[cdt-core-dev] C++ Parser

["Jason Brown" <brownjasonj@xxxxxxxxxxx>]

I want to use the parser to give me details of where C/C++ statements are, however I have so far failed to penetrate the AST with an instance of the ISourceElementRequestor (See code at the end).  Here is an example of what I’d like as information, take the following C code:

 

1: int main(int argc, char argv[])

2: {

3:  if (argc == 0) {

4:    printf("You didn't pass in any arguments");

5:    return -1;

6:  }

7:  else {

8:    printf("You passed in %d args\n",argc);

9:    return 1;

10:  }

11:}

 

I am particularly interested in understanding that the ‘If’ keyword is on line 3, the condition statement is also on line 3, the ‘else’ keyword is on line 7.  Then I need to know the details of the ‘then’ code block and the ‘else’ code block.

 

I traced through the parser code and it seems that it should be possible to get this information, but it seems that the line number is not stored, or it maybe stored if a new scope is generated for the ‘if’.  For those not familiar with the code this token reading etc. is all happening in the package cdt.internal.core.parser. and cdt.internal.core.parser.ast.

 

So right now my ISourceElementRequestor gets the codeBody call back for the ‘then’ block and the ‘else’ block, but I don’t seem to be able to determine  the details of the statements within the code bodies, nor the location of syntactic keywords.

 

Could someone please shed some light on this for me?  I am assuming that this kind of thing is already done for the editor that highlights keywords in the source files, but I am not sure.

 

Any insights will be very much appreciated. 

 

Jason

 

PS: Below is the code I’m using.

 

class CMySourceElementRequestor extends StructuralParseCallback

{

    private ParserMode mode = ParserMode.COMPLETE_PARSE;

 

            private void addElement (IASTDeclaration element){

                        if(inclusionLevel == 0){

                                    if( currentScope instanceof ASTScope )

                                                ((ASTScope)currentScope).addDeclaration(element);

                                    else if( currentScope instanceof ASTLinkageSpecification )

                                                ((ASTLinkageSpecification)currentScope).addDeclaration( element );

                        }

            }

           

            private void enterScope(IASTNode node){

                        if(node instanceof IASTScope){

                                    if(node instanceof ASTScope){

                                                ((ASTScope)node).initDeclarations();

                                    }

                                    pushScope((IASTScope)node);

                        }

            }

 

            private void exitScope(IASTNode node){

                        if(node instanceof IASTScope){

                                    popScope();

                        }

            }

           

            private void pushScope( IASTScope scope ){

                        scopeStack.addFirst( currentScope );

                        currentScope = scope;

            }

           

            private IASTScope popScope(){

                        IASTScope oldScope = currentScope;

                        currentScope = (scopeStack.size() > 0 ) ? (IASTScope) scopeStack.removeFirst() : null;

                        return oldScope;

            }

           

            public void enterFunctionBody( IASTFunction function )

            {

                        System.out.println("Enter function");

                        if(function.getOwnerTemplateDeclaration() == null)

                                    addElement(function);

                        else if(function.getOwnerTemplateDeclaration() instanceof IASTTemplateDeclaration)

                                    addElement((IASTTemplateDeclaration)function.getOwnerTemplateDeclaration());

            }

           

            public void exitFunctionBody( IASTFunction function )

            {

                        System.out.println("Exit function");

                        function.setHasFunctionBody( true );

            }

           

            public void enterCodeBlock( IASTCodeScope scope )

            {

                        System.out.println("Enter Code Block");

                        enterScope(scope);

            }

           

            public void exitCodeBlock( IASTCodeScope scope )

            {

                        System.out.println("Exit Code Block");

                        exitScope(scope);

            }

 

            public void enterCompilationUnit( IASTCompilationUnit compilationUnit )

            {

                        System.out.println("Enter Compilation Unit");

                        enterScope(compilationUnit);

            }

                       

            public void exitCompilationUnit( IASTCompilationUnit compilationUnit )

            {

                        System.out.println("Exit Compilation");

                        exitScope(compilationUnit);

                        this.compUnit = compilationUnit;

            }

 

            /**

             * @param finalPath

             * @return

             */

            public CodeReader createReader(String finalPath, Iterator workingCopies )

            {

                        return InternalParserUtil.createFileReader( finalPath );

            }

            /**

             * The parser asks the client if it wishes to time out

             * in case it is taking more than the expected time.

             * @return

             */

            public boolean parserTimeout()

            {

                        return false;

            }

}

 

/**

 * @author jason

 *

 * TODO To change the template for this generated type comment go to

 * Window - Preferences - Java - Code Style - Code Templates

 */

public class Test {

 

            public static void main(String[] args) {

                        IScanner myIScanner;

                        IParser myIParser;

                        CMySourceElementRequestor mySourceElementRequestor;

                       

                        try

                        {

                                    mySourceElementRequestor = new CMySourceElementRequestor();

                                    myIScanner = ParserFactory.createScanner("c:\\temp\\test.c",new ScannerInfo(),ParserMode.COMPLETE_PARSE,ParserLanguage.C, mySourceElementRequestor, null,null);

                                    myIParser = ParserFactory.createParser(myIScanner, mySourceElementRequestor, ParserMode.COMPLETE_PARSE, ParserLanguage.C,null);

                                    if (myIParser.parse() == true)

                                    {

                                                System.out.print("Parse successful");

                                    }

                                    else

                                    {

                                                System.out.print("Parse unsuccessful");

                                    }

                        }

                        catch (IOException e)

                        {

                                    return;

                        }

            }

}