I want to rewrite all messages in my code, I need replace only selectors, but I need be able to replace nested expressions f. e. :
[super foo:[someInstance someMessage:@""] foo2:[someInstance someMessage2]];
I tried do it with clang::Rewriter replaceText
and just generate new string,
but there is a problem: It would not be work if I change selectors length, because I replace nested messages with those old positions.
So, I assumed that I need to use clang::Rewriter ReplaceStmt(originalStatement, newStatement);
I am using RecursiveASTVisitor
to visit all messages, and I want to copy those messages objects, and replace selectors:
How can I do that?
I tried use ObjCMessageExpr::Create
but there is so meny args, I don't know how to get ASTContext &Context
and ArrayRef<SourceLocation> SeLocs
and Expr *Receiver
parameters from the original message.
What is the proper way to replace selectors in nested messages using clang tool (clang tooling interface)?
Update:
Should I use ReplaceStmtWithStmt
callback and ASTMatchFinder
?
Update:
I am using following function to rewrite text in file:
void ReplaceText(SourceLocation start, unsigned originalLength, StringRef string) {
m_rewriter.ReplaceText(start, originalLength, string);
m_rewriter.overwriteChangedFiles();
}
And I want to replace all messageExpr in code with new selector f.e: how it was:
[object someMessage:[object2 someMessage:obj3 calculate:obj4]];
how it should be:
[object newSelector:[object2 newSelector:obj3 newSelector:obj4]];
I am using ReqoursiveASTVisitor:
bool VisitStmt(Stmt *statement) {
if (ObjCMessageExpr *messageExpr = dyn_cast<ObjCMessageExpr>(statement)) {
ReplaceMessage(*messageExpr)
}
return true;
}
I created method for generating new message expr string:
string StringFromObjCMessageExpr(ObjCMessageExpr& messageExpression) {
std::ostringstream stringStream;
const string selectorString = messageExpression.getSelector().getAsString();
cout << selectorString << endl;
vector<string> methodParts;
split(selectorString, ParametersDelimiter, methodParts);
stringStream << "[" ;
const string receiver = GetStringFromLocations(m_compiler, messageExpression.getReceiverRange().getBegin(), messageExpression.getSelectorStartLoc());
stringStream << receiver;
clang::ObjCMessageExpr::arg_iterator argIterator = messageExpression.arg_begin();
for (vector<string>::const_iterator partsIterator = methodParts.begin();
partsIterator != methodParts.end();
++partsIterator) {
stringStream << "newSelector";
if (messageExpression.getNumArgs() != 0) {
const clang::Stmt *argument = *argIterator;
stringStream << ":" << GetStatementString(*argument) << " ";
++argIterator;
}
}
stringStream << "]";
return stringStream.str();
}
void ReplaceMessage(ObjCMessageExpr& messageExpression) {
SourceLocation locStart = messageExpression.getLocStart();
SourceLocation locEnd = messageExpression.getLocEnd();
string newExpr = StringFromObjCMessageExpr(messageExpression);
const int exprStringLegth = m_rewriter.getRangeSize(SourceRange(locStart, locEnd));
ReplaceText(locStart, exprStringLegth, newExpr);
}
The problem occurs when I try to replace nested messages, like that:
[simpleClass doSomeActionWithString:string3 andAnotherString:string4];
[simpleClass doSomeActionWithString:str andAnotherString:str2];
[simpleClass doSomeActionWithString:@"" andAnotherString:@"asdasdsad"];
[simpleClass setSimpleClassZAZAZAZAZAZAZAZA:[simpleClass getSimpleClassZAZAZAZAZAZAZAZA]];
the result is:
[simpleClass newSelector:string3 newSelector:string4 ];
[simpleClass newSelector:str newSelector:str2 ];
[simpleClass newSelector:@"" newSelector:@"asdasdsad" ];
[simpleClass newSelector:[simpleClass getSimp[simpleClass newSelector]];
because messageExpression has "old" value of getLocStart();
and getLocEnd();
How can I fix it?
You can rewrite selector name by replacing only continuous parts of selector name. For example, replace only underlined parts
To achieve this you require only
ObjCMessageExpr::getNumSelectorLocs()
ObjCMessageExpr::getSelectorLoc(index)
ObjCMessageExpr::getSelector().getNameForSlot(index).size()
.Overall, you can rewrite ObjCMessageExpr with the following RecursiveASTVisitor: