I want to parse c source code for extracting variables and functions from it. Is there any library available for this purpose?
I tried to achieve it through query language available in tree-sitter parser generator but when I run the program it says undefined reference to the query functions used in the file even I have included the header file (api.h) containing query functions. I tried to resolve these errors but couldn't so looking for some other library which can serve the purpose.
It's better to do it with Clang (e.g. cindex Python API).
For example, to find all function definitions in a translation unit:
#!/usr/bin/env python3
import sys
import clang.cindex
def find_functions(node):
if node.kind == clang.cindex.CursorKind.FUNCTION_DECL:
nm = node.spelling
print(f"Function {nm}")
else:
for c in node.get_children():
find_functions(c)
index = clang.cindex.Index.create()
tu = index.parse(sys.argv[1])
print('Translation unit:', tu.spelling)
find_functions(tu.cursor)
Related
I'm trying to create a code generator that takes input a JSON file and generates multiple classes in multiple files.
And my question is, is it possible to create multiple files for one input using build from dart lang?
Yes it is possible. There are currently many tools in available on pub.dev that have code generation. For creating a simple custom code generator, check out the package code_builder provided by the core Dart team.
You can use dart_style as well to format the output of the code_builder results.
Here is a simple example of the package in use (from the package's example):
import 'package:code_builder/code_builder.dart';
import 'package:dart_style/dart_style.dart';
final _dartfmt = DartFormatter();
// The string of the generated code for AnimalClass
String animalClass() {
final animal = Class((b) => b
..name = 'Animal'
..extend = refer('Organism')
..methods.add(Method.returnsVoid((b) => b
..name = 'eat'
..body = refer('print').call([literalString('Yum!')]).code)));
return _dartfmt.format('${animal.accept(DartEmitter())}');
}
In this example you can use the dart:io API to create a File and write the output from animalClass() (from the example) to the file:
final animalDart = File('animal.dart');
// write the new file to the disk
animalDart.createSync();
// write the contents of the class to the file
animalDart.writeAsStringSync(animalClass());
You can use the File API to read a .json from the path, then use jsonDecode on the contents of the file to access the contents of the JSON config.
I want to create a printer extension for OCaml using camlp5. My code would look like the example of this tutorial but instead of creating my own extension of the grammar, I would like to use OCaml's grammar to parse a program.
For that, I would like to use the Pcaml module to parse the given string with OCaml's grammar. Unfortunately, each time I try to use it, I get the:
Required module 'Pcaml' is unavailable
This is the part of my code where I load and open modules, as well as part of the code that uses Pcaml:
#load "pa_extprint.cmo";;
#load "q_MLast.cmo";;
#load "pa_o.cmo";;
open Pcaml;;
open Pprintf;;
let pa_ocaml = Grammar.Entry.create Pcaml.gram "pcaml_gram";;
I tried multiple command to run the program, like for example:
ocamlc -pp camlp5o -I +camlp5 gramlib.cma <my_file>.ml
What do I need to be able to use Pcaml and Pcaml.gram?
I recommend to use ocamlfind to build and link your programs. The only reason for newcomer against it, is that thing could become buggy when you use Windows without WSL. The compilation command without error is below
ocamlfind c -syntax camlp5o -package camlp5 -linkpkg a.ml
#load "pa_extprint.cmo";;
#load "q_MLast.cmo";;
#load "pa_o.cmo";;
open Pcaml;;
open Pprintf;;
let pa_ocaml : int Grammar.Entry.e = Grammar.Entry.create Pcaml.gram "pcaml_gram";;
FYI, your #load commands can and should be replaced by specifying right ocamlfind's packages.
I am trying to produce an Ada library for iOS.
However, it is necessary to perform the Ada elaboration manually.
I know that the compiler can produce an init symbol, that can be later imported and used. However, with the following GPR definition, it is not produced (the nm command does not list it). The naming is supposed to be <libname>init with <libname> corresponding to the value defined in the GPR directive Library_Name
The GPR is defined in the following fashion (this one is windows/style -see DLL references-, but the problems also applies when producing for iOS on a Mac):
project adalib is
for Languages use ("Ada");
for Source_Dirs use (project'Project_Dir & "./src");
for Library_Kind use "static"; --"static" on iOS will produce a .a file
for Library_Name use project'Name; -- will produce "libadalib.a"
for Library_Dir use project'Project_Dir & "./lib";
for Library_Src_Dir use project'Project_Dir & "./includes";
-- define your favorite compiler, builder, binder, linker options
end adalib;
I'm missing it : how to produce that symbol ?
I found the solution.
My GPR was missing this simple directive:
for Library_Interface use ("mypackage"); -- put whatever packages you want to expose, without .adb/.ads since we're talking about packages
With the above directive, I can find the adalibinit symbol via nm command.
When I import it in my ada code, I can also use it, see :
package body mypackage is
procedure Init_My_Lib
is
-- I want to call elaboration;
pragma import (C, ada_elaboration, "adalibinit");
begin
ada_elaboration;
-- further code
end Init_My_Lib;
-- rest of package
So, the full GPR should be:
project adalib is
for Languages use ("Ada");
for Source_Dirs use (project'Project_Dir & "./src");
for Library_Kind use "static"; -- will produce a .a file
for Library_Name use project'Name; -- will produce "libadalib.a"
for Library_Interface use ("mypackage"); -- <=== THIS IS HERE
for Library_Dir use project'Project_Dir & "./lib";
for Library_Src_Dir use project'Project_Dir & "./includes";
-- define your favorite compiler, builder, binder, linker options
end adalib;
I am doing my project on incremental deep drawing using ABAQUS.
I am trying to import a text file of loop program into abaqus script so that there is no need of entering amplitude values manually.
But I am getting an error when trying to import the data using the following code
f = open('data_x', 'r')
values=f.read()
values=f.readline()
Error:
data_x is not defined
Error NameError: name 'data_x' is not defined points that you are using data_x as a name in your code, not as a string (with quotes).
This means that in your code, you probably have something like
f = open(data_x)
Python is trying to figure out which value is associated with data_x, which is a Python name, not a string. Since it's not defined before getting to that line, you are getting an error.
If you want to store the name of a file and then open a file, write
data_x = 'data_x.txt'
f = open(data_x)
You could also directly write
f = open('data_x.txt')
Whichever solution you adopt, make sure that a correct path to the file is passed to the function open, so that it could find the file.
I have created a Wireshark dissector in Lua for an application over TCP. I am attempting to use zlib compression and base64 decryption. How do I actually create or call an existing c library in Lua?
The documentation I have seen just says that you can get the libraries and use either the require() call or the luaopen_ call, but not how to actually make the program find and recognize the actual library. All of this is being done in Windows.
You can't load any existing C library, which was not created for Lua, with plain Lua. It's not trivial at least.
*.so/*.dll must follow some specific standard, which is bluntly mentioned in programming in Lua#26.2 and lua-users wiki, code sample. Also similar question answered here.
There are two ways You could solve Your problem:
Writing Your own Lua zlib library wrapper, following those standards.
Taking some already finished solution:
zlib#luapower
lua-zlib
ffi
Bigger list #lua-users wiki
The same applies to base64 encoding/decoding. Only difference, there are already plain-Lua libraries for that. Code samples and couple of links #lua-users wiki.
NOTE: Lua module package managers like LuaRocks or
LuaDist MIGHT save You plenty of time.
Also, simply loading a Lua module usually consists of one line:
local zlib = require("zlib")
The module would be searched in places defined in Your Lua interpreter's luaconf.h file.
For 5.1 it's:
#if defined(_WIN32)
/*
** In Windows, any exclamation mark ('!') in the path is replaced by the
** path of the directory of the executable file of the current process.
*/
#define LUA_LDIR "!\\lua\\"
#define LUA_CDIR "!\\"
#define LUA_PATH_DEFAULT \
".\\?.lua;" LUA_LDIR"?.lua;" LUA_LDIR"?\\init.lua;" \
LUA_CDIR"?.lua;" LUA_CDIR"?\\init.lua"
#define LUA_CPATH_DEFAULT \
".\\?.dll;" LUA_CDIR"?.dll;" LUA_CDIR"loadall.dll"
#else
How do I actually create or call an existing c library in Lua?
An arbitrary library, not written for use by Lua? You generally can't.
A Lua consumable "module" must be linked against the Lua API -- the same version as the host interpreter, such as Lua5.1.dll in the root of the Wireshark directory -- and expose a C-callable function matching the lua_CFunction signature. Lua can load the library and call that function, and it's up to that function to actually expose functionality to Lua using the Lua API.
Your zlib and/or base64 libraries know nothing about Lua. If you had a Lua interpreter with a built-in FFI, or you found a FFI Lua module you could load, you could probably get this to work, but it's really more trouble than it's worth. Writing a Lua module is actually super easy, and you can tailor the interface to be more idiomatic for Lua.
I don't have zlib or a base64 C library handy, so for example's sake lets say we wanted to let our Lua script use the MessageBox function from the user32.dll library in Windows.
#include <windows.h>
#include "lauxlib.h"
static int luaMessageBox (lua_State* L) {
const char* message = luaL_checkstring(L,1);
MessageBox(NULL, message, "", MB_OK);
return 0;
}
int __declspec(dllexport) __cdecl luaopen_messagebox (lua_State* L) {
lua_register(L, "msgbox", luaMessageBox);
return 0;
}
To build this, we need to link against user32.dll (contains MessageBox) and lua5.1.dll (contains the Lua API). You can get Lua5.1.lib from the Wireshark source. Here's using Microsoft's compiler to produce messagebox.dll:
cl /LD /Ilua-5.1.4/src messagebox.c user32.lib lua5.1.lib
Now your Lua scripts can write:
require "messagebox"
msgbox("Hello, World!")
Your only option is to use a library library like alien. See my answer Disabling Desktop Composition using Lua Scripting for other FFI libraries.