[Cocci] Problems: Adding Include directives, Adding ({}) construct

[Cocci] Problems: Adding Include directives, Adding ({}) construct

[sebald.ziegler.cocci at ikolus.de]

Hi,

I am trying to use coccinelle to add an include directive before the other 
includes and one after the includes:

@PreInclude@
@@
+ #include "pre.h"
#include ...


@PostInclude@
@@
#include ...
+ #include "post.h"

this works well if the source file (all includes are always at the top of the 
file) contains more than one include directive. However, if there is only one 
include directive -> only the PreInclude rule is executed.

So for this program:
#include <stdio.h>

int main() {
    return 0;
}

This is the result:
#include "pre.h"
#include <stdio.h>

int main() {
    return 0;
}

So it seems that only one rule can match some code line/code pattern. Am I 
mistaken? What could be an approach that works for both the single include 
directive and multiple include directives case?


Another Question:
With the following rule I want to add a macro definition just above the main 
function:
@macro_square@
@@
+ #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
int main(int argc, char ** argv) {
...
}

If I execute spatch on the program above this error is reported (coccinelle 
version: 1.0.6):
plus: parse error: 
  File "/tmp/testing/test.c-brackets.cocci", line 3, column 21, charpos = 39
  around = '{',
  whole content = + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })

Is this kind of code not supported or did I make a mistake somewhere?

Thank you for any information and hints!

Regards,
Sebald

[Cocci] Problems: Adding Include directives, Adding ({}) construct

[Julia Lawall]

On Mon, 27 Feb 2017, sebald.ziegler.cocci at ikolus.de wrote:

> Hi,
>
> I am trying to use coccinelle to add an include directive before the other
> includes and one after the includes:
>
> @PreInclude@
> @@
> + #include "pre.h"
> #include ...
>
>
> @PostInclude@
> @@
> #include ...
> + #include "post.h"
>
> this works well if the source file (all includes are always at the top of the
> file) contains more than one include directive. However, if there is only one
> include directive -> only the PreInclude rule is executed.

Sorry not to have responded sooner.

This seems quite strange.  Each rule sees the result of the previous one,
so by the time it reaches the post include rule, there would be two
includes in the program.  I will check on it.

>
> So for this program:
> #include <stdio.h>
>
> int main() {
>     return 0;
> }
>
> This is the result:
> #include "pre.h"
> #include <stdio.h>
>
> int main() {
>     return 0;
> }
>
> So it seems that only one rule can match some code line/code pattern. Am I
> mistaken?

This is not correct.  Coccinelle works on the first rule, then provides
the resulting code to the second rule, and so on.

> What could be an approach that works for both the single include
> directive and multiple include directives case?
>
>
> Another Question:
> With the following rule I want to add a macro definition just above the main
> function:
> @macro_square@
> @@
> + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> int main(int argc, char ** argv) {
> ...
> }
>
> If I execute spatch on the program above this error is reported (coccinelle
> version: 1.0.6):
> plus: parse error:
>   File "/tmp/testing/test.c-brackets.cocci", line 3, column 21, charpos = 39
>   around = '{',
>   whole content = + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
>
> Is this kind of code not supported or did I make a mistake somewhere?

It is quite possible that ({ }) is not supported in the pattern matching
language.  There is a hackish solution:

@script:python r@
str;
@@

coccinelle.str = "({printf("SQUARE(x)\n"); x*x; })"

@macro_square@
idntifier r.str;
@@
+ #define SQUARE(x) str
int main(int argc, char ** argv) {
...
}

Coccinelle won't actually check that what you have put into the variable
str is an identifier.

julia

[Cocci] Problems: Adding Include directives, Adding ({}) construct

[sebald.ziegler.cocci at ikolus.de]

On Thursday, March 2, 2017 8:21:40 AM CET Julia Lawall wrote:
> On Mon, 27 Feb 2017, sebald.ziegler.cocci at ikolus.de wrote:
> > Hi,
> > 
> > I am trying to use coccinelle to add an include directive before the other
> > includes and one after the includes:
> > 
> > @PreInclude@
> > @@
> > + #include "pre.h"
> > #include ...
> > 
> > 
> > @PostInclude@
> > @@
> > #include ...
> > + #include "post.h"
> > 
> > this works well if the source file (all includes are always at the top of
> > the file) contains more than one include directive. However, if there is
> > only one include directive -> only the PreInclude rule is executed.
> 
> Sorry not to have responded sooner.
> 
> This seems quite strange.  Each rule sees the result of the previous one,
> so by the time it reaches the post include rule, there would be two
> includes in the program.  I will check on it.
> 
> > So for this program:
> > #include <stdio.h>
> > 
> > int main() {
> > 
> >     return 0;
> > 
> > }
> > 
> > This is the result:
> > #include "pre.h"
> > #include <stdio.h>
> > 
> > int main() {
> > 
> >     return 0;
> > 
> > }
> > 
> > So it seems that only one rule can match some code line/code pattern. Am I
> > mistaken?
> 
> This is not correct.  Coccinelle works on the first rule, then provides
> the resulting code to the second rule, and so on.
> 
> > What could be an approach that works for both the single include
> > directive and multiple include directives case?
> > 
> > 
> > Another Question:
> > With the following rule I want to add a macro definition just above the
> > main function:
> > @macro_square@
> > @@
> > + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> > int main(int argc, char ** argv) {
> > ...
> > }
> > 
> > If I execute spatch on the program above this error is reported
> > (coccinelle
> > version: 1.0.6):
> > 
> > plus: parse error:
> >   File "/tmp/testing/test.c-brackets.cocci", line 3, column 21, charpos =
> >   39
> >   around = '{',
> >   whole content = + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> > 
> > Is this kind of code not supported or did I make a mistake somewhere?
> 
> It is quite possible that ({ }) is not supported in the pattern matching
> language.  There is a hackish solution:
> 
> @script:python r@
> str;
> @@
> 
> coccinelle.str = "({printf("SQUARE(x)\n"); x*x; })"
> 
> @macro_square@
> idntifier r.str;
> @@
> + #define SQUARE(x) str
> int main(int argc, char ** argv) {
> ...
> }
> 
> Coccinelle won't actually check that what you have put into the variable
> str is an identifier.
> 
> julia

Thank you very much for your answer!
I used the workaround you described and can now generate those macros without 
errors. However, there is a weird thing happening: Before every second " a 
line break is added:

When I use this coccinelle script:
@script:python macros@
SQUARE_str;
@@
coccinelle.SQUARE_str = '({printf("SQUARE\n"); printf("SQUARE\n"); x*x; })'

@macro_wrapper_int_SQUARE_int@
identifier macros.SQUARE_str;
@@
+#define SQUARE(x) SQUARE_str
int main(int argc, char ** argv) {
...
}

Then this is generated as diff:
[...]
+#define SQUARE(x) ({printf("SQUARE
+"); printf("SQUARE
+"); x*x; })
[...]

Is there a simple solution for this?

Thanks,
Sebald

[Cocci] Problems: Adding Include directives, Adding ({}) construct

[Julia Lawall]

On Tue, 7 Mar 2017, sebald.ziegler.cocci at ikolus.de wrote:

> On Thursday, March 2, 2017 8:21:40 AM CET Julia Lawall wrote:
> > On Mon, 27 Feb 2017, sebald.ziegler.cocci at ikolus.de wrote:
> > > Hi,
> > >
> > > I am trying to use coccinelle to add an include directive before the other
> > > includes and one after the includes:
> > >
> > > @PreInclude@
> > > @@
> > > + #include "pre.h"
> > > #include ...
> > >
> > >
> > > @PostInclude@
> > > @@
> > > #include ...
> > > + #include "post.h"
> > >
> > > this works well if the source file (all includes are always at the top of
> > > the file) contains more than one include directive. However, if there is
> > > only one include directive -> only the PreInclude rule is executed.
> >
> > Sorry not to have responded sooner.
> >
> > This seems quite strange.  Each rule sees the result of the previous one,
> > so by the time it reaches the post include rule, there would be two
> > includes in the program.  I will check on it.
> >
> > > So for this program:
> > > #include <stdio.h>
> > >
> > > int main() {
> > >
> > >     return 0;
> > >
> > > }
> > >
> > > This is the result:
> > > #include "pre.h"
> > > #include <stdio.h>
> > >
> > > int main() {
> > >
> > >     return 0;
> > >
> > > }
> > >
> > > So it seems that only one rule can match some code line/code pattern. Am I
> > > mistaken?
> >
> > This is not correct.  Coccinelle works on the first rule, then provides
> > the resulting code to the second rule, and so on.
> >
> > > What could be an approach that works for both the single include
> > > directive and multiple include directives case?
> > >
> > >
> > > Another Question:
> > > With the following rule I want to add a macro definition just above the
> > > main function:
> > > @macro_square@
> > > @@
> > > + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> > > int main(int argc, char ** argv) {
> > > ...
> > > }
> > >
> > > If I execute spatch on the program above this error is reported
> > > (coccinelle
> > > version: 1.0.6):
> > >
> > > plus: parse error:
> > >   File "/tmp/testing/test.c-brackets.cocci", line 3, column 21, charpos =
> > >   39
> > >   around = '{',
> > >   whole content = + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> > >
> > > Is this kind of code not supported or did I make a mistake somewhere?
> >
> > It is quite possible that ({ }) is not supported in the pattern matching
> > language.  There is a hackish solution:
> >
> > @script:python r@
> > str;
> > @@
> >
> > coccinelle.str = "({printf("SQUARE(x)\n"); x*x; })"
> >
> > @macro_square@
> > idntifier r.str;
> > @@
> > + #define SQUARE(x) str
> > int main(int argc, char ** argv) {
> > ...
> > }
> >
> > Coccinelle won't actually check that what you have put into the variable
> > str is an identifier.
> >
> > julia
>
> Thank you very much for your answer!
> I used the workaround you described and can now generate those macros without
> errors. However, there is a weird thing happening: Before every second " a
> line break is added:
>
> When I use this coccinelle script:
> @script:python macros@
> SQUARE_str;
> @@
> coccinelle.SQUARE_str = '({printf("SQUARE\n"); printf("SQUARE\n"); x*x; })'
>
> @macro_wrapper_int_SQUARE_int@
> identifier macros.SQUARE_str;
> @@
> +#define SQUARE(x) SQUARE_str
> int main(int argc, char ** argv) {
> ...
> }
>
> Then this is generated as diff:
> [...]
> +#define SQUARE(x) ({printf("SQUARE
> +"); printf("SQUARE
> +"); x*x; })
> [...]
>
> Is there a simple solution for this?

Try \\n instead of \n.

julia

[Cocci] Problems: Adding Include directives, Adding ({}) construct

[Julia Lawall]

On Mon, 27 Feb 2017, sebald.ziegler.cocci at ikolus.de wrote:

> Hi,
>
> I am trying to use coccinelle to add an include directive before the other
> includes and one after the includes:
>
> @PreInclude@
> @@
> + #include "pre.h"
> #include ...
>
>
> @PostInclude@
> @@
> #include ...
> + #include "post.h"
>
> this works well if the source file (all includes are always at the top of the
> file) contains more than one include directive. However, if there is only one
> include directive -> only the PreInclude rule is executed.
>
> So for this program:
> #include <stdio.h>
>
> int main() {
>     return 0;
> }
>
> This is the result:
> #include "pre.h"
> #include <stdio.h>
>
> int main() {
>     return 0;
> }
>
> So it seems that only one rule can match some code line/code pattern. Am I
> mistaken? What could be an approach that works for both the single include
> directive and multiple include directives case?

It seems to be a special case for includes.  Includes know whether they
are the first or last include.  But when you add something before or after
an include, it loses this information.  Afterwards, a rule that wants to
add before the first include or after the last one does not apply.

julia

>
>
> Another Question:
> With the following rule I want to add a macro definition just above the main
> function:
> @macro_square@
> @@
> + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
> int main(int argc, char ** argv) {
> ...
> }
>
> If I execute spatch on the program above this error is reported (coccinelle
> version: 1.0.6):
> plus: parse error:
>   File "/tmp/testing/test.c-brackets.cocci", line 3, column 21, charpos = 39
>   around = '{',
>   whole content = + #define SQUARE(x) ({printf("SQUARE(x)\n"); x*x; })
>
> Is this kind of code not supported or did I make a mistake somewhere?
>
> Thank you for any information and hints!
>
> Regards,
> Sebald
> _______________________________________________
> Cocci mailing list
> Cocci at systeme.lip6.fr
> https://systeme.lip6.fr/mailman/listinfo/cocci
>