From eb03e424598d30fed68801af6d6ef6236d32e32e Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 19 Apr 2022 18:27:41 +0200 Subject: [PATCH] c++: Fix up CONSTRUCTOR_PLACEHOLDER_BOUNDARY handling [PR105256] The CONSTRUCTOR_PLACEHOLDER_BOUNDARY bit is supposed to separate PLACEHOLDER_EXPRs that should be replaced by one object or subobjects of it (variable, TARGET_EXPR slot, ...) from other PLACEHOLDER_EXPRs that should be replaced by different objects or subobjects. The bit is set when finding PLACEHOLDER_EXPRs inside of a CONSTRUCTOR, not looking into nested CONSTRUCTOR_PLACEHOLDER_BOUNDARY ctors, and we prevent elision of TARGET_EXPRs (through TARGET_EXPR_NO_ELIDE) whose initializer is a CONSTRUCTOR_PLACEHOLDER_BOUNDARY ctor. The following testcase ICEs though, we don't replace the placeholders in there at all, because CONSTRUCTOR_PLACEHOLDER_BOUNDARY isn't set on the TARGET_EXPR_INITIAL ctor, but on a ctor nested in such a ctor. replace_placeholders should be run on the whole TARGET_EXPR slot. So, the following patch fixes it by moving the CONSTRUCTOR_PLACEHOLDER_BOUNDARY bit from nested CONSTRUCTORs to the CONSTRUCTOR containing those (but only if it is closely nested, if there is some other tree sandwiched in between, it doesn't do it). 2022-04-19 Jakub Jelinek PR c++/105256 * typeck2.cc (process_init_constructor_array, process_init_constructor_record, process_init_constructor_union): Move CONSTRUCTOR_PLACEHOLDER_BOUNDARY flag from CONSTRUCTOR elements to the containing CONSTRUCTOR. * g++.dg/cpp0x/pr105256.C: New test. --- gcc/cp/typeck2.cc | 31 +++++++++++++++++++++++++++++++ gcc/testsuite/g++.dg/cpp0x/pr105256.C | 18 ++++++++++++++++++ 2 files changed, 49 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr105256.C diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc index 23ed81e..63d95c1 100644 --- a/gcc/cp/typeck2.cc +++ b/gcc/cp/typeck2.cc @@ -1515,6 +1515,14 @@ process_init_constructor_array (tree type, tree init, int nested, int flags, strip_array_types (TREE_TYPE (ce->value))))); picflags |= picflag_from_initializer (ce->value); + /* Propagate CONSTRUCTOR_PLACEHOLDER_BOUNDARY to outer + CONSTRUCTOR. */ + if (TREE_CODE (ce->value) == CONSTRUCTOR + && CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ce->value)) + { + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (init) = 1; + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ce->value) = 0; + } } /* No more initializers. If the array is unbounded, we are done. Otherwise, @@ -1560,6 +1568,14 @@ process_init_constructor_array (tree type, tree init, int nested, int flags, } picflags |= picflag_from_initializer (next); + /* Propagate CONSTRUCTOR_PLACEHOLDER_BOUNDARY to outer + CONSTRUCTOR. */ + if (TREE_CODE (next) == CONSTRUCTOR + && CONSTRUCTOR_PLACEHOLDER_BOUNDARY (next)) + { + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (init) = 1; + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (next) = 0; + } if (len > i+1) { tree range = build2 (RANGE_EXPR, size_type_node, @@ -1754,6 +1770,13 @@ process_init_constructor_record (tree type, tree init, int nested, int flags, if (fldtype != TREE_TYPE (field)) next = cp_convert_and_check (TREE_TYPE (field), next, complain); picflags |= picflag_from_initializer (next); + /* Propagate CONSTRUCTOR_PLACEHOLDER_BOUNDARY to outer CONSTRUCTOR. */ + if (TREE_CODE (next) == CONSTRUCTOR + && CONSTRUCTOR_PLACEHOLDER_BOUNDARY (next)) + { + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (init) = 1; + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (next) = 0; + } CONSTRUCTOR_APPEND_ELT (v, field, next); } @@ -1894,6 +1917,14 @@ process_init_constructor_union (tree type, tree init, int nested, int flags, ce->value = massage_init_elt (TREE_TYPE (ce->index), ce->value, nested, flags, complain); + /* Propagate CONSTRUCTOR_PLACEHOLDER_BOUNDARY to outer CONSTRUCTOR. */ + if (ce->value + && TREE_CODE (ce->value) == CONSTRUCTOR + && CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ce->value)) + { + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (init) = 1; + CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ce->value) = 0; + } return picflag_from_initializer (ce->value); } diff --git a/gcc/testsuite/g++.dg/cpp0x/pr105256.C b/gcc/testsuite/g++.dg/cpp0x/pr105256.C new file mode 100644 index 0000000..98ce5e8 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/pr105256.C @@ -0,0 +1,18 @@ +// PR c++/105256 +// { dg-do compile { target c++11 } } + +int bar (int &); + +struct S { + struct T { + struct U { + int i = bar (i); + } u; + }; +}; + +void +foo (S::T *p) +{ + *p = {}; +}; -- 2.7.4