is there a way to get the function call stack with pycparser ?
for example if i have code like this:
static int Func_1(int *val)
{
unsigned int data_1 = 0;
int result;
result = Func_2(val,
data_1
);
result = Func_3(val,
result
);
return result;
}
so with FuncDefVisitor i can retrieve Func_1 and with FuncCallVisitor i could retrieve Func_2 and Func_3
but how can i retrieve the information that e.g. Func_2 is called from within Func_1 ?
You can write a visitor that finds FuncDef nodes and runs another visitor on them that finds all FuncCall nodes. For example:
class FuncDefVisitor(c_ast.NodeVisitor):
def visit_FuncDef(self, node):
# Here node is a FuncDef node for the function definition.
v = FuncCallVisitor()
v.visit(node)
class FuncCallVisitor(c_ast.NodeVisitor):
def visit_FuncCall(self, node):
# do something
In visit_FuncDef, we create a new call visitor and run it on node, which means it only runs within the AST node for the function definition. It will find Func_2 and Func_3 in your code, but not func calls in other functions.
That said, note that you will only get the static call graph from this. In C functions can call others via function pointers and that's not something you can know statically in the general case.
Related
In WebhookScript, I can store a function in a variable with:
sub = function(a, b) {
return a - b
}
I'd like to store a function in a Global Variable so that I can use it in multiple Custom Actions. But if I've saved the above function as $sub$ then
sub2 = var('$sub$')
subX = sub(1,2)
causes an error:
Trying to invoke a non-function 'string' # line...
And
function subX(a,b){
var('$sub$')
}
when sub only contains return a - b, doesn't work either.
Obviously I need to convert the string to a function but I'm not sure whether that's possible.
I know this is a bit of an obscure language but if anyone knows how this can be done in similar languages like JavaScript and PHP, I'm happy to test out any guesses...
The solution here is to remove the function section and just enter the script, which inherits the execution scope so if my global variable $script$ is:
return 'hello ' + a
Then I can execute the function with:
a = 'world'
value = exec(var('$script$'))
echo(value)
(credit to Webhook.Site's support team for explaining this)
I have two sql statements to be executed with a validity check. My need is that I execute the 1st query and store the response in one object and check the object is empty or not and execute the second query if it is not empty.
So, I have tried something like
In rolerepository.scala=>
override val allQuery = s"""
select UserRoles.* from
(select CASE rbac.roleTypeID
ELSE rbac.name JOIN dirNetworkInfo ni
ON UserRoles.PersonID = ni.PersonID
where ni.Loginname = {loginName}
and UserRoles.roleName in ( 'Business User ','Administrator')"""
(This is just some sample of the query - it is not fully written here.)
Then I map it to an object with model class written outside
override def map2Object(implicit map: Map[String, Any]):
HierarchyEntryBillingRoleCheck = {
HierarchyEntryBillingRoleCheck(str("roleName"), oint("PersonID")) }
Then I have written the getall method to execute the query
override def getAll(implicit loginName: String):
Future[Seq[HierarchyEntryBillingRoleCheck]] = {
doQueryIgnoreRowErrors(allQuery, "loginName" -> loginName) }
Then I have written the method to check whether the response from the 1st sql is empty or not. This is were I'm stuck and not able to proceed further.
def method1()= {
val getallresponse = HierarchyEntryBillingRoleCheck
getallresponse.toString
if (getallresponse != " ")
billingMonthCheckRepository.getrepo()
}
I am getting an error (type mismatch) in last closing brace and I don't know what other logic can be used here.
Can any one of you please explain and give me some solution for this?
And i also tried to use for loop in controller but not getting how to do that.
i tried ->
def getAll(implicit queryParams: QueryParams,
billingMonthmodel:Seq[HierarchyEntryBillingRoleCheck]):
Action[AnyContent] = securityService.authenticate() { implicit request
=> withErrorRecovery { req =>
toJson {
repository.getAll(request.user.loginName)
for {
rolenamecheck <- billingMonthmodel
}yield rolenamecheck
}}}}
You don't say which db access method you are using. (I'm assuming anorm). One way of approaching this is:
Create a case class matching your table
Create a parser matching your case class
use Option (or Either) to return a row for a specific set of parameters
For example, perhaps you have:
case class UserRole (id:Int, loginName:String, roleName:String)
And then
object UserRole {
val sqlFields = "ur.id, ur.loginName, ur.roleName"
val userRoleParser = {
get[Int]("id") ~
get[String]("loginName") ~
get[String]("roleName") map {
case id ~ loginName ~ roleName => {
UserRole(id, loginName, roleName)
}
}
}
...
The parser maps the row to your case class. The next step is creating either single row methods like findById or findByLoginName and multi-row methods, perhaps allForRoleName or other generic filter methods. In your case there might (assuming a single role per loginName) be something like:
def findByLoginName(loginName:String):Option[UserRole) = DB.withConnection { implicit c =>
SQL(s"select $sqlFields from userRoles ur ...")
.on('loginName -> loginName)
.as(userRoleParser.singleOpt)
}
The .as(parser... is key. Typically, you'll need at least:
as(parser.singleOpt) which returns an Option of your case class
as(parser *) which returns a List of your case class (you'll need this if multiple roles could exist for a login
as(scalar[Long].singleOpt) which returns an Option[Long] and which is handy for returning counts or exists values
Then, to eventually return to your question a little more directly, you can call your find method, and if it returns something, continue with the second method call, perhaps like this:
val userRole = findByLoginName(loginName)
if (userRole.isDefined)
billingMonthCheckRepository.getrepo()
or, a little more idiomatically
findByLoginName(loginName).map { userRole =>
billingMonthCheckRepository.getrepo()
...
I've shown the find method returning an Option, but in reality we find it more useful to return an Either[String,(your case class)], and then the string contains the reason for failure. Either is cool.
On my version of play (2.3.x), the imports for the above are:
import play.api.db._
import play.api.Play.current
import anorm._
import anorm.SqlParser._
You're going to be doing this sort of thing a lot so worth finding a set of patterns that works for you.
WOW I don't know what's happening with the formatting here, I am really attempting to use the code formatter on the toolbar but I don't know why it won't format it, even when pressed multiple times. I invite the community to edit my code formatting because I can't figure it out. Apologies to OP.
Because I find Play's documentation to be very tough to trudge through if you're unfamiliar with it, I won't just leave a link to it only.
You have to inject an instance of your database into your controller. This will then give it to you as a global variable:
#Singleton
class LoginRegController #Inject()(**myDB: Database**, cc: ControllerComponents ) {
// do stuff
}
But, it's bad practice to actually use this connection within the controller, because the JDBC is a blocking operation, so you need to create a Model which takes the db as a parameter to a method. Don't set the constructor of the object to take the DB and store it as a field. For some reason this creates connection leaks and the connections won't release when they are done with your query. Not sure why, but that's how it is.
Create a Model object that you will use to execute your query. Instead of passing the DB through the object's constructor, pass it through the method you will create:
object DBChecker {
def attemptLogin(db:Database, password:String): String = {
}}
In your method, use the method .withConnection { conn => to access your JDBC connection. So, something like this:
object DBChecker {
def attemptLogin(db:Database, password:String):String = {
var username: String = ""
db.withConnection{ conn =>
val query:String = s"SELECT uploaded_by, date_added FROM tableName where PASSWORD = $password ;"
val stmt = conn.createStatement()
val qryResult:ResultSet = stmt.executeQuery(query)
// then iterate over your ResultSet to get the results from the query
if (qryResult.next()) {
userName = qryResult.getString("uploaded_by")
}
}
}
return username
}
// but note, please look into the use of PreparedStatement objects, doing it this way leaves you vulnerable to SQL injection.
In your Controller, as long as you import the object, you can then call that object's methods from your controller you made in Step 1.
import com.path.to.object.DBChecker
#Singleton
class LoginRegController #Inject()(myDB: Database, cc: ControllerComponents ) { def attemptLogin(pass:String) = Action {
implicit request: Request[AnyContent] => {
val result:String = DbChecker.attemptLogin(pass)
// do your work with the results here
}
I want to build a function for some code that I use often in my MQL4 programming that outputs to a file data resulting from optimisation runs.
I already have the working code but I am having a difficulty with passing parameters.
Some of the function parameters, that I need to access inside the function and so these need to be passed as parameters, are global, user defined variables - eg as: input int Moving_Average_period = .... ;.
The next time I use the function, this variable may not be required but another(s) will
This variable reference needs to appear in a FileWrite() statement eg:
FileWrite( h, Counter, Moving_Average_period, StopLoss, .......... );
any ideas please - thanks in advance.
Declare the function with an Array(s) in the call-signature:
Simply put,
void aFunctionWithValuesInARRAYs( int const anArrayOfINTs[],
double const anArrayOfDOUBLEs[],
datetime const anArrayOfDATETIMEs[]
) {
// ------------------------ ^
// PROCESS DATA AS YOU NEED +-- pre-loading and updating values
// ------------------------ in each anArrayOf*s[] is a very
// Q.E.D. flexible external-responsibility
...
}
I was able to store functions into a table. But now I have no idea of how to invoke them. The final table will have about 100 calls, so if possible, I'd like to invoke them as if in a foreach loop. Thanks!
Here is how the table was defined:
game_level_hints = game_level_hints or {}
game_level_hints.levels = {}
game_level_hints.levels["level0"] = function()
return
{
[on_scene("scene0")] =
{
talk("hint0"),
talk("hint1"),
talk("hint2")
},
[on_scene("scene1")] =
{
talk("hint0"),
talk("hint1"),
talk("hint2")
}
}
end
Aaand the function definitions:
function on_scene(sceneId)
-- some code
return sceneId
end
function talk(areaId)
-- some code
return areaId
end
EDIT:
I modified the functions so they'll have a little more context. Basically, they return strings now. And what I was hoping to happen is that at then end of invoking the functions, I'll have a table (ideally the levels table) containing all these strings.
Short answer: to call a function (reference) stored in an array, you just add (parameters), as you'd normally do:
local function func(a,b,c) return a,b,c end
local a = {myfunc = func}
print(a.myfunc(3,4,5)) -- prints 3,4,5
In fact, you can simplify this to
local a = {myfunc = function(a,b,c) return a,b,c end}
print(a.myfunc(3,4,5)) -- prints 3,4,5
Long answer: You don't describe what your expected results are, but what you wrote is likely not to do what you expect it to do. Take this fragment:
game_level_hints.levels["level0"] = function()
return
{
[on_scene("scene0")] =
{
talk("hint0"),
}
}
end
[This paragraph no longer applies after the question has been updated] You reference on_scene and talk functions, but you don't "store" those functions in the table (since you explicitly referenced them in your question, I presume the question is about these functions). You actually call these functions and store the values they return (they both return nil), so when this fragment is executed, you get "table index is nil" error as you are trying to store nil using nil as the index.
If you want to call the function you stored in game_level_hints.levels["level0"], you just do game_level_hints.levels["level0"]()
Using what you guys answered and commented, I was able to come up with the following code as a solution:
asd = game_level_hints.levels["level0"]()
Now, asd contains the area strings I need. Although ideally, I intended to be able to access the data like:
asd[1][1]
accessing it like:
asd["scene0"][1]
to retrieve the area data would suffice. I'll just have to work around the keys.
Thanks, guys.
It's not really clear what you're trying to do. Inside your anonymous function, you're returning a table that uses on_scene's return value as keys. But your on_scene doesn't return anything. Same thing for talk.
I'm going to assume that you wanted on_scene and talk to get called when invoking each levels in your game_level_hints table.
If so, this is how you can do it:
local maxlevel = 99
for i = 0, maxlevel do
game_level_hints.levels["level" .. i] = function()
on_scene("scene" .. i)
talk("hint" .. i)
end
end
-- ...
for levelname, levelfunc in pairs(game_level_hints.levels) do
levelfunc()
end
I'm using EF5.0 in an ASP.NET MVC app. My Entity Model is named 'DataModel'. Included in the model is a table-valued function that exists in my MSSQL database, named MatchingEntries. It returns a table of integer ids.
I've looked at the DataModel.Context.cs file, that gets generated via the .tt (T4) template file. It has the following code in it:
[EdmFunction("DataEntities", "MatchingEntries")]
public virtual IQueryable<Nullable<int>> MatchingEntries(string term)
{
var termParameter = term != null ?
new ObjectParameter("Term", term) :
new ObjectParameter("Term", typeof(string));
return ((IObjectContextAdapter)this).ObjectContext.CreateQuery<Nullable<int>>("[DataEntities].[MatchingEntries](#Term)", termParameter);
}
The error I am getting results from using this method twice within the one query, such as:
IQueryable<int> one = db.MatchingEntries("\"one*\"");
IQueryable<int> two = db.MatchingEntries("\"two*\"");
List<int> both = one.Intersect(two).ToList();
The error is:
A parameter named 'Term' already exists in the parameter collection. Parameter names must be unique in the parameter collection.
Parameter name: parameter
Is this a known limitation of the classes generated from an EDMX for table-valued functions? With LINQ2SQL I am able to execute this a a single query to the database (that does a JOIN between the 2 outputs from MatchingEntries) and it replaces the parameter name #Term with #p0 and #p1 for the two different instances of the call. I'd like to make Entity Framework do the same.
So, my question is, how can I get EF to work in the same manner and avoid the 'Duplicate parameter' error?
My fallback is to evaluate each call to db.MatchingEntries separately, by putting ToList() after them. My other idea has been to replace the ObjectParameter name in the T4 generated Context.cs class with something randomly generated each time. These feel like hacks that I should be able to avoid.
This answer is Linq to Entities specific. This doesn't have to be done in Linq to SQL (Linqpad).
Thanks to this question I got a pointer to a viable solution:
extend the autogenerated DBContext class (partial class)
add a method with two parameters in the partial class
at calling, pass an index as second parameter
Detailed Answer:
DataEntitys.my.cs:
[EdmFunction("DataEntities", "MatchingEntries")]
public virtual IQueryable<Nullable<int>> MatchingEntries(string term, int index)
{
string param_name = String.Format("k_{0}", index);
var termParameter = term != null ?
new ObjectParameter(param_name, term) :
new ObjectParameter(param_name, typeof(string));
return ((IObjectContextAdapter)this).
ObjectContext.CreateQuery<Nullable<int>>(
String.Format("[DataEntities].[MatchingEntries](#{0})", param_name),
termParameter);
}
Call the function:
foreach (string teil in such)
{
index++;
if (teil.Trim() != "")
res = res.Join(db.MatchingEntries("\"" + teil + "*\"", index), l => l.ID, s => s.KEY, (l, s) => l);
}