Document whichsig and kin

2 files changed, 29 insertions, 4 deletions

diff --git a/embed.fnc b/embed.fnc
index 18f80fe73e..4101fdd724 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -2603,10 +2603,10 @@ Apd	|bool	|dump_c_backtrace|NN PerlIO* fp|int max_depth|int skip
 #endif
 : FIXME
 p	|void	|watch		|NN char** addr
-Am	|I32	|whichsig	|NN const char* sig
-Ap	|I32    |whichsig_sv    |NN SV* sigsv
-Ap	|I32    |whichsig_pv    |NN const char* sig
-Ap	|I32    |whichsig_pvn   |NN const char* sig|STRLEN len
+Amd	|I32	|whichsig	|NN const char* sig
+Apd	|I32    |whichsig_sv    |NN SV* sigsv
+Apd	|I32    |whichsig_pv    |NN const char* sig
+Apd	|I32    |whichsig_pvn   |NN const char* sig|STRLEN len
 : used to check for NULs in pathnames and other names
 AiRdp	|bool	|is_safe_syscall|NN const char *pv|STRLEN len|NN const char *what|NN const char *op_name
 #ifdef PERL_CORE
diff --git a/mg.c b/mg.c
index 3708bd50fe..9b6b4cc895 100644
--- a/mg.c
+++ b/mg.c
@@ -3305,6 +3305,31 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     return 0;
 }
 
+/*
+=for apidoc_section Signals
+=for apidoc whichsig
+=for apidoc_item whichsig_pv
+=for apidoc_item whichsig_pvn
+=for apidoc_item whichsig_sv
+
+These all convert a signal name into its corresponding signal number;
+returning -1 if no corresponding number was found.
+
+They differ only in the source of the signal name:
+
+C<whichsig_pv> takes the name from the C<NUL>-terminated string starting at
+C<sig>.
+
+C<whichsig> is merely a different spelling, a synonym, of C<whichsig_pv>.
+
+C<whichsig_pvn> takes the name from the string starting at C<sig>, with length
+C<len> bytes.
+
+C<whichsig_sv> takes the name from the PV stored in the SV C<sigsv>.
+
+=cut
+*/
+
 I32
 Perl_whichsig_sv(pTHX_ SV *sigsv)
 {