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Subject[PATCH v3 3/5] Creates macro to avoid variable shadowing
Date
Creates DEF_FIELD_ADDR_VAR as a more generic version of the DEF_FIELD_ADD
macro, allowing usage of a variable name other than the struct element name.
Also, sets DEF_FIELD_ADDR as a specific usage of DEF_FILD_ADDR_VAR in which
the var name is the same as the struct element name.
Then, makes use of DEF_FIELD_ADDR_VAR to create a variable of another name,
in order to avoid variable shadowing.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
scripts/mod/file2alias.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 7be43697ff84..ed468313ddeb 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -95,12 +95,20 @@ extern struct devtable *__start___devtable[], *__stop___devtable[];
*/
#define DEF_FIELD(m, devid, f) \
typeof(((struct devid *)0)->f) f = TO_NATIVE(*(typeof(f) *)((m) + OFF_##devid##_##f))
+
+/* Define a variable v that holds the address of field f of struct devid
+ * based at address m. Due to the way typeof works, for a field of type
+ * T[N] the variable has type T(*)[N], _not_ T*.
+ */
+#define DEF_FIELD_ADDR_VAR(m, devid, f, v) \
+ typeof(((struct devid *)0)->f) *v = ((m) + OFF_##devid##_##f)
+
/* Define a variable f that holds the address of field f of struct devid
* based at address m. Due to the way typeof works, for a field of type
* T[N] the variable has type T(*)[N], _not_ T*.
*/
#define DEF_FIELD_ADDR(m, devid, f) \
- typeof(((struct devid *)0)->f) *f = ((m) + OFF_##devid##_##f)
+ DEF_FIELD_ADDR_VAR(m, devid, f, f)

/* Add a table entry. We test function type matches while we're here. */
#define ADD_TO_DEVTABLE(device_id, type, function) \
@@ -644,7 +652,7 @@ static void do_pnp_card_entries(void *symval, unsigned long size,

for (i = 0; i < count; i++) {
unsigned int j;
- DEF_FIELD_ADDR(symval + i*id_size, pnp_card_device_id, devs);
+ DEF_FIELD_ADDR(symval + i * id_size, pnp_card_device_id, devs);

for (j = 0; j < PNP_MAX_DEVICES; j++) {
const char *id = (char *)(*devs)[j].id;
@@ -656,10 +664,13 @@ static void do_pnp_card_entries(void *symval, unsigned long size,

/* find duplicate, already added value */
for (i2 = 0; i2 < i && !dup; i2++) {
- DEF_FIELD_ADDR(symval + i2*id_size, pnp_card_device_id, devs);
+ DEF_FIELD_ADDR_VAR(symval + i2 * id_size,
+ pnp_card_device_id,
+ devs, devs_dup);

for (j2 = 0; j2 < PNP_MAX_DEVICES; j2++) {
- const char *id2 = (char *)(*devs)[j2].id;
+ const char *id2 =
+ (char *)(*devs_dup)[j2].id;

if (!id2[0])
break;
--
2.19.1
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