| Subject: | [PATCH] Build op trees that more closely resemble what core does |
| Date: | Mon, 13 Apr 2020 22:51:32 +0100 |
| To: | bug-XS-Parse-Sublike [...] rt.cpan.org |
| From: | ilmari [...] ilmari.org (Dagfinn Ilmari Mannsåker) |
Hi Paul,
Out of curiosity I was looking at the B::Concise and B::Deparse output
for async subs, and noticed their signatures weren't recognised, and
that empty ones had a stub op that normal subs didn't.
After groveling around perly.y (and its history) for a bit, I came up
with the attached patch, which makes subs with signatures constructed by
'func' from t/func.xs have identical optrees to regular subs, both on
5.30 and blead.
- ilmari
--
- Twitter seems more influential [than blogs] in the 'gets reported in
the mainstream press' sense at least. - Matt McLeod
- That'd be because the content of a tweet is easier to condense down
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From 9a0a3615b966206ced303edeebaa185b6cbca80c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilmari@ilmari.org>
Date: Mon, 13 Apr 2020 22:19:08 +0100
Subject: [PATCH] Build op trees that more closely resemble what core does
This improves the deparseability of custom-built subs.
- Eliminate stub op if we have a signature and an empty body
- Append a nextstate at the end of the arg check blocks
- On 5.31.5 and later, wrap the whole arg-checking sequence in
a nulle-out ex-argcheck op.
---
hax/parse_subsignature.c.inc | 10 ++++++++--
lib/XS/Parse/Sublike.xs | 25 ++++++++++++++++++++++++-
2 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/hax/parse_subsignature.c.inc b/hax/parse_subsignature.c.inc
index fa3274e..e42f2cb 100644
--- a/hax/parse_subsignature.c.inc
+++ b/hax/parse_subsignature.c.inc
@@ -205,10 +205,16 @@ endofelems:
OP *checkop = newUNOP_AUX(OP_ARGCHECK, 0, NULL, aux);
+ checkop = op_prepend_elem(OP_LINESEQ, newSTATEOP(0, NULL, NULL),
+ op_prepend_elem(OP_LINESEQ, checkop, elems));
+
+ /* a nextstate at the end handles context correctly for an empty
+ * sub body */
+ checkop = op_append_elem(OP_LINESEQ, checkop, newSTATEOP(0, NULL, NULL));
+
LEAVE;
- return op_prepend_elem(OP_LINESEQ, newSTATEOP(0, NULL, NULL),
- op_prepend_elem(OP_LINESEQ, checkop, elems));
+ return checkop;
}
#endif
diff --git a/lib/XS/Parse/Sublike.xs b/lib/XS/Parse/Sublike.xs
index 3d37ce7..40482cb 100644
--- a/lib/XS/Parse/Sublike.xs
+++ b/lib/XS/Parse/Sublike.xs
@@ -88,6 +88,21 @@ static int parse2(pTHX_ const struct XSParseSublikeHooks *hooksA, const struct X
sigop = op_prepend_elem(OP_LINESEQ, newSTATEOP(0, NULL, NULL),
newUNOP_AUX(OP_ARGCHECK, 0, NULL, aux));
+
+ /* a nextstate at the end handles context correctly for an empty
+ * sub body */
+ sigop = op_append_elem(OP_LINESEQ, sigop, newSTATEOP(0, NULL, NULL));
+
+#if HAVE_PERL_VERSION(5,31,5)
+ /* wrap the list of arg ops in a NULL aux op. This serves two
+ * purposes. First, it makes the arg list a separate subtree
+ * from the body of the sub, and secondly the null op may in
+ * future be upgraded to an OP_SIGNATURE when implemented. For
+ * now leave it as ex-argcheck
+ */
+ sigop = newUNOP_AUX(OP_ARGCHECK, 0, sigop, NULL);
+ op_null(sigop);
+#endif
}
else
#endif
@@ -111,8 +126,16 @@ static int parse2(pTHX_ const struct XSParseSublikeHooks *hooksA, const struct X
SvREFCNT_inc(PL_compcv);
#ifdef HAVE_PARSE_SUBSIGNATURE
- if(sigop)
+ if(sigop) {
+ /* parse_block() returns an empy block as a stub op.
+ * no need to keep that if we we have a signature.
+ */
+ if (ctx.body->op_type == OP_STUB) {
+ op_free(ctx.body);
+ ctx.body = NULL;
+ }
ctx.body = op_append_list(OP_LINESEQ, sigop, ctx.body);
+ }
#endif
if(PL_parser->error_count) {
--
2.20.1