/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#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.
*/
{
    const char* mProgramName;
    FILE* mInput;
    char* mInputName;
    FILE* mOutput;
    char* mOutputName;
    int mHelp;
}
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 gHelpSwitch = {"--help", "-h", 0, NULL, "Information on usage."};

static Switch* gSwitches[] = {
        &gInputSwitch,
        &gOutputSwitch,
        &gHelpSwitch
};


char* scanWhite(char* inScan)
/*
**  Scan for whitespace.
*/
{
    char* retval = inScan;

    while('\0' != *retval && 0 == isspace(*retval))
    {
        retval++;
    }

    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 nm2tsv(Options* inOptions)
/*
**  Read all input.
**  Output tab separated value data.
**
**  We expect our data to be in a particular format.
**  nm --format=bsd --size-sort --print-file-name --demangle
*/
{
    int retval = 0;
    char lineBuffer[4096];  /* yes, the are some very large symbols */
    char* module = NULL;
    char* size = NULL;
    char* type = NULL;
    char* symbol = NULL;

    /*
    **  Read in the nm file.
    */
    while(0 == retval && NULL != fgets(lineBuffer, sizeof(lineBuffer), inOptions->mInput))
    {
        trimWhite(lineBuffer);

        /*
        ** Find the various pieces of information we'll be looking for.
        */
        size = strchr(lineBuffer, ':');
        if(NULL != size)
        {
            *size = '\0';
            size++;

            module = strrchr(lineBuffer, '/');
            if(NULL == module)
            {
                module = lineBuffer;
            }
            else
            {
                *module = '\0';
                module++;
            }

            type = scanWhite(size);
            *type = '\0';
            type++;

            symbol = type + 1;
            *symbol = '\0';
            symbol++;

            /*
            **  Skip certain types.
            */
            switch(*type)
            {
                case '-':
                    continue;
                    break;
                default:
                    break;
            }

            /*
            **  Simply output the data with a little more interpretation.
            **  First is size.
            */
            fprintf(inOptions->mOutput, "%s\t", size);

            /*
            **  Type, CODE or DATA
            */
            switch(toupper(*type))
            {
                case 'T': /* text (code) */
                case 'W': /* weak symbol ??? */
                    fprintf(inOptions->mOutput, "CODE\t");
                    break;
                default:
                    fprintf(inOptions->mOutput, "DATA\t");
                    break;
            }

            /*
            **  Scope, PUBLIC, STATIC, or UNDEF
            */
            if(islower(*type))
            {
                fprintf(inOptions->mOutput, "STATIC\t");
            }
            else
            {
                switch(*type)
                {
                    case '?':
                        fprintf(inOptions->mOutput, "UNDEF\t");
                        break;
                    default:
                        fprintf(inOptions->mOutput, "PUBLIC\t");
                        break;
                }
            }

            /*
            **  Module name, segment.
            */
            fprintf(inOptions->mOutput, "%s\t", module);
            fprintf(inOptions->mOutput, "%c\t", toupper(*type));

            /*
            **  Origin
            */
            fprintf(inOptions->mOutput, "UNDEF:%s:%c\t", module, toupper(*type));

            /*
            **  Symbol is last.
            */
            fprintf(inOptions->mOutput, "%s\n", symbol);
        }
        else
        {
            retval = __LINE__;
            ERROR_REPORT(retval, lineBuffer, "Malformed input line.");
        }
    }

    if(0 == retval && 0 != ferror(inOptions->mInput))
    {
        retval = __LINE__;
        ERROR_REPORT(retval, inOptions->mInputName, "Unable to read file.");
    }

    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
            {
                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 normalizes nm output for use by other tools.\n");
    printf("GNU nm is assumed for symbol type determination.\n");
    printf("i.e. Use this tool to parse the output of:\n");
    printf("\t/usr/bin/nm --format=bsd --size-sort --print-file-name --demangle <exefile>\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 = nm2tsv(&options);
    }

    cleanOptions(&options);
    return retval;
}

