diff options
Diffstat (limited to 'op.c')
| -rw-r--r-- | op.c | 56 |
1 files changed, 42 insertions, 14 deletions
@@ -888,10 +888,23 @@ S_modkids(pTHX_ OP *o, I32 type) return o; } +/* Propagate lvalue ("modifiable") context to an op and it's children. + * 'type' represents the context type, roughly based on the type of op that + * would do the modifying, although local() is represented by OP_NULL. + * It's responsible for detecting things that can't be modified, flag + * things that need to behave specially in an lvalue context (e.g., "$$x = 5" + * might have to vivify a reference in $x), and so on. + * + * For example, "$a+1 = 2" would cause mod() to be called with o being + * OP_ADD and type being OP_SASSIGN, and would output an error. + */ + OP * Perl_mod(pTHX_ OP *o, I32 type) { OP *kid; + /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */ + int localize = -1; if (!o || PL_error_count) return o; @@ -904,6 +917,7 @@ Perl_mod(pTHX_ OP *o, I32 type) switch (o->op_type) { case OP_UNDEF: + localize = 0; PL_modcount++; return o; case OP_CONST: @@ -1060,6 +1074,7 @@ Perl_mod(pTHX_ OP *o, I32 type) break; case OP_COND_EXPR: + localize = 1; for (kid = cUNOPo->op_first->op_sibling; kid; kid = kid->op_sibling) mod(kid, type); break; @@ -1080,6 +1095,7 @@ Perl_mod(pTHX_ OP *o, I32 type) case OP_HSLICE: if (type == OP_LEAVESUBLV) o->op_private |= OPpMAYBE_LVSUB; + localize = 1; /* FALL THROUGH */ case OP_AASSIGN: case OP_NEXTSTATE: @@ -1088,6 +1104,7 @@ Perl_mod(pTHX_ OP *o, I32 type) break; case OP_RV2SV: ref(cUNOPo->op_first, o->op_type); + localize = 1; /* FALL THROUGH */ case OP_GV: case OP_AV2ARYLEN: @@ -1096,7 +1113,11 @@ Perl_mod(pTHX_ OP *o, I32 type) case OP_ANDASSIGN: case OP_ORASSIGN: case OP_DORASSIGN: + PL_modcount++; + break; + case OP_AELEMFAST: + localize = 1; PL_modcount++; break; @@ -1112,17 +1133,13 @@ Perl_mod(pTHX_ OP *o, I32 type) /* FALL THROUGH */ case OP_PADSV: PL_modcount++; - if (!type) - { /* XXX DAPM 2002.08.25 tmp assert test */ - /* XXX */ assert(av_fetch(PL_comppad_name, (o->op_targ), FALSE)); - /* XXX */ assert(*av_fetch(PL_comppad_name, (o->op_targ), FALSE)); - + if (!type) /* local() */ Perl_croak(aTHX_ "Can't localize lexical variable %s", PAD_COMPNAME_PV(o->op_targ)); - } break; case OP_PUSHMARK: + localize = 0; break; case OP_KEYS: @@ -1153,6 +1170,7 @@ Perl_mod(pTHX_ OP *o, I32 type) o->op_private |= OPpLVAL_DEFER; if (type == OP_LEAVESUBLV) o->op_private |= OPpMAYBE_LVSUB; + localize = 1; PL_modcount++; break; @@ -1160,11 +1178,13 @@ Perl_mod(pTHX_ OP *o, I32 type) case OP_LEAVE: case OP_ENTER: case OP_LINESEQ: + localize = 0; if (o->op_flags & OPf_KIDS) mod(cLISTOPo->op_last, type); break; case OP_NULL: + localize = 0; if (o->op_flags & OPf_SPECIAL) /* do BLOCK */ goto nomod; else if (!(o->op_flags & OPf_KIDS)) @@ -1175,6 +1195,7 @@ Perl_mod(pTHX_ OP *o, I32 type) } /* FALL THROUGH */ case OP_LIST: + localize = 0; for (kid = cLISTOPo->op_first; kid; kid = kid->op_sibling) mod(kid, type); break; @@ -1197,10 +1218,21 @@ Perl_mod(pTHX_ OP *o, I32 type) if (type == OP_AASSIGN || type == OP_SASSIGN) o->op_flags |= OPf_SPECIAL|OPf_REF; - else if (!type) { - o->op_private |= OPpLVAL_INTRO; - o->op_flags &= ~OPf_SPECIAL; - PL_hints |= HINT_BLOCK_SCOPE; + else if (!type) { /* local() */ + switch (localize) { + case 1: + o->op_private |= OPpLVAL_INTRO; + o->op_flags &= ~OPf_SPECIAL; + PL_hints |= HINT_BLOCK_SCOPE; + break; + case 0: + break; + case -1: + if (ckWARN(WARN_SYNTAX)) { + Perl_warner(aTHX_ packWARN(WARN_SYNTAX), + "Useless localization of %s", OP_DESC(o)); + } + } } else if (type != OP_GREPSTART && type != OP_ENTERSUB && type != OP_LEAVESUBLV) @@ -5104,10 +5136,6 @@ Perl_ck_fun(pTHX_ OP *o) */ priv = OPpDEREF; if (kid->op_type == OP_PADSV) { - /*XXX DAPM 2002.08.25 tmp assert test */ - /*XXX*/ assert(av_fetch(PL_comppad_name, (kid->op_targ), FALSE)); - /*XXX*/ assert(*av_fetch(PL_comppad_name, (kid->op_targ), FALSE)); - name = PAD_COMPNAME_PV(kid->op_targ); /* SvCUR of a pad namesv can't be trusted * (see PL_generation), so calc its length |