Re: [PATCH v1 13/13] tools headers: Rename noinline to __noinline

Michael S. Tsirkin
2024-03-11T15:44:08Z

On Sat, Mar 09, 2024 at 06:05:08PM -0800, Ian Rogers wrote:
> An issue was reported with clang and llvm libc where the noinline
> attribute [1] was being expanded due to the #define in
> linux/compiler.h (now in compiler_attributes.h). The expansion caused
> the __attribute__ to appear twice and break the build. To avoid this
> conflict, rename noinline to __noinline which is more consistent with
> other compiler attributes.
>
> [1] https://clang.llvm.org/docs/AttributeReference.html#noinline

Following this link, I don't see __noinline there - only __noinline__ and
noinline. What's up?

Als, pls add an empty line before tags.

> Reported-by: Christopher Di Bella <cjdb@google.com>
>
> Signed-off-by: Ian Rogers <irogers@google.com>

tags should not have empty lines between them.

> ---
> tools/include/linux/compiler_attributes.h | 4 ++--
> tools/perf/arch/x86/tests/bp-modify.c | 4 ++--
> tools/perf/bench/find-bit-bench.c | 2 +-
> tools/perf/tests/bp_account.c | 2 +-
> tools/perf/tests/bp_signal.c | 2 +-
> tools/perf/tests/bp_signal_overflow.c | 2 +-
> tools/perf/tests/dwarf-unwind.c | 12 ++++++------
> tools/perf/tests/workloads/leafloop.c | 8 ++++----
> tools/perf/tests/workloads/thloop.c | 4 ++--
> 9 files changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/tools/include/linux/compiler_attributes.h b/tools/include/linux/compiler_attributes.h
> index 9bfaec783e48..1ff3d85f5af3 100644
> --- a/tools/include/linux/compiler_attributes.h
> +++ b/tools/include/linux/compiler_attributes.h
> @@ -267,12 +267,12 @@
> # define __flatten __attribute__((flatten))
>
> /*
> - * Note the missing underscores.
> + * Note, the kernel version is missing the underscores.
> *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute
> * clang: mentioned
> */
> -#define noinline __attribute__((__noinline__))
> +#define __noinline __attribute__((__noinline__))
>
> /*
> * Optional: only supported since gcc >= 8
> diff --git a/tools/perf/arch/x86/tests/bp-modify.c b/tools/perf/arch/x86/tests/bp-modify.c
> index 0924ccd9e36d..65493ff7a76f 100644
> --- a/tools/perf/arch/x86/tests/bp-modify.c
> +++ b/tools/perf/arch/x86/tests/bp-modify.c
> @@ -15,13 +15,13 @@
> #include "tests/tests.h"
> #include "arch-tests.h"
>
> -static noinline int bp_1(void)
> +static __noinline int bp_1(void)
> {
> pr_debug("in %s\n", __func__);
> return 0;
> }
>
> -static noinline int bp_2(void)
> +static __noinline int bp_2(void)
> {
> pr_debug("in %s\n", __func__);
> return 0;
> diff --git a/tools/perf/bench/find-bit-bench.c b/tools/perf/bench/find-bit-bench.c
> index 7e25b0e413f6..dd97a51649bc 100644
> --- a/tools/perf/bench/find-bit-bench.c
> +++ b/tools/perf/bench/find-bit-bench.c
> @@ -31,7 +31,7 @@ static const char *const bench_usage[] = {
> static unsigned int accumulator;
> static unsigned int use_of_val;
>
> -static noinline void workload(int val)
> +static __noinline void workload(int val)
> {
> use_of_val += val;
> accumulator++;
> diff --git a/tools/perf/tests/bp_account.c b/tools/perf/tests/bp_account.c
> index 6f921db33cf9..459f61752a71 100644
> --- a/tools/perf/tests/bp_account.c
> +++ b/tools/perf/tests/bp_account.c
> @@ -34,7 +34,7 @@
>
> static volatile long the_var;
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> return 0;
> }
> diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
> index 1f2908f02389..484a7e7f96ee 100644
> --- a/tools/perf/tests/bp_signal.c
> +++ b/tools/perf/tests/bp_signal.c
> @@ -59,7 +59,7 @@ static void __test_function(volatile long *ptr)
> }
> #endif
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> __test_function(&the_var);
> the_var++;
> diff --git a/tools/perf/tests/bp_signal_overflow.c b/tools/perf/tests/bp_signal_overflow.c
> index 4e897c2cf26b..9436bf2973f8 100644
> --- a/tools/perf/tests/bp_signal_overflow.c
> +++ b/tools/perf/tests/bp_signal_overflow.c
> @@ -30,7 +30,7 @@
>
> static int overflows;
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> return time(NULL);
> }
> diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
> index d01aa931fe81..a669c69a9242 100644
> --- a/tools/perf/tests/dwarf-unwind.c
> +++ b/tools/perf/tests/dwarf-unwind.c
> @@ -109,7 +109,7 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
> return strcmp((const char *) symbol, funcs[idx]);
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__thread(struct thread *thread)
> {
> struct perf_sample sample;
> unsigned long cnt = 0;
> @@ -140,7 +140,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thr
>
> static int global_unwind_retval = -INT_MAX;
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__compare(void *p1, void *p2)
> {
> /* Any possible value should be 'thread' */
> struct thread *thread = *(struct thread **)p1;
> @@ -159,7 +159,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p
> return p1 - p2;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_3(struct thread *thread)
> {
> struct thread *array[2] = {thread, thread};
> void *fp = &bsearch;
> @@ -178,7 +178,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *th
> return global_unwind_retval;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_2(struct thread *thread)
> {
> int ret;
>
> @@ -187,7 +187,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *th
> return ret;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_1(struct thread *thread)
> {
> int ret;
>
> @@ -196,7 +196,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *th
> return ret;
> }
>
> -noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
> +__noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
> int subtest __maybe_unused)
> {
> struct machine *machine;
> diff --git a/tools/perf/tests/workloads/leafloop.c b/tools/perf/tests/workloads/leafloop.c
> index 1bf5cc97649b..89d2cec2f461 100644
> --- a/tools/perf/tests/workloads/leafloop.c
> +++ b/tools/perf/tests/workloads/leafloop.c
> @@ -4,18 +4,18 @@
> #include "../tests.h"
>
> /* We want to check these symbols in perf script */
> -noinline void leaf(volatile int b);
> -noinline void parent(volatile int b);
> +__noinline void leaf(volatile int b);
> +__noinline void parent(volatile int b);
>
> static volatile int a;
>
> -noinline void leaf(volatile int b)
> +__noinline void leaf(volatile int b)
> {
> for (;;)
> a += b;
> }
>
> -noinline void parent(volatile int b)
> +__noinline void parent(volatile int b)
> {
> leaf(b);
> }
> diff --git a/tools/perf/tests/workloads/thloop.c b/tools/perf/tests/workloads/thloop.c
> index 457b29f91c3e..e252efb76203 100644
> --- a/tools/perf/tests/workloads/thloop.c
> +++ b/tools/perf/tests/workloads/thloop.c
> @@ -9,14 +9,14 @@
> static volatile sig_atomic_t done;
>
> /* We want to check this symbol in perf report */
> -noinline void test_loop(void);
> +__noinline void test_loop(void);
>
> static void sighandler(int sig __maybe_unused)
> {
> done = 1;
> }
>
> -noinline void test_loop(void)
> +__noinline void test_loop(void)
> {
> while (!done);
> }
> --
> 2.44.0.278.ge034bb2e1d-goog