Capture Mozilla's codesighs, for use in executable sizing....

third_party/codesighs/maptsvdifftool.c

+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is maptsvdifftool.c code, released
+ * Oct 3, 2002.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2002
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Garrett Arch Blythe, 03-October-2002
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <ctype.h>
+
+#define ERROR_REPORT(num, val, msg)   fprintf(stderr, "error(%d):\t\"%s\"\t%s\n", (num), (val), (msg));
+#define CLEANUP(ptr)    do { if(NULL != ptr) { free(ptr); ptr = NULL; } } while(0)
+
+
+typedef struct __struct_Options
+/*
+**  Options to control how we perform.
+**
+**  mProgramName    Used in help text.
+**  mInput          File to read for input.
+**                  Default is stdin.
+**  mInputName      Name of the file.
+**  mOutput         Output file, append.
+**                  Default is stdout.
+**  mOutputName     Name of the file.
+**  mHelp           Whether or not help should be shown.
+**  mSummaryOnly    Only output a signle line.
+**  mZeroDrift      Output zero drift data.
+**  mNegation       Perform negation heuristics on the symbol drifts.
+*/
+{
+    const char* mProgramName;
+    FILE* mInput;
+    char* mInputName;
+    FILE* mOutput;
+    char* mOutputName;
+    int mHelp;
+    int mSummaryOnly;
+    int mZeroDrift;
+    int mNegation;
+}
+Options;
+
+
+typedef struct __struct_Switch
+/*
+**  Command line options.
+*/
+{
+    const char* mLongName;
+    const char* mShortName;
+    int mHasValue;
+    const char* mValue;
+    const char* mDescription;
+}
+Switch;
+
+#define DESC_NEWLINE "\n\t\t"
+
+static Switch gInputSwitch = {"--input", "-i", 1, NULL, "Specify input file." DESC_NEWLINE "stdin is default."};
+static Switch gOutputSwitch = {"--output", "-o", 1, NULL, "Specify output file." DESC_NEWLINE "Appends if file exists." DESC_NEWLINE "stdout is default."};
+static Switch gSummarySwitch = {"--summary", "-s", 0, NULL, "Only output a single line." DESC_NEWLINE "The cumulative size changes." DESC_NEWLINE "Overrides all other output options."};
+static Switch gZeroDriftSwitch = {"--zerodrift", "-z", 0, NULL, "Output zero drift data." DESC_NEWLINE "Reports symbol changes even when there is no net drift."};
+static Switch gNegationSwitch = {"--negation", "-n", 0, NULL, "Use negation heuristics." DESC_NEWLINE "When symbol sizes are inferred by offset, order changes cause noise." DESC_NEWLINE "This helps see through the noise by eliminating equal and opposite drifts."};
+static Switch gHelpSwitch = {"--help", "-h", 0, NULL, "Information on usage."};
+
+static Switch* gSwitches[] = {
+        &gInputSwitch,
+        &gOutputSwitch,
+        &gSummarySwitch,
+        &gZeroDriftSwitch,
+        &gNegationSwitch,
+        &gHelpSwitch
+};
+
+
+typedef struct __struct_SizeComposition
+/*
+**  Used to keep which parts positive and negative resulted in the total.
+*/
+{
+    int mPositive;
+    int mNegative;
+}
+SizeComposition;
+
+
+typedef struct __struct_SizeStats
+/*
+**  Keep track of sizes.
+**  Use signed integers so that negatives are valid, in which case we shrunk.
+*/
+{
+    int mCode;
+    SizeComposition mCodeComposition;
+
+    int mData;
+    SizeComposition mDataComposition;
+}
+SizeStats;
+
+
+typedef enum __enum_SegmentClass
+/*
+**  What type of data a segment holds.
+*/
+{
+        CODE,
+        DATA
+}
+SegmentClass;
+
+
+typedef struct __struct_SymbolStats
+/*
+**  Symbol level stats.
+*/
+{
+    char* mSymbol;
+    int mSize;
+}
+SymbolStats;
+
+
+typedef struct __struct_ObjectStats
+/*
+**  Object level stats.
+*/
+{
+    char* mObject;
+    int mSize;
+    SizeComposition mComposition;
+    SymbolStats* mSymbols;
+    unsigned mSymbolCount;
+}
+ObjectStats;
+
+
+typedef struct __struct_SegmentStats
+/*
+**  Segment level stats.
+*/
+{
+    char* mSegment;
+    SegmentClass mClass;
+    int mSize;
+    SizeComposition mComposition;
+    ObjectStats* mObjects;
+    unsigned mObjectCount;
+}
+SegmentStats;
+
+
+typedef struct __struct_ModuleStats
+/*
+**  Module level stats.
+*/
+{
+    char* mModule;
+    SizeStats mSize;
+    SegmentStats* mSegments;
+    unsigned mSegmentCount;
+}
+ModuleStats;
+
+
+static int moduleCompare(const void* in1, const void* in2)
+/*
+**  qsort helper.
+*/
+{
+    int retval = 0;
+
+    ModuleStats* one = (ModuleStats*)in1;
+    ModuleStats* two = (ModuleStats*)in2;
+
+    int oneSize = (one->mSize.mCode + one->mSize.mData);
+    int twoSize = (two->mSize.mCode + two->mSize.mData);
+
+    if(oneSize < twoSize)
+    {
+        retval = 1;
+    }
+    else if(oneSize > twoSize)
+    {
+        retval = -1;
+    }
+    else
+    {
+        retval = strcmp(one->mModule, two->mModule);
+        if(0 > oneSize && 0 > twoSize)
+        {
+            retval *= -1;
+        }
+    }
+
+    return retval;
+}
+
+
+static int segmentCompare(const void* in1, const void* in2)
+/*
+**  qsort helper.
+*/
+{
+    int retval = 0;
+
+    SegmentStats* one = (SegmentStats*)in1;
+    SegmentStats* two = (SegmentStats*)in2;
+
+    if(one->mSize < two->mSize)
+    {
+        retval = 1;
+    }
+    else if(one->mSize > two->mSize)
+    {
+        retval = -1;
+    }
+    else
+    {
+        retval = strcmp(one->mSegment, two->mSegment);
+        if(0 > one->mSize && 0 > two->mSize)
+        {
+            retval *= -1;
+        }
+    }
+
+    return retval;
+}
+
+
+static int objectCompare(const void* in1, const void* in2)
+/*
+**  qsort helper.
+*/
+{
+    int retval = 0;
+
+    ObjectStats* one = (ObjectStats*)in1;
+    ObjectStats* two = (ObjectStats*)in2;
+
+    if(one->mSize < two->mSize)
+    {
+        retval = 1;
+    }
+    else if(one->mSize > two->mSize)
+    {
+        retval = -1;
+    }
+    else
+    {
+        retval = strcmp(one->mObject, two->mObject);
+        if(0 > one->mSize && 0 > two->mSize)
+        {
+            retval *= -1;
+        }
+    }
+
+    return retval;
+}
+
+
+static int symbolCompare(const void* in1, const void* in2)
+/*
+**  qsort helper.
+*/
+{
+    int retval = 0;
+
+    SymbolStats* one = (SymbolStats*)in1;
+    SymbolStats* two = (SymbolStats*)in2;
+
+    if(one->mSize < two->mSize)
+    {
+        retval = 1;
+    }
+    else if(one->mSize > two->mSize)
+    {
+        retval = -1;
+    }
+    else
+    {
+        retval = strcmp(one->mSymbol, two->mSymbol);
+        if(0 > one->mSize && 0 > two->mSize)
+        {
+            retval *= -1;
+        }
+    }
+
+    return retval;
+}
+
+
+void trimWhite(char* inString)
+/*
+**  Remove any whitespace from the end of the string.
+*/
+{
+    int len = strlen(inString);
+
+    while(len)
+    {
+        len--;
+
+        if(isspace(*(inString + len)))
+        {
+            *(inString + len) = '\0';
+        }
+        else
+        {
+            break;
+        }
+    }
+}
+
+
+int difftool(Options* inOptions)
+/*
+**  Read a diff file and spit out relevant information.
+*/
+{
+    int retval = 0;
+    char lineBuffer[0x500];
+    SizeStats overall;
+    ModuleStats* modules = NULL;
+    unsigned moduleCount = 0;
+    unsigned moduleLoop = 0;
+    ModuleStats* theModule = NULL;
+    unsigned segmentLoop = 0;
+    SegmentStats* theSegment = NULL;
+    unsigned objectLoop = 0;
+    ObjectStats* theObject = NULL;
+    unsigned symbolLoop = 0;
+    SymbolStats* theSymbol = NULL;
+    unsigned allSymbolCount = 0;
+
+    memset(&overall, 0, sizeof(overall));
+
+    /*
+    **  Read the entire diff file.
+    **  We're only interested in lines beginning with < or >
+    */
+    while(0 == retval && NULL != fgets(lineBuffer, sizeof(lineBuffer), inOptions->mInput))
+    {
+        trimWhite(lineBuffer);
+
+        if(('<' == lineBuffer[0] || '>' == lineBuffer[0]) && ' ' == lineBuffer[1])
+        {
+            int additive = 0;
+            char* theLine = &lineBuffer[2];
+            int scanRes = 0;
+            int size;
+            char segClass[0x10];
+            char scope[0x10];
+            char module[0x100];
+            char segment[0x40];
+            char object[0x100];
+            char* symbol = NULL;
+
+            /*
+            **  Figure out if the line adds or subtracts from something.
+            */
+            if('>' == lineBuffer[0])
+            {
+                additive = __LINE__;
+            }
+
+
+            /*
+            **  Scan the line for information.
+            */
+            scanRes = sscanf(theLine,
+                "%x\t%s\t%s\t%s\t%s\t%s\t",
+                (unsigned*)&size,
+                segClass,
+                scope,
+                module,
+                segment,
+                object);
+
+            if(6 == scanRes)
+            {
+                SegmentClass segmentClass = DATA;
+
+                symbol = strrchr(theLine, '\t') + 1;
+
+                if(0 == strcmp(segClass, "CODE"))
+                {
+                    segmentClass = CODE;
+                }
+                else if(0 == strcmp(segClass, "DATA"))
+                {
+                    segmentClass = DATA;
+                }
+                else
+                {
+                    retval = __LINE__;
+                    ERROR_REPORT(retval, segClass, "Unable to determine segment class.");
+                }
+
+                if(0 == retval)
+                {
+                    unsigned moduleIndex = 0;
+
+                    /*
+                    **  Find, in succession, the following things:
+                    **      the module
+                    **      the segment
+                    **      the object
+                    **      the symbol
+                    **  Failure to find any one of these means to create it.
+                    */
+                    
+                    for(moduleIndex = 0; moduleIndex < moduleCount; moduleIndex++)
+                    {
+                        if(0 == strcmp(modules[moduleIndex].mModule, module))
+                        {
+                            break;
+                        }
+                    }
+                    
+                    if(moduleIndex == moduleCount)
+                    {
+                        void* moved = NULL;
+                        
+                        moved = realloc(modules, sizeof(ModuleStats) * (1 + moduleCount));
+                        if(NULL != moved)
+                        {
+                            modules = (ModuleStats*)moved;
+                            moduleCount++;
+                            memset(modules + moduleIndex, 0, sizeof(ModuleStats));
+                            
+                            modules[moduleIndex].mModule = strdup(module);
+                            if(NULL == modules[moduleIndex].mModule)
+                            {
+                                retval = __LINE__;
+                                ERROR_REPORT(retval, module, "Unable to duplicate string.");
+                            }
+                        }
+                        else
+                        {
+                            retval = __LINE__;
+                            ERROR_REPORT(retval, inOptions->mProgramName, "Unable to increase module array.");
+                        }
+                    }
+                    
+                    if(0 == retval)
+                    {
+                        unsigned segmentIndex = 0;
+                        theModule = (modules + moduleIndex);
+                        
+                        for(segmentIndex = 0; segmentIndex < theModule->mSegmentCount; segmentIndex++)
+                        {
+                            if(0 == strcmp(segment, theModule->mSegments[segmentIndex].mSegment))
+                            {
+                                break;
+                            }
+                        }
+                        
+                        if(segmentIndex == theModule->mSegmentCount)
+                        {
+                            void* moved = NULL;
+                            
+                            moved = realloc(theModule->mSegments, sizeof(SegmentStats) * (theModule->mSegmentCount + 1));
+                            if(NULL != moved)
+                            {
+                                theModule->mSegments = (SegmentStats*)moved;
+                                theModule->mSegmentCount++;
+                                memset(theModule->mSegments + segmentIndex, 0, sizeof(SegmentStats));
+                                
+                                theModule->mSegments[segmentIndex].mClass = segmentClass;
+                                theModule->mSegments[segmentIndex].mSegment = strdup(segment);
+                                if(NULL == theModule->mSegments[segmentIndex].mSegment)
+                                {
+                                    retval = __LINE__;
+                                    ERROR_REPORT(retval, segment, "Unable to duplicate string.");
+                                }
+                            }
+                            else
+                            {
+                                retval = __LINE__;
+                                ERROR_REPORT(retval, inOptions->mProgramName, "Unable to increase segment array.");
+                            }
+                        }
+                        
+                        if(0 == retval)
+                        {
+                            unsigned objectIndex = 0;
+                            theSegment = (theModule->mSegments + segmentIndex);
+                            
+                            for(objectIndex = 0; objectIndex < theSegment->mObjectCount; objectIndex++)
+                            {
+                                if(0 == strcmp(object, theSegment->mObjects[objectIndex].mObject))
+                                {
+                                    break;
+                                }
+                            }
+                            
+                            if(objectIndex == theSegment->mObjectCount)
+                            {
+                                void* moved = NULL;
+                                
+                                moved = realloc(theSegment->mObjects, sizeof(ObjectStats) * (1 + theSegment->mObjectCount));
+                                if(NULL != moved)
+                                {
+                                    theSegment->mObjects = (ObjectStats*)moved;
+                                    theSegment->mObjectCount++;
+                                    memset(theSegment->mObjects + objectIndex, 0, sizeof(ObjectStats));
+                                    
+                                    theSegment->mObjects[objectIndex].mObject = strdup(object);
+                                    if(NULL == theSegment->mObjects[objectIndex].mObject)
+                                    {
+                                        retval = __LINE__;
+                                        ERROR_REPORT(retval, object, "Unable to duplicate string.");
+                                    }
+                                }
+                                else
+                                {
+                                    retval = __LINE__;
+                                    ERROR_REPORT(retval, inOptions->mProgramName, "Unable to increase object array.");
+                                }
+                            }
+                            
+                            if(0 == retval)
+                            {
+                                unsigned symbolIndex = 0;
+                                theObject = (theSegment->mObjects + objectIndex);
+                                
+                                for(symbolIndex = 0; symbolIndex < theObject->mSymbolCount; symbolIndex++)
+                                {
+                                    if(0 == strcmp(symbol, theObject->mSymbols[symbolIndex].mSymbol))
+                                    {
+                                        break;
+                                    }
+                                }
+                                
+                                if(symbolIndex == theObject->mSymbolCount)
+                                {
+                                    void* moved = NULL;
+                                    
+                                    moved = realloc(theObject->mSymbols, sizeof(SymbolStats) * (1 + theObject->mSymbolCount));
+                                    if(NULL != moved)
+                                    {
+                                        theObject->mSymbols = (SymbolStats*)moved;
+                                        theObject->mSymbolCount++;
+                                        allSymbolCount++;
+                                        memset(theObject->mSymbols + symbolIndex, 0, sizeof(SymbolStats));
+                                        
+                                        theObject->mSymbols[symbolIndex].mSymbol = strdup(symbol);
+                                        if(NULL == theObject->mSymbols[symbolIndex].mSymbol)
+                                        {
+                                            retval = __LINE__;
+                                            ERROR_REPORT(retval, symbol, "Unable to duplicate string.");
+                                        }
+                                    }
+                                    else
+                                    {
+                                        retval = __LINE__;
+                                        ERROR_REPORT(retval, inOptions->mProgramName, "Unable to increase symbol array.");
+                                    }
+                                }
+                                
+                                if(0 == retval)
+                                {
+                                    theSymbol = (theObject->mSymbols + symbolIndex);
+
+                                    /*
+                                    **  Update our various totals.
+                                    */
+                                    if(additive)
+                                    {
+                                        if(CODE == segmentClass)
+                                        {
+                                            overall.mCode += size;
+                                            theModule->mSize.mCode += size;
+                                        }
+                                        else if(DATA == segmentClass)
+                                        {
+                                            overall.mData += size;
+                                            theModule->mSize.mData += size;
+                                        }
+
+                                        theSegment->mSize += size;
+                                        theObject->mSize += size;
+                                        theSymbol->mSize += size;
+                                    }
+                                    else
+                                    {
+                                        if(CODE == segmentClass)
+                                        {
+                                            overall.mCode -= size;
+                                            theModule->mSize.mCode -= size;
+                                        }
+                                        else if(DATA == segmentClass)
+                                        {
+                                            overall.mData -= size;
+                                            theModule->mSize.mData -= size;
+                                        }
+
+                                        theSegment->mSize -= size;
+                                        theObject->mSize -= size;
+                                        theSymbol->mSize -= size;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            else
+            {
+                retval = __LINE__;
+                ERROR_REPORT(retval, inOptions->mInputName, "Unable to scan line data.");
+            }
+        }
+    }
+
+    if(0 == retval && 0 != ferror(inOptions->mInput))
+    {
+        retval = __LINE__;
+        ERROR_REPORT(retval, inOptions->mInputName, "Unable to read file.");
+    }
+
+    /*
+    **  Next, it is time to perform revisionist history of sorts.
+    **  If the negation switch is in play, we perfrom the following
+    **      aggressive steps:
+    **
+    **  For each section, find size changes which have an equal and
+    **      opposite change, and set them both to zero.
+    **  However, you can only do this if the number of negating changes
+    **      is even, as if it is odd, then any one of the many could be
+    **      at fault for the actual change.
+    **
+    **  This orginally exists to make the win32 codesighs reports more
+    **      readable/meaningful.
+    */
+    if(0 == retval && 0 != inOptions->mNegation)
+    {
+        ObjectStats** objArray = NULL;
+        SymbolStats** symArray = NULL;
+
+        /*
+        **  Create arrays big enough to hold all symbols.
+        **  As well as an array to keep the owning object at the same index.
+        **  We will keep the object around as we may need to modify the size.
+        */
+        objArray = (ObjectStats**)malloc(allSymbolCount * sizeof(ObjectStats*));
+        symArray = (SymbolStats**)malloc(allSymbolCount * sizeof(SymbolStats*));
+        if(NULL == objArray || NULL == symArray)
+        {
+            retval = __LINE__;
+            ERROR_REPORT(retval, inOptions->mProgramName, "Unable to allocate negation array memory.");
+        }
+        else
+        {
+            unsigned arrayCount = 0;
+            unsigned arrayLoop = 0;
+
+            /*
+            **  Go through and perform the steps on each section/segment.
+            */
+            for(moduleLoop = 0; moduleLoop < moduleCount; moduleLoop++)
+            {
+                theModule = modules + moduleLoop;
+
+                for(segmentLoop = 0; segmentLoop < theModule->mSegmentCount; segmentLoop++)
+                {
+                    theSegment = theModule->mSegments + segmentLoop;
+
+                    /*
+                    **  Collect all symbols under this section.
+                    **  The symbols are spread out between all the objects,
+                    **      so keep track of both independently at the
+                    **      same index.
+                    */
+                    arrayCount = 0;
+
+                    for(objectLoop = 0; objectLoop < theSegment->mObjectCount; objectLoop++)
+                    {
+                        theObject = theSegment->mObjects + objectLoop;
+
+                        for(symbolLoop = 0; symbolLoop < theObject->mSymbolCount; symbolLoop++)
+                        {
+                            theSymbol = theObject->mSymbols + symbolLoop;
+
+                            objArray[arrayCount] = theObject;
+                            symArray[arrayCount] = theSymbol;
+                            arrayCount++;
+                        }
+                    }
+
+                    /*
+                    **  Now that we have a list of symbols, go through each
+                    **      and see if there is a chance of negation.
+                    */
+                    for(arrayLoop = 0; arrayLoop < arrayCount; arrayLoop++)
+                    {
+                        /*
+                        **  If the item is NULL, it was already negated.
+                        **  Don't do this for items with a zero size.
+                        */
+                        if(NULL != symArray[arrayLoop] && 0 != symArray[arrayLoop]->mSize)
+                        {
+                            unsigned identicalValues = 0;
+                            unsigned oppositeValues = 0;
+                            unsigned lookLoop = 0;
+                            const int lookingFor = symArray[arrayLoop]->mSize;
+
+                            /*
+                            **  Count the number of items with this value.
+                            **  Count the number of items with the opposite equal value.
+                            **  If they are equal, go through and negate all sizes.
+                            */
+                            for(lookLoop = arrayLoop; lookLoop < arrayCount; lookLoop++)
+                            {
+                                /*
+                                **  Skip negated items.
+                                **  Skip zero length items.
+                                */
+                                if(NULL == symArray[lookLoop] || 0 == symArray[lookLoop]->mSize)
+                                {
+                                    continue;
+                                }
+
+                                if(lookingFor == symArray[lookLoop]->mSize)
+                                {
+                                    identicalValues++;
+                                }
+                                else if((-1 * lookingFor) == symArray[lookLoop]->mSize)
+                                {
+                                    oppositeValues++;
+                                }
+                            }
+                            
+                            if(0 != identicalValues && identicalValues == oppositeValues)
+                            {
+                                unsigned negationLoop = 0;
+
+                                for(negationLoop = arrayLoop; 0 != identicalValues || 0 != oppositeValues; negationLoop++)
+                                {
+                                    /*
+                                    **  Skip negated items.
+                                    **  Skip zero length items.
+                                    */
+                                    if(NULL == symArray[negationLoop] || 0 == symArray[negationLoop]->mSize)
+                                    {
+                                        continue;
+                                    }
+
+                                    /*
+                                    **  Negate any size matches.
+                                    **  Reflect the change in the object as well.
+                                    **  Clear the symbol.
+                                    */
+                                    if(lookingFor == symArray[negationLoop]->mSize)
+                                    {
+                                        objArray[negationLoop]->mSize -= lookingFor;
+                                        symArray[negationLoop]->mSize = 0;
+                                        symArray[negationLoop] = NULL;
+
+                                        identicalValues--;
+                                    }
+                                    else if((-1 * lookingFor) == symArray[negationLoop]->mSize)
+                                    {
+                                        objArray[negationLoop]->mSize += lookingFor;
+                                        symArray[negationLoop]->mSize = 0;
+                                        symArray[negationLoop] = NULL;
+
+                                        oppositeValues--;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        CLEANUP(objArray);
+        CLEANUP(symArray);
+    }
+
+
+    /*
+    **  If all went well, time to report.
+    */
+    if(0 == retval)
+    {
+        /*
+        **  Loop through our data once more, so that the symbols can
+        **      propigate their changes upwards in a positive/negative
+        **      fashion.
+        **  This will help give the composite change more meaning.
+        */
+        for(moduleLoop = 0; moduleLoop < moduleCount; moduleLoop++)
+        {
+            theModule = modules + moduleLoop;
+            
+            /*
+            **  Skip if there is zero drift, or no net change.
+            */
+            if(0 == inOptions->mZeroDrift && 0 == (theModule->mSize.mCode + theModule->mSize.mData))
+            {
+                continue;
+            }
+
+            for(segmentLoop = 0; segmentLoop < theModule->mSegmentCount; segmentLoop++)
+            {
+                theSegment = theModule->mSegments + segmentLoop;
+                
+                /*
+                **  Skip if there is zero drift, or no net change.
+                */
+                if(0 == inOptions->mZeroDrift && 0 == theSegment->mSize)
+                {
+                    continue;
+                }
+                
+                for(objectLoop = 0; objectLoop < theSegment->mObjectCount; objectLoop++)
+                {
+                    theObject = theSegment->mObjects + objectLoop;
+                    
+                    /*
+                    **  Skip if there is zero drift, or no net change.
+                    */
+                    if(0 == inOptions->mZeroDrift && 0 == theObject->mSize)
+                    {
+                        continue;
+                    }
+
+                    for(symbolLoop = 0; symbolLoop < theObject->mSymbolCount; symbolLoop++)
+                    {
+                        theSymbol = theObject->mSymbols + symbolLoop;
+                        
+                        /*
+                        **  Propagate the composition all the way to the top.
+                        **  Sizes of zero change are skipped.
+                        */
+                        if(0 < theSymbol->mSize)
+                        {
+                            theObject->mComposition.mPositive += theSymbol->mSize;
+                            theSegment->mComposition.mPositive += theSymbol->mSize;
+                            if(CODE == theSegment->mClass)
+                            {
+                                overall.mCodeComposition.mPositive += theSymbol->mSize;
+                                theModule->mSize.mCodeComposition.mPositive += theSymbol->mSize;
+                            }
+                            else if(DATA == theSegment->mClass)
+                            {
+                                overall.mDataComposition.mPositive += theSymbol->mSize;
+                                theModule->mSize.mDataComposition.mPositive += theSymbol->mSize;
+                            }
+                        }
+                        else if(0 > theSymbol->mSize)
+                        {
+                            theObject->mComposition.mNegative += theSymbol->mSize;
+                            theSegment->mComposition.mNegative += theSymbol->mSize;
+                            if(CODE == theSegment->mClass)
+                            {
+                                overall.mCodeComposition.mNegative += theSymbol->mSize;
+                                theModule->mSize.mCodeComposition.mNegative += theSymbol->mSize;
+                            }
+                            else if(DATA == theSegment->mClass)
+                            {
+                                overall.mDataComposition.mNegative += theSymbol->mSize;
+                                theModule->mSize.mDataComposition.mNegative += theSymbol->mSize;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+
+        if(inOptions->mSummaryOnly)
+        {
+            fprintf(inOptions->mOutput, "%+d (%+d/%+d)\n", overall.mCode + overall.mData, overall.mCodeComposition.mPositive + overall.mDataComposition.mPositive, overall.mCodeComposition.mNegative + overall.mDataComposition.mNegative);
+        }
+        else
+        {
+            fprintf(inOptions->mOutput, "Overall Change in Size\n");
+            fprintf(inOptions->mOutput, "\tTotal:\t%+11d (%+d/%+d)\n", overall.mCode + overall.mData, overall.mCodeComposition.mPositive + overall.mDataComposition.mPositive, overall.mCodeComposition.mNegative + overall.mDataComposition.mNegative);
+            fprintf(inOptions->mOutput, "\tCode:\t%+11d (%+d/%+d)\n", overall.mCode, overall.mCodeComposition.mPositive, overall.mCodeComposition.mNegative);
+            fprintf(inOptions->mOutput, "\tData:\t%+11d (%+d/%+d)\n", overall.mData, overall.mDataComposition.mPositive, overall.mDataComposition.mNegative);
+        }
+
+        /*
+        **  Check what else we should output.
+        */
+        if(0 == inOptions->mSummaryOnly && NULL != modules && moduleCount)
+        {
+            const char* segmentType = NULL;
+
+            /*
+            **  We're going to sort everything.
+            */
+            qsort(modules, moduleCount, sizeof(ModuleStats), moduleCompare);
+            for(moduleLoop = 0; moduleLoop < moduleCount; moduleLoop++)
+            {
+                theModule = modules + moduleLoop;
+
+                qsort(theModule->mSegments, theModule->mSegmentCount, sizeof(SegmentStats), segmentCompare);
+
+                for(segmentLoop = 0; segmentLoop < theModule->mSegmentCount; segmentLoop++)
+                {
+                    theSegment = theModule->mSegments + segmentLoop;
+
+                    qsort(theSegment->mObjects, theSegment->mObjectCount, sizeof(ObjectStats), objectCompare);
+
+                    for(objectLoop = 0; objectLoop < theSegment->mObjectCount; objectLoop++)
+                    {
+                        theObject = theSegment->mObjects + objectLoop;
+
+                        qsort(theObject->mSymbols, theObject->mSymbolCount, sizeof(SymbolStats), symbolCompare);
+                    }
+                }
+            }
+
+            /*
+            **  Loop through for output.
+            */
+            for(moduleLoop = 0; moduleLoop < moduleCount; moduleLoop++)
+            {
+                theModule = modules + moduleLoop;
+
+                /*
+                **  Skip if there is zero drift, or no net change.
+                */
+                if(0 == inOptions->mZeroDrift && 0 == (theModule->mSize.mCode + theModule->mSize.mData))
+                {
+                    continue;
+                }
+
+                fprintf(inOptions->mOutput, "\n");
+                fprintf(inOptions->mOutput, "%s\n", theModule->mModule);
+                fprintf(inOptions->mOutput, "\tTotal:\t%+11d (%+d/%+d)\n", theModule->mSize.mCode + theModule->mSize.mData, theModule->mSize.mCodeComposition.mPositive + theModule->mSize.mDataComposition.mPositive, theModule->mSize.mCodeComposition.mNegative + theModule->mSize.mDataComposition.mNegative);
+                fprintf(inOptions->mOutput, "\tCode:\t%+11d (%+d/%+d)\n", theModule->mSize.mCode, theModule->mSize.mCodeComposition.mPositive, theModule->mSize.mCodeComposition.mNegative);
+                fprintf(inOptions->mOutput, "\tData:\t%+11d (%+d/%+d)\n", theModule->mSize.mData, theModule->mSize.mDataComposition.mPositive, theModule->mSize.mDataComposition.mNegative);
+
+                for(segmentLoop = 0; segmentLoop < theModule->mSegmentCount; segmentLoop++)
+                {
+                    theSegment = theModule->mSegments + segmentLoop;
+
+                    /*
+                    **  Skip if there is zero drift, or no net change.
+                    */
+                    if(0 == inOptions->mZeroDrift && 0 == theSegment->mSize)
+                    {
+                        continue;
+                    }
+
+                    if(CODE == theSegment->mClass)
+                    {
+                        segmentType = "CODE";
+                    }
+                    else if(DATA == theSegment->mClass)
+                    {
+                        segmentType = "DATA";
+                    }
+
+                    fprintf(inOptions->mOutput, "\t%+11d (%+d/%+d)\t%s (%s)\n", theSegment->mSize, theSegment->mComposition.mPositive, theSegment->mComposition.mNegative, theSegment->mSegment, segmentType);
+
+                    for(objectLoop = 0; objectLoop < theSegment->mObjectCount; objectLoop++)
+                    {
+                        theObject = theSegment->mObjects + objectLoop;
+
+                        /*
+                        **  Skip if there is zero drift, or no net change.
+                        */
+                        if(0 == inOptions->mZeroDrift && 0 == theObject->mSize)
+                        {
+                            continue;
+                        }
+
+                        fprintf(inOptions->mOutput, "\t\t%+11d (%+d/%+d)\t%s\n", theObject->mSize, theObject->mComposition.mPositive, theObject->mComposition.mNegative, theObject->mObject);
+                        
+                        for(symbolLoop = 0; symbolLoop < theObject->mSymbolCount; symbolLoop++)
+                        {
+                            theSymbol = theObject->mSymbols + symbolLoop;
+
+                            /*
+                            **  Skip if there is zero drift, or no net change.
+                            */
+                            if(0 == inOptions->mZeroDrift && 0 == theSymbol->mSize)
+                            {
+                                continue;
+                            }
+
+                            fprintf(inOptions->mOutput, "\t\t\t%+11d\t%s\n", theSymbol->mSize, theSymbol->mSymbol);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    /*
+    **  Cleanup time.
+    */
+    for(moduleLoop = 0; moduleLoop < moduleCount; moduleLoop++)
+    {
+        theModule = modules + moduleLoop;
+        
+        for(segmentLoop = 0; segmentLoop < theModule->mSegmentCount; segmentLoop++)
+        {
+            theSegment = theModule->mSegments + segmentLoop;
+            
+            for(objectLoop = 0; objectLoop < theSegment->mObjectCount; objectLoop++)
+            {
+                theObject = theSegment->mObjects + objectLoop;
+                
+                for(symbolLoop = 0; symbolLoop < theObject->mSymbolCount; symbolLoop++)
+                {
+                    theSymbol = theObject->mSymbols + symbolLoop;
+                    
+                    CLEANUP(theSymbol->mSymbol);
+                }
+                
+                CLEANUP(theObject->mSymbols);
+                CLEANUP(theObject->mObject);
+            }
+            
+            CLEANUP(theSegment->mObjects);
+            CLEANUP(theSegment->mSegment);
+        }
+        
+        CLEANUP(theModule->mSegments);
+        CLEANUP(theModule->mModule);
+    }
+    CLEANUP(modules);
+    
+    return retval;
+}
+
+
+int initOptions(Options* outOptions, int inArgc, char** inArgv)
+/*
+**  returns int     0 if successful.
+*/
+{
+    int retval = 0;
+    int loop = 0;
+    int switchLoop = 0;
+    int match = 0;
+    const int switchCount = sizeof(gSwitches) / sizeof(gSwitches[0]);
+    Switch* current = NULL;
+
+    /*
+    **  Set any defaults.
+    */
+    memset(outOptions, 0, sizeof(Options));
+    outOptions->mProgramName = inArgv[0];
+    outOptions->mInput = stdin;
+    outOptions->mInputName = strdup("stdin");
+    outOptions->mOutput = stdout;
+    outOptions->mOutputName = strdup("stdout");
+
+    if(NULL == outOptions->mOutputName || NULL == outOptions->mInputName)
+    {
+        retval = __LINE__;
+        ERROR_REPORT(retval, "stdin/stdout", "Unable to strdup.");
+    }
+
+    /*
+    **  Go through and attempt to do the right thing.
+    */
+    for(loop = 1; loop < inArgc && 0 == retval; loop++)
+    {
+        match = 0;
+        current = NULL;
+
+        for(switchLoop = 0; switchLoop < switchCount && 0 == retval; switchLoop++)
+        {
+            if(0 == strcmp(gSwitches[switchLoop]->mLongName, inArgv[loop]))
+            {
+                match = __LINE__;
+            }
+            else if(0 == strcmp(gSwitches[switchLoop]->mShortName, inArgv[loop]))
+            {
+                match = __LINE__;
+            }
+
+            if(match)
+            {
+                if(gSwitches[switchLoop]->mHasValue)
+                {
+                    /*
+                    **  Attempt to absorb next option to fullfill value.
+                    */
+                    if(loop + 1 < inArgc)
+                    {
+                        loop++;
+
+                        current = gSwitches[switchLoop];
+                        current->mValue = inArgv[loop];
+                    }
+                }
+                else
+                {
+                    current = gSwitches[switchLoop];
+                }
+
+                break;
+            }
+        }
+
+        if(0 == match)
+        {
+            outOptions->mHelp = __LINE__;
+            retval = __LINE__;
+            ERROR_REPORT(retval, inArgv[loop], "Unknown command line switch.");
+        }
+        else if(NULL == current)
+        {
+            outOptions->mHelp = __LINE__;
+            retval = __LINE__;
+            ERROR_REPORT(retval, inArgv[loop], "Command line switch requires a value.");
+        }
+        else
+        {
+            /*
+            ** Do something based on address/swtich.
+            */
+            if(current == &gInputSwitch)
+            {
+                CLEANUP(outOptions->mInputName);
+                if(NULL != outOptions->mInput && stdin != outOptions->mInput)
+                {
+                    fclose(outOptions->mInput);
+                    outOptions->mInput = NULL;
+                }
+
+                outOptions->mInput = fopen(current->mValue, "r");
+                if(NULL == outOptions->mInput)
+                {
+                    retval = __LINE__;
+                    ERROR_REPORT(retval, current->mValue, "Unable to open input file.");
+                }
+                else
+                {
+                    outOptions->mInputName = strdup(current->mValue);
+                    if(NULL == outOptions->mInputName)
+                    {
+                        retval = __LINE__;
+                        ERROR_REPORT(retval, current->mValue, "Unable to strdup.");
+                    }
+                }
+            }
+            else if(current == &gOutputSwitch)
+            {
+                CLEANUP(outOptions->mOutputName);
+                if(NULL != outOptions->mOutput && stdout != outOptions->mOutput)
+                {
+                    fclose(outOptions->mOutput);
+                    outOptions->mOutput = NULL;
+                }
+
+                outOptions->mOutput = fopen(current->mValue, "a");
+                if(NULL == outOptions->mOutput)
+                {
+                    retval = __LINE__;
+                    ERROR_REPORT(retval, current->mValue, "Unable to open output file.");
+                }
+                else
+                {
+                    outOptions->mOutputName = strdup(current->mValue);
+                    if(NULL == outOptions->mOutputName)
+                    {
+                        retval = __LINE__;
+                        ERROR_REPORT(retval, current->mValue, "Unable to strdup.");
+                    }
+                }
+            }
+            else if(current == &gHelpSwitch)
+            {
+                outOptions->mHelp = __LINE__;
+            }
+            else if(current == &gSummarySwitch)
+            {
+                outOptions->mSummaryOnly = __LINE__;
+            }
+            else if(current == &gZeroDriftSwitch)
+            {
+                outOptions->mZeroDrift = __LINE__;
+            }
+            else if(current == &gNegationSwitch)
+            {
+                outOptions->mNegation = __LINE__;
+            }
+            else
+            {
+                retval = __LINE__;
+                ERROR_REPORT(retval, current->mLongName, "No handler for command line switch.");
+            }
+        }
+    }
+
+    return retval;
+}
+
+
+void cleanOptions(Options* inOptions)
+/*
+**  Clean up any open handles.
+*/
+{
+    CLEANUP(inOptions->mInputName);
+    if(NULL != inOptions->mInput && stdin != inOptions->mInput)
+    {
+        fclose(inOptions->mInput);
+    }
+    CLEANUP(inOptions->mOutputName);
+    if(NULL != inOptions->mOutput && stdout != inOptions->mOutput)
+    {
+        fclose(inOptions->mOutput);
+    }
+
+    memset(inOptions, 0, sizeof(Options));
+}
+
+
+void showHelp(Options* inOptions)
+/*
+**  Show some simple help text on usage.
+*/
+{
+    int loop = 0;
+    const int switchCount = sizeof(gSwitches) / sizeof(gSwitches[0]);
+    const char* valueText = NULL;
+
+    printf("usage:\t%s [arguments]\n", inOptions->mProgramName);
+    printf("\n");
+    printf("arguments:\n");
+
+    for(loop = 0; loop < switchCount; loop++)
+    {
+        if(gSwitches[loop]->mHasValue)
+        {
+            valueText = " <value>";
+        }
+        else
+        {
+            valueText = "";
+        }
+
+        printf("\t%s%s\n", gSwitches[loop]->mLongName, valueText);
+        printf("\t %s%s", gSwitches[loop]->mShortName, valueText);
+        printf(DESC_NEWLINE "%s\n\n", gSwitches[loop]->mDescription);
+    }
+
+    printf("This tool takes the diff of two sorted tsv files to form a summary report\n");
+    printf("of code and data size changes which is hoped to be human readable.\n");
+}
+
+
+int main(int inArgc, char** inArgv)
+{
+    int retval = 0;
+    Options options;
+
+    retval = initOptions(&options, inArgc, inArgv);
+    if(options.mHelp)
+    {
+        showHelp(&options);
+    }
+    else if(0 == retval)
+    {
+        retval = difftool(&options);
+    }
+
+    cleanOptions(&options);
+    return retval;
+}
+