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Author Topic: Bug in podump?  (Read 5403 times)

iZzz32

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Bug in podump?
« on: November 11, 2011, 11:14:59 PM »
Code: [Select]
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).

Offline Vortex

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Re: Bug in podump?
« Reply #1 on: November 12, 2011, 11:33:55 AM »
Hello,

Can you attach the object file? I can repeat the test for you.
Code it... That's all...

iZzz32

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Re: Bug in podump?
« Reply #2 on: November 12, 2011, 10:42:54 PM »
echo int i; > test.c && pocc /c test.c && podump test.obj

Offline Vortex

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Re: Bug in podump?
« Reply #3 on: November 13, 2011, 11:07:38 AM »
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]
test.c(1): warning #2099: Missing type specifier; assuming 'int'.
test.c(1): error #2001: Syntax error: expected ';' but found 'int'.
Code it... That's all...

iZzz32

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Re: Bug in podump?
« Reply #4 on: November 13, 2011, 11:59:20 AM »
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.
« Last Edit: November 13, 2011, 12:05:36 PM by iZzz32 »

Offline Vortex

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Re: Bug in podump?
« Reply #5 on: November 13, 2011, 04:28:15 PM »
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...
Code it... That's all...

Offline frankie

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Re: Bug in podump?
« Reply #6 on: November 14, 2011, 09:58:19 AM »
Yes it seems a bug. Probably the *podump* code try to read beyond the file end.
If you try:
Code: [Select]
echo int i; > test.c && pocc /c test.c && podump /ALL test.objPodump produce requested output then stops with the error.
« Last Edit: November 14, 2011, 05:23:48 PM by frankie »
It is better to be hated for what you are than to be loved for what you are not. - Andre Gide

CommonTater

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Re: Bug in podump?
« Reply #7 on: November 14, 2011, 04:11:55 PM »
Yes it seems a bug. Probably the *podump* code try to read beyond the file end.
If you try:
Code: [Select]
echo int i; > test.c && pocc /c test.c && podump /ALL test.objPodump 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.


« Last Edit: November 14, 2011, 05:22:34 PM by frankie »

iZzz32

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Re: Bug in podump?
« Reply #8 on: November 14, 2011, 04:50:19 PM »
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).

Offline frankie

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Re: Bug in podump?
« Reply #9 on: November 14, 2011, 05:21:36 PM »
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.
« Last Edit: November 14, 2011, 05:25:51 PM by frankie »
It is better to be hated for what you are than to be loved for what you are not. - Andre Gide

Offline Vortex

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Re: Bug in podump?
« Reply #10 on: November 14, 2011, 08:49:18 PM »
Hi iZzz32,

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

Code: [Select]
\masm32\bin\dumpbin /all test.obj
Code it... That's all...

iZzz32

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Re: Bug in podump?
« Reply #11 on: November 15, 2011, 12:09:47 PM »
Vortex, I'm very sorry about that PM.
Dumpbin from MASM32 v10 works just fine:
Quote from: dumpbin.exe /all foo.obj
Code: [Select]
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.

Offline Vortex

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Re: Bug in podump?
« Reply #12 on: November 15, 2011, 08:17:58 PM »
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
Code it... That's all...