emit warning about function calls that were encountered too early

to enforce their prototype

p4raw-id: //depot/perl@3723

diff --git a/op.c b/op.c
index b605e66..e284d4b 100644 (file)
--- a/op.c
+++ b/op.c
@@ -4707,6 +4707,7 @@ Perl_ck_rvconst(pTHX_ register OP *o)
            kid->op_type = OP_GV;
            SvREFCNT_dec(kid->op_sv);
            kid->op_sv = SvREFCNT_inc(gv);
+           kid->op_ppaddr = PL_ppaddr[OP_GV];
        }
     }
     return o;
@@ -5451,9 +5452,11 @@ Perl_ck_subr(pTHX_ OP *o)
        o->op_private |= (cvop->op_private & OPpENTERSUB_AMPER);
        null(cvop);             /* disable rv2cv */
        tmpop = (SVOP*)((UNOP*)cvop)->op_first;
-       if (tmpop->op_type == OP_GV) {
+       if (tmpop->op_type == OP_GV && !(o->op_private & OPpENTERSUB_AMPER)) {
            cv = GvCVu(tmpop->op_sv);
-           if (cv && SvPOK(cv) && !(o->op_private & OPpENTERSUB_AMPER)) {
+           if (!cv)
+               tmpop->op_private |= OPpEARLY_CV;
+           else if (SvPOK(cv)) {
                namegv = CvANON(cv) ? (GV*)tmpop->op_sv : CvGV(cv);
                proto = SvPV((SV*)cv, n_a);
            }
@@ -5738,6 +5741,18 @@ Perl_peep(pTHX_ register OP *o)
                    GvAVn(((GVOP*)o)->op_gv);
                }
            }
+           else if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_UNSAFE)) {
+               GV *gv = cGVOPo->op_gv;
+               if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX(GvCV(gv))) {
+                   /* XXX could check prototype here instead of just carping */
+                   SV *sv = sv_newmortal();
+                   gv_efullname3(sv, gv, Nullch);
+                   Perl_warner(aTHX_ WARN_UNSAFE,
+                               "%s() called too early to check prototype",
+                               SvPV_nolen(sv));
+               }
+           }
+
            o->op_seq = PL_op_seqmax++;
            break;
 

diff --git a/op.h b/op.h
index 4de4647..dd6307c 100644 (file)
--- a/op.h
+++ b/op.h
@@ -127,6 +127,8 @@ typedef U32 PADOFFSET;
   /* OP_RV2CV only */
 #define OPpENTERSUB_AMPER      8       /* Used & form to call. */
 #define OPpENTERSUB_NOPAREN    128     /* bare sub call (without parens) */
+  /* OP_GV only */
+#define OPpEARLY_CV            32      /* foo() called before sub foo was parsed */
   /* OP_?ELEM only */
 #define OPpLVAL_DEFER          16      /* Defer creation of array/hash elem */
   /* for OP_RV2?V, lower bits carry hints */

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index f5717c5..b3265ff 100644 (file)
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -74,6 +74,16 @@ C<'>-delimited regular expression.
 by parentheses turns into a function, with all the list operators arguments
 found inside the parentheses.  See L<perlop/Terms and List Operators (Leftward)>.
 
+=item %s() called too early to check prototype
+
+(W) You've called a function that has a prototype before the parser saw a
+definition or declaration for it, and Perl could not check that the call
+conforms to the prototype.  You need to either add an early prototype
+declaration for the subroutine in question, or move the subroutine
+definition ahead of the call to get proper prototype checking.  Alternatively,
+if you are certain that you're calling the function correctly, you may put
+an ampersand before the name to avoid the warning.  See L<perlsub>.
+
 =item %s argument is not a HASH element
 
 (F) The argument to exists() must be a hash element, such as