Re: [Cocci] [RFC] coccinelle: add style check for assignment in if

[Kris Borer]

On Wed, Aug 12, 2015 at 10:00 AM, Julia Lawall <julia.law...@lip6.fr> wrote:

> Thanks for the contribution.  Have you checked very carefully that it
> doesn't eg pull XXX out of if (E && XXX)?  (I don't know if it does or it
> doesn't, but it is a common pitfall with this issue).
>
> thanks,
> julia
>

​I tested it and it seems okay. The details are below. Let me know if you
meant something else or would like a more involved test.

​bash> cat test.c
int f() {
    return 0;
}

int main() {

    int a;

    // if1 good
    if( a = f() ) {
        a = 1;
    }

    // if1 bad
    if( a == 1 && (a = f()) ) {
        a = 1;
    }

    // if2 good
    if( (a = f()) < 0 ) {
        a = 1;
    }

    // if2 bad
    if( a == 1 && (a = f()) < 0 ) {
        a = 1;
    }

    // if4 good
    if( (a = f()) < 0 && a != 0 ) {
        a = 1;
    }
    // if4 bad
    if( a == 1 && (a = f()) < 0 && a != 0 ) {
        a = 1;
    }

    // if5 good
    if( (a = f()) < 0 && a != 0 ) {
        a = 1;
    }
    // if5 bad
    if( a == 1 && (a = f()) < 0 && a != 0 ) {
        a = 1;
    }

    return 0;
}
bash> spatch --sp-file assignment_in_if.cocci test.c
init_defs_builtins: /usr/local/lib/coccinelle/standard.h
warning: if4: metavariable E3 not used in the - or context code
HANDLING: test.c
diff =
--- test.c
+++ /tmp/cocci-output-11515-32ee81-test.c
@@ -7,7 +7,8 @@ int main() {
     int a;

     // if1 good
-    if( a = f() ) {
+    a = f();
+    if(a) {
         a = 1;
     }

@@ -17,7 +18,8 @@ int main() {
     }

     // if2 good
-    if( (a = f()) < 0 ) {
+    a = f();
+    if(a < 0 ) {
         a = 1;
     }

@@ -27,7 +29,8 @@ int main() {
     }

     // if4 good
-    if( (a = f()) < 0 && a != 0 ) {
+    a = f();
+    if(a < 0 && a != 0 ) {
         a = 1;
     }
     // if4 bad
@@ -36,7 +39,8 @@ int main() {
     }

     // if5 good
-    if( (a = f()) < 0 && a != 0 ) {
+    a = f();
+    if(a < 0 && a != 0 ) {
         a = 1;
     }
     // if5 bad
​
Thanks,

​Kris Borer​

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