diff options
| -rw-r--r-- | libgo/runtime/print.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/libgo/runtime/print.c b/libgo/runtime/print.c index 1656a99..ba0b86a 100644 --- a/libgo/runtime/print.c +++ b/libgo/runtime/print.c @@ -11,7 +11,9 @@ //static Lock debuglock; -static void go_vprintf(const char*, va_list); +// Clang requires this function to not be inlined (see below). +static void go_vprintf(const char*, va_list) +__attribute__((noinline)); // write to goroutine-local buffer if diverting output, // or else standard error. @@ -61,6 +63,24 @@ runtime_prints(const char *s) gwrite(s, runtime_findnull((const byte*)s)); } +#if defined (__clang__) && (defined (__i386__) || defined (__x86_64__)) +// LLVM's code generator does not currently support split stacks for vararg +// functions, so we disable the feature for this function under Clang. This +// appears to be OK as long as: +// - this function only calls non-inlined, internal-linkage (hence no dynamic +// loader) functions compiled with split stacks (i.e. go_vprintf), which can +// allocate more stack space as required; +// - this function itself does not occupy more than BACKOFF bytes of stack space +// (see libgcc/config/i386/morestack.S). +// These conditions are currently known to be satisfied by Clang on x86-32 and +// x86-64. Note that signal handlers receive slightly less stack space than they +// would normally do if they happen to be called while this function is being +// run. If this turns out to be a problem we could consider increasing BACKOFF. +void +runtime_printf(const char *s, ...) +__attribute__((no_split_stack)); +#endif + void runtime_printf(const char *s, ...) { |