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 "Breakpoint.h"
  21 #import "DebuggerModel.h"
  22 #import "NSXMLElementAdditions.h"
  23 #import "StackFrame.h"
  24
  25 @implementation DebuggerBackEnd {
  26   // The connection to the debugger engine.
  27   uint16_t _port;
  28   ProtocolClient* _client;
  29 }
  30
  31 - (instancetype)initWithPort:(NSUInteger)aPort autoAttach:(BOOL)doAttach
  32 {
  33   if (self = [super init]) {
  34     _port = aPort;
  35     _client = [[ProtocolClient alloc] initWithDelegate:self];
  36
  37     _autoAttach = doAttach;
  38     if (doAttach)
  39       [_client connectOnPort:_port];
  40   }
  41   return self;
  42 }
  43
  44 - (void)dealloc {
  45   [_client release];
  46   [super dealloc];
  47 }
  48
  49 // Getters /////////////////////////////////////////////////////////////////////
  50 #pragma mark Getters
  51
  52 /**
  53  * Gets the port number
  54  */
  55 - (uint16_t)port {
  56   return _port;
  57 }
  58
  59 /**
  60  * Sets the attached state of the debugger. This will open and close the
  61  * connection as appropriate.
  62  */
  63 - (void)setAutoAttach:(BOOL)flag {
  64   if (flag == _autoAttach)
  65     return;
  66
  67   if (_autoAttach)
  68     [_client disconnect];
  69   else
  70     [_client connectOnPort:_port];
  71
  72   _autoAttach = flag;
  73 }
  74
  75 // Commands ////////////////////////////////////////////////////////////////////
  76 #pragma mark Commands
  77
  78 /**
  79  * Tells the debugger to continue running the script. Returns the current stack frame.
  80  */
  81 - (void)run {
  82   [_client sendCommandWithFormat:@"run" handler:^(NSXMLDocument* message) {
  83     [self debuggerStep:message];
  84   }];
  85 }
  86
  87 /**
  88  * Tells the debugger to step into the current command.
  89  */
  90 - (void)stepIn {
  91   [_client sendCommandWithFormat:@"step_into" handler:^(NSXMLDocument* message) {
  92     [self debuggerStep:message];
  93   }];
  94 }
  95
  96 /**
  97  * Tells the debugger to step out of the current context
  98  */
  99 - (void)stepOut {
 100   [_client sendCommandWithFormat:@"step_out" handler:^(NSXMLDocument* message) {
 101     [self debuggerStep:message];
 102   }];
 103 }
 104
 105 /**
 106  * Tells the debugger to step over the current function
 107  */
 108 - (void)stepOver {
 109   [_client sendCommandWithFormat:@"step_over" handler:^(NSXMLDocument* message) {
 110     [self debuggerStep:message];
 111   }];
 112 }
 113
 114 /**
 115  * Halts execution of the script.
 116  */
 117 - (void)stop {
 118   [_client disconnect];
 119   self.model.status = @"Stopped";
 120 }
 121
 122 /**
 123  * Ends the current debugging session.
 124  */
 125 - (void)detach {
 126   [_client sendCommandWithFormat:@"detach"];
 127   self.model.status = @"Stopped";
 128 }
 129
 130 - (void)loadStackFrame:(StackFrame*)frame {
 131   if (frame.loaded)
 132     return;
 133
 134   // Get the source code of the file. Escape % in URL chars.
 135   if ([frame.filename length]) {
 136     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 137       frame.source = [[message rootElement] base64DecodedValue];
 138     };
 139     [_client sendCommandWithFormat:@"source -f %@" handler:handler, frame.filename];
 140   }
 141
 142   // Get the names of all the contexts.
 143   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 144     [self loadContexts:message forFrame:frame];
 145   };
 146   [_client sendCommandWithFormat:@"context_names -d %d" handler:handler, frame.index];
 147
 148   // This frame will be fully loaded.
 149   frame.loaded = YES;
 150 }
 151
 152 - (void)loadVariableNode:(VariableNode*)variable
 153            forStackFrame:(StackFrame*)frame {
 154   if (variable.children.count == variable.childCount)
 155     return;
 156
 157   [self loadVariableNode:variable forStackFrame:frame dataPage:0 loadedData:@[]];
 158 }
 159
 160 - (void)loadVariableNode:(VariableNode*)variable
 161            forStackFrame:(StackFrame*)frame
 162                 dataPage:(unsigned int)dataPage
 163               loadedData:(NSArray*)loadedData {
 164   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 165     /*
 166      <response>
 167        <property> <!-- this is the one we requested -->
 168          <property ... /> <!-- these are what we want -->
 169        </property>
 170      </repsonse>
 171      */
 172
 173     // Detach all the children so we can insert them into another document.
 174     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 175     NSArray* children = [parent children];
 176     [parent setChildren:nil];
 177
 178     // Check to see if there are more children to load.
 179     NSArray* newLoadedData = [loadedData arrayByAddingObjectsFromArray:children];
 180
 181     NSInteger totalChildren = [[[parent attributeForName:@"numchildren"] stringValue] integerValue];
 182     if ([newLoadedData count] < (NSUInteger)totalChildren) {
 183       [self loadVariableNode:variable
 184                forStackFrame:frame
 185                     dataPage:dataPage + 1
 186                   loadedData:newLoadedData];
 187     } else {
 188       [variable setChildrenFromXMLChildren:newLoadedData];
 189     }
 190   };
 191   [_client sendCommandWithFormat:@"property_get -d %d -n %@ -p %u" handler:handler, frame.index, variable.fullName, dataPage];
 192 }
 193
 194 // Breakpoint Management ///////////////////////////////////////////////////////
 195 #pragma mark Breakpoints
 196
 197 /**
 198  * Send an add breakpoint command
 199  */
 200 - (void)addBreakpoint:(Breakpoint*)bp {
 201   if (!self.model.connected)
 202     return;
 203
 204   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 205     [bp setDebuggerId:[[[[message rootElement] attributeForName:@"id"] stringValue] intValue]];
 206   };
 207   if (bp.type == kBreakpointTypeFile) {
 208     NSString* file = [ProtocolClient escapedFilePathURI:[bp transformedPath]];
 209     [_client sendCommandWithFormat:@"breakpoint_set -t line -f %@ -n %i" handler:handler, file, [bp line]];
 210   } else if (bp.type == kBreakpointTypeFunctionEntry) {
 211     [_client sendCommandWithFormat:@"breakpoint_set -t call -m %@" handler:handler, bp.functionName];
 212   }
 213 }
 214
 215 /**
 216  * Removes a breakpoint
 217  */
 218 - (void)removeBreakpoint:(Breakpoint*)bp {
 219   if (!self.model.connected)
 220     return;
 221
 222   [_client sendCommandWithFormat:@"breakpoint_remove -d %i", [bp debuggerId]];
 223 }
 224
 225 /**
 226  * Sends a string to be evaluated by the engine.
 227  */
 228 - (void)evalScript:(NSString*)str callback:(void (^)(NSString*))callback {
 229   if (!self.model.connected)
 230     return;
 231
 232   NSData* stringData = [str dataUsingEncoding:NSUTF8StringEncoding];
 233   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 234     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 235     NSString* value = [parent base64DecodedValue];
 236     callback(value);
 237   };
 238   [_client sendCustomCommandWithFormat:@"eval -i {txn} -- %@"
 239                                handler:handler, [stringData base64EncodedStringWithOptions:0]];
 240 }
 241
 242 // Protocol Client Delegate ////////////////////////////////////////////////////
 243 #pragma mark Protocol Client Delegate
 244
 245 - (void)debuggerEngineConnected:(ProtocolClient*)client {
 246   [_model onNewConnection];
 247 }
 248
 249 /**
 250  * Called when the connection is finally closed. This will reopen the listening
 251  * socket if the debugger remains attached.
 252  */
 253 - (void)debuggerEngineDisconnected:(ProtocolClient*)client {
 254   [_model onDisconnect];
 255
 256   if (self.autoAttach)
 257     [_client connectOnPort:_port];
 258 }
 259
 260 - (void)protocolClient:(ProtocolClient*)client receivedInitialMessage:(NSXMLDocument*)message {
 261   [self handleInitialResponse:message];
 262 }
 263
 264 - (void)protocolClient:(ProtocolClient*)client receivedErrorMessage:(NSXMLDocument*)message {
 265   NSArray* error = [[message rootElement] elementsForName:@"error"];
 266   if ([error count] > 0) {
 267     NSLog(@"Xdebug error: %@", error);
 268     NSString* errorMessage = [[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue];
 269     _model.lastError = errorMessage;
 270   }
 271 }
 272
 273 // Specific Response Handlers //////////////////////////////////////////////////
 274 #pragma mark Response Handlers
 275
 276 /**
 277  * Initial packet received. We've started a brand-new connection to the engine.
 278  */
 279 - (void)handleInitialResponse:(NSXMLDocument*)response {
 280   if (!self.autoAttach) {
 281     [_client sendCommandWithFormat:@"detach"];
 282     return;
 283   }
 284
 285   // Register any breakpoints that exist offline.
 286   for (Breakpoint* bp in self.model.breakpointManager.breakpoints)
 287     [self addBreakpoint:bp];
 288
 289   // TODO: update the status.
 290 }
 291
 292 /**
 293  * Receiver for status updates. This just freshens up the UI.
 294  */
 295 - (void)updateStatus:(NSXMLDocument*)response {
 296   NSString* status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 297   self.model.status = status;
 298   if (!status || [status isEqualToString:@"Stopped"]) {
 299     [_model onDisconnect];
 300   } else if ([status isEqualToString:@"Stopping"]) {
 301     [_client sendCommandWithFormat:@"stop"];
 302   }
 303 }
 304
 305 /**
 306  * Step in/out/over and run all take this path. We first get the status of the
 307  * debugger and then request fresh stack information.
 308  */
 309 - (void)debuggerStep:(NSXMLDocument*)response {
 310   [self updateStatus:response];
 311   if (!self.model.connected)
 312     return;
 313
 314   [_client sendCommandWithFormat:@"stack_depth" handler:^(NSXMLDocument* message) {
 315     [self rebuildStack:message];
 316   }];
 317 }
 318
 319 /**
 320  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 321  * it.
 322  */
 323 - (void)rebuildStack:(NSXMLDocument*)response {
 324   NSUInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 325
 326   // Send a request to get each frame of the stack, which will be added to this
 327   // array. When the final frame arrives, the |tempStack| is released.
 328   __block NSMutableArray* tempStack = [[NSMutableArray alloc] init];
 329
 330   for (NSUInteger i = 0; i < depth; ++i) {
 331     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 332       [tempStack addObject:[self transformXMLToStackFrame:message]];
 333       if (i == depth - 1) {
 334         [self.model updateStack:[tempStack autorelease]];
 335       }
 336     };
 337     [_client sendCommandWithFormat:@"stack_get -d %d" handler:handler, i];
 338   }
 339 }
 340
 341 /**
 342  * Creates a StackFrame object from an NSXMLDocument response from the "stack_get"
 343  * command.
 344  */
 345 - (StackFrame*)transformXMLToStackFrame:(NSXMLDocument*)response {
 346   NSXMLElement* xmlframe = (NSXMLElement*)[[[response rootElement] children] objectAtIndex:0];
 347   StackFrame* frame = [[[StackFrame alloc] init] autorelease];
 348   frame.index = [[[xmlframe attributeForName:@"level"] stringValue] intValue];
 349   frame.filename = [[xmlframe attributeForName:@"filename"] stringValue];
 350   frame.lineNumber = [[[xmlframe attributeForName:@"lineno"] stringValue] intValue];
 351   frame.function = [[xmlframe attributeForName:@"where"] stringValue];
 352   return frame;
 353 }
 354
 355 /**
 356  * Enumerates all the contexts of a given stack frame. We then in turn get the
 357  * contents of each one of these contexts.
 358  */
 359 - (void)loadContexts:(NSXMLDocument*)response forFrame:(StackFrame*)frame {
 360   NSXMLElement* contextNames = [response rootElement];
 361   for (NSXMLElement* context in [contextNames children]) {
 362     NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 363
 364     // Fetch each context's variables.
 365     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 366       NSMutableArray* variables = [NSMutableArray array];
 367
 368       // Merge the frame's existing variables.
 369       if (frame.variables)
 370         [variables addObjectsFromArray:frame.variables];
 371
 372       // Add these new variables.
 373       NSArray* addVariables = [[message rootElement] children];
 374       if (addVariables) {
 375         for (NSXMLElement* elm in addVariables) {
 376           VariableNode* node = [[VariableNode alloc] initWithXMLNode:elm];
 377           [variables addObject:[node autorelease]];
 378         }
 379       }
 380
 381       frame.variables = variables;
 382     };
 383     [_client sendCommandWithFormat:@"context_get -d %d -c %d" handler:handler, frame.index, cid];
 384   }
 385 }
 386
 387 @end