More embed.fnc plowing

Message-ID: <20050713154919.GA24586@petdance.com>

p4raw-id: //depot/perl@25138

10 files changed, 285 insertions, 182 deletions

diff --git a/embed.fnc b/embed.fnc
index 527d8e4422..4669f7df29 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -87,7 +87,7 @@ END_EXTERN_C
 /* functions with flag 'n' should come before here */
 START_EXTERN_C
 #  include "pp_proto.h"
-Ap	|SV*	|amagic_call	|SV* left|SV* right|int method|int dir
+Ap	|SV*	|amagic_call	|NN SV* left|NN SV* right|int method|int dir
 Ap	|bool	|Gv_AMupdate	|NN HV* stash
 ApR	|CV*	|gv_handler	|NULLOK HV* stash|I32 id
 p	|OP*	|append_elem	|I32 optype|NULLOK OP* first|NULLOK OP* last
@@ -248,16 +248,16 @@ p	|OP*	|gen_constant_list|OP* o
 #if !defined(HAS_GETENV_LEN)
 p	|char*	|getenv_len	|NN const char* key|NN unsigned long *len
 #endif
-Ap	|void	|gp_free	|GV* gv
-Ap	|GP*	|gp_ref		|GP* gp
+Ap	|void	|gp_free	|NULLOK GV* gv
+Ap	|GP*	|gp_ref		|NULLOK GP* gp
 Ap	|GV*	|gv_AVadd	|NN GV* gv
 Ap	|GV*	|gv_HVadd	|NN GV* gv
 Ap	|GV*	|gv_IOadd	|NN GV* gv
-ApR	|GV*	|gv_autoload4	|HV* stash|NN const char* name|STRLEN len|I32 method
-Ap	|void	|gv_check	|HV* stash
-Ap	|void	|gv_efullname	|SV* sv|const GV* gv
-Apmb	|void	|gv_efullname3	|SV* sv|const GV* gv|const char* prefix
-Ap	|void	|gv_efullname4	|SV* sv|const GV* gv|const char* prefix|bool keepmain
+ApR	|GV*	|gv_autoload4	|NULLOK HV* stash|NN const char* name|STRLEN len|I32 method
+Ap	|void	|gv_check	|NN HV* stash
+Ap	|void	|gv_efullname	|NN SV* sv|NN const GV* gv
+Apmb	|void	|gv_efullname3	|NN SV* sv|NN const GV* gv|NULLOK const char* prefix
+Ap	|void	|gv_efullname4	|NN SV* sv|NN const GV* gv|NULLOK const char* prefix|bool keepmain
 Ap	|GV*	|gv_fetchfile	|NN const char* name
 Apd	|GV*	|gv_fetchmeth	|HV* stash|const char* name|STRLEN len \
 				|I32 level
@@ -740,7 +740,7 @@ Apd	|void	|sv_vcatpvf	|NN SV* sv|const char* pat|va_list* args
 Apd	|void	|sv_catpv	|NN SV* sv|const char* ptr
 Amdb	|void	|sv_catpvn	|NN SV* sv|const char* ptr|STRLEN len
 Amdb	|void	|sv_catsv	|NN SV* dsv|SV* ssv
-Apd	|void	|sv_chop	|NN SV* sv|const char* ptr
+Apd	|void	|sv_chop	|NN SV* sv|NULLOK const char* ptr
 pd	|I32	|sv_clean_all
 pd	|void	|sv_clean_objs
 Apd	|void	|sv_clear	|NN SV* sv
@@ -933,10 +933,10 @@ Apd	|void	|sv_force_normal_flags|NN SV *sv|U32 flags
 Ap	|void	|tmps_grow	|I32 n
 Apd	|SV*	|sv_rvweaken	|NN SV *sv
 p	|int	|magic_killbackrefs|NN SV *sv|NN MAGIC *mg
-Ap	|OP*	|newANONATTRSUB	|I32 floor|OP *proto|OP *attrs|OP *block
-Ap	|CV*	|newATTRSUB	|I32 floor|OP *o|OP *proto|OP *attrs|OP *block
-Apr	|void	|newMYSUB	|I32 floor|OP *o|OP *proto|OP *attrs|OP *block
-p	|OP *	|my_attrs	|NN OP *o|OP *attrs
+Ap	|OP*	|newANONATTRSUB	|I32 floor|NULLOK OP *proto|NULLOK OP *attrs|NULLOK OP *block
+Ap	|CV*	|newATTRSUB	|I32 floor|NULLOK OP *o|NULLOK OP *proto|NULLOK OP *attrs|OP *block
+Apr	|void	|newMYSUB	|I32 floor|NULLOK OP *o|NULLOK OP *proto|NULLOK OP *attrs|NULLOK OP *block
+p	|OP *	|my_attrs	|NN OP *o|NULLOK OP *attrs
 p	|void	|boot_core_xsutils
 #if defined(USE_ITHREADS)
 Apa	|PERL_CONTEXT*|cx_dup	|PERL_CONTEXT* cx|I32 ix|I32 max|CLONE_PARAMS* param
@@ -1064,7 +1064,7 @@ pR	|OP*	|ck_unpack	|NN OP *o
 sR	|bool	|is_handle_constructor|NN const OP *o|I32 numargs
 sR	|I32	|is_list_assignment|const OP *o
 s	|void	|cop_free	|NN COP *cop
-s	|OP*	|modkids	|OP *o|I32 type
+s	|OP*	|modkids	|NULLOK OP *o|I32 type
 s	|OP*	|scalarboolean	|NN OP *o
 sR	|OP*	|newDEFSVOP
 sR	|OP*	|new_logop	|I32 type|I32 flags|NN OP **firstp|NN OP **otherp
@@ -1128,7 +1128,7 @@ sR	|const char *|get_num	|NN const char *ppat|NN I32 *lenptr
 #endif
 
 #if defined(PERL_IN_PP_CTL_C) || defined(PERL_DECL_PROT)
-sR	|OP*	|docatch	|OP *o
+sR	|OP*	|docatch	|NULLOK OP *o
 s	|void	|docatch_body
 sR	|OP*	|dofindlabel	|OP *o|const char *label|OP **opstack|OP **oplimit
 sR	|OP*	|doparseform	|SV *sv
@@ -1138,8 +1138,8 @@ sR	|I32	|dopoptolabel	|NN const char *label
 sR	|I32	|dopoptoloop	|I32 startingblock
 sR	|I32	|dopoptosub	|I32 startingblock
 sR	|I32	|dopoptosub_at	|const PERL_CONTEXT* cxstk|I32 startingblock
-s	|void	|save_lines	|AV *array|SV *sv
-sR	|OP*	|doeval		|int gimme|OP** startop|CV* outside|U32 seq
+s	|void	|save_lines	|NULLOK AV *array|NN SV *sv
+sR	|OP*	|doeval		|int gimme|NULLOK OP** startop|NULLOK CV* outside|U32 seq
 sR	|PerlIO *|doopen_pm	|const char *name|const char *mode
 sR	|bool	|path_is_absolute|NN const char *name
 #endif
@@ -1147,7 +1147,7 @@ sR	|bool	|path_is_absolute|NN const char *name
 #if defined(PERL_IN_PP_HOT_C) || defined(PERL_DECL_PROT)
 s	|void	|do_oddball	|NN HV *hash|NN SV **relem|NN SV **firstrelem
 sR	|CV*	|get_db_sub	|NN SV **svp|NN CV *cv
-sR	|SV*	|method_common	|NN SV* meth|U32* hashp
+sR	|SV*	|method_common	|NN SV* meth|NULLOK U32* hashp
 #endif
 
 #if defined(PERL_IN_PP_SYS_C) || defined(PERL_DECL_PROT)
@@ -1184,14 +1184,14 @@ Es	|int	|cl_is_anything	|NN const struct regnode_charclass_class *cl
 Es	|void	|cl_init	|NN struct RExC_state_t*|NN struct regnode_charclass_class *cl
 Es	|void	|cl_init_zero	|NN struct RExC_state_t*|NN struct regnode_charclass_class *cl
 Es	|void	|cl_and		|NN struct regnode_charclass_class *cl \
-				|const struct regnode_charclass_class *and_with
+				|NN const struct regnode_charclass_class *and_with
 Es	|void	|cl_or		|NN struct RExC_state_t*|NN struct regnode_charclass_class *cl \
 				|NN const struct regnode_charclass_class *or_with
 Es	|I32	|study_chunk	|struct RExC_state_t*|regnode **scanp|I32 *deltap \
 				|regnode *last|struct scan_data_t *data \
 				|U32 flags|U32 depth
 Es	|I32	|add_data	|struct RExC_state_t*|I32 n|const char *s
-rs	|void	|re_croak2	|const char* pat1|const char* pat2|...
+rs	|void	|re_croak2	|NN const char* pat1|NN const char* pat2|...
 Es	|I32	|regpposixcc	|struct RExC_state_t*|I32 value
 Es	|void	|checkposixcc	|struct RExC_state_t*
 
@@ -1204,12 +1204,13 @@ Es	|I32	|make_trie	|struct RExC_state_t*|regnode *startbranch \
 ERs	|I32	|regmatch	|NN regnode *prog
 ERs	|I32	|regrepeat	|NN const regnode *p|I32 max
 ERs	|I32	|regrepeat_hard	|NN regnode *p|I32 max|NN I32 *lp
-ERs	|I32	|regtry		|regexp *prog|char *startpos
-ERs	|bool	|reginclass	|NN const regnode *n|NN const U8 *p|STRLEN *lenp|bool do_utf8sv_is_utf8
+ERs	|I32	|regtry		|NN regexp *prog|NN char *startpos
+ERs	|bool	|reginclass	|NN const regnode *n|NN const U8 *p|NULLOK STRLEN *lenp\
+				|bool do_utf8sv_is_utf8
 Es	|CHECKPOINT|regcppush	|I32 parenfloor
 Es	|char*|regcppop
 Es	|char*|regcp_set_to	|I32 ss
-Es	|void	|cache_re	|regexp *prog
+Es	|void	|cache_re	|NN regexp *prog
 ERs	|U8*	|reghop		|U8 *pos|I32 off
 ERs	|U8*	|reghop3	|U8 *pos|I32 off|U8 *lim
 ERs	|U8*	|reghopmaybe	|U8 *pos|I32 off
@@ -1221,11 +1222,11 @@ Es	|void	|to_byte_substr	|NN regexp * prog
 
 #if defined(PERL_IN_DUMP_C) || defined(PERL_DECL_PROT)
 s	|CV*	|deb_curcv	|I32 ix
-s	|void	|debprof	|const OP *o
+s	|void	|debprof	|NN const OP *o
 #endif
 
 #if defined(PERL_IN_SCOPE_C) || defined(PERL_DECL_PROT)
-s	|SV*	|save_scalar_at	|SV **sptr
+s	|SV*	|save_scalar_at	|NN SV **sptr
 #endif
 
 #if defined(PERL_IN_GV_C) || defined(PERL_IN_SV_C) || defined(PERL_IN_PAD_C) || defined(PERL_DECL_PROT)
@@ -1242,10 +1243,10 @@ s	|void	|sv_del_backref	|NN SV *target|NN SV *ref
 sR	|SV *	|varname	|NULLOK GV *gv|const char gvtype|PADOFFSET targ \
 				|NULLOK SV *keyname|I32 aindex|int subscript_type
 #  ifdef DEBUGGING
-s	|void	|del_sv	|SV *p
+s	|void	|del_sv	|NN SV *p
 #  endif
 #  if !defined(NV_PRESERVES_UV)
-s	|int	|sv_2iuv_non_preserve	|SV *sv|I32 numtype
+s	|int	|sv_2iuv_non_preserve	|NN SV *sv|I32 numtype
 #  endif
 sR	|I32	|expect_number	|NN char** pattern
 #
@@ -1264,43 +1265,43 @@ sM	|void	|sv_release_COW	|SV *sv|const char *pvx|STRLEN len|SV *after
 #if defined(PERL_IN_TOKE_C) || defined(PERL_DECL_PROT)
 s	|void	|check_uni
 s	|void	|force_next	|I32 type
-s	|char*	|force_version	|char *start|int guessing
-s	|char*	|force_word	|char *start|int token|int check_keyword \
+s	|char*	|force_version	|NN char *start|int guessing
+s	|char*	|force_word	|NN char *start|int token|int check_keyword \
 				|int allow_pack|int allow_tick
-s	|SV*	|tokeq		|SV *sv
+s	|SV*	|tokeq		|NN SV *sv
 s	|int	|pending_ident
-s	|char*	|scan_const	|NN char *start
-s	|char*	|scan_formline	|NN char *s
-s	|char*	|scan_heredoc	|NN char *s
+sR	|char*	|scan_const	|NN char *start
+sR	|char*	|scan_formline	|NN char *s
+sR	|char*	|scan_heredoc	|NN char *s
 s	|char*	|scan_ident	|NN char *s|NN const char *send|NN char *dest \
 				|STRLEN destlen|I32 ck_uni
-s	|char*	|scan_inputsymbol|char *start
-s	|char*	|scan_pat	|char *start|I32 type
-s	|char*	|scan_str	|char *start|int keep_quoted|int keep_delims
-s	|char*	|scan_subst	|char *start
-s	|char*	|scan_trans	|char *start
-s	|char*	|scan_word	|char *s|char *dest|STRLEN destlen \
-				|int allow_package|STRLEN *slp
-s	|char*	|skipspace	|char *s
-s	|char*	|swallow_bom	|U8 *s
+sR	|char*	|scan_inputsymbol|NN char *start
+sR	|char*	|scan_pat	|NN char *start|I32 type
+sR	|char*	|scan_str	|NN char *start|int keep_quoted|int keep_delims
+sR	|char*	|scan_subst	|NN char *start
+sR	|char*	|scan_trans	|NN char *start
+s	|char*	|scan_word	|NN char *s|NN char *dest|STRLEN destlen \
+				|int allow_package|NN STRLEN *slp
+sR	|char*	|skipspace	|NN char *s
+sR	|char*	|swallow_bom	|NN U8 *s
 s	|void	|checkcomma	|NN char *s|NN const char *name|NN const char *what
-s	|void	|force_ident	|const char *s|int kind
-s	|void	|incline	|char *s
-s	|int	|intuit_method	|char *s|GV *gv
-s	|int	|intuit_more	|char *s
-s	|I32	|lop		|I32 f|int x|char *s
-rs	|void	|missingterm	|char *s
-s	|void	|no_op		|const char *what|char *s
+s	|void	|force_ident	|NN const char *s|int kind
+s	|void	|incline	|NN char *s
+s	|int	|intuit_method	|NN char *s|NN GV *gv
+s	|int	|intuit_more	|NN char *s
+s	|I32	|lop		|I32 f|int x|NN char *s
+rs	|void	|missingterm	|NULLOK char *s
+s	|void	|no_op		|NN const char *what|NULLOK char *s
 s	|void	|set_csh
-s	|I32	|sublex_done
-s	|I32	|sublex_push
-s	|I32	|sublex_start
+sR	|I32	|sublex_done
+sR	|I32	|sublex_push
+sR	|I32	|sublex_start
 sR	|char *	|filter_gets	|NN SV *sv|NN PerlIO *fp|STRLEN append
 sR	|HV *	|find_in_my_stash|NN const char *pkgname|I32 len
 s	|SV*	|new_constant	|const char *s|STRLEN len|const char *key|SV *sv \
 				|SV *pv|const char *type
 #  if defined(DEBUGGING)
-s	|int	|tokereport	|const char *s|I32 rv
+s	|int	|tokereport	|NN const char *s|I32 rv
 #  endif
 s	|int	|ao		|int toketype
 s	|void	|depcom
@@ -1315,7 +1316,7 @@ s	|I32	|cr_textfilter	|int idx|NULLOK SV *sv|int maxlen
 #endif
 
 #if defined(PERL_IN_UNIVERSAL_C) || defined(PERL_DECL_PROT)
-s	|SV*|isa_lookup	|HV *stash|const char *name|HV *name_stash|int len|int level
+s	|SV*|isa_lookup	|NULLOK HV *stash|NN const char *name|NULLOK HV *name_stash|int len|int level
 #endif
 
 #if defined(PERL_IN_LOCALE_C) || defined(PERL_DECL_PROT)
@@ -1344,41 +1345,41 @@ START_EXTERN_C
 
 Apd	|void	|sv_setsv_flags	|NN SV* dsv|NULLOK SV* ssv|I32 flags
 Apd	|void	|sv_catpvn_flags|NN SV* sv|NN const char* ptr|STRLEN len|I32 flags
-Apd	|void	|sv_catsv_flags	|NN SV* dsv|SV* ssv|I32 flags
+Apd	|void	|sv_catsv_flags	|NN SV* dsv|NULLOK SV* ssv|I32 flags
 Apd	|STRLEN	|sv_utf8_upgrade_flags|NN SV *sv|I32 flags
-Apd	|char*	|sv_pvn_force_flags|SV* sv|STRLEN* lp|I32 flags
+Apd	|char*	|sv_pvn_force_flags|NN SV* sv|NULLOK STRLEN* lp|I32 flags
 Apd	|void	|sv_copypv	|NN SV* dsv|NN SV* ssv
 Ap	|char*	|my_atof2	|NN const char *s|NN NV* value
 Apn	|int	|my_socketpair	|int family|int type|int protocol|int fd[2]
 #ifdef PERL_OLD_COPY_ON_WRITE
-pMXE	|SV*	|sv_setsv_cow	|SV* dsv|SV* ssv
+pMXE	|SV*	|sv_setsv_cow	|NN SV* dsv|NN SV* ssv
 #endif
 
 #if defined(USE_PERLIO) && !defined(USE_SFIO)
-Ap	|int	|PerlIO_close		|PerlIO *f
-Ap	|int	|PerlIO_fill		|PerlIO *f
-Ap	|int	|PerlIO_fileno		|PerlIO *f
-Ap	|int	|PerlIO_eof		|PerlIO *f
-Ap	|int	|PerlIO_error		|PerlIO *f
-Ap	|int	|PerlIO_flush		|PerlIO *f
-Ap	|void	|PerlIO_clearerr	|PerlIO *f
-Ap	|void	|PerlIO_set_cnt		|PerlIO *f|int cnt
-Ap	|void	|PerlIO_set_ptrcnt	|PerlIO *f|NN STDCHAR *ptr|int cnt
-Ap	|void	|PerlIO_setlinebuf	|PerlIO *f
-Ap	|SSize_t|PerlIO_read		|PerlIO *f|NN void *buf|Size_t count
-Ap	|SSize_t|PerlIO_write		|PerlIO *f|NN const void *buf|Size_t count
-Ap	|SSize_t|PerlIO_unread		|PerlIO *f|NN const void *buf|Size_t count
-Ap	|Off_t	|PerlIO_tell		|PerlIO *f
-Ap	|int	|PerlIO_seek		|PerlIO *f|Off_t offset|int whence
+Ap	|int	|PerlIO_close		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_fill		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_fileno		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_eof		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_error		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_flush		|NULLOK PerlIO *f
+Ap	|void	|PerlIO_clearerr	|NULLOK PerlIO *f
+Ap	|void	|PerlIO_set_cnt		|NULLOK PerlIO *f|int cnt
+Ap	|void	|PerlIO_set_ptrcnt	|NULLOK PerlIO *f|NN STDCHAR *ptr|int cnt
+Ap	|void	|PerlIO_setlinebuf	|NULLOK PerlIO *f
+Ap	|SSize_t|PerlIO_read		|NULLOK PerlIO *f|NN void *buf|Size_t count
+Ap	|SSize_t|PerlIO_write		|NULLOK PerlIO *f|NN const void *buf|Size_t count
+Ap	|SSize_t|PerlIO_unread		|NULLOK PerlIO *f|NN const void *buf|Size_t count
+Ap	|Off_t	|PerlIO_tell		|NULLOK PerlIO *f
+Ap	|int	|PerlIO_seek		|NULLOK PerlIO *f|Off_t offset|int whence
 
-Ap	|STDCHAR *|PerlIO_get_base	|PerlIO *f
-Ap	|STDCHAR *|PerlIO_get_ptr	|PerlIO *f
-ApR	|int	  |PerlIO_get_bufsiz	|PerlIO *f
-ApR	|int	  |PerlIO_get_cnt	|PerlIO *f
+Ap	|STDCHAR *|PerlIO_get_base	|NULLOK PerlIO *f
+Ap	|STDCHAR *|PerlIO_get_ptr	|NULLOK PerlIO *f
+ApR	|int	  |PerlIO_get_bufsiz	|NULLOK PerlIO *f
+ApR	|int	  |PerlIO_get_cnt	|NULLOK PerlIO *f
 
-Ap	|PerlIO *|PerlIO_stdin
-Ap	|PerlIO *|PerlIO_stdout
-Ap	|PerlIO *|PerlIO_stderr
+ApR	|PerlIO *|PerlIO_stdin
+ApR	|PerlIO *|PerlIO_stdout
+ApR	|PerlIO *|PerlIO_stderr
 #endif /* PERLIO_LAYERS */
 
 p	|void	|deb_stack_all
@@ -1399,7 +1400,7 @@ pd	|void	|pad_setsv	|PADOFFSET po|NN SV* sv
 pd	|void	|pad_block_start|int full
 pd	|void	|pad_tidy	|padtidy_type type
 pd 	|void	|do_dump_pad	|I32 level|NN PerlIO *file|NULLOK PADLIST *padlist|int full
-pd	|void	|pad_fixup_inner_anons|NN PADLIST *padlist|CV *old_cv|CV *new_cv
+pd	|void	|pad_fixup_inner_anons|NN PADLIST *padlist|NN CV *old_cv|NN CV *new_cv
 
 pd	|void	|pad_push	|NN PADLIST *padlist|int depth
 pR	|HV*	|pad_compname_type|const PADOFFSET po
@@ -1415,17 +1416,17 @@ sd	|void	|cv_dump	|NN const CV *cv|NN const char *title
 pdR	|CV*	|find_runcv	|NULLOK U32 *db_seqp
 p	|void	|free_tied_hv_pool
 #if defined(DEBUGGING)
-pR	|int	|get_debug_opts	|const char **s|bool givehelp
+pR	|int	|get_debug_opts	|NN const char **s|bool givehelp
 #endif
-Ap	|void	|save_set_svflags|SV* sv|U32 mask|U32 val
+Ap	|void	|save_set_svflags|NULLOK SV* sv|U32 mask|U32 val
 Apod	|void	|hv_assert	|NN HV* tb
 
 ApdR	|SV*	|hv_scalar	|NN HV* hv
 ApoR	|I32*	|hv_riter_p	|NN HV* hv
 ApoR	|HE**	|hv_eiter_p	|NN HV* hv
 Apo	|void	|hv_riter_set	|NN HV* hv|I32 riter
-Apo	|void	|hv_eiter_set	|NN HV* hv|HE* eiter
-Apo	|void	|hv_name_set	|NN HV* hv|const char *name|I32 len|int flags
+Apo	|void	|hv_eiter_set	|NN HV* hv|NULLOK HE* eiter
+Apo	|void	|hv_name_set	|NN HV* hv|NULLOK const char *name|I32 len|int flags
 Apd	|void	|hv_clear_placeholders	|NN HV* hb
 ApoR	|I32*	|hv_placeholders_p	|NN HV* hv
 ApoR	|I32	|hv_placeholders_get	|NN HV* hv
@@ -1519,7 +1520,7 @@ dpR	|bool	|is_gv_magical_sv|NN SV *name|U32 flags
 ApR	|bool	|stashpv_hvname_match|NN const COP *cop|NN const HV *hv
 
 #ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
-p	|void	|dump_sv_child	|SV *sv
+p	|void	|dump_sv_child	|NN SV *sv
 #endif
 
 #ifdef PERL_DONT_CREATE_GVSV
diff --git a/gv.c b/gv.c
index d307124907..27268407e6 100644
--- a/gv.c
+++ b/gv.c
@@ -1191,10 +1191,8 @@ Perl_gv_fullname3(pTHX_ SV *sv, const GV *gv, const char *prefix)
 void
 Perl_gv_efullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain)
 {
-    const GV *egv = GvEGV(gv);
-    if (!egv)
-	egv = gv;
-    gv_fullname4(sv, egv, prefix, keepmain);
+    const GV * const egv = GvEGV(gv);
+    gv_fullname4(sv, egv ? egv : gv, prefix, keepmain);
 }
 
 void
diff --git a/hv.c b/hv.c
index 63149ac792..0745b67311 100644
--- a/hv.c
+++ b/hv.c
@@ -1729,7 +1729,7 @@ Perl_hv_undef(pTHX_ HV *hv)
     if ((name = HvNAME_get(hv))) {
         if(PL_stashcache)
 	    hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
-	Perl_hv_name_set(aTHX_ hv, 0, 0, 0);
+	Perl_hv_name_set(aTHX_ hv, Nullch, 0, 0);
     }
     SvFLAGS(hv) &= ~SVf_OOK;
     Safefree(HvARRAY(hv));
@@ -1871,7 +1871,8 @@ Perl_hv_name_set(pTHX_ HV *hv, const char *name, I32 len, int flags)
 {
     struct xpvhv_aux *iter;
     U32 hash;
-    (void)flags;
+
+    PERL_UNUSED_ARG(flags);
 
     if (SvOOK(hv)) {
 	iter = HvAUX(hv);
diff --git a/op.c b/op.c
index b7f560b435..55a976bfc9 100644
--- a/op.c
+++ b/op.c
@@ -161,7 +161,7 @@ Perl_Slab_Free(pTHX_ void *op)
 STATIC const char*
 S_gv_ename(pTHX_ GV *gv)
 {
-    SV* tmpsv = sv_newmortal();
+    SV* const tmpsv = sv_newmortal();
     gv_efullname3(tmpsv, gv, Nullch);
     return SvPV_nolen_const(tmpsv);
 }
@@ -3743,7 +3743,8 @@ Perl_newLOOPOP(pTHX_ I32 flags, I32 debuggable, OP *expr, OP *block)
     OP* o;
     const bool once = block && block->op_flags & OPf_SPECIAL &&
       (block->op_type == OP_ENTERSUB || block->op_type == OP_NULL);
-    (void)debuggable;
+
+    PERL_UNUSED_ARG(debuggable);
 
     if (expr) {
 	if (once && expr->op_type == OP_CONST && !SvTRUE(((SVOP*)expr)->op_sv))
@@ -3753,8 +3754,8 @@ Perl_newLOOPOP(pTHX_ I32 flags, I32 debuggable, OP *expr, OP *block)
 	    expr = newUNOP(OP_DEFINED, 0,
 		newASSIGNOP(0, newDEFSVOP(), 0, expr) );
 	} else if (expr->op_flags & OPf_KIDS) {
-            const OP *k1 = ((UNOP*)expr)->op_first;
-            const OP *k2 = (k1) ? k1->op_sibling : NULL;
+	    const OP * const k1 = ((UNOP*)expr)->op_first;
+	    const OP * const k2 = k1 ? k1->op_sibling : NULL;
 	    switch (expr->op_type) {
 	      case OP_NULL:
 		if (k2 && k2->op_type == OP_READLINE
@@ -3806,15 +3807,16 @@ whileline, OP *expr, OP *block, OP *cont, I32 has_my)
     OP *listop;
     OP *o;
     U8 loopflags = 0;
-    (void)debuggable;
+
+    PERL_UNUSED_ARG(debuggable);
 
     if (expr && (expr->op_type == OP_READLINE || expr->op_type == OP_GLOB
 		 || (expr->op_type == OP_NULL && expr->op_targ == OP_GLOB))) {
 	expr = newUNOP(OP_DEFINED, 0,
 	    newASSIGNOP(0, newDEFSVOP(), 0, expr) );
     } else if (expr && (expr->op_flags & OPf_KIDS)) {
-	const OP *k1 = ((UNOP*)expr)->op_first;
-	const OP *k2 = (k1) ? k1->op_sibling : NULL;
+	const OP * const k1 = ((UNOP*)expr)->op_first;
+	const OP * const k2 = (k1) ? k1->op_sibling : NULL;
 	switch (expr->op_type) {
 	  case OP_NULL:
 	    if (k2 && k2->op_type == OP_READLINE
@@ -4205,7 +4207,8 @@ Perl_op_const_sv(pTHX_ const OP *o, CV *cv)
 void
 Perl_newMYSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
 {
-    (void)floor;
+    PERL_UNUSED_ARG(floor);
+
     if (o)
 	SAVEFREEOP(o);
     if (proto)
@@ -4905,7 +4908,7 @@ Perl_oopsCV(pTHX_ OP *o)
 {
     Perl_croak(aTHX_ "NOT IMPL LINE %d",__LINE__);
     /* STUB */
-    (void)o;
+    PERL_UNUSED_ARG(o);
     NORETURN_FUNCTION_END;
 }
 
@@ -5069,7 +5072,7 @@ Perl_ck_eval(pTHX_ OP *o)
     dVAR;
     PL_hints |= HINT_BLOCK_SCOPE;
     if (o->op_flags & OPf_KIDS) {
-	SVOP *kid = (SVOP*)cUNOPo->op_first;
+	SVOP * const kid = (SVOP*)cUNOPo->op_first;
 
 	if (!kid) {
 	    o->op_flags &= ~OPf_KIDS;
@@ -5143,7 +5146,7 @@ Perl_ck_exists(pTHX_ OP *o)
 {
     o = ck_fun(o);
     if (o->op_flags & OPf_KIDS) {
-	OP *kid = cUNOPo->op_first;
+	OP * const kid = cUNOPo->op_first;
 	if (kid->op_type == OP_ENTERSUB) {
 	    (void) ref(kid, o->op_type);
 	    if (kid->op_type != OP_RV2CV && !PL_error_count)
diff --git a/pad.c b/pad.c
index f60aeaf6dd..db1ee0f7aa 100644
--- a/pad.c
+++ b/pad.c
@@ -1539,7 +1539,7 @@ Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
 	if (namesv && namesv != &PL_sv_undef
 	    && *SvPVX_const(namesv) == '&')
 	{
-	    CV *innercv = (CV*)curpad[ix];
+	    CV * const innercv = (CV*)curpad[ix];
 	    assert(CvWEAKOUTSIDE(innercv));
 	    assert(CvOUTSIDE(innercv) == old_cv);
 	    CvOUTSIDE(innercv) = new_cv;
diff --git a/perlio.c b/perlio.c
index 9cd24d2bf9..e36a7308c0 100644
--- a/perlio.c
+++ b/perlio.c
@@ -66,7 +66,7 @@ int mkstemp(char*);
 /* Call the callback or PerlIOBase, and return failure. */
 #define Perl_PerlIO_or_Base(f, callback, base, failure, args) 	\
 	if (PerlIOValid(f)) {					\
-		const PerlIO_funcs *tab = PerlIOBase(f)->tab;	\
+		const PerlIO_funcs * const tab = PerlIOBase(f)->tab;\
 		if (tab && tab->callback)			\
 			return (*tab->callback) args;		\
 		else						\
@@ -79,7 +79,7 @@ int mkstemp(char*);
 /* Call the callback or fail, and return failure. */
 #define Perl_PerlIO_or_fail(f, callback, failure, args) 	\
 	if (PerlIOValid(f)) {					\
-		const PerlIO_funcs *tab = PerlIOBase(f)->tab;	\
+		const PerlIO_funcs * const tab = PerlIOBase(f)->tab;\
 		if (tab && tab->callback)			\
 			return (*tab->callback) args;		\
 		SETERRNO(EINVAL, LIB_INVARG);			\
@@ -91,7 +91,7 @@ int mkstemp(char*);
 /* Call the callback or PerlIOBase, and be void. */
 #define Perl_PerlIO_or_Base_void(f, callback, base, args) 	\
 	if (PerlIOValid(f)) {					\
-		const PerlIO_funcs *tab = PerlIOBase(f)->tab;	\
+		const PerlIO_funcs * const tab = PerlIOBase(f)->tab;\
 		if (tab && tab->callback)			\
 			(*tab->callback) args;			\
 		else						\
@@ -103,7 +103,7 @@ int mkstemp(char*);
 /* Call the callback or fail, and be void. */
 #define Perl_PerlIO_or_fail_void(f, callback, args) 		\
 	if (PerlIOValid(f)) {					\
-		const PerlIO_funcs *tab = PerlIOBase(f)->tab;	\
+		const PerlIO_funcs * const tab = PerlIOBase(f)->tab;\
 		if (tab && tab->callback)			\
 			(*tab->callback) args;			\
 		else						\
@@ -747,7 +747,7 @@ PerlIO_find_layer(pTHX_ const char *name, STRLEN len, int load)
     if ((SSize_t) len <= 0)
 	len = strlen(name);
     for (i = 0; i < PL_known_layers->cur; i++) {
-	PerlIO_funcs *f = PL_known_layers->array[i].funcs;
+	PerlIO_funcs * const f = PL_known_layers->array[i].funcs;
 	if (memEQ(f->name, name, len) && f->name[len] == 0) {
 	    PerlIO_debug("%.*s => %p\n", (int) len, name, (void*)f);
 	    return f;
@@ -759,10 +759,10 @@ PerlIO_find_layer(pTHX_ const char *name, STRLEN len, int load)
 	    Perl_croak(aTHX_ "Recursive call to Perl_load_module in PerlIO_find_layer");
 	    return NULL;
 	} else {
-	    SV *pkgsv = newSVpvn("PerlIO", 6);
-	    SV *layer = newSVpvn(name, len);
-	    CV *cv  = get_cv("PerlIO::Layer::NoWarnings", FALSE);
-    	    ENTER;
+	    SV * const pkgsv = newSVpvn("PerlIO", 6);
+	    SV * const layer = newSVpvn(name, len);
+	    CV * const cv    = get_cv("PerlIO::Layer::NoWarnings", FALSE);
+	    ENTER;
 	    SAVEINT(PL_in_load_module);
 	    if (cv) {
 		SAVEGENERICSV(PL_warnhook);
@@ -866,8 +866,8 @@ XS(XS_io_MODIFY_SCALAR_ATTRIBUTES)
 SV *
 PerlIO_tab_sv(pTHX_ PerlIO_funcs *tab)
 {
-    HV *stash = gv_stashpv("PerlIO::Layer", TRUE);
-    SV *sv = sv_bless(newRV_noinc(newSViv(PTR2IV(tab))), stash);
+    HV * const stash = gv_stashpv("PerlIO::Layer", TRUE);
+    SV * const sv = sv_bless(newRV_noinc(newSViv(PTR2IV(tab))), stash);
     return sv;
 }
 
@@ -889,9 +889,9 @@ XS(XS_PerlIO__Layer__find)
 	Perl_croak(aTHX_ "Usage class->find(name[,load])");
     else {
 	STRLEN len;
-	const char *name = SvPV_const(ST(1), len);
+	const char * const name = SvPV_const(ST(1), len);
 	const bool load = (items > 2) ? SvTRUE(ST(2)) : 0;
-	PerlIO_funcs *layer = PerlIO_find_layer(aTHX_ name, len, load);
+	PerlIO_funcs * const layer = PerlIO_find_layer(aTHX_ name, len, load);
 	ST(0) =
 	    (layer) ? sv_2mortal(PerlIO_tab_sv(aTHX_ layer)) :
 	    &PL_sv_undef;
@@ -979,7 +979,7 @@ PerlIO_parse_layers(pTHX_ PerlIO_list_t *av, const char *names)
 		    }
 		}
 		if (e > s) {
-		    PerlIO_funcs *layer =
+		    PerlIO_funcs * const layer =
 			PerlIO_find_layer(aTHX_ s, llen, 1);
 		    if (layer) {
 			PerlIO_list_push(aTHX_ av, layer,
@@ -1134,7 +1134,7 @@ Perl_boot_core_PerlIO(pTHX)
 PerlIO_funcs *
 PerlIO_default_layer(pTHX_ I32 n)
 {
-    PerlIO_list_t *av = PerlIO_default_layers(aTHX);
+    PerlIO_list_t * const av = PerlIO_default_layers(aTHX);
     if (n < 0)
 	n += av->cur;
     return PerlIO_layer_fetch(aTHX_ av, n, PERLIO_FUNCS_CAST(&PerlIO_stdio));
@@ -1351,7 +1351,7 @@ int
 PerlIO__close(pTHX_ PerlIO *f)
 {
     if (PerlIOValid(f)) {
-	PerlIO_funcs *tab = PerlIOBase(f)->tab;
+	PerlIO_funcs * const tab = PerlIOBase(f)->tab;
 	if (tab && tab->Close)
 	    return (*tab->Close)(aTHX_ f);
 	else
@@ -1445,7 +1445,7 @@ PerlIO_resolve_layers(pTHX_ const char *layers,
 	 * for it
 	 */
 	if (SvROK(arg) && !sv_isobject(arg)) {
-	    PerlIO_funcs *handler = PerlIO_layer_from_ref(aTHX_ SvRV(arg));
+	    PerlIO_funcs * const handler = PerlIO_layer_from_ref(aTHX_ SvRV(arg));
 	    if (handler) {
 		def = PerlIO_list_alloc(aTHX);
 		PerlIO_list_push(aTHX_ def, handler, &PL_sv_undef);
@@ -1512,7 +1512,7 @@ PerlIO_openn(pTHX_ const char *layers, const char *mode, int fd,
 	    PerlIOl *l = *f;
 	    layera = PerlIO_list_alloc(aTHX);
 	    while (l) {
-		SV *arg = (l->tab->Getarg)
+		SV * const arg = (l->tab->Getarg)
 			? (*l->tab->Getarg) (aTHX_ &l, NULL, 0)
 			: &PL_sv_undef;
 		PerlIO_list_push(aTHX_ layera, l->tab, arg);
@@ -1530,7 +1530,7 @@ PerlIO_openn(pTHX_ const char *layers, const char *mode, int fd,
 	 */
 	n = layera->cur - 1;
 	while (n >= 0) {
-	    PerlIO_funcs *t = PerlIO_layer_fetch(aTHX_ layera, n, NULL);
+	    PerlIO_funcs * const t = PerlIO_layer_fetch(aTHX_ layera, n, NULL);
 	    if (t && t->Open) {
 		tab = t;
 		break;
@@ -1709,7 +1709,7 @@ int
 PerlIO_has_base(PerlIO *f)
 {
      if (PerlIOValid(f)) {
-          const PerlIO_funcs *tab = PerlIOBase(f)->tab;
+	  const PerlIO_funcs * const tab = PerlIOBase(f)->tab;
 
 	  if (tab)
 	       return (tab->Get_base != NULL);
@@ -1725,7 +1725,7 @@ int
 PerlIO_fast_gets(PerlIO *f)
 {
     if (PerlIOValid(f) && (PerlIOBase(f)->flags & PERLIO_F_FASTGETS)) {
-	 const PerlIO_funcs *tab = PerlIOBase(f)->tab;
+	 const PerlIO_funcs * const tab = PerlIOBase(f)->tab;
 
 	 if (tab)
 	      return (tab->Set_ptrcnt != NULL);
@@ -1741,7 +1741,7 @@ int
 PerlIO_has_cntptr(PerlIO *f)
 {
     if (PerlIOValid(f)) {
-	const PerlIO_funcs *tab = PerlIOBase(f)->tab;
+	const PerlIO_funcs * const tab = PerlIOBase(f)->tab;
 
 	if (tab)
 	     return (tab->Get_ptr != NULL && tab->Get_cnt != NULL);
@@ -1757,7 +1757,7 @@ int
 PerlIO_canset_cnt(PerlIO *f)
 {
     if (PerlIOValid(f)) {
-	  const PerlIO_funcs *tab = PerlIOBase(f)->tab;
+	  const PerlIO_funcs * const tab = PerlIOBase(f)->tab;
 
 	  if (tab)
 	       return (tab->Set_ptrcnt != NULL);
@@ -2667,7 +2667,7 @@ PerlIOStdio_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab
 {
     PerlIO *n;
     if (PerlIOValid(f) && PerlIOValid(n = PerlIONext(f))) {
-        PerlIO_funcs *toptab = PerlIOBase(n)->tab;
+	PerlIO_funcs * const toptab = PerlIOBase(n)->tab;
         if (toptab == tab) {
 	    /* Top is already stdio - pop self (duplicate) and use original */
 	    PerlIO_pop(aTHX_ f);
diff --git a/pp_ctl.c b/pp_ctl.c
index c53c6d5d6a..7adfd697b7 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -2902,7 +2902,7 @@ STATIC OP *
 S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 {
     dVAR; dSP;
-    OP *saveop = PL_op;
+    OP * const saveop = PL_op;
 
     PL_in_eval = ((saveop && saveop->op_type == OP_REQUIRE)
 		  ? (EVAL_INREQUIRE | (PL_in_eval & EVAL_INEVAL))
diff --git a/pp_hot.c b/pp_hot.c
index 07eb58553c..b150ac9538 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -2969,17 +2969,15 @@ PP(pp_method_named)
 STATIC SV *
 S_method_common(pTHX_ SV* meth, U32* hashp)
 {
-    SV* sv;
     SV* ob;
     GV* gv;
     HV* stash;
     STRLEN namelen;
-    const char* packname = 0;
+    const char* packname = Nullch;
     SV *packsv = Nullsv;
     STRLEN packlen;
-    const char *name = SvPV_const(meth, namelen);
-
-    sv = *(PL_stack_base + TOPMARK + 1);
+    const char * const name = SvPV_const(meth, namelen);
+    SV * const sv = *(PL_stack_base + TOPMARK + 1);
 
     if (!sv)
 	Perl_croak(aTHX_ "Can't call method \"%s\" on an undefined value", name);
@@ -2992,8 +2990,6 @@ S_method_common(pTHX_ SV* meth, U32* hashp)
 	GV* iogv;
 
 	/* this isn't a reference */
-	packname = Nullch;
-
         if(SvOK(sv) && (packname = SvPV_const(sv, packlen))) {
           const HE* const he = hv_fetch_ent(PL_stashcache, sv, 0, 0);
           if (he) { 
@@ -3085,7 +3081,7 @@ S_method_common(pTHX_ SV* meth, U32* hashp)
 		packname = CopSTASHPV(PL_curcop);
 	    }
 	    else if (stash) {
-		HEK *packhek = HvNAME_HEK(stash);
+		HEK * const packhek = HvNAME_HEK(stash);
 		if (packhek) {
 		    packname = HEK_KEY(packhek);
 		    packlen = HEK_LEN(packhek);
diff --git a/proto.h b/proto.h
index 0dc9b03adb..640ab78283 100644
--- a/proto.h
+++ b/proto.h
@@ -76,7 +76,10 @@ END_EXTERN_C
 /* functions with flag 'n' should come before here */
 START_EXTERN_C
 #  include "pp_proto.h"
-PERL_CALLCONV SV*	Perl_amagic_call(pTHX_ SV* left, SV* right, int method, int dir);
+PERL_CALLCONV SV*	Perl_amagic_call(pTHX_ SV* left, SV* right, int method, int dir)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
 PERL_CALLCONV bool	Perl_Gv_AMupdate(pTHX_ HV* stash)
 			__attribute__nonnull__(pTHX_1);
 
@@ -512,10 +515,21 @@ PERL_CALLCONV GV*	Perl_gv_autoload4(pTHX_ HV* stash, const char* name, STRLEN le
 			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_2);
 
-PERL_CALLCONV void	Perl_gv_check(pTHX_ HV* stash);
-PERL_CALLCONV void	Perl_gv_efullname(pTHX_ SV* sv, const GV* gv);
-/* PERL_CALLCONV void	Perl_gv_efullname3(pTHX_ SV* sv, const GV* gv, const char* prefix); */
-PERL_CALLCONV void	Perl_gv_efullname4(pTHX_ SV* sv, const GV* gv, const char* prefix, bool keepmain);
+PERL_CALLCONV void	Perl_gv_check(pTHX_ HV* stash)
+			__attribute__nonnull__(pTHX_1);
+
+PERL_CALLCONV void	Perl_gv_efullname(pTHX_ SV* sv, const GV* gv)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
+/* PERL_CALLCONV void	Perl_gv_efullname3(pTHX_ SV* sv, const GV* gv, const char* prefix)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2); */
+
+PERL_CALLCONV void	Perl_gv_efullname4(pTHX_ SV* sv, const GV* gv, const char* prefix, bool keepmain)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
 PERL_CALLCONV GV*	Perl_gv_fetchfile(pTHX_ const char* name)
 			__attribute__nonnull__(pTHX_1);
 
@@ -2527,7 +2541,9 @@ STATIC I32	S_dopoptosub(pTHX_ I32 startingblock)
 STATIC I32	S_dopoptosub_at(pTHX_ const PERL_CONTEXT* cxstk, I32 startingblock)
 			__attribute__warn_unused_result__;
 
-STATIC void	S_save_lines(pTHX_ AV *array, SV *sv);
+STATIC void	S_save_lines(pTHX_ AV *array, SV *sv)
+			__attribute__nonnull__(pTHX_2);
+
 STATIC OP*	S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 			__attribute__warn_unused_result__;
 
@@ -2654,7 +2670,8 @@ STATIC void	S_cl_init_zero(pTHX_ struct RExC_state_t*, struct regnode_charclass_
 			__attribute__nonnull__(pTHX_2);
 
 STATIC void	S_cl_and(pTHX_ struct regnode_charclass_class *cl, const struct regnode_charclass_class *and_with)
-			__attribute__nonnull__(pTHX_1);
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
 
 STATIC void	S_cl_or(pTHX_ struct RExC_state_t*, struct regnode_charclass_class *cl, const struct regnode_charclass_class *or_with)
 			__attribute__nonnull__(pTHX_1)
@@ -2664,7 +2681,9 @@ STATIC void	S_cl_or(pTHX_ struct RExC_state_t*, struct regnode_charclass_class *
 STATIC I32	S_study_chunk(pTHX_ struct RExC_state_t*, regnode **scanp, I32 *deltap, regnode *last, struct scan_data_t *data, U32 flags, U32 depth);
 STATIC I32	S_add_data(pTHX_ struct RExC_state_t*, I32 n, const char *s);
 STATIC void	S_re_croak2(pTHX_ const char* pat1, const char* pat2, ...)
-			__attribute__noreturn__;
+			__attribute__noreturn__
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
 
 STATIC I32	S_regpposixcc(pTHX_ struct RExC_state_t*, I32 value);
 STATIC void	S_checkposixcc(pTHX_ struct RExC_state_t*);
@@ -2687,7 +2706,9 @@ STATIC I32	S_regrepeat_hard(pTHX_ regnode *p, I32 max, I32 *lp)
 			__attribute__nonnull__(pTHX_3);
 
 STATIC I32	S_regtry(pTHX_ regexp *prog, char *startpos)
-			__attribute__warn_unused_result__;
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
 
 STATIC bool	S_reginclass(pTHX_ const regnode *n, const U8 *p, STRLEN *lenp, bool do_utf8sv_is_utf8)
 			__attribute__warn_unused_result__
@@ -2697,7 +2718,9 @@ STATIC bool	S_reginclass(pTHX_ const regnode *n, const U8 *p, STRLEN *lenp, bool
 STATIC CHECKPOINT	S_regcppush(pTHX_ I32 parenfloor);
 STATIC char*	S_regcppop(pTHX);
 STATIC char*	S_regcp_set_to(pTHX_ I32 ss);
-STATIC void	S_cache_re(pTHX_ regexp *prog);
+STATIC void	S_cache_re(pTHX_ regexp *prog)
+			__attribute__nonnull__(pTHX_1);
+
 STATIC U8*	S_reghop(pTHX_ U8 *pos, I32 off)
 			__attribute__warn_unused_result__;
 
@@ -2729,11 +2752,15 @@ STATIC void	S_to_byte_substr(pTHX_ regexp * prog)
 
 #if defined(PERL_IN_DUMP_C) || defined(PERL_DECL_PROT)
 STATIC CV*	S_deb_curcv(pTHX_ I32 ix);
-STATIC void	S_debprof(pTHX_ const OP *o);
+STATIC void	S_debprof(pTHX_ const OP *o)
+			__attribute__nonnull__(pTHX_1);
+
 #endif
 
 #if defined(PERL_IN_SCOPE_C) || defined(PERL_DECL_PROT)
-STATIC SV*	S_save_scalar_at(pTHX_ SV **sptr);
+STATIC SV*	S_save_scalar_at(pTHX_ SV **sptr)
+			__attribute__nonnull__(pTHX_1);
+
 #endif
 
 #if defined(PERL_IN_GV_C) || defined(PERL_IN_SV_C) || defined(PERL_IN_PAD_C) || defined(PERL_DECL_PROT)
@@ -2769,10 +2796,14 @@ STATIC SV *	S_varname(pTHX_ GV *gv, const char gvtype, PADOFFSET targ, SV *keyna
 			__attribute__warn_unused_result__;
 
 #  ifdef DEBUGGING
-STATIC void	S_del_sv(pTHX_ SV *p);
+STATIC void	S_del_sv(pTHX_ SV *p)
+			__attribute__nonnull__(pTHX_1);
+
 #  endif
 #  if !defined(NV_PRESERVES_UV)
-STATIC int	S_sv_2iuv_non_preserve(pTHX_ SV *sv, I32 numtype);
+STATIC int	S_sv_2iuv_non_preserve(pTHX_ SV *sv, I32 numtype)
+			__attribute__nonnull__(pTHX_1);
+
 #  endif
 STATIC I32	S_expect_number(pTHX_ char** pattern)
 			__attribute__warn_unused_result__
@@ -2803,17 +2834,26 @@ STATIC void	S_sv_release_COW(pTHX_ SV *sv, const char *pvx, STRLEN len, SV *afte
 #if defined(PERL_IN_TOKE_C) || defined(PERL_DECL_PROT)
 STATIC void	S_check_uni(pTHX);
 STATIC void	S_force_next(pTHX_ I32 type);
-STATIC char*	S_force_version(pTHX_ char *start, int guessing);
-STATIC char*	S_force_word(pTHX_ char *start, int token, int check_keyword, int allow_pack, int allow_tick);
-STATIC SV*	S_tokeq(pTHX_ SV *sv);
+STATIC char*	S_force_version(pTHX_ char *start, int guessing)
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_force_word(pTHX_ char *start, int token, int check_keyword, int allow_pack, int allow_tick)
+			__attribute__nonnull__(pTHX_1);
+
+STATIC SV*	S_tokeq(pTHX_ SV *sv)
+			__attribute__nonnull__(pTHX_1);
+
 STATIC int	S_pending_ident(pTHX);
 STATIC char*	S_scan_const(pTHX_ char *start)
+			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_1);
 
 STATIC char*	S_scan_formline(pTHX_ char *s)
+			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_1);
 
 STATIC char*	S_scan_heredoc(pTHX_ char *s)
+			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_1);
 
 STATIC char*	S_scan_ident(pTHX_ char *s, const char *send, char *dest, STRLEN destlen, I32 ck_uni)
@@ -2821,32 +2861,76 @@ STATIC char*	S_scan_ident(pTHX_ char *s, const char *send, char *dest, STRLEN de
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3);
 
-STATIC char*	S_scan_inputsymbol(pTHX_ char *start);
-STATIC char*	S_scan_pat(pTHX_ char *start, I32 type);
-STATIC char*	S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims);
-STATIC char*	S_scan_subst(pTHX_ char *start);
-STATIC char*	S_scan_trans(pTHX_ char *start);
-STATIC char*	S_scan_word(pTHX_ char *s, char *dest, STRLEN destlen, int allow_package, STRLEN *slp);
-STATIC char*	S_skipspace(pTHX_ char *s);
-STATIC char*	S_swallow_bom(pTHX_ U8 *s);
+STATIC char*	S_scan_inputsymbol(pTHX_ char *start)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_scan_pat(pTHX_ char *start, I32 type)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_scan_subst(pTHX_ char *start)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_scan_trans(pTHX_ char *start)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_scan_word(pTHX_ char *s, char *dest, STRLEN destlen, int allow_package, STRLEN *slp)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2)
+			__attribute__nonnull__(pTHX_5);
+
+STATIC char*	S_skipspace(pTHX_ char *s)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+STATIC char*	S_swallow_bom(pTHX_ U8 *s)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
 STATIC void	S_checkcomma(pTHX_ char *s, const char *name, const char *what)
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3);
 
-STATIC void	S_force_ident(pTHX_ const char *s, int kind);
-STATIC void	S_incline(pTHX_ char *s);
-STATIC int	S_intuit_method(pTHX_ char *s, GV *gv);
-STATIC int	S_intuit_more(pTHX_ char *s);
-STATIC I32	S_lop(pTHX_ I32 f, int x, char *s);
+STATIC void	S_force_ident(pTHX_ const char *s, int kind)
+			__attribute__nonnull__(pTHX_1);
+
+STATIC void	S_incline(pTHX_ char *s)
+			__attribute__nonnull__(pTHX_1);
+
+STATIC int	S_intuit_method(pTHX_ char *s, GV *gv)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
+STATIC int	S_intuit_more(pTHX_ char *s)
+			__attribute__nonnull__(pTHX_1);
+
+STATIC I32	S_lop(pTHX_ I32 f, int x, char *s)
+			__attribute__nonnull__(pTHX_3);
+
 STATIC void	S_missingterm(pTHX_ char *s)
 			__attribute__noreturn__;
 
-STATIC void	S_no_op(pTHX_ const char *what, char *s);
+STATIC void	S_no_op(pTHX_ const char *what, char *s)
+			__attribute__nonnull__(pTHX_1);
+
 STATIC void	S_set_csh(pTHX);
-STATIC I32	S_sublex_done(pTHX);
-STATIC I32	S_sublex_push(pTHX);
-STATIC I32	S_sublex_start(pTHX);
+STATIC I32	S_sublex_done(pTHX)
+			__attribute__warn_unused_result__;
+
+STATIC I32	S_sublex_push(pTHX)
+			__attribute__warn_unused_result__;
+
+STATIC I32	S_sublex_start(pTHX)
+			__attribute__warn_unused_result__;
+
 STATIC char *	S_filter_gets(pTHX_ SV *sv, PerlIO *fp, STRLEN append)
 			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_1)
@@ -2858,7 +2942,9 @@ STATIC HV *	S_find_in_my_stash(pTHX_ const char *pkgname, I32 len)
 
 STATIC SV*	S_new_constant(pTHX_ const char *s, STRLEN len, const char *key, SV *sv, SV *pv, const char *type);
 #  if defined(DEBUGGING)
-STATIC int	S_tokereport(pTHX_ const char *s, I32 rv);
+STATIC int	S_tokereport(pTHX_ const char *s, I32 rv)
+			__attribute__nonnull__(pTHX_1);
+
 #  endif
 STATIC int	S_ao(pTHX_ int toketype);
 STATIC void	S_depcom(pTHX);
@@ -2873,7 +2959,9 @@ STATIC I32	S_cr_textfilter(pTHX_ int idx, SV *sv, int maxlen);
 #endif
 
 #if defined(PERL_IN_UNIVERSAL_C) || defined(PERL_DECL_PROT)
-STATIC SV*	S_isa_lookup(pTHX_ HV *stash, const char *name, HV *name_stash, int len, int level);
+STATIC SV*	S_isa_lookup(pTHX_ HV *stash, const char *name, HV *name_stash, int len, int level)
+			__attribute__nonnull__(pTHX_2);
+
 #endif
 
 #if defined(PERL_IN_LOCALE_C) || defined(PERL_DECL_PROT)
@@ -2918,7 +3006,9 @@ PERL_CALLCONV void	Perl_sv_catsv_flags(pTHX_ SV* dsv, SV* ssv, I32 flags)
 PERL_CALLCONV STRLEN	Perl_sv_utf8_upgrade_flags(pTHX_ SV *sv, I32 flags)
 			__attribute__nonnull__(pTHX_1);
 
-PERL_CALLCONV char*	Perl_sv_pvn_force_flags(pTHX_ SV* sv, STRLEN* lp, I32 flags);
+PERL_CALLCONV char*	Perl_sv_pvn_force_flags(pTHX_ SV* sv, STRLEN* lp, I32 flags)
+			__attribute__nonnull__(pTHX_1);
+
 PERL_CALLCONV void	Perl_sv_copypv(pTHX_ SV* dsv, SV* ssv)
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2);
@@ -2929,7 +3019,10 @@ PERL_CALLCONV char*	Perl_my_atof2(pTHX_ const char *s, NV* value)
 
 PERL_CALLCONV int	Perl_my_socketpair(int family, int type, int protocol, int fd[2]);
 #ifdef PERL_OLD_COPY_ON_WRITE
-PERL_CALLCONV SV*	Perl_sv_setsv_cow(pTHX_ SV* dsv, SV* ssv);
+PERL_CALLCONV SV*	Perl_sv_setsv_cow(pTHX_ SV* dsv, SV* ssv)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
 #endif
 
 #if defined(USE_PERLIO) && !defined(USE_SFIO)
@@ -2966,9 +3059,15 @@ PERL_CALLCONV int	Perl_PerlIO_get_cnt(pTHX_ PerlIO *f)
 			__attribute__warn_unused_result__;
 
 
-PERL_CALLCONV PerlIO *	Perl_PerlIO_stdin(pTHX);
-PERL_CALLCONV PerlIO *	Perl_PerlIO_stdout(pTHX);
-PERL_CALLCONV PerlIO *	Perl_PerlIO_stderr(pTHX);
+PERL_CALLCONV PerlIO *	Perl_PerlIO_stdin(pTHX)
+			__attribute__warn_unused_result__;
+
+PERL_CALLCONV PerlIO *	Perl_PerlIO_stdout(pTHX)
+			__attribute__warn_unused_result__;
+
+PERL_CALLCONV PerlIO *	Perl_PerlIO_stderr(pTHX)
+			__attribute__warn_unused_result__;
+
 #endif /* PERLIO_LAYERS */
 
 PERL_CALLCONV void	Perl_deb_stack_all(pTHX);
@@ -3006,7 +3105,9 @@ PERL_CALLCONV void	Perl_do_dump_pad(pTHX_ I32 level, PerlIO *file, PADLIST *padl
 			__attribute__nonnull__(pTHX_2);
 
 PERL_CALLCONV void	Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
-			__attribute__nonnull__(pTHX_1);
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2)
+			__attribute__nonnull__(pTHX_3);
 
 
 PERL_CALLCONV void	Perl_pad_push(pTHX_ PADLIST *padlist, int depth)
@@ -3036,7 +3137,8 @@ PERL_CALLCONV CV*	Perl_find_runcv(pTHX_ U32 *db_seqp)
 PERL_CALLCONV void	Perl_free_tied_hv_pool(pTHX);
 #if defined(DEBUGGING)
 PERL_CALLCONV int	Perl_get_debug_opts(pTHX_ const char **s, bool givehelp)
-			__attribute__warn_unused_result__;
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
 
 #endif
 PERL_CALLCONV void	Perl_save_set_svflags(pTHX_ SV* sv, U32 mask, U32 val);
@@ -3184,7 +3286,9 @@ PERL_CALLCONV bool	Perl_stashpv_hvname_match(pTHX_ const COP *cop, const HV *hv)
 
 
 #ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
-PERL_CALLCONV void	Perl_dump_sv_child(pTHX_ SV *sv);
+PERL_CALLCONV void	Perl_dump_sv_child(pTHX_ SV *sv)
+			__attribute__nonnull__(pTHX_1);
+
 #endif
 
 #ifdef PERL_DONT_CREATE_GVSV
diff --git a/toke.c b/toke.c
index 33ec2c460e..ae56a6fec6 100644
--- a/toke.c
+++ b/toke.c
@@ -9085,7 +9085,7 @@ S_scan_ident(pTHX_ register char *s, register const char *send, char *dest, STRL
 {
     register char *d;
     register char *e;
-    char *bracket = 0;
+    char *bracket = Nullch;
     char funny = *s++;
 
     if (isSPACE(*s))
@@ -9263,7 +9263,7 @@ S_scan_pat(pTHX_ char *start, I32 type)
     char *s = scan_str(start,FALSE,FALSE);
 
     if (!s) {
-	char *delimiter = skipspace(start);
+	char * const delimiter = skipspace(start);
 	Perl_croak(aTHX_ *delimiter == '?'
 		   ? "Search pattern not terminated or ternary operator parsed as search pattern"
 		   : "Search pattern not terminated" );