From fc72d1ed3c8b11437981487755a7d6edfaf06d22 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Wed, 16 Nov 2016 16:30:41 -0500 Subject: [PATCH] Fix tuple decomposition decltype. * decl.c (store_decomp_type, lookup_decomp_type): New. (cp_finish_decomp): Call store_decomp_type. * semantics.c (finish_decltype_type): Call lookup_decomp_type. * cp-tree.h: Declare lookup_decomp_type. From-SVN: r242513 --- gcc/cp/ChangeLog | 7 +++++++ gcc/cp/cp-tree.h | 1 + gcc/cp/decl.c | 18 ++++++++++++++++++ gcc/cp/semantics.c | 2 +- gcc/testsuite/g++.dg/cpp1z/decomp17.C | 15 +++++++++++++++ gcc/tree.h | 3 +-- 6 files changed, 43 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp17.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 0bcb730cb1c..fdbd1536002 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,10 @@ +2016-11-16 Jason Merrill + + * decl.c (store_decomp_type, lookup_decomp_type): New. + (cp_finish_decomp): Call store_decomp_type. + * semantics.c (finish_decltype_type): Call lookup_decomp_type. + * cp-tree.h: Declare lookup_decomp_type. + 2016-11-15 Jakub Jelinek * decl.c (cp_finish_decomp): For DECL_NAMESPACE_SCOPE_P decl, diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 0dcb8971edd..cb1b9faef0e 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -5808,6 +5808,7 @@ extern tree start_decl (const cp_declarator *, cp_decl_specifier_seq *, int, extern void start_decl_1 (tree, bool); extern bool check_array_initializer (tree, tree, tree); extern void cp_finish_decl (tree, tree, bool, tree, int); +extern tree lookup_decomp_type (tree); extern void cp_finish_decomp (tree, tree, unsigned int); extern int cp_complete_array_type (tree *, tree, bool); extern int cp_complete_array_type_or_error (tree *, tree, bool, tsubst_flags_t); diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 23ba087a86f..c54a2de0af6 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -7293,6 +7293,22 @@ get_tuple_decomp_init (tree decl, unsigned i) } } +/* It's impossible to recover the decltype of a tuple decomposition variable + based on the actual type of the variable, so store it in a hash table. */ +static GTY(()) hash_map *decomp_type_table; +static void +store_decomp_type (tree v, tree t) +{ + if (!decomp_type_table) + decomp_type_table = hash_map::create_ggc (13); + decomp_type_table->put (v, t); +} +tree +lookup_decomp_type (tree v) +{ + return *decomp_type_table->get (v); +} + /* Finish a decomposition declaration. DECL is the underlying declaration "e", FIRST is the head of a chain of decls for the individual identifiers chained through DECL_CHAIN in reverse order and COUNT is the number of @@ -7467,6 +7483,8 @@ cp_finish_decomp (tree decl, tree first, unsigned int count) v[i]); goto error_out; } + /* Save the decltype away before reference collapse. */ + store_decomp_type (v[i], eltype); eltype = cp_build_reference_type (eltype, !lvalue_p (init)); TREE_TYPE (v[i]) = eltype; layout_decl (v[i], 0); diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c index dc5ad13f681..96c67a59a00 100644 --- a/gcc/cp/semantics.c +++ b/gcc/cp/semantics.c @@ -8902,7 +8902,7 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p, return unlowered_expr_type (expr); else /* Expr is a reference variable for the tuple case. */ - return non_reference (TREE_TYPE (expr)); + return lookup_decomp_type (expr); } switch (TREE_CODE (expr)) diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp17.C b/gcc/testsuite/g++.dg/cpp1z/decomp17.C new file mode 100644 index 00000000000..484094b6c58 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/decomp17.C @@ -0,0 +1,15 @@ +// { dg-options -std=c++1z } + +#include + +template struct same_type; +template struct same_type {}; + +int main() { + int i; + std::tuple tuple = { 1, i, 1 }; + auto &[v, r, rr] = tuple; + same_type{}; + same_type{}; + same_type{}; +} diff --git a/gcc/tree.h b/gcc/tree.h index 6a98b6ee0b6..0a82a4aceb8 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -2457,8 +2457,7 @@ extern void decl_value_expr_insert (tree, tree); /* In a VAR_DECL or PARM_DECL, the location at which the value may be found, if transformations have made this more complicated than evaluating the - decl itself. This should only be used for debugging; once this field has - been set, the decl itself may not legitimately appear in the function. */ + decl itself. */ #define DECL_HAS_VALUE_EXPR_P(NODE) \ (TREE_CHECK3 (NODE, VAR_DECL, PARM_DECL, RESULT_DECL) \ ->decl_common.decl_flag_2) -- 2.30.2