Silence -Wunused-parameter my_perl under threads.

For S_ functions, remove the context.
For Perl_ functions, add PERL_UNUSED_CONTEXT.

Tricky because sometimes depends on DEBUGGING, and sometimes
on whether we are have PERL_IMPLICIT_SYS.

(Why all the mathoms Perl_is_uni_... and Perl_is_utf8_...
functions are not being whined about is a mystery.)

vutil.c (included via util.c) has one of these, but it's cpan/,
and a known problem: https://rt.cpan.org/Ticket/Display.html?id=96100

10 files changed, 48 insertions, 6 deletions

diff --git a/deb.c b/deb.c
index d16103eb1e..433ae11ddb 100644
--- a/deb.c
+++ b/deb.c
@@ -94,6 +94,8 @@ Perl_debstackptrs(pTHX)
 		  PTR2UV(PL_mainstack), PTR2UV(AvARRAY(PL_curstack)),
 		  PTR2UV(PL_mainstack), PTR2UV(AvFILLp(PL_curstack)),
 		  PTR2UV(AvMAX(PL_curstack)));
+#else
+    PERL_UNUSED_CONTEXT;
 #endif /* DEBUGGING */
     return 0;
 }
diff --git a/doio.c b/doio.c
index 762903ec16..feb52dff95 100644
--- a/doio.c
+++ b/doio.c
@@ -1198,6 +1198,7 @@ int
 Perl_mode_from_discipline(pTHX_ const char *s, STRLEN len)
 {
     int mode = O_BINARY;
+    PERL_UNUSED_CONTEXT;
     if (s) {
 	while (*s) {
 	    if (*s == ':') {
@@ -2049,6 +2050,7 @@ Perl_cando(pTHX_ Mode_t mode, bool effective, const Stat_t *statbufp)
     dVAR;
 
     PERL_ARGS_ASSERT_CANDO;
+    PERL_UNUSED_CONTEXT;
 
 #ifdef DOSISH
     /* [Comments and code from Len Reed]
@@ -2107,6 +2109,10 @@ static bool
 S_ingroup(pTHX_ Gid_t testgid, bool effective)
 {
     dVAR;
+#ifndef PERL_IMPLICIT_SYS
+    /* PERL_IMPLICIT_SYS like Win32: getegid() etc. require the context. */
+    PERL_UNUSED_CONTEXT;
+#endif
     if (testgid == (effective ? PerlProc_getegid() : PerlProc_getgid()))
 	return TRUE;
 #ifdef HAS_GETGROUPS
diff --git a/embed.fnc b/embed.fnc
index 4d06b34a15..45b48388eb 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -668,7 +668,7 @@ AMp	|UV	|to_uni_title	|UV c|NN U8 *p|NN STRLEN *lenp
 ADMpPR	|bool	|isIDFIRST_lazy	|NN const char* p
 ADMpPR	|bool	|isALNUM_lazy	|NN const char* p
 #ifdef PERL_IN_UTF8_C
-sR	|U8	|to_lower_latin1|const U8 c|NULLOK U8 *p|NULLOK STRLEN *lenp
+snR	|U8	|to_lower_latin1|const U8 c|NULLOK U8 *p|NULLOK STRLEN *lenp
 #endif
 #if defined(PERL_IN_UTF8_C) || defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_REGEXEC_C)
 EXp        |UV        |_to_fold_latin1|const U8 c|NN U8 *p|NN STRLEN *lenp|const unsigned int flags
diff --git a/embed.h b/embed.h
index 28c0aa3c49..b2863c0b03 100644
--- a/embed.h
+++ b/embed.h
@@ -1708,7 +1708,7 @@
 #define is_utf8_common(a,b,c,d)	S_is_utf8_common(aTHX_ a,b,c,d)
 #define swash_scan_list_line(a,b,c,d,e,f,g)	S_swash_scan_list_line(aTHX_ a,b,c,d,e,f,g)
 #define swatch_get(a,b,c)	S_swatch_get(aTHX_ a,b,c)
-#define to_lower_latin1(a,b,c)	S_to_lower_latin1(aTHX_ a,b,c)
+#define to_lower_latin1		S_to_lower_latin1
 #  endif
 #  if defined(PERL_IN_UTF8_C) || defined(PERL_IN_PP_C)
 #define _to_upper_title_latin1(a,b,c,d)	Perl__to_upper_title_latin1(aTHX_ a,b,c,d)
diff --git a/mathoms.c b/mathoms.c
index a1c20b015a..b284a381ae 100644
--- a/mathoms.c
+++ b/mathoms.c
@@ -728,6 +728,7 @@ bool
 Perl_is_utf8_string_loc(pTHX_ const U8 *s, STRLEN len, const U8 **ep)
 {
     PERL_ARGS_ASSERT_IS_UTF8_STRING_LOC;
+    PERL_UNUSED_CONTEXT;
 
     return is_utf8_string_loclen(s, len, ep, 0);
 }
@@ -1278,84 +1279,98 @@ Perl_is_uni_alpha(pTHX_ UV c)
 bool
 Perl_is_uni_ascii(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isASCII_uni(c);
 }
 
 bool
 Perl_is_uni_blank(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isBLANK_uni(c);
 }
 
 bool
 Perl_is_uni_space(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isSPACE_uni(c);
 }
 
 bool
 Perl_is_uni_digit(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isDIGIT_uni(c);
 }
 
 bool
 Perl_is_uni_upper(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isUPPER_uni(c);
 }
 
 bool
 Perl_is_uni_lower(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isLOWER_uni(c);
 }
 
 bool
 Perl_is_uni_cntrl(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isCNTRL_L1(c);
 }
 
 bool
 Perl_is_uni_graph(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isGRAPH_uni(c);
 }
 
 bool
 Perl_is_uni_print(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isPRINT_uni(c);
 }
 
 bool
 Perl_is_uni_punct(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isPUNCT_uni(c);
 }
 
 bool
 Perl_is_uni_xdigit(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isXDIGIT_uni(c);
 }
 
 bool
 Perl_is_uni_alnum_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isWORDCHAR_LC_uvchr(c);
 }
 
 bool
 Perl_is_uni_alnumc_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isALPHANUMERIC_LC_uvchr(c);
 }
 
 bool
 Perl_is_uni_idfirst_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     /* XXX Should probably be something that resolves to the old IDFIRST, but
      * this function is deprecated, so not bothering */
     return isIDFIRST_LC_uvchr(c);
@@ -1364,24 +1379,28 @@ Perl_is_uni_idfirst_lc(pTHX_ UV c)
 bool
 Perl_is_uni_alpha_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isALPHA_LC_uvchr(c);
 }
 
 bool
 Perl_is_uni_ascii_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isASCII_LC_uvchr(c);
 }
 
 bool
 Perl_is_uni_blank_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isBLANK_LC_uvchr(c);
 }
 
 bool
 Perl_is_uni_space_lc(pTHX_ UV c)
 {
+    PERL_UNUSED_CONTEXT;
     return isSPACE_LC_uvchr(c);
 }
 
@@ -1550,6 +1569,7 @@ Perl_is_utf8_ascii(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_ASCII;
+    PERL_UNUSED_CONTEXT;
 
     return isASCII_utf8(p);
 }
@@ -1560,6 +1580,7 @@ Perl_is_utf8_blank(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_BLANK;
+    PERL_UNUSED_CONTEXT;
 
     return isBLANK_utf8(p);
 }
@@ -1570,6 +1591,7 @@ Perl_is_utf8_space(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_SPACE;
+    PERL_UNUSED_CONTEXT;
 
     return isSPACE_utf8(p);
 }
@@ -1580,6 +1602,7 @@ Perl_is_utf8_perl_space(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_PERL_SPACE;
+    PERL_UNUSED_CONTEXT;
 
     /* Only true if is an ASCII space-like character, and ASCII is invariant
      * under utf8, so can just use the macro */
@@ -1592,6 +1615,7 @@ Perl_is_utf8_perl_word(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_PERL_WORD;
+    PERL_UNUSED_CONTEXT;
 
     /* Only true if is an ASCII word character, and ASCII is invariant
      * under utf8, so can just use the macro */
@@ -1614,6 +1638,7 @@ Perl_is_utf8_posix_digit(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_POSIX_DIGIT;
+    PERL_UNUSED_CONTEXT;
 
     /* Only true if is an ASCII digit character, and ASCII is invariant
      * under utf8, so can just use the macro */
@@ -1646,6 +1671,7 @@ Perl_is_utf8_cntrl(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_CNTRL;
+    PERL_UNUSED_CONTEXT;
 
     return isCNTRL_utf8(p);
 }
@@ -1686,6 +1712,7 @@ Perl_is_utf8_xdigit(pTHX_ const U8 *p)
     dVAR;
 
     PERL_ARGS_ASSERT_IS_UTF8_XDIGIT;
+    PERL_UNUSED_CONTEXT;
 
     return isXDIGIT_utf8(p);
 }
diff --git a/op.c b/op.c
index 9be7188fe8..2bd0fa938f 100644
--- a/op.c
+++ b/op.c
@@ -375,6 +375,7 @@ Perl_opslab_free(pTHX_ OPSLAB *slab)
     dVAR;
     OPSLAB *slab2;
     PERL_ARGS_ASSERT_OPSLAB_FREE;
+    PERL_UNUSED_CONTEXT;
     DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
     assert(slab->opslab_refcnt == 1);
     for (; slab; slab = slab2) {
diff --git a/pp_ctl.c b/pp_ctl.c
index 8957a8ceed..71542dba6d 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -1395,6 +1395,9 @@ S_dopoptosub_at(pTHX_ const PERL_CONTEXT *cxstk, I32 startingblock)
     I32 i;
 
     PERL_ARGS_ASSERT_DOPOPTOSUB_AT;
+#ifndef DEBUGGING
+    PERL_UNUSED_CONTEXT;
+#endif
 
     for (i = startingblock; i >= 0; i--) {
 	const PERL_CONTEXT * const cx = &cxstk[i];
diff --git a/proto.h b/proto.h
index 35325941a1..3c8888e4cc 100644
--- a/proto.h
+++ b/proto.h
@@ -7724,7 +7724,7 @@ STATIC SV*	S_swatch_get(pTHX_ SV* swash, UV start, UV span)
 #define PERL_ARGS_ASSERT_SWATCH_GET	\
 	assert(swash)
 
-STATIC U8	S_to_lower_latin1(pTHX_ const U8 c, U8 *p, STRLEN *lenp)
+STATIC U8	S_to_lower_latin1(const U8 c, U8 *p, STRLEN *lenp)
 			__attribute__warn_unused_result__;
 
 #endif
diff --git a/regcomp.c b/regcomp.c
index 1a0024f3e7..b7a7b35f51 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -3026,6 +3026,7 @@ S_construct_ahocorasick_from_trie(pTHX_ RExC_state_t *pRExC_state, regnode *sour
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_CONSTRUCT_AHOCORASICK_FROM_TRIE;
+    PERL_UNUSED_CONTEXT;
 #ifndef DEBUGGING
     PERL_UNUSED_ARG(depth);
 #endif
@@ -15231,6 +15232,7 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_REGINSERT;
+    PERL_UNUSED_CONTEXT;
     PERL_UNUSED_ARG(depth);
 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
     DEBUG_PARSE_FMT("inst"," - %s",PL_reg_name[op]);
diff --git a/utf8.c b/utf8.c
index 060aadab53..1e8f3f988e 100644
--- a/utf8.c
+++ b/utf8.c
@@ -869,6 +869,7 @@ Perl_valid_utf8_to_uvchr(pTHX_ const U8 *s, STRLEN *retlen)
     UV uv = *s;
 
     PERL_ARGS_ASSERT_VALID_UTF8_TO_UVCHR;
+    PERL_UNUSED_CONTEXT;
 
     if (retlen) {
         *retlen = expectlen;
@@ -1056,7 +1057,6 @@ Perl_bytes_cmp_utf8(pTHX_ const U8 *b, STRLEN blen, const U8 *u, STRLEN ulen)
     const U8 *const uend = u + ulen;
 
     PERL_ARGS_ASSERT_BYTES_CMP_UTF8;
-
     PERL_UNUSED_CONTEXT;
 
     while (b < bend && u < uend) {
@@ -1123,6 +1123,7 @@ Perl_utf8_to_bytes(pTHX_ U8 *s, STRLEN *len)
     U8 *d;
 
     PERL_ARGS_ASSERT_UTF8_TO_BYTES;
+    PERL_UNUSED_CONTEXT;
 
     /* ensure valid UTF-8 and chars < 256 before updating string */
     while (s < send) {
@@ -1174,7 +1175,6 @@ Perl_bytes_from_utf8(pTHX_ const U8 *s, STRLEN *len, bool *is_utf8)
     I32 count = 0;
 
     PERL_ARGS_ASSERT_BYTES_FROM_UTF8;
-
     PERL_UNUSED_CONTEXT;
     if (!*is_utf8)
         return (U8 *)start;
@@ -1490,7 +1490,7 @@ Perl_to_uni_title(pTHX_ UV c, U8* p, STRLEN *lenp)
 }
 
 STATIC U8
-S_to_lower_latin1(pTHX_ const U8 c, U8* p, STRLEN *lenp)
+S_to_lower_latin1(const U8 c, U8* p, STRLEN *lenp)
 {
     /* We have the latin1-range values compiled into the core, so just use
      * those, converting the result to utf8.  Since the result is always just
@@ -1540,6 +1540,7 @@ Perl__to_fold_latin1(pTHX_ const U8 c, U8* p, STRLEN *lenp, const unsigned int f
     UV converted;
 
     PERL_ARGS_ASSERT__TO_FOLD_LATIN1;
+    PERL_UNUSED_CONTEXT;
 
     assert (! (flags & FOLD_FLAGS_LOCALE));