[PATCH v1 2/2] ACPICA: Silence 'unused-but-set variable' warning

Ammar Faizi
2022-12-23T14:25:03Z

@num_carats is used for debugging, passed to the 'ACPI_DEBUG_PRINT()'
macro. But this macro will expand to nothing when debug is disabled,
resulting in the following (clang-16):

drivers/acpi/acpica/nsaccess.c:295:6: error: variable 'num_carats' set \
but not used [-Werror,-Wunused-but-set-variable]
u32 num_carats;
^
1 error generated.

Move the variable declaration inside the else block to reduce the scope,
then add '(void)num_carats' to silence the warning when debug is disabled.

Cc: LLVM Mailing List <llvm@lists.linux.dev>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
drivers/acpi/acpica/nsaccess.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/acpica/nsaccess.c b/drivers/acpi/acpica/nsaccess.c
index a0c1a665dfc1..d73d052c5b3b 100644
--- a/drivers/acpi/acpica/nsaccess.c
+++ b/drivers/acpi/acpica/nsaccess.c
@@ -292,7 +292,6 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
struct acpi_namespace_node *current_node = NULL;
struct acpi_namespace_node *this_node = NULL;
u32 num_segments;
- u32 num_carats;
acpi_name simple_name;
acpi_object_type type_to_check_for;
acpi_object_type this_search_type;
@@ -394,6 +393,7 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
"Path is absolute from root [%p]\n",
this_node));
} else {
+ u32 num_carats = 0;
/* Pathname is relative to current scope, start there */

ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
@@ -406,7 +406,6 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
* the parent node for each prefix instance.
*/
this_node = prefix_node;
- num_carats = 0;
while (*path == (u8) AML_PARENT_PREFIX) {

/* Name is fully qualified, no search rules apply */
@@ -449,6 +448,7 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
"Search scope is [%4.4s], path has %u carat(s)\n",
acpi_ut_get_node_name
(this_node), num_carats));
+ (void)num_carats;
}
}

--
Ammar Faizi