[Scummvm-cvs-logs] SF.net SVN: scummvm:[52023] tools/branches/gsoc2010-decompiler/decompiler

[pidgeot at users.sourceforge.net]

Revision: 52023
          http://scummvm.svn.sourceforge.net/scummvm/?rev=52023&view=rev
Author:   pidgeot
Date:     2010-08-12 00:54:04 +0000 (Thu, 12 Aug 2010)

Log Message:
-----------
DECOMPILER: Add explanatory comments

Modified Paths:
--------------
    tools/branches/gsoc2010-decompiler/decompiler/codegen.cpp
    tools/branches/gsoc2010-decompiler/decompiler/codegen.h
    tools/branches/gsoc2010-decompiler/decompiler/control_flow.cpp
    tools/branches/gsoc2010-decompiler/decompiler/graph.h
    tools/branches/gsoc2010-decompiler/decompiler/instruction.h

Modified: tools/branches/gsoc2010-decompiler/decompiler/codegen.cpp
===================================================================
--- tools/branches/gsoc2010-decompiler/decompiler/codegen.cpp	2010-08-12 00:37:09 UTC (rev 52022)
+++ tools/branches/gsoc2010-decompiler/decompiler/codegen.cpp	2010-08-12 00:54:04 UTC (rev 52023)
@@ -178,11 +178,10 @@
 		}
 
 		// Print output
-		// TODO: Proper indenting
 		GroupPtr p = GET(entryPoint);
 		while (p != NULL) {
 			for (std::vector<CodeLine>::iterator it = p->_code.begin(); it != p->_code.end(); ++it) {
-				if (it->_unindentBefore /*&& _indentLevel != 0*/)
+				if (it->_unindentBefore)
 					_indentLevel--;
 				_output << boost::format("%08X: %s") % p->_start->_address % indentString(it->_line) << std::endl;
 				if (it->_indentAfter)

Modified: tools/branches/gsoc2010-decompiler/decompiler/codegen.h
===================================================================
--- tools/branches/gsoc2010-decompiler/decompiler/codegen.h	2010-08-12 00:37:09 UTC (rev 52022)
+++ tools/branches/gsoc2010-decompiler/decompiler/codegen.h	2010-08-12 00:54:04 UTC (rev 52023)
@@ -35,16 +35,19 @@
 
 class Function;
 
+/**
+ * Types of stack entries.
+ */
 enum StackEntryType {
-	seInt,
-	seVar,
-	seBinOp,
-	seUnaryOp,
-	seDup,
-	seArray,
-	seString,
-	seList,
-	seCall
+	seInt,     ///< Integer
+	seVar,     ///< Variable
+	seBinOp,   ///< Binary operation
+	seUnaryOp, ///< Unary operation
+	seDup,     ///< Duplicated entry
+	seArray,   ///< Array access
+	seString,  ///< String
+	seList,    ///< List
+	seCall     ///< Function call
 };
 
 class StackEntry;

Modified: tools/branches/gsoc2010-decompiler/decompiler/control_flow.cpp
===================================================================
--- tools/branches/gsoc2010-decompiler/decompiler/control_flow.cpp	2010-08-12 00:37:09 UTC (rev 52022)
+++ tools/branches/gsoc2010-decompiler/decompiler/control_flow.cpp	2010-08-12 00:54:04 UTC (rev 52023)
@@ -38,11 +38,14 @@
 ControlFlow::ControlFlow(const std::vector<Instruction> &insts, Engine *engine) : _insts(insts) {
 	_engine = engine;
 
+	// Automatically add a function if we're not supposed to look for more functions and no functions are defined
+	// This avoids a special case for when no real functions exist in the script
 	if (engine->_functions.empty() && !_engine->detectMoreFuncs())
 		engine->_functions[insts.begin()->_address] = Function(insts.begin(), insts.end());
 
 	GroupPtr prev = NULL;
 	int id = 0;
+	// Create vertices
 	for (ConstInstIterator it = insts.begin(); it != insts.end(); ++it) {
 		GraphVertex cur = boost::add_vertex(_g);
 		_addrMap[it->_address] = cur;
@@ -50,12 +53,14 @@
 		PUT_ID(cur, id);
 		id++;
 
+		// Add reference to vertex if function starts here
 		if (_engine->_functions.find(it->_address) != _engine->_functions.end())
 			_engine->_functions[it->_address]._v = cur;
 
 		prev = GET(cur);
 	}
 
+	// Add regular edges
 	FuncMap::iterator fn;
 	GraphVertex last;
 	bool addEdge = false;
@@ -77,6 +82,7 @@
 
 	}
 
+	// Add jump edges
 	for (ConstInstIterator it = insts.begin(); it != insts.end(); ++it) {
 		switch(it->_type) {
 		case kJump:
@@ -185,6 +191,7 @@
 					return;
 				}
 				if (fn->second._startIt == fn->second._endIt) {
+					// We already know this is an entry point, we only need to detect the end point
 					detectEndPoint = true;
 					break;
 				}
@@ -279,13 +286,16 @@
 		}
 
 		expectedStackLevel = grCur->_stackLevel;
+		// If expected stack level decreases in next vertex, then use next vertex level as expected level
 		if (expectedStackLevel > grNext->_stackLevel && grNext->_stackLevel >= 0) {
 			expectedStackLevel = grNext->_stackLevel;
+			// Also set the stack level of the current group to remember that we expect it to be lower
 			grCur->_stackLevel = expectedStackLevel;
 		}
 
 		stackLevel += curInst->_stackChange;
 
+		// For stack operations, the new stack level becomes the expected stack level starting from the next group
 		if (curInst->_type == kStack) {
 			expectedStackLevel = stackLevel;
 			grNext->_stackLevel = stackLevel;

Modified: tools/branches/gsoc2010-decompiler/decompiler/graph.h
===================================================================
--- tools/branches/gsoc2010-decompiler/decompiler/graph.h	2010-08-12 00:37:09 UTC (rev 52022)
+++ tools/branches/gsoc2010-decompiler/decompiler/graph.h	2010-08-12 00:54:04 UTC (rev 52023)
@@ -323,6 +323,7 @@
 				output << " ";
 				if (param->_type != kString) {
 					if (inst->_type == kCondJump || inst->_type == kCondJumpRel || inst->_type == kJump || inst->_type == kJumpRel || inst->_type == kCall) {
+						// Output numerical arguments to jumps in hexadecimal
 						switch (param->_type) {
 						case kSByte:
 						case kShort:
@@ -363,6 +364,7 @@
 };
 
 namespace boost {
+
 /**
  * Add a reference to a pointer.
  */
@@ -377,8 +379,9 @@
 	if (--(p->_refCount) == 0)
 		delete p;
 }
-}
 
+} // End of namespace boost
+
 class Engine;
 
 /**

Modified: tools/branches/gsoc2010-decompiler/decompiler/instruction.h
===================================================================
--- tools/branches/gsoc2010-decompiler/decompiler/instruction.h	2010-08-12 00:37:09 UTC (rev 52022)
+++ tools/branches/gsoc2010-decompiler/decompiler/instruction.h	2010-08-12 00:54:04 UTC (rev 52023)
@@ -120,6 +120,7 @@
 			if (param != inst._params.begin())
 				output << ",";
 			if (inst._type == kCondJump || inst._type == kCondJumpRel || inst._type == kJump || inst._type == kJumpRel || inst._type == kCall) {
+				// Output numerical arguments to jumps in hexadecimal
 				switch (param->_type) {
 				case kSByte:
 				case kShort:


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