I have seen some 3rd party source code with comments in /*M ... M*/ style. But what 'M' stands for? (Perhaps it is used with some kind of version control, or code documentation system (like doxygen)?)
I saw it in many (if not all) source code files in opencv.
You may browse Itseez's opencv repository under GitHub by clicking
here.
Oh. I forget to mention, the comment style seems to exist only in the head of the file, and it seems to declare the license.
Example:
/*M///////////////////////////////////////////////////////////////////////////////////////
//
// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
// By downloading, copying, installing or using the software you agree to this license.
// If you do not agree to this license, do not download, install,
// copy or use the software.
//
//
// License Agreement
// For Open Source Computer Vision Library
[...]
//
//M*/
Note: Doesn't correlate to version control and even C++
This is a problem of cross-OS EOL-problem (Win|*Nix) and visualization of not-native EOL
^M (really such string) in CRLF in pure-CR world and Linux|Mac GUIs
Example for opengl.hpp (from your sample repo): first lines
/*M///////////////////////////////////////////////////////////////////////////////////////
//
are, with proper rendering
/*
///////////////////////////////////////////////////////////////////////////////////////
//
and all glithes are results of ugly configured core.CRLF in author's Git (or ignoring it at all)
Related
I have question about replacing <THC/THC.h> method.
Recently, I'm working on installing different loss functions compiled with cpp and cuda.
However, what I faced was a fatal error of
'THC/THC.h': No such file or directory
I found out that TH(C) methods were currently deprecated in recent version of pytorch, and was replaced by ATen API (https://discuss.pytorch.org/t/question-about-thc-thc-h/147145/8).
For sure, downgrading my pytorch version will solve the problem. However, due to my GPU compatibility issue, I have no choice but to modify the script by myself. Therefore, my question can be summarized into follows.
First, how can I replace codes that have dependency of TH(C) method using ATen API?. Below are codes that I have to modify, replacing those three lines looked enough for my case.
#include <THC/THC.h>
extern THCState *state;
cudaStream_t stream = THCState_getCurrentStream(state);
Second, will single modification on cpp file be enough to clear the issue that I'm facing right now? (This is just a minor question, answer on first question will suffice me).
For reference, I attach the github link of the file I'm trying to build (https://github.com/sshaoshuai/Pointnet2.PyTorch).
After struggling for a while, I found the answer for my own.
In case of THCState_getCurrentStream, it could directly be replaced by at::cuda::getCurrentCUDAStream(). Therefore, modified code block was formulated as below.
//Comment Out
//#include <THE/THC.h>
//extern THCState *state;
//cudaStream_t stream = THCState_getCurrentStream(state);
//Replace with
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/CUDAEvent.h>
cudaStream_t stream = at::cuda::getCurrentCUDAStream();
After replacing the whole source code, I was able to successfully build the module.
Hope this helps.
I have seen some 3rd party source code with comments in /*M ... M*/ style. But what 'M' stands for? (Perhaps it is used with some kind of version control, or code documentation system (like doxygen)?)
I saw it in many (if not all) source code files in opencv.
You may browse Itseez's opencv repository under GitHub by clicking
here.
Oh. I forget to mention, the comment style seems to exist only in the head of the file, and it seems to declare the license.
Example:
/*M///////////////////////////////////////////////////////////////////////////////////////
//
// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
// By downloading, copying, installing or using the software you agree to this license.
// If you do not agree to this license, do not download, install,
// copy or use the software.
//
//
// License Agreement
// For Open Source Computer Vision Library
[...]
//
//M*/
Note: Doesn't correlate to version control and even C++
This is a problem of cross-OS EOL-problem (Win|*Nix) and visualization of not-native EOL
^M (really such string) in CRLF in pure-CR world and Linux|Mac GUIs
Example for opengl.hpp (from your sample repo): first lines
/*M///////////////////////////////////////////////////////////////////////////////////////
//
are, with proper rendering
/*
///////////////////////////////////////////////////////////////////////////////////////
//
and all glithes are results of ugly configured core.CRLF in author's Git (or ignoring it at all)
I have a file that generates cc code using flex. When I use the version 2.5.4a-10 the codes works as expected.
If I use bit more recent version 2.5.37 or even newer like 2.6 the generated code seems not to allocate anything. It uses some pointers defined with nullptr and crashes.
I think the syntax has changed in between these versions. I find it also strange that Debian/Ubuntu have a package called flex-old saying:
flex is a tool for generating scanners: programs which recognize lexical
patterns in text. This is the old 2.5.4a version, which is no longer
being developed. You should normally choose flex, unless you have
legacy lexer files that do not work with a modern flex.
This product includes software developed by the University of California,
Berkeley and its contributors. The upstream source code can be found at
http://flex.sourceforge.net/
(Editor's note: Flex has moved to Github but v2.5.4a is not there.)
That version seems to be a big deal for others I suspect. Getting to my question:
Is there any manual or guide of what I have to do in order to port that code to generate some c++ code that works in more recent versions of flex?
EDIT: Here is my simple example taken from something larger:
int num_lines = 0, num_chars = 0;
%%
\n ++num_lines; ++num_chars;
. ++num_chars;
%%
int main()
{
yy_init=1;
yylex();
printf( "# of lines = %d, # of chars = %d\n",
num_lines, num_chars );
return 0;
}
flex it with flex file.l and build it with gcc lex.yy.c -lfl. Now, if you used version 2.5.4 it will work. With later versions it translates and compiles just fine, but when you run the program you will get segmentation fault.
I found the problem myself. The variable yy_init can be explicitly set in that old version. In newer versions it is not allowed. I'm not sure if that is intended, maybe someone can explain why this behavior is observed. I find it a bit strange.
If someone has a similar problem, you might want to take a look at the yy_init variable. Other than that I had no issues.
I'm trying to understand source code of SDL-1.2.15, and to find out how it renders stuff on windows. But I can't find where the rendering is happening. I looked inside SDL-1.2.15/src/video folder, and there is a ton of subfolders, and I don't know what any of these stands for. See for yourself.
aalib/ directfb/ ipod/ os2fslib/ quartz/ windib/
ataricommon/ dummy/ maccommon/ photon/ riscos/ windx5/
bwindow/ fbcon/ macdsp/ picogui/ svga/ wscons/
caca/ gapi/ macrom/ ps2gs/ symbian/ x11/
dc/ gem/ nanox/ ps3/ vgl/ xbios/
dga/ ggi/ nds/ qtopia/ wincommon/ Xext/
Is this documented somewhere? This is a pretty popular library, so it probably is documented, right? Right? What's the point of having source code if you can't even understand it, if you can't find functions you are using.
While not all the names are self-explanatory, they contain some hints.
directfb, fbcon (framebuffer console) and X (x11, Xext) are output layers on Linux (unix).
The ones starting with win indicate they are for Windows. More specifically, windib should be about device independent bitmaps (DIBs), dx5 about DirectX 5, and wincommon about some common stuff. Indeed, using grep shows that (only) these folders contain Windows-specific code:
grep -r windows.h src/video/*
[ lists files in the win* folders ]
You could also just compile the package on Windows and see which files were compiled (which folders contain object files)
However, to find out what it actually does, you should rather study the function you're interested in (e.g. SDL_BlitSurface), look at it's implementation, and then look at the implementation of the functions it uses. Start in SDL_video.h (and notice that SDL_BlitSurface is just a define).
You should use some tool to search the code base. Grep or some IDE. Or both.
First of all, why not SDL2?
These are different SDL's video drivers. You can get what driver is used by your program by calling SDL_VideoDriverName. Which driver will be used determined by target platform (e.g. operating system - most drivers are platform-specific), environment variable SDL_VIDEODRIVER, or calling side.
I have a code written in Atmel Studio to read/write data from a SD card. I am using FatFs here. My problem is the code doesn't compile when I use some of the functions (f_chdir, f_getcwd...) in FatFs. Some functions works fine (f_puts, f_open, f_mount, f_mkdir...). All these functions are located in same header file (ff.h, ff.c)
The error says "undefined reference to -function-, ld returned 1 exit status". When I go to the error it shows the end of the code while it is suppose to show where the error is.
I cannot understand the problem with my code. Any help is appreciated.
Just ran into this using the SD card for a project using SAM4S Xplained Pro (Atmel 7, ASF 3.20).
Make sure you have all the asf projects (fatfs, sd_mmc, memory access control, and then the other basics e.g. pmc, gpio, and maybe a few more). My asf did NOT include sd_mmc_mem.c and sd_mmc_mem.h for some reason, so I had to include those myself. Also remember to do the sd_mmc_init() at the top of your main loop. As for the configuration...
If you look closely at ffconf.h, the first thing it does is include conf_fatfs.h, which (wait for it!) is EXACTLY the same file line by line as ffconf.h. All the variables are defined there first and foremost (and guarded by an #ifndef FFCONF and NOT an CONF_FATFS) aka that's where it counts..
Go into conf_fatfs.h and change _USE_STRFUNC to 1 or 2 et voila.
Also note that in the places where you use it, you'll have to #include the ff.h preceded by either ffconf.h or conf_access.h
ASF is a real snake pit if you don't know what you're looking for.
Enjoy.
By default, the memory control access interface is disabled in the ASF wizard. In order to enable the memory control access, please follow the steps below.
Open the ASF wizard (Alt + W).
Enable the Memory Control Access as follows.
ASF SD sd_mmc_mem.h memory access enable
Finally, click the “Apply” option to make the changes.
This adds sd_mmc_mem.h /.c files
Open the ffconf.h in your favorite editor and set _FS_RPATH to 2. From ffconf.h:
#define _FS_RPATH 0
/* This option configures relative path feature.
/
/ 0: Disable relative path feature and remove related functions.
/ 1: Enable relative path feature. f_chdir() and f_chdrive() are available.
/ 2: f_getcwd() function is available in addition to 1.
/
/ Note that directory items read via f_readdir() are affected by this option. */
Which features of the fatfs library are included in your build is configurable, so that you don't have to lose valuable ROM space (as well as a few bytes of RAM) for functions you're not using.
For versions of the FatFS library prior to 0.8a, _FS_RPATH supports only values 0 and 1; f_getcwd is not available in these versions.
Additionally, in versions prior to 0.8, it is necessary for C++ code to explicitly include its headers as C headers to avoid name mangling:
extern "C" {
#include "ff.h"
}
From version 0.8 onwards, it does this internally. You can find the new versions here if you're still working with an old one -- the comment you left leads me to believe that this might be the case.
Check if _FS_MINIMZE in ffconf.h is 0 to have all functions available.
In my version that I downloaded from elm-chan it was by default set to 3 and lead to the compiler error: undefined reference.
In file ffconf.h, set #define _USE_FIND to 1.
/* This option switches filtered directory read functions, f_findfirst() and
/ f_findnext(). (0:Disable, 1:Enable 2:Enable with matching altname[] too) */
I needed to use f_findfirst() and f_findnext() functions and i was getting undefined reference errors.
Now this solved my problem.
Drive/directory handling functions are under #if _FS_RPATH >= 1 (or similar preprocessors) .