From 4d65a07d54bd9371475648f7de9d4b6a01238813 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Tue, 5 Jan 2021 16:56:44 -0500 Subject: [PATCH] c++: Add some conversion sanity checking. Another change I was working on revealed that for complex numbers we were building a ck_identity with build_conv, leading to the wrong active member in the union being set. Rather than add another enumeration of the appropriate conversion codes, I factored that out. gcc/cp/ChangeLog: * call.c (has_next): Factor out from... (next_conversion): ...here. (strip_standard_conversion): And here. (is_subseq): And here. (build_conv): Check it. (standard_conversion): Don't call build_conv for ck_identity. --- gcc/cp/call.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 182ea94bb7c..218157088ef 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -761,12 +761,26 @@ alloc_conversions (size_t n) return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); } +/* True iff the active member of conversion::u for code CODE is NEXT. */ + +static inline bool +has_next (conversion_kind code) +{ + return !(code == ck_identity + || code == ck_ambig + || code == ck_list + || code == ck_aggr); +} + static conversion * build_conv (conversion_kind code, tree type, conversion *from) { conversion *t; conversion_rank rank = CONVERSION_RANK (from); + /* Only call this function for conversions that use u.next. */ + gcc_assert (from == NULL || has_next (code)); + /* Note that the caller is responsible for filling in t->cand for user-defined conversions. */ t = alloc_conversion (code); @@ -863,10 +877,7 @@ static conversion * next_conversion (conversion *conv) { if (conv == NULL - || conv->kind == ck_identity - || conv->kind == ck_ambig - || conv->kind == ck_list - || conv->kind == ck_aggr) + || !has_next (conv->kind)) return NULL; return conv->u.next; } @@ -879,10 +890,7 @@ strip_standard_conversion (conversion *conv) { while (conv && conv->kind != ck_user - && conv->kind != ck_ambig - && conv->kind != ck_list - && conv->kind != ck_aggr - && conv->kind != ck_identity) + && has_next (conv->kind)) conv = next_conversion (conv); return conv; } @@ -1266,13 +1274,15 @@ standard_conversion (tree to, tree from, tree expr, bool c_cast_p, (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags, complain); - if (part_conv) + if (!part_conv) + conv = NULL; + else if (part_conv->kind == ck_identity) + /* Leave conv alone. */; + else { conv = build_conv (part_conv->kind, to, conv); conv->rank = part_conv->rank; } - else - conv = NULL; return conv; } @@ -10619,10 +10629,7 @@ is_subseq (conversion *ics1, conversion *ics2) ics2 = next_conversion (ics2); if (ics2->kind == ck_user - || ics2->kind == ck_ambig - || ics2->kind == ck_aggr - || ics2->kind == ck_list - || ics2->kind == ck_identity) + || !has_next (ics2->kind)) /* At this point, ICS1 cannot be a proper subsequence of ICS2. We can get a USER_CONV when we are comparing the second standard conversion sequence of two user conversion -- 2.30.2