[cdt-dev] Refactorings that operate in regions with preprocessor directi

[nchen.dev@xxxxxxx]

Hi

(Cross-posting on cdt-dev and ptp-dev since this probably interests both groups)

I am trying to implement some refactorings for OpenMP (see http://dev.eclipse.org/mhonarc/lists/ptp-dev/msg04520.html) using PTP. I am using the CDT ASTRewrite (org.eclipse.cdt.core.dom.rewrite.ASTRewrite) to create the changes. The problem is that ASTRewrite discards directives in the source code under certain situations. I know that it happens when I try to use insertBefore(...) and the statement to be inserted is in a block that contains a preprocessor directive in it. I have not tried it with replace(...) or remove(...) yet to see if this problem also occurs there.

I observe the same problem when using "Extract Local Variable" refactoring in CDT.

Here is an example:

======================
Before refactoring
======================

float a[100];

void function() {
	int i;
	getConstant(); // <----------- Select this statement for "Extract Local Variable"
#pragma omp parallel for
	for (i = 0; i < 100; i++) {
		a[i] += 1.4142;
	}
}

int getConstant() {
	return 42;
}

======================
After refactoring
======================
float a[100];

void function() {
	int i;
    int extractedLocalVariable = getConstant();
    extractedLocalVariable;
    for (i = 0; i < 100; i++) {  //<--------------- Notice that the #pragma omp directive is gone
		a[i] += 1.4142;
	}
}

int getConstant() {
	return 42;
}

In the example, the parameters to insertBefore(...) would be something like

insertBefore(
parent // The IASTCompoundStatement of function()
insertionPoint // The original function call to getConstant();
node // The extractedLocalVariable
textEditGroup // Assume it's null
);

As you can see, the #pragma omp is contained within the parent node and is discarded during the refactoring process.

Am I missing something with the way I am using ASTRewrite or is it a known limitation? Is there a way to get around this limitation since it affects any refactoring that has to operate for OpenMP?

Thanks!

--
Nick Chen