Bug in podump?

[iZzz32]

Code Select Expand


C:\>podump C:\1.obj

Dump of C:\1.obj

File type: OBJ
PODUMP: fatal error: Access denied.

It tries to SetEndOfFile on the input file for some reason even though the file is opened with GENERIC_READ access. It fails, of course. PODUMP v6.50.1 (from the Pelles C 6.50 RC4) under Windows XP SP3 (32-bit).

[Vortex]

Hello,

Can you attach the object file? I can repeat the test for you.

[iZzz32]

echo int i; > test.c && pocc /c test.c && podump test.obj

[Vortex]

echo int i; > test.c && pocc /c test.c && podump test.obj

Are you sure that echo is a C command?

pocc /c test.c

Code Select Expand

test.c(1): warning #2099: Missing type specifier; assuming 'int'.
test.c(1): error #2001: Syntax error: expected ';' but found 'int'.

[iZzz32]

Are you joking? It's a shell command, it overwrites test.c with int i;, then compiles it and dumps the resulting .obj.
Ok, try to dump any .obj file with podump.

PS: trying to dump an empty file also produces a funny error message.

[Vortex]

Are you joking? It's a shell command, it overwrites test.c with int i;, then compiles it and dumps the resulting .obj.

echo is a MS-DOS shell command and not a native C command. My question was a simple one...

[frankie]

Yes it seems a bug. Probably the *podump* code try to read beyond the file end.
If you try:

Code Select Expand

echo int i; > test.c && pocc /c test.c && podump /ALL test.obj
Podump produce requested output then stops with the error.

[CommonTater]

Yes it seems a bug. Probably the *podump* code try to read beyond the file end.
If you try:

Code Select Expand

echo int i; > test.c && pocc /c test.c && podump /ALL test.obj
Podump produce requested output then stops with the error.

FWIW... I found out the hard way that .C and .H files need at least one CR/LF pair at the end. 

The "cheap and dirty" method by shell command does not necessarily add this for you.

[iZzz32]

CommonTater, newline at the end of file is required by the C standard, but Pelles C (as the most of the other compilers) can handle .c files without newline too (however there's a warning at /W1). And anyway echo command always puts a newline at the end of a string (at least in Windows).

[frankie]

Podump dumps *object* files (so don't care of source files newlines).
Pocc compile anyway the source .c file (the newline request is only a warning).
The behaviour of podump is the same with other object files.

[Vortex]

Hi iZzz32,

If you have the Masm32 package or Visual Studio installed, can you try dumpbin?

Code Select Expand

\masm32\bin\dumpbin /all test.obj

[iZzz32]

Vortex, I'm very sorry about that PM.
Dumpbin from MASM32 v10 works just fine:

Code Select Expand


Microsoft (R) COFF Binary File Dumper Version 5.12.8078
Copyright (C) Microsoft Corp 1992-1998. All rights reserved.

Dump of file foo.obj

File Type: COFF OBJECT

FILE HEADER VALUES
             14C machine (i386)
               2 number of sections
        4EC244D7 time date stamp Tue Nov 15 14:54:15 2011
              74 file pointer to symbol table
               7 number of symbols
               0 size of optional header
             100 characteristics
                   32 bit word machine

SECTION HEADER #1
    .bss name
       0 physical address
       0 virtual address
       0 size of raw data
       0 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
C0300080 flags
         Uninitialized Data
         4 byte align
         Read Write

SECTION HEADER #2
.drectve name
       0 physical address
       0 virtual address
      10 size of raw data
      64 file pointer to raw data
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
     A00 flags
         Info
         Remove
         (no align specified)

RAW DATA #2
  00000000: 20 2D 64 65 66 61 75 6C 74 6C 69 62 3A 63 72 74   -defaultlib:crt

   Linker Directives
   -----------------
   -defaultlib:crt

COFF SYMBOL TABLE
000 00000000 DEBUG  notype       Filename     | .file
    foo.c
002 00000000 SECT1  notype       Static       | .bss
    Section length    0, #relocs    0, #linenums    0, checksum        0
004 00000004 UNDEF  notype       External     | _foo
005 00000000 SECT2  notype       Static       | .drectve
    Section length   10, #relocs    0, #linenums    0, checksum        0

String Table Size = 0x0 bytes

  Summary

           0 .bss
          10 .drectve


Anyway, podump behaves the same on different machines, with or without AV software, so it is obviously a bug in podump. Something wrong with cleanup code, I think.

[Vortex]

Hi iZzz32,

There is nothing to be sorry about the PM. Everything is fine and no any problem. As you said, there is probably a bug related to podump.exe