Allow control of 2nd arg to segsetjmp() via -DSCOPE_SAVES_SIGNAL_MASK.

(So Alan and Ilya can try setting via hints.)
Verified Linux "works" with it true and fails to re-enable SIGINT if false.
Restoring sigmask in Perl_sighandler() if handler dies is not equivalent;
doing the save everywhere seems to restart read() correctly, but just
doing it once "round" the handler does not.

p4raw-id: //depot/perlio@8401

diff --git a/scope.h b/scope.h
index 3e05962..d45bd94 100644 (file)
--- a/scope.h
+++ b/scope.h
@@ -35,6 +35,10 @@
 #define SAVEt_GENERIC_PVREF    34
 #define SAVEt_PADSV            35
 
+#ifndef SCOPE_SAVES_SIGNAL_MASK
+#define SCOPE_SAVES_SIGNAL_MASK 1
+#endif
+
 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
@@ -307,7 +311,7 @@ typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
            DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
                             ce, PL_top_env));                  \
            JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
-           EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, 1));\
+           EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
            (ce).je_noset = 1;                                  \
        }                                                       \
        else                                                    \
@@ -356,7 +360,7 @@ typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
                         &cur_env, PL_top_env));                        \
        cur_env.je_prev = PL_top_env;                                   \
        OP_REG_TO_MEM;                                                  \
-       cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, 1);            \
+       cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
        OP_MEM_TO_REG;                                                  \
        PL_top_env = &cur_env;                                          \
        cur_env.je_mustcatch = FALSE;                                   \