coregrind/m_libcprint.c

/* -*- mode: C; c-basic-offset: 3; -*- */

/*--------------------------------------------------------------------*/
/*--- Libc printing.                                 m_libcprint.c ---*/
/*--------------------------------------------------------------------*/
 
/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2000-2013 Julian Seward 
      jseward@acm.org

   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.

   The GNU General Public License is contained in the file COPYING.
*/

#include "pub_core_basics.h"
#include "pub_core_vki.h"
#include "pub_core_debuglog.h"
#include "pub_core_gdbserver.h"  // VG_(gdb_printf)
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcfile.h"   // VG_(write)(), VG_(write_socket)()
#include "pub_core_libcprint.h"
#include "pub_core_libcproc.h"   // VG_(getpid)(), VG_(read_millisecond_timer()
#include "pub_core_mallocfree.h" // VG_(malloc)
#include "pub_core_options.h"
#include "pub_core_clreq.h"      // For RUNNING_ON_VALGRIND


/* ---------------------------------------------------------------------
   Writing to file or a socket
   ------------------------------------------------------------------ */

/* The destination sinks for normal and XML output.  These have their
   initial values here; they are set to final values by
   m_main.main_process_cmd_line_options().  See comment at the top of
   that function for the associated logic. 
   After startup, the gdbserver monitor command might temporarily
   set the fd of log_output_sink to -2 to indicate that output is
   to be given to gdb rather than output to the startup fd */
OutputSink VG_(log_output_sink) = {  2, False }; /* 2 = stderr */
OutputSink VG_(xml_output_sink) = { -1, False }; /* disabled */
 
/* Do the low-level send of a message to the logging sink. */
static
void send_bytes_to_logging_sink ( OutputSink* sink, const HChar* msg, Int nbytes )
{
   if (sink->is_socket) {
      Int rc = VG_(write_socket)( sink->fd, msg, nbytes );
      if (rc == -1) {
         // For example, the listener process died.  Switch back to stderr.
         sink->is_socket = False;
         sink->fd = 2;
         VG_(write)( sink->fd, msg, nbytes );
      }
   } else {
      /* sink->fd could have been set to -1 in the various
         sys-wrappers for sys_fork, if --child-silent-after-fork=yes
         is in effect.  That is a signal that we should not produce
         any more output. */
      if (sink->fd >= 0)
         VG_(write)( sink->fd, msg, nbytes );
      else if (sink->fd == -2 && nbytes > 0)
         /* send to gdb the provided data, which must be
            a null terminated string with len >= 1 */
         VG_(gdb_printf)("%s", msg);
   }
}


/* ---------------------------------------------------------------------
   printf() and friends
   ------------------------------------------------------------------ */

/* --------- printf --------- */

typedef 
   struct {
      HChar       buf[512];
      Int         buf_used;
      OutputSink* sink;
   } 
   printf_buf_t;

// Adds a single char to the buffer.  When the buffer gets sufficiently
// full, we write its contents to the logging sink.
static void add_to__printf_buf ( HChar c, void *p )
{
   printf_buf_t *b = (printf_buf_t *)p;
   
   if (b->buf_used > sizeof(b->buf) - 2 ) {
      send_bytes_to_logging_sink( b->sink, b->buf, b->buf_used );
      b->buf_used = 0;
   }
   b->buf[b->buf_used++] = c;
   b->buf[b->buf_used]   = 0;
   vg_assert(b->buf_used < sizeof(b->buf));
}

static UInt vprintf_to_buf ( printf_buf_t* b,
                             const HChar *format, va_list vargs )
{
   UInt ret = 0;
   if (b->sink->fd >= 0 || b->sink->fd == -2) {
      ret = VG_(debugLog_vprintf) 
               ( add_to__printf_buf, b, format, vargs );
   }
   return ret;
}

static UInt vprintf_WRK ( OutputSink* sink,
                          const HChar *format, va_list vargs )
{
   printf_buf_t myprintf_buf
      = { "", 0, sink };
   UInt ret
      = vprintf_to_buf(&myprintf_buf, format, vargs);
   // Write out any chars left in the buffer.
   if (myprintf_buf.buf_used > 0) {
      send_bytes_to_logging_sink( myprintf_buf.sink,
                                  myprintf_buf.buf,
                                  myprintf_buf.buf_used );
   }
   return ret;
}

UInt VG_(vprintf) ( const HChar *format, va_list vargs )
{
   return vprintf_WRK( &VG_(log_output_sink), format, vargs );
}

UInt VG_(printf) ( const HChar *format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs, format);
   ret = VG_(vprintf)(format, vargs);
   va_end(vargs);
   return ret;
}

UInt VG_(vprintf_xml) ( const HChar *format, va_list vargs )
{
   return vprintf_WRK( &VG_(xml_output_sink), format, vargs );
}

UInt VG_(printf_xml) ( const HChar *format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs, format);
   ret = VG_(vprintf_xml)(format, vargs);
   va_end(vargs);
   return ret;
}

static UInt emit_WRK ( const HChar* format, va_list vargs )
{
   if (VG_(clo_xml)) {
      return VG_(vprintf_xml)(format, vargs);
   } else if (VG_(log_output_sink).fd == -2) {
      return VG_(vprintf) (format, vargs);
   } else {
      return VG_(vmessage)(Vg_UserMsg, format, vargs);
   }
}
UInt VG_(emit) ( const HChar* format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs, format);
   ret = emit_WRK(format, vargs);
   va_end(vargs);
   return ret;
}

/* --------- sprintf --------- */

/* If we had an explicit buf structure here, it would contain only one
   field, indicating where the next char is to go.  So use p directly
   for that, rather than having it be a pointer to a structure. */

static void add_to__sprintf_buf ( HChar c, void *p )
{
   HChar** b = p;
   *(*b)++ = c;
}

UInt VG_(vsprintf) ( HChar* buf, const HChar *format, va_list vargs )
{
   Int ret;
   HChar* sprintf_ptr = buf;

   ret = VG_(debugLog_vprintf) 
            ( add_to__sprintf_buf, &sprintf_ptr, format, vargs );
   add_to__sprintf_buf('\0', &sprintf_ptr);

   vg_assert(VG_(strlen)(buf) == ret);

   return ret;
}

UInt VG_(sprintf) ( HChar* buf, const HChar *format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs,format);
   ret = VG_(vsprintf)(buf, format, vargs);
   va_end(vargs);
   return ret;
}


/* --------- snprintf --------- */

/* The return value of VG_(snprintf) and VG_(vsnprintf) differs from
   what is defined in C99. Let S be the size of the buffer as given in
   the 2nd argument.
   Return value R:
     R < S:  The output string was successfully written to the buffer.
             It is null-terminated and R == strlen( output string )
     R == S: The supplied buffer was too small to hold the output string.
             The first S-1 characters of the output string were written
             to the buffer followed by the terminating null character.
*/

typedef 
   struct {
      HChar* buf;
      Int    buf_size;
      Int    buf_used;
   } 
   snprintf_buf_t;

static void add_to__snprintf_buf ( HChar c, void* p )
{
   snprintf_buf_t* b = p;
   if (b->buf_size > 0 && b->buf_used < b->buf_size) {
      b->buf[b->buf_used++] = c;
      if (b->buf_used < b->buf_size)
         b->buf[b->buf_used] = 0;
      else
         b->buf[b->buf_size-1] = 0; /* pre: b->buf_size > 0 */
   } 
}

UInt VG_(vsnprintf) ( HChar* buf, Int size, const HChar *format, va_list vargs )
{
   snprintf_buf_t b;
   b.buf      = buf;
   b.buf_size = size < 0 ? 0 : size;
   b.buf_used = 0;
   if (b.buf_size > 0)
      b.buf[0] = 0; // ensure to null terminate buf if empty format
   (void) VG_(debugLog_vprintf) 
             ( add_to__snprintf_buf, &b, format, vargs );

   return b.buf_used;
}

UInt VG_(snprintf) ( HChar* buf, Int size, const HChar *format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs,format);
   ret = VG_(vsnprintf)(buf, size, format, vargs);
   va_end(vargs);
   return ret;
}


/* --------- vcbprintf --------- */

void VG_(vcbprintf)( void(*char_sink)(HChar, void* opaque),
                     void* opaque,
                     const HChar* format, va_list vargs )
{
   (void) VG_(debugLog_vprintf)
             ( char_sink, opaque, format, vargs );
}


/* --------- fprintf ---------- */

/* This is like [v]fprintf, except it writes to a file handle using
   VG_(write). */

#define VGFILE_BUFSIZE  8192

struct _VgFile {
   HChar buf[VGFILE_BUFSIZE];
   UInt  num_chars;   // number of characters in buf
   Int   fd;          // file descriptor to write to
};


static void add_to__vgfile ( HChar c, void *p )
{
   VgFile *fp = p;

   fp->buf[fp->num_chars++] = c;

   if (fp->num_chars == VGFILE_BUFSIZE) {
      VG_(write)(fp->fd, fp->buf, fp->num_chars);
      fp->num_chars = 0;
   }
}

VgFile *VG_(fopen)(const HChar *name, Int flags, Int mode)
{
   SysRes res = VG_(open)(name, flags, mode);

   if (sr_isError(res))
      return NULL;

   VgFile *fp = VG_(malloc)("fopen", sizeof(VgFile));

   fp->fd = sr_Res(res);
   fp->num_chars = 0;

   return fp;
}


UInt VG_(vfprintf) ( VgFile *fp, const HChar *format, va_list vargs )
{
   return VG_(debugLog_vprintf)(add_to__vgfile, fp, format, vargs);
}

UInt VG_(fprintf) ( VgFile *fp, const HChar *format, ... )
{
   UInt ret;
   va_list vargs;
   va_start(vargs,format);
   ret = VG_(vfprintf)(fp, format, vargs);
   va_end(vargs);
   return ret;
}

void VG_(fclose)( VgFile *fp )
{
   // Flush the buffer.
   if (fp->num_chars)
      VG_(write)(fp->fd, fp->buf, fp->num_chars);

   VG_(free)(fp);
}

/* ---------------------------------------------------------------------
   percentify()
   ------------------------------------------------------------------ */

// Percentify n/m with d decimal places.  Includes the '%' symbol at the end.
// Right justifies in 'buf'.
void VG_(percentify)(ULong n, ULong m, UInt d, Int n_buf, HChar buf[]) 
{
   Int i, len, space;
   ULong p1;
   HChar fmt[32];   // large enough

   if (m == 0) {
      // Have to generate the format string in order to be flexible about
      // the width of the field.
      VG_(sprintf)(fmt, "%%%ds", n_buf);
      // fmt is now "%<n_buf>s" where <d> is 1,2,3...
      VG_(sprintf)(buf, fmt, "--%");
      return;
   }
   
   p1 = (100*n) / m;
    
   if (d == 0) {
      VG_(sprintf)(buf, "%llu%%", p1);  // FIXME: unsafe
   } else {
      ULong p2;
      UInt  ex;
      switch (d) {
      case 1: ex = 10;    break;
      case 2: ex = 100;   break;
      case 3: ex = 1000;  break;
      default: VG_(core_panic)("Currently can only handle 3 decimal places");
      }
      p2 = ((100*n*ex) / m) % ex;
      // Have to generate the format string in order to be flexible about
      // the width of the post-decimal-point part.
      VG_(sprintf)(fmt, "%%llu.%%0%ullu%%%%", d);
      // fmt is now "%llu.%0<d>llu%%" where <d> is 1,2,3...
      VG_(sprintf)(buf, fmt, p1, p2);   // FIXME: unsafe
   }

   len = VG_(strlen)(buf);
   space = n_buf - len;
   if (space < 0) space = 0;     /* Allow for v. small field_width */
   i = len;

   /* Right justify in field */
   for (     ; i >= 0;    i--)  buf[i + space] = buf[i];
   for (i = 0; i < space; i++)  buf[i] = ' ';
}


/* ---------------------------------------------------------------------
   elapsed_wallclock_time()
   ------------------------------------------------------------------ */

/* Get the elapsed wallclock time since startup into buf, which must
   16 chars long.  This is unchecked.  It also relies on the
   millisecond timer having been set to zero by an initial read in
   m_main during startup. */

void VG_(elapsed_wallclock_time) ( /*OUT*/HChar* buf, SizeT bufsize )
{
   UInt t, ms, s, mins, hours, days;

   vg_assert(bufsize > 20);

   t  = VG_(read_millisecond_timer)(); /* milliseconds */

   ms = t % 1000;
   t /= 1000; /* now in seconds */

   s = t % 60;
   t /= 60; /* now in minutes */

   mins = t % 60;
   t /= 60; /* now in hours */

   hours = t % 24;
   t /= 24; /* now in days */

   days = t;

   VG_(sprintf)(buf, "%02u:%02u:%02u:%02u.%03u ", days, hours, mins, s, ms);
}


/* ---------------------------------------------------------------------
   message()
   ------------------------------------------------------------------ */

/* A buffer for accumulating VG_(message) style output.  This is
   pretty much the same as VG_(printf)'s scheme, with two differences:

   * The message buffer persists between calls, so that multiple
     calls to VG_(message) can build up output.

   * Whenever the first character on a line is emitted, the
     ==PID== style preamble is stuffed in before it.
*/
typedef 
   struct {
      HChar buf[512+128];
      Int   buf_used;
      Bool  atLeft; /* notionally, is the next char position at the
                       leftmost column? */
      /* Current message kind - changes from call to call */
      VgMsgKind kind;
      /* destination */
      OutputSink* sink;
   } 
   vmessage_buf_t;

static vmessage_buf_t vmessage_buf
   = { "", 0, True, Vg_UserMsg, &VG_(log_output_sink) };


// Adds a single char to the buffer.  We aim to have at least 128
// bytes free in the buffer, so that it's always possible to emit
// the preamble into the buffer if c happens to be the character
// following a \n.  When the buffer gets too full, we write its
// contents to the logging sink.
static void add_to__vmessage_buf ( HChar c, void *p )
{
   HChar tmp[64];
   vmessage_buf_t* b = (vmessage_buf_t*)p;

   vg_assert(b->buf_used >= 0 && b->buf_used < sizeof(b->buf)-128);

   if (UNLIKELY(b->atLeft)) {
      // insert preamble
      HChar ch;
      Int   i, depth;

      // Print one '>' in front of the messages for each level of
      // self-hosting being performed.
      // Do not print such '>' if sim hint "no-inner-prefix" given
      // (useful to run regression tests in an outer/inner setup
      // and avoid the diff failing due to these unexpected '>').
      depth = RUNNING_ON_VALGRIND;
      if (depth > 0 
          && !SimHintiS(SimHint_no_inner_prefix, VG_(clo_sim_hints))) {
         if (depth > 10)
            depth = 10; // ?!?!
         for (i = 0; i < depth; i++) {
            b->buf[b->buf_used++] = '>';
         }
      }

      if (Vg_FailMsg == b->kind) {
         // "valgrind: " prefix.
         b->buf[b->buf_used++] = 'v';
         b->buf[b->buf_used++] = 'a';
         b->buf[b->buf_used++] = 'l';
         b->buf[b->buf_used++] = 'g';
         b->buf[b->buf_used++] = 'r';
         b->buf[b->buf_used++] = 'i';
         b->buf[b->buf_used++] = 'n';
         b->buf[b->buf_used++] = 'd';
         b->buf[b->buf_used++] = ':';
         b->buf[b->buf_used++] = ' ';
      } else {
         switch (b->kind) {
            case Vg_UserMsg:       ch = '='; break;
            case Vg_DebugMsg:      ch = '-'; break;
            case Vg_ClientMsg:     ch = '*'; break;
            default:               ch = '?'; break;
         }

         b->buf[b->buf_used++] = ch;
         b->buf[b->buf_used++] = ch;

         if (VG_(clo_time_stamp)) {
            VG_(elapsed_wallclock_time)(tmp, sizeof tmp);
            for (i = 0; tmp[i]; i++)
               b->buf[b->buf_used++] = tmp[i];
         }

         VG_(sprintf)(tmp, "%d", VG_(getpid)());
         tmp[sizeof(tmp)-1] = 0;
         for (i = 0; tmp[i]; i++)
            b->buf[b->buf_used++] = tmp[i];

         b->buf[b->buf_used++] = ch;
         b->buf[b->buf_used++] = ch;
         b->buf[b->buf_used++] = ' ';
      }

      /* We can't possibly have stuffed 96 chars in merely as a result
         of making the preamble (can we?) */
      vg_assert(b->buf_used < sizeof(b->buf)-32);
   }

   b->buf[b->buf_used++] = c;
   b->buf[b->buf_used]   = 0;
   
   if (b->buf_used >= sizeof(b->buf) - 128) {
      send_bytes_to_logging_sink( b->sink, b->buf, b->buf_used );
      b->buf_used = 0;
   }

   b->atLeft = c == '\n';
}


UInt VG_(vmessage) ( VgMsgKind kind, const HChar* format, va_list vargs )
{
   UInt ret;

   /* Note (carefully) that the buf persists from call to call, unlike
      with the other printf variants in earlier parts of this file. */
   vmessage_buf_t* b = &vmessage_buf; /* shorthand for convenience */

   /* We have to set this each call, so that the correct flavour
      of preamble is emitted at each \n. */
   b->kind = kind;

   ret = VG_(debugLog_vprintf) ( add_to__vmessage_buf,
                                 b, format, vargs );

   /* If the message finished exactly with a \n, then flush it at this
      point.  If not, assume more bits of the same line will turn up
      in later messages, so don't bother to flush it right now. */

   if (b->atLeft && b->buf_used > 0) {
      send_bytes_to_logging_sink( b->sink, b->buf, b->buf_used );
      b->buf_used = 0;
   }

   return ret;
}

/* Send a simple single-part message. */
UInt VG_(message) ( VgMsgKind kind, const HChar* format, ... )
{
   UInt count;
   va_list vargs;
   va_start(vargs,format);
   count = VG_(vmessage) ( kind, format, vargs );
   va_end(vargs);
   return count;
}

static void revert_to_stderr ( void )
{
   VG_(log_output_sink).fd = 2; /* stderr */
   VG_(log_output_sink).is_socket = False;
}

/* VG_(message) variants with hardwired first argument. */

UInt VG_(fmsg) ( const HChar* format, ... )
{
   UInt count;
   va_list vargs;
   va_start(vargs,format);
   count = VG_(vmessage) ( Vg_FailMsg, format, vargs );
   va_end(vargs);
   return count;
}

void VG_(fmsg_bad_option) ( const HChar* opt, const HChar* format, ... )
{
   va_list vargs;
   va_start(vargs,format);
   revert_to_stderr();
   VG_(message) (Vg_FailMsg, "Bad option: %s\n", opt);
   VG_(vmessage)(Vg_FailMsg, format, vargs );
   VG_(message) (Vg_FailMsg, "Use --help for more information or consult the user manual.\n");
   va_end(vargs);
   VG_(exit)(1);
}

UInt VG_(umsg) ( const HChar* format, ... )
{
   UInt count;
   va_list vargs;
   va_start(vargs,format);
   count = VG_(vmessage) ( Vg_UserMsg, format, vargs );
   va_end(vargs);
   return count;
}

UInt VG_(dmsg) ( const HChar* format, ... )
{
   UInt count;
   va_list vargs;
   va_start(vargs,format);
   count = VG_(vmessage) ( Vg_DebugMsg, format, vargs );
   va_end(vargs);
   return count;
}

/* Flush any output that has accumulated in vmessage_buf as a 
   result of previous calls to VG_(message) et al. */
void VG_(message_flush) ( void )
{
   vmessage_buf_t* b = &vmessage_buf;
   send_bytes_to_logging_sink( b->sink, b->buf, b->buf_used );
   b->buf_used = 0;
}

__attribute__((noreturn))
void VG_(err_missing_prog) ( void  )
{
   revert_to_stderr();
   VG_(fmsg)("no program specified\n");
   VG_(fmsg)("Use --help for more information.\n");
   VG_(exit)(1);
}

__attribute__((noreturn))
void VG_(err_config_error) ( const HChar* format, ... )
{
   va_list vargs;
   va_start(vargs,format);
   revert_to_stderr();
   VG_(message) (Vg_FailMsg, "Startup or configuration error:\n   ");
   VG_(vmessage)(Vg_FailMsg, format, vargs );
   VG_(message) (Vg_FailMsg, "Unable to start up properly.  Giving up.\n");
   va_end(vargs);
   VG_(exit)(1);
}


/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/