| Message ID | 20171006235023.11952-5-f4bug@amsat.org |
|---|---|
| State | New |
| Headers | show |
| Series | use g_new() family of functions | expand |
On 10/06/2017 08:48 PM, Philippe Mathieu-Daudé wrote: > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > scripts/coccinelle/g_new.cocci | 46 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 46 insertions(+) > > diff --git a/scripts/coccinelle/g_new.cocci b/scripts/coccinelle/g_new.cocci > index 368f0c5651..9643ce3f23 100644 > --- a/scripts/coccinelle/g_new.cocci > +++ b/scripts/coccinelle/g_new.cocci > @@ -127,6 +127,52 @@ T **m; > - *m = g_malloc0(sizeof(**m)); > + *m = g_new0(T *, 1); > > +//////////////////////////////////////// > +// > +// no point in zeroing the allocation > +// > + > +// the loop right afterwards fully initializes the memory > +@@ > +type T; > +identifier a, i; > +expression c, e; > +@@ > +( > +-a = g_new0(T, c); > + ... when != a, c > ++a = g_new(T, c); > + for (i = 0; i < c; i++) { > + a[i] = e; > + } > +| > +-a = g_try_new0(T, c); > + ... when != a, c > ++a = g_try_new(T, c); > + for (i = 0; i < c; i++) { > + a[i] = e; > + } > +) > + > +// compound literals > +@@ > +type T; > +identifier p; > +expression s, e; > +@@ > +( > +- p = g_malloc0(s); > ++ p = g_malloc(s); > +| > +- p = g_try_malloc0(s); > ++ p = g_try_malloc(s); > +| > +- p = g_new0(T, 1); > ++ p = g_new(T, 1); > +) > + ... when != p > + *p = e; It seems I misunderstood compound literals, I somehow believed this would imply uninitialized fields would be zeroed. So this transformation leads to incorrect code. > + > //////////////////////////////////////// > // > // last transformations: cleanups >
diff --git a/scripts/coccinelle/g_new.cocci b/scripts/coccinelle/g_new.cocci index 368f0c5651..9643ce3f23 100644 --- a/scripts/coccinelle/g_new.cocci +++ b/scripts/coccinelle/g_new.cocci @@ -127,6 +127,52 @@ T **m; - *m = g_malloc0(sizeof(**m)); + *m = g_new0(T *, 1); +//////////////////////////////////////// +// +// no point in zeroing the allocation +// + +// the loop right afterwards fully initializes the memory +@@ +type T; +identifier a, i; +expression c, e; +@@ +( +-a = g_new0(T, c); + ... when != a, c ++a = g_new(T, c); + for (i = 0; i < c; i++) { + a[i] = e; + } +| +-a = g_try_new0(T, c); + ... when != a, c ++a = g_try_new(T, c); + for (i = 0; i < c; i++) { + a[i] = e; + } +) + +// compound literals +@@ +type T; +identifier p; +expression s, e; +@@ +( +- p = g_malloc0(s); ++ p = g_malloc(s); +| +- p = g_try_malloc0(s); ++ p = g_try_malloc(s); +| +- p = g_new0(T, 1); ++ p = g_new(T, 1); +) + ... when != p + *p = e; + //////////////////////////////////////// // // last transformations: cleanups
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> --- scripts/coccinelle/g_new.cocci | 46 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)