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//{{{  Banner                                           

//============================================================================

//

//      trace.cxx

//

//      Host side implementation of the infrastructure trace facilities.

//

//============================================================================

//####COPYRIGHTBEGIN####

//                                                                          

// ----------------------------------------------------------------------------

// Copyright (C) 2002 Bart Veer

// Copyright (C) 1998, 1999, 2000, 2001 Red Hat, Inc.

//

// This file is part of the eCos host tools.

//

// This program is free software; you can redistribute it and/or modify it 

// under the terms of the GNU General Public License as published by the Free 

// Software Foundation; either version 2 of the License, or (at your option) 

// any later version.

// 

// This program is distributed in the hope that it will be useful, but WITHOUT 

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 

// more details.

// 

// You should have received a copy of the GNU General Public License along with

// this program; if not, write to the Free Software Foundation, Inc., 

// 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

//

// ----------------------------------------------------------------------------

//                                                                          

//####COPYRIGHTEND####

//============================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   bartv

// Contact(s):  bartv

// Date:        1998/12/07

// Version:     0.01

// Purpose:     To provide a host-side implementation of the eCos tracing

//              facilities.

//

//####DESCRIPTIONEND####

//============================================================================

//}}}

//{{{  #include's                                       

// Make sure that the host-side extensions get prototyped

// as well. Note that the tracing code needs to interact

// with the assertion facilities to set up an appropriate

// callback.

#define CYG_DECLARE_HOST_ASSERTION_SUPPORT

#include "pkgconf/infra.h"

#include "cyg/infra/cyg_type.h"

#include "cyg/infra/cyg_ass.h"

// Without this #define the tracing enums and prototypes are

// not visible.

#define CYGDBG_USE_TRACING

#include "cyg/infra/cyg_trac.h"

// The standard C++ string class is used extensively

#include <string>

// Add a few C headers

#include <cctype>

#include <cstring>

#include <cstdio>

//}}}

//{{{  Description                                      

// -------------------------------------------------------------------------

// The tracing macros end up calling one of the following routines:

//

// void cyg_tracenomsg(cyg_uint32 what, const char* fn, const char* file, cyg_uint32 line)

// void cyg_tracemsg(  ..., const char* msg)

// void cyg_tracemsg2( ..., CYG_ADDRWORD arg0, CYG_ADDRWORD arg1 )

// void cyg_tracemsg4( ..., CYG_ADDRWORD arg0, CYG_ADDRWORD arg1, ... )

// void cyg_tracemsg6( ..., CYG_ADDRWORD arg0, CYG_ADDRWORD arg1, ... )

// void cyg_tracemsg8( ..., CYG_ADDRWORD arg0, CYG_ADDRWORD arg1, ... )

//

// For the 2/4/6/8 variants the msg argument is essentially a printf()

// style format string. However the intention is that the implementation

// of the trace code can delay doing the formatting until the trace

// information is actually needed (with obvious consequences for

// generated strings). Such an implementation would significantly 

// reduce the overheads associated with tracing, and is what is implemented

// here.

//

// CYG_ADDRWORD is likely to be either "int" or the platform-specific

// 64 bit data type: it should be big enough to hold either a pointer

// or any normal integral type. This causes problems on machines which

// have e.g. 32 bit int and 64 bit long: any 32 bit quantities will

// have been converted to 64 bit quantities in the calling code, and

// it is no longer possible to just pass the format string to sprintf().

// Instead what amounts to a re-implementation of sprintf() is needed

// here.

//

// The basic implementation of this trace code is as follows:

//

// 1) a static array of data structures to hold the trace data. The

//    size can be configured. There is a current index into this

//    array.

//

// 2) the various trace functions simply update this array and the

//    counter.

//

// 3) all of the trace functions also check a static to see whether

//    or not it is necessary to install a trace handler. This cannot

//    be done by means of a static object due to constructor priority

//    ordering problems.

//

// 4) the callback function does all the hardware of the formatting

//    etc.

//}}}

//{{{  Types and statics                                

// ----------------------------------------------------------------------------

// A data structure rather than a class is used to hold the trace data.

// This guarantees that the array gets put in the bss section and is properly

// zeroed. A "valid" field in the structure can be checked when dumping the

// array.

typedef struct trace_entry {

    bool            valid;

    cyg_uint32      what;

    cyg_uint32      line;

    const char*     fn;

    const char*     file;

    const char*     msg;

    CYG_ADDRWORD    data[8];

} trace_entry;

#ifndef CYGNUM_INFRA_TRACE_VECTOR_SIZE

# define CYGNUM_INFRA_TRACE_VECTOR_SIZE 2048

#endif

static trace_entry  tracevec[CYGNUM_INFRA_TRACE_VECTOR_SIZE];

static volatile int trace_index = 0;

// Forward declaration of the callback function, for convenience.

static void trace_callback(void (*)(const char*));

// Has the callback been installed yet?

static bool callback_installed = false;

//}}}

//{{{  The trace functions themselves                   

// ----------------------------------------------------------------------------

// The functions that get called by the trace macros. Typically these work

// as follows:

//

// 1) read and increment the trace index. This makes tracing marginally usable

//    in multi-threaded systems.

//

// 2) invalidate the entry that is about to be updated. Again this helps a bit

//    with multi-threaded systems.

//

// 3) fill in all the fields as per the command-line arguments, zeroing

//    unused fields.

//

// 4) set the valid flag to true, which means the contents can now be output.

//

// This is by no means sufficient to guarantee that a call to dump the trace

// vector in some other thread can work safely, but it may help a little bit.

extern "C" void

cyg_tracenomsg(const char* fn, const char* file, cyg_uint32 line)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = cyg_trace_trace;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = 0;

    tracevec[i].data[0] = 0;

    tracevec[i].data[1] = 0;

    tracevec[i].data[2] = 0;

    tracevec[i].data[3] = 0;

    tracevec[i].data[4] = 0;

    tracevec[i].data[5] = 0;

    tracevec[i].data[6] = 0;

    tracevec[i].data[7] = 0;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

extern "C" void

cyg_tracemsg(cyg_uint32 what, const char* fn, const char* file, cyg_uint32 line, const char* msg)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = what;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = msg;

    tracevec[i].data[0] = 0;

    tracevec[i].data[1] = 0;

    tracevec[i].data[2] = 0;

    tracevec[i].data[3] = 0;

    tracevec[i].data[4] = 0;

    tracevec[i].data[5] = 0;

    tracevec[i].data[6] = 0;

    tracevec[i].data[7] = 0;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

extern "C" void

cyg_tracemsg2(cyg_uint32 what, const char* fn, const char* file, cyg_uint32 line, const char *msg,

              CYG_ADDRWORD arg0, CYG_ADDRWORD arg1)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = what;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = msg;

    tracevec[i].data[0] = arg0;

    tracevec[i].data[1] = arg1;

    tracevec[i].data[2] = 0;

    tracevec[i].data[3] = 0;

    tracevec[i].data[4] = 0;

    tracevec[i].data[5] = 0;

    tracevec[i].data[6] = 0;

    tracevec[i].data[7] = 0;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

extern "C" void

cyg_tracemsg4(cyg_uint32 what, const char *fn, const char* file, cyg_uint32 line, const char *msg,

              CYG_ADDRWORD arg0, CYG_ADDRWORD arg1,

              CYG_ADDRWORD arg2, CYG_ADDRWORD arg3)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = what;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = msg;

    tracevec[i].data[0] = arg0;

    tracevec[i].data[1] = arg1;

    tracevec[i].data[2] = arg2;

    tracevec[i].data[3] = arg3;

    tracevec[i].data[4] = 0;

    tracevec[i].data[5] = 0;

    tracevec[i].data[6] = 0;

    tracevec[i].data[7] = 0;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

extern "C" void

cyg_tracemsg6(cyg_uint32 what, const char *fn, const char* file, cyg_uint32 line, const char *msg,

              CYG_ADDRWORD arg0, CYG_ADDRWORD arg1,

              CYG_ADDRWORD arg2, CYG_ADDRWORD arg3,

              CYG_ADDRWORD arg4, CYG_ADDRWORD arg5)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = what;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = msg;

    tracevec[i].data[0] = arg0;

    tracevec[i].data[1] = arg1;

    tracevec[i].data[2] = arg2;

    tracevec[i].data[3] = arg3;

    tracevec[i].data[4] = arg4;

    tracevec[i].data[5] = arg5;

    tracevec[i].data[6] = 0;

    tracevec[i].data[7] = 0;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

extern "C" void

cyg_tracemsg8(cyg_uint32 what, const char* fn, const char* file, cyg_uint32 line, const char *msg,

              CYG_ADDRWORD arg0, CYG_ADDRWORD arg1,

              CYG_ADDRWORD arg2, CYG_ADDRWORD arg3,

              CYG_ADDRWORD arg4, CYG_ADDRWORD arg5,

              CYG_ADDRWORD arg6, CYG_ADDRWORD arg7)

{

    int i               = trace_index;

    tracevec[i].valid   = false;

    trace_index         = (trace_index + 1) % CYGNUM_INFRA_TRACE_VECTOR_SIZE;

    tracevec[i].what    = what;

    tracevec[i].fn      = fn;

    tracevec[i].file    = file;

    tracevec[i].line    = line;

    tracevec[i].msg     = msg;

    tracevec[i].data[0] = arg0;

    tracevec[i].data[1] = arg1;

    tracevec[i].data[2] = arg2;

    tracevec[i].data[3] = arg3;

    tracevec[i].data[4] = arg4;

    tracevec[i].data[5] = arg5;

    tracevec[i].data[6] = arg6;

    tracevec[i].data[7] = arg7;

    tracevec[i].valid   = true;

    if (!callback_installed) {

        cyg_assert_install_failure_callback("Trace", &trace_callback);

        callback_installed = true;

    }

}

//}}}

//{{{  Output callback                                  

// ----------------------------------------------------------------------------

// Dumping the output. The assertion code will invoke a single callback

// function, cyg_trace_dummy::trace_callback(), with a function pointer

// that can be used for the actual output.

//

// The trace_callback() function loops through the various entries in the

// vector, ignoring invalid ones, and invoking output_entry() for the

// valid ones.

//

// There are a number of utility routines:

//

//     trim_file() is used to take a full pathname and return just the

//     final part of it as a C++ string. There is an upper bound on the

//     length of this string.

//

//     trim_linenum() formats the linenumber sensibly.

//

//     trim_function() is used to parse a __PRETTY_FUNCTION__ value

//     and produce something more manageable.

//

//     parse_msg() is used to construct the full trace message.

//     Because of possible 32/64 bit confusion it is not possible

//     to just use sprintf() for this.

static std::string

trim_file(const char* file)

{

    // If the output is to look reasonable then the result should be a

    // fixed length. 20 characters is reasonable for now.

    const int max_filename_len = 20;

    if (0 == file) {

        return std::string(max_filename_len, ' ');

    }

    // Move to the end of the string, and then back again until

    // a directory separator is found. Given the number of levels

    // in a typical eCos directory hierarchy it is probably not

    // worthwhile outputting any of that information.

    const char * pEnd = file + strlen(file);

    while ((pEnd > file) && ('/' != *pEnd) && ('\\' != *pEnd)) {

        pEnd--;

    }

    if (pEnd != file)

        pEnd++;

    std::string result = "";

    int         i      = 0;

    for ( ;(*pEnd != '\0') && (i < max_filename_len); i++, pEnd++) {

        result += *pEnd;

    }

    for ( ; i < max_filename_len; i++) {

        result += ' ';

    }

    return result;

}

// The linenumber output should be up to four digits, right-padded

// with spaces. sprintf() will do the trick nicely.

static std::string

trim_linenum(cyg_uint32 line)

{

    char buf[32];

    sprintf(buf, "%-4d", (int) line);

    return buf;

}

// Extract a function name. On the target side function names

// are usually obtained via __PRETTY_FUNCTION__, and the resulting

// output is a bit on the large side: return value, arguments, etc

// are all included. On the host side the function name is normally

// supplied explicitly and should not be trimmed at all.

//

// Padding is not appropriate since the function name is likely

// to be followed immediately by the argument list. No maximum

// length is imposed - arguably that is a bad idea.

static std::string

trim_function(const char* fn)

{

    if (0 == fn) {

        return "<unknown>";

    }

#if 1

    return fn;

#else

    // This implements the target-side behaviour.

    //

    // First locate the opening bracket. The function name can

    // be identified by walking backwards from that.

    const char *s;

    for (s = fn; ('\0' != *s) && ('(' != *s); s++);

    for ( ; (s > fn) && (*s != ' '); s--);

    if ( s > fn) s++;

    std::string result = "";

    while ( ('\0' != *s) && ('(' != *s) )

        result += *s++;

    return result;

#endif

}

// The trace format string contained a %s. It is necessary to check

// whether the argument is still valid, and return a suitable

// approximation to the actual data.

static std::string

trim_string(const char * arg)

{

    const int max_string_len = 20;

    std::string result = "";

    if (0 == arg) {

        return result;

    }

    int i;

    for ( i = 0; (i < max_string_len) && ('\0' != *arg) && isprint(*arg); i++, arg++) {

        result += *arg;

    }

    return result;

}

// ----------------------------------------------------------------------------

// Parse a printf() style format string and do the appropriate expansions.

// Because of possible confusion between 32 and 64 bit integers it is not

// possible to use sprintf() itself.

//

// It is assumed that the format string is valid, as are most of the

// arguments. The possible exception is %s arguments where a little bit of

// checking happens first.

static std::string

parse_msg(const char* msg, trace_entry& entry)

{

    if (0 == msg) {

        return "";

    }

    // Keep track of the number of arguments in the trace_entry

    // that have been processed.

    int args_index = 0;

    // A utility buffer for sprintf(), e.g. for integer-> string conversions.

    char util_buf[64];

    std::string result = "";

    for ( ; '\0' != *msg; msg++) {

        if ('%' != *msg) {

            result += *msg;

            continue;

        }

        // We have a format string. Extract all of it.

        std::string format = "%";

        msg++;

        // The first part of the format string may be one or more flags.

        while ( ('-' == *msg) || ('+' == *msg) || (' ' == *msg) ||

                ('#' == *msg) || ('0' == *msg) ) {

            format += *msg++;

        }

        // Next comes the width. If this is an asterix it is necessary to

        // substitute in an actual argument.

        if ('*' == *msg) {

            int width = (args_index < 8) ? (int) entry.data[args_index++] : 0;

            sprintf(util_buf, "%d", width);

            format += util_buf;

            msg++;

        } else {

            // Otherwise the width should be one or more digits

            while( isdigit(*msg) ) {

                format += *msg++;

            }

        }

        // Look for a precision, again coping with an asterix.

        if ('.' == *msg) {

            format += *msg++;

            if ('*' == *msg) {

                int precision = (args_index < 8) ? (int) entry.data[args_index++] : 0;

                sprintf(util_buf, "%d", precision);

                format += util_buf;

                msg++;

            } else {

                // The precision should be one or more digits, with an optional -

                if ('-' == *msg) {

                    format += *msg++;

                }

                while (isdigit(*msg)) {

                    format += *msg++;

                }

            }

        }

        // Now look for h,l and L. These have to be remembered.

        bool short_version = false;

        bool long_version  = false;

        if ('h' == *msg) {

            format        += *msg++;

            short_version  = true;

        } else if (('l' == *msg) || ('L' == *msg)) {

            format        += *msg++;

            long_version   = true;

        }

        // The end of the format string has been reached.

        int format_ch  = *msg;

        format        += *msg;

        // If we have already formatted too many arguments, there is no point

        // in trying to do the actual formatting.

        if ( 8 <= args_index ) {

            continue;

        }

        CYG_ADDRWORD val = entry.data[args_index++];

        switch( format_ch ) {

          case '%' :

              result += '%';

              break;

          case 'd' :

          case 'i' :

          case 'o' :

          case 'u' :

          case 'x' :

          case 'X' :

              // "format" contains the appropriate format string.

              // Invoke sprintf() using util_buf, doing the

              // appropriate cast, and then append the output

              // of util_buf.

              //

              // This is not totally robust. If a ridiculous

              // precision has been specified then util_buf may

              // overflow.

              if (long_version) {

                  sprintf(util_buf, format.c_str(), (long) val);

              } else {

                  // The implicit cast rules mean that shorts do not

                  // require any special attention.

                  sprintf(util_buf, format.c_str(), (int) val);

              }

              result += util_buf;

              break;

          case 'c' :

              sprintf(util_buf, format.c_str(), (int) val);

              result += util_buf;

              break;

          case 'p' :

              sprintf(util_buf, format.c_str(), (void *) val);

              result += util_buf;

              break;

          case 's' :

          {

              std::string data = trim_string((char *) val);

              sprintf(util_buf, format.c_str(), data.c_str());

              result += util_buf;

              break;

          }

          default :

              // Any attempt to do floating point conversions would be

              // rather tricky given the casts that have been applied.

              // There is no point in doing anything for unrecognised

              // sequences.

              break;

        }

    }

    return result;

}

// ----------------------------------------------------------------------------

static void

output_entry(void (*pOutputFn)(const char*), trace_entry& entry)

{

    std::string output  = trim_file(entry.file)    + " " +

                          trim_linenum(entry.line) + " " +

                          trim_function(entry.fn)  + " ";

    if (0 != entry.msg) {

        switch( entry.what) {

          case cyg_trace_trace  : output += " '"; break;

          case cyg_trace_enter  : output += "{{"; break;

          case cyg_trace_args   : output += "(("; break;

          case cyg_trace_return : output += "}}"; break;

          default               : output += " ?";

        }

        output += parse_msg(entry.msg, entry);