[cocci] How can I find all static variable declarations?

[cocci] How can I find all static variable declarations?

[Eric Wheeler]

Hello,

I'm trying to find all static variable declarations (either global or 
within a function:

	static int global_x, y, z;

	void foo()
	{
		static int a, b, c;
	}

with a patch like this:

	@ rule1 @
	identifier I;
	type T;
	@@
	static T I;
	+ // static ^^

It gets single variable declarations:
	   static gint iv[4];
	+  // static ^^

but not multiple variable declarations like the foo() example above 
because 'I' only matches a single variable in the rule.

It also matches functions, but I really only want variables (if possible):
	 static void subph( int nx, int ny );
	+// static ^^

I tried an identfier list:
	@ rule1 @
	identifier list IL;
	type T;
	@@
	static T IL;
	+ // static ^^

but gives the error:

	init_defs_builtins: /usr/lib64/coccinelle/standard.h
	minus: parse error: 
	  File "nec-static.cocci", line 5, column 9, charpos = 50
	  around = 'IL',
	  whole content = static T IL;

What is the right way to do this?

I'm just printing the diffs so I can inspect the code, sort of using 
`spatch` like a semantic grep.  Is there an official way to do "semantic 
greps"?


--
Eric Wheeler

Re: [cocci] How can I find all static variable declarations?

[Julia Lawall]

On Tue, 1 Mar 2022, Eric Wheeler wrote:

> Hello,
>
> I'm trying to find all static variable declarations (either global or
> within a function:
>
> 	static int global_x, y, z;
>
> 	void foo()
> 	{
> 		static int a, b, c;
> 	}
>
> with a patch like this:
>
> 	@ rule1 @
> 	identifier I;
> 	type T;
> 	@@
> 	static T I;
> 	+ // static ^^
>
> It gets single variable declarations:
> 	   static gint iv[4];
> 	+  // static ^^
>
> but not multiple variable declarations like the foo() example above
> because 'I' only matches a single variable in the rule.
>
> It also matches functions, but I really only want variables (if possible):
> 	 static void subph( int nx, int ny );
> 	+// static ^^
>
> I tried an identfier list:
> 	@ rule1 @
> 	identifier list IL;
> 	type T;
> 	@@
> 	static T IL;
> 	+ // static ^^
>
> but gives the error:
>
> 	init_defs_builtins: /usr/lib64/coccinelle/standard.h
> 	minus: parse error:
> 	  File "nec-static.cocci", line 5, column 9, charpos = 50
> 	  around = 'IL',
> 	  whole content = static T IL;
>
> What is the right way to do this?

What you tried should have worked.  And it should not have matched
function definitions.  I will check on it.

>
> I'm just printing the diffs so I can inspect the code, sort of using
> `spatch` like a semantic grep.  Is there an official way to do "semantic
> greps"?

Use * instead of - or + for the things you are interested in.  You will
still get a diff, but the - lines are the ones that match what you wanted
to see.

julia

Re: [cocci] How can I find all static variable declarations?

[Eric Wheeler]

On Wed, 2 Mar 2022, Julia Lawall wrote:
> On Tue, 1 Mar 2022, Eric Wheeler wrote:
> > Hello,
> >
> > I'm trying to find all static variable declarations (either global or
> > within a function:
> >
> > 	static int global_x, y, z;
> >
> > 	void foo()
> > 	{
> > 		static int a, b, c;
> > 	}
> >
> > with a patch like this:
> >
> > 	@ rule1 @
> > 	identifier I;
> > 	type T;
> > 	@@
> > 	static T I;
> > 	+ // static ^^
> >
> > It gets single variable declarations:
> > 	   static gint iv[4];
> > 	+  // static ^^
> >
> > but not multiple variable declarations like the foo() example above
> > because 'I' only matches a single variable in the rule.
> >
> > It also matches functions, but I really only want variables (if possible):
> > 	 static void subph( int nx, int ny );
> > 	+// static ^^
> >
> > I tried an identfier list:
> > 	@ rule1 @
> > 	identifier list IL;
> > 	type T;
> > 	@@
> > 	static T IL;
> > 	+ // static ^^
> >
> > but gives the error:
> >
> > 	init_defs_builtins: /usr/lib64/coccinelle/standard.h
> > 	minus: parse error:
> > 	  File "nec-static.cocci", line 5, column 9, charpos = 50
> > 	  around = 'IL',
> > 	  whole content = static T IL;
> >
> > What is the right way to do this?
> 
> What you tried should have worked.  And it should not have matched
> function definitions.  I will check on it.

Thanks for checking!

FYI:

]# spatch --version
spatch version 1.1.1-00044-gb2a4b9b compiled with OCaml version 4.05.0
Flags passed to the configure script: --prefix=/usr/local/coccinelle-git
OCaml scripting support: yes
Python scripting support: yes
Syntax of regular expressions: PCRE

Let me know if there if you have a patch or git update and I'll try it out.

> 
> >
> > I'm just printing the diffs so I can inspect the code, sort of using
> > `spatch` like a semantic grep.  Is there an official way to do "semantic
> > greps"?
> 
> Use * instead of - or + for the things you are interested in.  You will
> still get a diff, but the - lines are the ones that match what you wanted
> to see.

Neat!  I'll give it a try.

--
Eric Wheeler



> 
> julia
>