cocci: avoid normalization rules for memcpy

Some of the rules for using COPY_ARRAY instead of memcpy with sizeof are
intended to reduce the number of sizeof variants to deal with.  They can
have unintended side effects if only they match, but not the one for the
COPY_ARRAY conversion at the end.

Avoid these side effects by instead using a self-contained rule for each
combination of array and pointer for source and destination which lists
all sizeof variants inline.

This lets "make contrib/coccinelle/array.cocci.patch" take 15% longer on
my machine, but gives peace of mind that no incomplete transformation
will be generated.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/coccinelle/array.cocci b/contrib/coccinelle/array.cocci
index 9a4f00cb1bdc2e189fa3ccb41d842988e2430a92..aa759379508895ba002c531a13bde3f8995f9251 100644 (file)
--- a/contrib/coccinelle/array.cocci
+++ b/contrib/coccinelle/array.cocci
@@ -1,60 +1,58 @@
 @@
-expression dst, src, n, E;
+type T;
+T *dst_ptr;
+T *src_ptr;
+expression n;
 @@
-  memcpy(dst, src, n * sizeof(
-- E[...]
-+ *(E)
-  ))
+- memcpy(dst_ptr, src_ptr, (n) * \( sizeof(T)
+-                                \| sizeof(*(dst_ptr))
+-                                \| sizeof(*(src_ptr))
+-                                \| sizeof(dst_ptr[...])
+-                                \| sizeof(src_ptr[...])
+-                                \) )
++ COPY_ARRAY(dst_ptr, src_ptr, n)
 
 @@
 type T;
-T *ptr;
-T[] arr;
-expression E, n;
+T *dst_ptr;
+T[] src_arr;
+expression n;
 @@
-(
-  memcpy(ptr, E,
-- n * sizeof(*(ptr))
-+ n * sizeof(T)
-  )
-|
-  memcpy(arr, E,
-- n * sizeof(*(arr))
-+ n * sizeof(T)
-  )
-|
-  memcpy(E, ptr,
-- n * sizeof(*(ptr))
-+ n * sizeof(T)
-  )
-|
-  memcpy(E, arr,
-- n * sizeof(*(arr))
-+ n * sizeof(T)
-  )
-)
+- memcpy(dst_ptr, src_arr, (n) * \( sizeof(T)
+-                                \| sizeof(*(dst_ptr))
+-                                \| sizeof(*(src_arr))
+-                                \| sizeof(dst_ptr[...])
+-                                \| sizeof(src_arr[...])
+-                                \) )
++ COPY_ARRAY(dst_ptr, src_arr, n)
 
 @@
 type T;
-T *dst_ptr;
+T[] dst_arr;
 T *src_ptr;
+expression n;
+@@
+- memcpy(dst_arr, src_ptr, (n) * \( sizeof(T)
+-                                \| sizeof(*(dst_arr))
+-                                \| sizeof(*(src_ptr))
+-                                \| sizeof(dst_arr[...])
+-                                \| sizeof(src_ptr[...])
+-                                \) )
++ COPY_ARRAY(dst_arr, src_ptr, n)
+
+@@
+type T;
 T[] dst_arr;
 T[] src_arr;
 expression n;
 @@
-(
-- memcpy(dst_ptr, src_ptr, (n) * sizeof(T))
-+ COPY_ARRAY(dst_ptr, src_ptr, n)
-|
-- memcpy(dst_ptr, src_arr, (n) * sizeof(T))
-+ COPY_ARRAY(dst_ptr, src_arr, n)
-|
-- memcpy(dst_arr, src_ptr, (n) * sizeof(T))
-+ COPY_ARRAY(dst_arr, src_ptr, n)
-|
-- memcpy(dst_arr, src_arr, (n) * sizeof(T))
+- memcpy(dst_arr, src_arr, (n) * \( sizeof(T)
+-                                \| sizeof(*(dst_arr))
+-                                \| sizeof(*(src_arr))
+-                                \| sizeof(dst_arr[...])
+-                                \| sizeof(src_arr[...])
+-                                \) )
 + COPY_ARRAY(dst_arr, src_arr, n)
-)
 
 @@
 type T;