:(NSXMLDocument*)response
 492 {
 493   NSInteger transaction = [connection_ transactionIDFromResponse:response];
 494
 495   /*
 496    <response>
 497      <property> <!-- this is the one we requested -->
 498        <property ... /> <!-- these are what we want -->
 499      </property>
 500    </repsonse>
 501    */
 502
 503   // Detach all the children so we can insert them into another document.
 504   NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 505   NSArray* children = [parent children];
 506   [parent setChildren:nil];
 507
 508   [delegate receivedProperties:children forTransaction:transaction];
 509 }
 510
 511 /**
 512  * Callback from a |-evalScript:| request.
 513  */
 514 - (void)evalScriptReceived:(NSXMLDocument*)response
 515 {
 516   NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 517   NSString* value = [parent base64DecodedValue];
 518   [delegate scriptWasEvaluatedWithResult:value];
 519 }
 520
 521 /**
 522  * Callback for setting a breakpoint.
 523  */
 524 - (void)breakpointReceived:(NSXMLDocument*)response
 525 {
 526   NSNumber* transaction = [NSNumber numberWithInt:[connection_ transactionIDFromResponse:response]];
 527   Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 528   if (!bp)
 529     return;
 530
 531   [callbackContext_ removeObjectForKey:callbackContext_];
 532   [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 533 }
 534
 535 // Private /////////////////////////////////////////////////////////////////////
 536
 537 - (void)recordCallback:(SEL)callback forTransaction:(NSNumber*)txn
 538 {
 539   [callTable_ setObject:NSStringFromSelector(callback) forKey:txn];
 540 }
 541
 542 @end