[cfe-dev] Basic source-to-source transformation with Clang

[Manuel Klimek]

On Mon, Jul 9, 2012 at 9:32 AM, Satya Prakash Prasad <
satyaprakash.prasad at gmail.com> wrote:

> Thanks once again. I am really thankful to Manuel and others in group
> who gave me more insight and confidence to work with CLANG.
>
> However please note that when I used the below code to print the C++
> code (input as an input param : rewritecode test.cpp):
>
>                         Stmt *i =  cast<Stmt>(*I);
>                         SourceManager &SourceMgr =
> TheCompInst.getSourceManager();
>                         SourceLocation ST = i->getSourceRange().getBegin();
>                         const char * code = SourceMgr.getCharacterData(ST);
>                         std::cout << "STMT  : " << code << "\n";
>

Do the same for getEnd(), then you have a char * for the end, and you can
print to that character...

Cheers,
/Manuel


>
> Ii prints additional line than what I want each time. Example if my
> test.cpp file is like below:
>
> int inc(int &p)
> {
>         p++;
>         printf("%s %d",__FILE__,__LINE__);
>         printf("In inc [%d]\n", p);
>         return p;
> }
>
>
> I get output like:
>
> STMT : p++;
>         printf("In inc [%d]\n", p);
>         return p;
> }
> ......................................................
>
> How can I print only a single line of code at a time and not its
> consecutive one. I cannot tokenize it with '\n' as there are can
> multiple lines for a single statement. I would also really appreciate
> if I can get some reference of good books either offline / online to
> refer for beginners level.
>
> Thanks in advance.
>
> Regards,
> Prakash
>
> On Fri, Jul 6, 2012 at 7:30 PM, Manuel Klimek <klimek at google.com> wrote:
> > On Fri, Jul 6, 2012 at 2:33 PM, Satya Prakash Prasad
> > <satyaprakash.prasad at gmail.com> wrote:
> >>
> >> Thanks for the information as provided, but I get output like below:
> >>
> >> (CallExpr 0x1a85c480 'int'
> >>   (ImplicitCastExpr 0x1a85c468 'int (*)(const char *restrict, ...)'
> >> <FunctionToPointerDecay>
> >>     (DeclRefExpr 0x1a85c3e8 'int (const char *restrict, ...)' lvalue
> >> Function 0x1a84e8e0 'printf' 'int (const char *restrict, ...)'))
> >>   (ImplicitCastExpr 0x1a85c4b8 'const char *' <ArrayToPointerDecay>
> >>     (StringLiteral 0x1a85c388 'const char [13]' lvalue "In inc [%d]\n"))
> >>   (ImplicitCastExpr 0x1a85c4d0 'int' <LValueToRValue>
> >>     (DeclRefExpr 0x1a85c3c0 'int' lvalue ParmVar 0x1a85c100 'p' 'int
> &')))
> >>
> >> Kindly note that my requirement is to print the C++ code itself like
> >> dumpAll() method generated for above for below C++ code:
> >
> >
> > If you want to print the C++ code that produce the AST, you'll want to
> get
> > the SourceRange, and use SourceManager's getCharacterData() method to get
> > the underlying data - that will get you the C++ code as it was written by
> > the user.
> >
> > Cheers,
> > /Manuel
> >>
> >>
> >> p++;
> >>
> >> Similarly for other like:
> >>
> >> dumpAll()
> >>
> >> (CallExpr 0x1a85dec8 'int'
> >>   (ImplicitCastExpr 0x1a85deb0 'int (*)(const char *restrict, ...)'
> >> <FunctionToPointerDecay>
> >>     (DeclRefExpr 0x1a85de88 'int (const char *restrict, ...)' lvalue
> >> Function 0x1a84e8e0 'printf' 'int (const char *restrict, ...)'))
> >>   (ImplicitCastExpr 0x1a85df08 'const char *' <ArrayToPointerDecay>
> >>     (StringLiteral 0x1a85cdd8 'const char [19]' lvalue "y = [%d] z =
> >> [%d]\n"))
> >>   (ImplicitCastExpr 0x1a85df20 'int' <LValueToRValue>
> >>     (DeclRefExpr 0x1a85ce18 'int' lvalue Var 0x1a85c6f0 'y' 'int'))
> >>   (ImplicitCastExpr 0x1a85df38 'int' <LValueToRValue>
> >>     (DeclRefExpr 0x1a85de60 'int' lvalue Var 0x1a85c760 'z' 'int')))
> >>
> >> While C++ Code:
> >>
> >> printf("y = [%d] z = [%d]\n", y , z);
> >>
> >> Thanks in advance.
> >>
> >> Regards,
> >> Prakash
> >>
> >>
> >> On Fri, Jul 6, 2012 at 4:22 PM, Manuel Klimek <klimek at google.com>
> wrote:
> >> > On Fri, Jul 6, 2012 at 12:25 PM, Satya Prakash Prasad
> >> > <satyaprakash.prasad at gmail.com> wrote:
> >> >>
> >> >> I made some progress with whatever support I received from this
> >> >> discussion forum. Thanks to all who responded to my request. My
> >> >> requirement now is to find a way I can print CLANG AST code to C++ /
> C
> >> >> human readable statements:
> >> >>
> >> >>     bool VisitStmt(Stmt *s) {
> >> >>         if (isa<CompoundStmt>(s)) {
> >> >>                 CompoundStmt *S = cast<CompoundStmt>(s);
> >> >>                 for (CompoundStmt::body_iterator  I =
> S->body_begin(),
> >> >> E = S->body_end(); I != E; ++I)
> >> >>                 {
> >> >>                         Stmt *i =  cast<Stmt>(*I);
> >> >>                         //How can I print the C++ / C statement which
> >> >> CLANG is processing
> >> >
> >> >
> >> > You can use i->dumpAll() if you want to see what's going on.
> >> >
> >> > Cheers,
> >> > /Manuel
> >> >
> >> >>
> >> >>                 }
> >> >>         }
> >> >>
> >> >>         return true;
> >> >>     }
> >> >>
> >> >> Regards,
> >> >> Prakash
> >> >>
> >> >> _______________________________________________
> >> >> cfe-dev mailing list
> >> >> cfe-dev at cs.uiuc.edu
> >> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> >> >
> >> >
> >
> >
>
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