As an assembly beginner, this error I'm getting boggles my mind. I'm working on a homework assignment (not asking for solutions), and I'm trying to store the size of a string in a variable.
So I declare a string, 'message'...
; init message as a string with a line break
message BYTE "You already know what the next", 0dh, 0ah
BYTE "variable will be, don't you?", 0
...and afterwards, I use...
len EQU $-message ; get the size of 'message'
...to get the size of message. However, when I tried renaming 'len' to 'length'...
length EQU $-message
Visual Studio (2015 Enterprise) spits out an error saying...
"initializer magnitude too large for specified size"
so........ why is this happening?
Just wondering why I can't name the variable 'length'.
LENGTH is actually an operator.
Visual Studio 2013 produces just a syntax error for such usage, though.
Related
I'm trying to send midi messages from some Julia code I've written, but I'm having trouble with the midiOutOpen function. I'm following this tutorial here, but the output I'm getting from the function doesn't make sense.
This is my Julia code:
const CALLBACK_NULL = uint32(0x00000001)
function openoutputdevice(id::Uint32)
handle = uint32(0)
err = ccall((:midiOutOpen, :Winmm), stdcall,
Uint32,
(Ptr{Uint32}, Uint32, Ptr{Uint32}, Ptr{Uint32}, Uint32),
&handle, id, C_NULL, C_NULL, CALLBACK_NULL)
println(hex(err))
handle
end
The handle is always 0, and the error that's being returned is "10". I've grepped through the Windows header files, and this doesn't seem to match up with any of the errors that can be expected from the function (see here), so I'm more inclined to think that I'm mapping the wrong Julia data types in the ccall. It's been a long time since I've done anything C-related, so I'm hoping there's something obviously wrong with this. The only odd thing I've seen is that CALLBACK_NULL is defined in mmsyscom.h as 0x000000001 - a 9 digit hex number, even though the function doc specifies a DWORD for the final parameter to midiOutOpen.
Any ideas?
The error is MMSYSERR_INVALFLAG because CALLBACK_NULL is defined as:
#define CALLBACK_NULL 0x00000000l
That is a lowercase-letter-"L" at the end, not the number 1 (one). The call succeeds when this value is corrected.
What kind of regex spells I need to put to Eclipse 'Regex error parser' to get PC Lint prints to "problems" view (in Eclipse C/C++ Kepler).
Current lint format is -"format=LINT %t%(: %f:%l %) %n %m"
which prints:
LINT Info: Y:\path\to\file.c:91 732 Loss of sign (assignment) (int to unsigned long)
What I need is first identify that is it info, warning or error and then get:
1. File: 'Y:\path\to\file.c'
2: line: '91'
3: description: '732 Loss of sign ...'
I found one example which did not work for me (most likely the format is different) and I've tried to create my own regex command unsuccessfully.
It is also possible to change the PC-Lint format if it helps.
We are using the following format option:
+ffn
-"format=\q%f\q,%l %t[%n]: \t%m\n"
And our Eclipse regex is:
"(.*\\.*\\.*(h|cpp))",([0-9]*).*((Note|Warning|Error|Info)\[[0-9].*\]): *(.*)
File is $1 Line is $3 and as Description we used Lint $4 $6
Which turns into something like:
Lint Warning[534] Ignoring return value of function...
In the problems overview of Eclipse.
In my CRC8.c I have this function:
BOOL isCRCValid(const UINT8 *ptr, UINT8 Len, UINT8 CRCChar){
return CRCChar == generateCRC(ptr, Len); //generareCRC returns a UINT8
}
It's is declared in CRC8.h, but PC Lint returns me the following.
Info 714: Symbol 'isCRCValid(const unsigned char *, unsigned char, unsigned
char)' not referenced
Info 830: Location cited in prior message
Help says 714 is:
714: Symbol 'Symbol' (Location) not referenced -- The named external
variable or external function was defined but not referenced. This
message is suppressed for unit checkout (-u option).
and 830 is:
830 Location cited in prior message -- Message 830 is a vehicle to
convey in 'canonical form' the location information embedded within
some other message. For example, consider the (somewhat simplified)
message:
file x.c line 37: Declaration for 'x' conflicts with line 22
This contains the location ("line 22") embedded in the text of the
message. Embedded location information is not normally understood by
editors and IDE's (Interactive Development Environments) which can
only position to the nominal location (line 37 in this example). By
adding this additional message with the nominal location of line 22
the user can, by stepping to the next message and, in this case, see
what the 'conflict' is all about. This message and message 831 below
do not follow the ordinary rules for message suppression. If they did
then when the option -w2 was employed to turn the warning level down
to 2 these messages (at level 3) would also vanish. Instead they
continue to function as expected. To inhibit them you need to
explicitly turn them off using one of:
-e830
-e831
They may be restored via +e830 and +e831; they state of suppression
can be saved and restored via the -save -restore options. Options such
as -e8* and -e{831} will have no effect.
As I'm newbie with PC Lint, and relative newbie with C, I'm not achieving resolving this problem.
Can anyone help me with this problem?
The message simply means that PCLint didn't find anything that actually uses this function, so it could be dead code/candidate for removal.
It could also mean that you did not use the input arguments in your function.
WCHAR wszName;
In the debugger displays multiple "squares" and each addressed 0xcdcd
printf("Description: %ws\n", pIfRow->wszName); //prints nothing
Is there a reason it can not get the name from XP?
(All other info in MIB_IFTABLE is correct)
Thanks
0xcdcdcdcd indicates that wszName was never initialized. It is the default value of heap-allocated memory in the Debug build. Review the code that copies a string into wszName, it is not working. Presumably the call to GetIfTable() failed or you're iterating the table wrong.
I am trying to write an interface between RSPEC (ruby flavoured BDD) and a Windows application. The application itself is written in an obscure language, but it has a C API to provide access. I've gone with Ruby/DL but am having difficulties getting even the most basic call to a DLL method to work. Here is what I have so far, in a file called gt4r.rb:
require 'dl/import'
module Gt4r
extend DL::Importable
dlload 'c:\\gtdev\\r321\\bin\\gtvapi'
# GTD initialization/termination functions
extern 'int GTD_init(char *[], char *, char *)'
extern 'int GTD_initialize(char *, char *, char *)'
extern 'int GTD_done(void)'
extern 'int GTD_get_error_message(int, char **)'
end
My reading so far suggests that this is all I need to get going, so I wrote up a RSPEC example:
require 'gt4r'
##test_environment = "INCLUDE=C:\\graphtalk\\env\\aiadev\\config\\aiadev.ini"
##normal_user = "BMCHARGUE"
describe Gt4r do
it 'initializes' do
rv = Gt4r.gTD_initialize ##normal_user, ##normal_user, ##test_environment
rv.should == 0
end
end
And when run...
C:\code\GraphTalk>spec -fs -rgt4r gt4r_spec.rb
Gt4r
- initializes (FAILED - 1)
1)
'Gt4r initializes' FAILED
expected: 0,
got: 13 (using ==)
./gt4r_spec.rb:9:
Finished in 0.031 seconds
1 example, 1 failure
The return value (13) is an actual return code, meaning an error, but when I try to add the gTD_get_error_message call to my RSPEC, I can't get the parameters to work.
Am I heading in the right direction and can anyone point to the next thing I can try?
Thanks,
Brett
A follow up to this question, showing the part that fails when I try to get the error message from my target library:
require 'gt4r'
##test_environment = "INCLUDE=C:\\graphtalk\\env\\aiadev\\config\\aiadev.ini"
##normal_user = "BMCHARGUE"
describe Gt4r do
it 'initializes' do
rv = Gt4r.gTD_initialize ##normal_user, ##normal_user, ##test_environment
Gt4r.gTD_get_error_message rv, #msg
#msg.should == ""
rv.should == 0
end
end
I expect the error message to be returned in #msg, but when run I get the following:
Gt4r
(eval):5: [BUG] Segmentation fault
ruby 1.8.6 (2008-08-11) [i386-mswin32]
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
And this if I use a symbol (:msg) instead:
C:\code\GraphTalk\gt4r_dl>spec -fs -rgt4r gt4r_spec.rb
Gt4r
- initializes (ERROR - 1)
1)
NoMethodError in 'Gt4r initializes'
undefined method `to_ptr' for :msg:Symbol
(eval):5:in `call'
(eval):5:in `gTD_get_error_message'
./gt4r_spec.rb:9:
Finished in 0.046 seconds
1 example, 1 failure
Clearly I am missing something about passing parameters between ruby and C, but what?
The general consensus is you want to avoid DL as much as possible. The (english) documentation is quite sketchy and the interface is difficult to use for anything but trivial examples.
Ruby native C interface is MUCH easier to program against. Or you could use FFI, which fills a similiar niche to DL, originally comes from the rubinius project and has recently been ported to "normal" ruby. It has a nicer interface and is much less painful to use:
http://blog.headius.com/2008/10/ffi-for-ruby-now-available.html
The return value (13) is an actual
return code, meaning an error, but
when I try to add the
gTD_get_error_message call to my
RSPEC, I can't get the parameters to
work.
It might help posting the error instead of the code that worked :)
Basically, once you start having to deal with pointers as in (int, char **), things get ugly.
You need to allocate the data pointer for msg to be written to, since otherise C will have nowhere to write the error messages. Use DL.mallo.