I see
(in Version 1.2.49, Linux Foundation ):
png_uint_32 png_get_iCCP(png_structp png_ptr, png_infop info_ptr, png_charpp name, int * compression_type, png_charpp profile, png_uint_32 * proflen);
And (in version 1.6.37):
png_uint_32 png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, png_charpp name, int *compression_type, png_bytepp profile, png_uint_32 *proflen);
The main difference is the incompatible change of the fifth parameter, from type char ** to type png_byte **.
Now, I definitely accept that the newer form is correct.
But that doesn't help if you want to be able to build with any version of the library.
My basic question is: When did this change take place?
One annoying part of this change is that it went unnoted in the API documentation, probably in part because said documentation doesn't even mention types.
I figure the compile-time test will look something like:
#if (PNG_LIBPNG_VER>=10402)
but that I would need to know what number to put in.
I figure my alternative is to write some autoconf tests.
As an additional question: Are there any other incompatible API changes in libpng's history?
I am using intel pin as my primary DBI tool.
I am interested to know how can I trace all variables allocated in a program .
suppose, we have the following snippet in C:
int *ptr_one, *ptr_two, g;
ptr_one = (int *)malloc(sizeof(int));
ptr_two = (int *)malloc(sizeof(int));
*ptr_one = 25;
*ptr_two = 24;
g = 130;
free(ptr_two);
g = 210;
*ptr_two = 50;
I want to know how can I trace specific variables / memory references in my program . for example on the above code, I like to trace the variable "g" in my program with Intel Pin, how it can be done?
for dynamically allocated variables, I'm monitoring malloc/free calls & follow their addresses, but for static ones I do not have any idea .
Another matter is, for dynamically allocated variables, I like to trace them across the whole program, suppose in the above code, I want to monitor (ptr_two) variable changes and modification during my program from start to finish .
If anyone have some idea about that, it can be nice to share it here, sample codes appreciated in Intel Pin .
thank you all .
Simply stated, you can't associate a name from your source code (be it variable or function name) with a memory location on the compiled binary: this information is (probably) lost on the final binary.
This is not true in two cases:
1) If your binary is exporting functions: in this case other binaries must have a means to call the function by name (minus some subtleties), in which case the information must be available somewhere; for example on Windows, binaries that export functions, variables or classes have an export table.
2) You have symbolic information: in your example, either for the global variable or other local variable, you have to use the symbolic information provided by the compiler.
On Linux you will need an external tool / library / program (e.g. libelf.so or libdwarf.so) to parse the symbolic information from the symbol tables (usually dynsym / symtab) if the binary is not stripped.
On windows you have to rely on the program database (*.pdb files); the format is mostly undocumented (although MS is trying to document it) and you have to use either the DbgHelp API or the DIA SDK.
As stated by the PIN user guide (emphasis is mine):
Pin provides access to function names using the symbol object (SYM).
Symbol objects only provide information about the function symbols in
the application. Information about other types of symbols (e.g. data
symbols), must be obtained independently by the tool.
If you have symbolic information you can then associate a variable name - obtained from an external tool - with an address (relative to the module base for global vars or a stack location for local ones). At runtime it is then just a matter of converting the relative address to a virtual one.
In a mozille extension I run:
SecSess.Logger.info("ctypes test");
Components.utils.import("resource://gre/modules/ctypes.jsm");
SecSess.Logger.info("1");
this.lib = ctypes.open("libcrypto.so");
SecSess.Logger.info("2");
var a = new Uint8Array(1<<10);
SecSess.Logger.info("3");
var ptr = new ctypes.uint8_t.ptr(a.buffer);
SecSess.Logger.info("4");
Why this ugly logging after each step you might ask? Well this code fails without showing me an error. (or at least I can't find the error message)
This is printed:
ctypes test
1
2
3
So the 5th log message is never printed which means the following statement never completes:
var ptr = new ctypes.uint8_t.ptr(a.buffer);
This is a simplified version of some old code I have to work with and which I also found online as being valid. However it doesn't work. This add-on wasn't developped using the new SDK with jpm. Quite frankly I don't know how and when it was developped but I need to run some tests on it. It comes with a few source files ordered in a components and a modules directory and a chrome.manifest and install.rdf in the root. I copied these files to the extension directory of Mozilla in order for it to work. The extension executes but there seems to be a problem with ctypes. Aren't ctypes fully supported anymore or are these old style add-on no longer valid for the modern Firefox?
Regards,
Roel
I think they landed a a patch to disallow making a pointer from buffers. I'll double check.
Edit:
Ah per this: https://developer.mozilla.org/en-US/docs/Mozilla/js-ctypes/Using_js-ctypes/Working_with_ArrayBuffers, you don't have to wrap it with a ctypes.uint8_t.ptr just pass it like a.buffer to wherever you need it. :)
I'm just learning F#, and setting up a FAKE build harness for a hello-world-like application. (Though the phrase "Hell world" does occasionally come to mind... :-) I'm using a Mac and emacs (generally trying to avoid GUI IDEs by preference).
After a bit of fiddling about with documentation, here's how I'm invoking the F# compiler via FAKE:
let buildDir = #"./build-app/" // Where application build products go
Target "CompileApp" (fun _ -> // Compile application source code
!! #"src/app/**/*.fs" // Look for F# source files
|> Seq.toList // Convert FileIncludes to string list
|> Fsc (fun p -> // which is what the Fsc task wants
{p with //
FscTarget = Exe //
Platform = AnyCpu //
Output = (buildDir + "hello-fsharp.exe") }) // *** Writing to . instead of buildDir?
) //
That uses !! to make a FileIncludes of all the sources in the usual way, then uses Seq.toList to change that to a string list of filenames, which is then handed off to the Fsc task. Simple enough, and it even seems to work:
...
Starting Target: CompileApp (==> SetVersions)
FSC with args:[|"-o"; "./build-app/hello-fsharp.exe"; "--target:exe"; "--platform:anycpu";
"/Users/sgr/Documents/laboratory/hello-fsharp/src/app/hello-fsharp.fs"|]
Finished Target: CompileApp
...
However, despite what the console output above says, the actual build products go to the top-level directory, not the build directory. The message above looks like the -o argument is being passed to the compiler with an appropriate filename, but the executable gets put in . instead of ./build-app/.
So, 2 questions:
Is this a reasonable way to be invoking the F# compiler in a FAKE build harness?
What am I misunderstanding that is causing the build products to go to the wrong place?
This, or a very similar problem, was reported in FAKE issue #521 and seems to have been fixed in FAKE pull request #601, which see.
Explanation of the Problem
As is apparently well-known to everyone but me, the F# compiler as implemented in FSharp.Compiler.Service has a practice of skipping its first argument. See FSharp.Compiler.Service/tests/service/FscTests.fs around line 127, where we see the following nicely informative comment:
// fsc parser skips the first argument by default;
// perhaps this shouldn't happen in library code.
Whether it should or should not happen, it's what does happen. Since the -o came first in the arguments generated by FscHelper, it was dutifully ignored (along with its argument, apparently). Thus the assembly went to the default place, not the place specified.
Solutions
The temporary workaround was to specify --out:destinationFile in the OtherParams field of the FscParams setter in addition to the Output field; the latter is the sacrificial lamb to be ignored while the former gets the job done.
The longer term solution is to fix the arguments generated by FscHelper to have an extra throwaway argument at the front; then these 2 problems will annihilate in a puff of greasy black smoke. (It's kind of balletic in its beauty, when you think about it.) This is exactly what was just merged into the master by #forki23:
// Always prepend "fsc.exe" since fsc compiler skips the first argument
let optsArr = Array.append [|"fsc.exe"|] optsArr
So that solution should be in the newest version of FAKE (3.11.0).
The answers to my 2 questions are thus:
Yes, this appears to be a reasonable way to invoke the F# compiler.
I didn't misunderstand anything; it was just a bug and a fix is in the pipeline.
More to the point: the actual misunderstanding was that I should have checked the FAKE issues and pull requests to see if anybody else had reported this sort of thing, and that's what I'll do next time.
I was wondering if you know of any way to use prolog for stream processing, that is, some kind of reactive programming, or at least to let a query run on a knowledge base that is continuously updated (effectively a stream), and continuously output the output of the reasoning?
Anything implemented in the popular "prologs", such as SWI-prolog?
You can use Logtalk's support for event-driven programming to define monitors that watch for knowledge base update events and react accordingly. You can run Logtalk using most Prolog systems as the backed compiler, including SWI-Prolog.
The event-driven features are described e.g. in the user manual:
http://logtalk.org/manuals/userman/events.html
The current distribution contains some examples of using events and monitors. An interesting one considering your question is the bricks example:
https://github.com/LogtalkDotOrg/logtalk3/tree/master/examples/bricks
Running this example first and then looking at its code should give you as good idea of what you can do with system wide events and monitors.
XSB has stream processing capabilities. See page 14 in the
XSB Manual
I'm working on something related, in project pqConsole already there is the basic capability: report to the user structured data, containing actionable areas (links) that call back in Prolog current state, hence the possibility to expose actions and react appropriately (hopefully).
It's strictly related to pqConsole::win_write_html, showcasing recent Qt capabilities of SWI-Prolog.
Here an example of a snippet producing only a simple formatted report, I'll try now to add the reactive part, so you can evaluate if you find expressive this basic system. Hints are welcome...
/* File: win_html_write_test.pl
Author: Carlo,,,
Created: Aug 27 2013
Purpose: example usage win_html_write/1
*/
:- module(win_html_write_test,
[dir2list/1
]).
:- [library(http/html_write)].
:- [library(dirtree)].
dir2list(Path) :-
dirtree(Path, DirTree),
% sortree(compare_by_attr(name), DirTree, Sorted), !,
DirTree = Sorted,
phrase(html([\css,
\logo,
hr([]),
ul(\dirtree2html(Sorted, [])),
br([])]), Tokens),
with_output_to(atom(X), print_html(Tokens)),
win_html_write(X),
dump_page_to_debug(X).
css --> html(style(type='text/css',
['.size{color:blue;}'
])).
logo --> html(img([src=':/swipl.png'],[])).
dirtree2html(element(dir, A, S), Parents) -->
html(li([\elem2html(A),
ul(\elements2html(S, [A|Parents]))])).
dirtree2html(element(file, A, []), _Parents) -->
html(li(\elem2html(A))).
elem2html(A) -->
{memberchk(name=N, A),
memberchk(size=S, A)
},
html([span([class=name], N), ' : ', span([class=size], S)]).
elements2html([E|Es], Parents) -->
dirtree2html(E, Parents),
elements2html(Es, Parents).
elements2html([], _Parents) --> [].
dump_page_to_debug(X) :-
open('page_to_debug.html', write, S),
format(S, '<html>~n~s~n</html>~n', [X]),
close(S).
This snippet depends on dirtree, that should be installed with
?- pack_install(dirtree).
edit With 3 modifications now the report has the ability to invoke editing of files:
call to get paths in structure
dir2list(Path) :-
dirtree(Path, DirTreeT),
assign_path(DirTreeT, DirTree),
...
request a specialized output for files only
dirtree2html(element(file, A, []), _Parents) -->
html(li(\file2html(A))).
finally, the 'handler' - here just place a request to invoke the editor
file2html(A) -->
{memberchk(name=N, A),
memberchk(path=P, A),
memberchk(size=S, A)
},
html([span([class=name],
[a([href='writeln(editing(\'~s\')), edit(\'~s\')'-[N,P]], N)]
), ' : ', span([class=size], S)]).
and now the file names are clickable, write a message and get edited if requested: a picture
You should check out RTEC: Run-Time Event Calculus:
https://github.com/aartikis/RTEC
RTEC is an open-source Event Calculus dialect optimised for stream reasoning. It is written in Prolog and has been tested under YAP 6.2.
Feature highlights:
Interval-based.
Sliding window reasoning.
Interval manipulation constructs for non-inertial fluents.
Caching for hierarchical knowledge bases.
Support for out-of-order data streams.
Indexing for handling efficiently irrelevant data.
There is also a mention of it on the SWI-Prolog website:
https://www.swi-prolog.org/pack/file_details/prologmud_I7/prolog/ec_planner/RTEC/README.md
which presumably relies on:
https://www.swi-prolog.org/pldoc/doc/_SWI_/library/dialect/yap.pl
I don't know why this hasn't been brought up so far, but in SWI-Prolog there is prolog_listen, which can, amongst other things, monitor dynamic updates to the database: