[perl #120462] Exempt $a and $b from ‘used once’ warnings

diff --git a/ext/B/t/optree_varinit.t b/ext/B/t/optree_varinit.t
index 3287179..ca2b59b 100644 (file)
--- a/ext/B/t/optree_varinit.t
+++ b/ext/B/t/optree_varinit.t
@@ -108,9 +108,9 @@ EOT_EOT
 # 3        <$> gvsv(*a) s/OURINTR ->4
 EONT_EONT
 
-checkOptree ( name     => 'local $a',
-             prog      => 'local $a',
-             errs      => ['Name "main::a" used only once: possible typo at -e line 1.'],
+checkOptree ( name     => 'local $c',
+             prog      => 'local $c',
+             errs      => ['Name "main::c" used only once: possible typo at -e line 1.'],
              bcopts    => '-basic',
              strip_open_hints => 1,
              expect    => <<'EOT_EOT', expect_nt => <<'EONT_EONT');
@@ -118,13 +118,13 @@ checkOptree ( name        => 'local $a',
 1     <0> enter ->2
 2     <;> nextstate(main 1 -e:1) v:>,<,%,{ ->3
 -     <1> ex-rv2sv vKM/129 ->4
-3        <#> gvsv[*a] s/LVINTRO ->4
+3        <#> gvsv[*c] s/LVINTRO ->4
 EOT_EOT
 # 4  <@> leave[1 ref] vKP/REFC ->(end)
 # 1     <0> enter ->2
 # 2     <;> nextstate(main 1 -e:1) v:>,<,%,{ ->3
 # -     <1> ex-rv2sv vKM/129 ->4
-# 3        <$> gvsv(*a) s/LVINTRO ->4
+# 3        <$> gvsv(*c) s/LVINTRO ->4
 EONT_EONT
 
 pass("MY, OUR, LOCAL, BOTH SUB AND MAIN, = undef");
@@ -238,9 +238,9 @@ EOT_EOT
 # 4           <$> gvsv(*a) s/OURINTR ->5
 EONT_EONT
 
-checkOptree ( name     => 'local $a=undef',
-             prog      => 'local $a=undef',
-             errs      => ['Name "main::a" used only once: possible typo at -e line 1.'],
+checkOptree ( name     => 'local $c=undef',
+             prog      => 'local $c=undef',
+             errs      => ['Name "main::c" used only once: possible typo at -e line 1.'],
              note      => 'locals are rare, probably not worth doing',
              bcopts    => '-basic',
              strip_open_hints => 1,
@@ -251,7 +251,7 @@ checkOptree ( name  => 'local $a=undef',
 5     <2> sassign vKS/2 ->6
 3        <0> undef s ->4
 -        <1> ex-rv2sv sKRM*/129 ->5
-4           <#> gvsv[*a] s/LVINTRO ->5
+4           <#> gvsv[*c] s/LVINTRO ->5
 EOT_EOT
 # 6  <@> leave[1 ref] vKP/REFC ->(end)
 # 1     <0> enter ->2
@@ -259,7 +259,7 @@ EOT_EOT
 # 5     <2> sassign vKS/2 ->6
 # 3        <0> undef s ->4
 # -        <1> ex-rv2sv sKRM*/129 ->5
-# 4           <$> gvsv(*a) s/LVINTRO ->5
+# 4           <$> gvsv(*c) s/LVINTRO ->5
 EONT_EONT
 
 checkOptree ( name     => 'sub {my $a=()}',
@@ -359,9 +359,9 @@ EOT_EOT
 # 6  <@> leave[1 ref] vKP/REFC
 EONT_EONT
 
-checkOptree ( name     => 'local $a=()',
-             prog      => 'local $a=()',
-             errs      => ['Name "main::a" used only once: possible typo at -e line 1.'],
+checkOptree ( name     => 'local $c=()',
+             prog      => 'local $c=()',
+             errs      => ['Name "main::c" used only once: possible typo at -e line 1.'],
               #todo    => 'probly not worth doing',
              bcopts    => '-exec',
              strip_open_hints => 1,
@@ -369,14 +369,14 @@ checkOptree ( name        => 'local $a=()',
 1  <0> enter 
 2  <;> nextstate(main 1 -e:1) v:>,<,%,{
 3  <0> stub sP
-4  <#> gvsv[*a] s/LVINTRO
+4  <#> gvsv[*c] s/LVINTRO
 5  <2> sassign vKS/2
 6  <@> leave[1 ref] vKP/REFC
 EOT_EOT
 # 1  <0> enter 
 # 2  <;> nextstate(main 1 -e:1) v:>,<,%,{
 # 3  <0> stub sP
-# 4  <$> gvsv(*a) s/LVINTRO
+# 4  <$> gvsv(*c) s/LVINTRO
 # 5  <2> sassign vKS/2
 # 6  <@> leave[1 ref] vKP/REFC
 EONT_EONT

diff --git a/gv.c b/gv.c
index 905d131..62652fe 100644 (file)
--- a/gv.c
+++ b/gv.c
@@ -1670,10 +1670,10 @@ S_gv_magicalize(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len,
     PERL_ARGS_ASSERT_GV_MAGICALIZE;
     
     if (stash != PL_defstash) { /* not the main stash */
-       /* We only have to check for three names here: EXPORT, ISA
+       /* We only have to check for a few names here: a, b, EXPORT, ISA
           and VERSION. All the others apply only to the main stash or to
           CORE (which is checked right after this). */
-       if (len > 2) {
+       if (len) {
            const char * const name2 = name + 1;
            switch (*name) {
            case 'E':
@@ -1688,6 +1688,11 @@ S_gv_magicalize(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len,
                if (strEQ(name2, "ERSION"))
                    GvMULTI_on(gv);
                break;
+           case 'a':
+           case 'b':
+               if (len == 1 && sv_type == SVt_PV)
+                   GvMULTI_on(gv);
+               /* FALL THROUGH */
            default:
                goto try_core;
            }
@@ -2016,6 +2021,10 @@ S_gv_magicalize(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len,
            SvREFCNT_dec(sv);
        }
        break;
+       case 'a':
+       case 'b':
+           if (len == 1 && sv_type == SVt_PV)
+               GvMULTI_on(gv);
        }
     }
 

diff --git a/op.c b/op.c
index 5f48939..111da3c 100644 (file)
--- a/op.c
+++ b/op.c
@@ -9902,8 +9902,6 @@ S_simplify_sort(pTHX_ OP *o)
 
     PERL_ARGS_ASSERT_SIMPLIFY_SORT;
 
-    GvMULTI_on(gv_fetchpvs("a", GV_ADD|GV_NOTQUAL, SVt_PV));
-    GvMULTI_on(gv_fetchpvs("b", GV_ADD|GV_NOTQUAL, SVt_PV));
     kid = kUNOP->op_first;                             /* get past null */
     if (!(have_scopeop = kid->op_type == OP_SCOPE)
      && kid->op_type != OP_LEAVE)

diff --git a/t/lib/warnings/1global b/t/lib/warnings/1global
index 2c54e37..51acd17 100644 (file)
--- a/t/lib/warnings/1global
+++ b/t/lib/warnings/1global
@@ -10,25 +10,25 @@ EXPECT
 ########
 -w
 # warnable code, warnings enabled via command line switch
-$a =+ 3 ;
+$c =+ 3 ;
 EXPECT
 Reversed += operator at - line 3.
-Name "main::a" used only once: possible typo at - line 3.
+Name "main::c" used only once: possible typo at - line 3.
 ########
 #! perl -w
 # warnable code, warnings enabled via #! line
-$a =+ 3 ;
+$c =+ 3 ;
 EXPECT
 Reversed += operator at - line 3.
-Name "main::a" used only once: possible typo at - line 3.
+Name "main::c" used only once: possible typo at - line 3.
 ########
 
 # warnable code, warnings enabled via compile time $^W
 BEGIN { $^W = 1 }
-$a =+ 3 ;
+$c =+ 3 ;
 EXPECT
 Reversed += operator at - line 4.
-Name "main::a" used only once: possible typo at - line 4.
+Name "main::c" used only once: possible typo at - line 4.
 ########
 -w
 # warnable code, warnings enabled via command line switch

diff --git a/t/lib/warnings/gv b/t/lib/warnings/gv
index 67ee1d4..f333445 100644 (file)
--- a/t/lib/warnings/gv
+++ b/t/lib/warnings/gv
@@ -130,6 +130,10 @@ $x = 1;
 if ($x) {
     print $y;
 }
+$a++; # These two should
+$b++; # be exempt.
+$Foo::a++;
+$Foo::b++;
 EXPECT
 Name "main::y" used only once: possible typo at - line 5.
 Use of uninitialized value $y in print at - line 5.