diff options
| author | Ian Rogers <[email protected]> | 2020-05-30 01:20:13 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <[email protected]> | 2020-06-01 12:24:21 -0300 |
| commit | 21f2b7c13335eeec498569927d87c7381c3b54fa (patch) | |
| tree | abb274291b945d3690e9e10622b82e26c0f7902d | |
| parent | 9300acc6fed8e957c8d60f6f8e4451b508feea2c (diff) | |
tools compiler.h: Add attribute to disable tail calls
Tail call optimizations can remove stack frames that are used in
unwinding tests. Add an attribute that can be used to disable the tail
call optimization. Tested on clang and GCC.
Committer notes:
Old versions of clang don't like that __attribute__((optimize)), so add
an ifdef to make it go away.
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: [email protected]
Cc: Jakub Kicinski <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Quentin Monnet <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
| -rw-r--r-- | tools/include/linux/compiler-gcc.h | 12 | ||||
| -rw-r--r-- | tools/include/linux/compiler.h | 3 |
2 files changed, 15 insertions, 0 deletions
diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h index 95c072b70d0e..b9d4322e1e65 100644 --- a/tools/include/linux/compiler-gcc.h +++ b/tools/include/linux/compiler-gcc.h @@ -27,6 +27,18 @@ #define __pure __attribute__((pure)) #endif #define noinline __attribute__((noinline)) +#ifdef __has_attribute +#if __has_attribute(disable_tail_calls) +#define __no_tail_call __attribute__((disable_tail_calls)) +#endif +#endif +#ifndef __no_tail_call +#if GCC_VERSION > 40201 +#define __no_tail_call __attribute__((optimize("no-optimize-sibling-calls"))) +#else +#define __no_tail_call +#endif +#endif #ifndef __packed #define __packed __attribute__((packed)) #endif diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 180f7714a5f1..9f9002734e19 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -47,6 +47,9 @@ #ifndef noinline #define noinline #endif +#ifndef __no_tail_call +#define __no_tail_call +#endif /* Are two types/vars the same type (ignoring qualifiers)? */ #ifndef __same_type |