From 77b4604223e6e40ad6f6918a7cd63380fcc931ce Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Tue, 31 Jul 2018 15:37:11 +0000 Subject: [PATCH] [c++] Fix DECL_BY_REFERENCE of clone parms Consider test.C compiled at -O0 -g: ... class string { public: string (const char *p) { this->p = p ; } string (const string &s) { this->p = s.p; } private: const char *p; }; class foo { public: foo (string dir_hint) {} }; int main (void) { std::string s = "This is just a string"; foo bar(s); return 0; } ... When parsing foo::foo, the dir_hint parameter gets a DECL_ARG_TYPE of 'struct string & restrict'. Then during finish_struct, we call clone_constructors_and_destructors and create clones for foo::foo, and set the DECL_ARG_TYPE in the same way. Later on, during finish_function, cp_genericize is called for the original foo::foo, which sets the type of parm dir_hint to DECL_ARG_TYPE, and sets DECL_BY_REFERENCE of dir_hint to 1. After that, during maybe_clone_body update_cloned_parm is called with: ... (gdb) call debug_generic_expr (parm.typed.type) struct string & restrict (gdb) call debug_generic_expr (cloned_parm.typed.type) struct string ... The type of the cloned_parm is then set to the type of parm, but DECL_BY_REFERENCE is not set. When doing cp_genericize for the clone later on, TREE_ADDRESSABLE (TREE_TYPE ()) is no longer true for the updated type for the parm, so DECL_BY_REFERENCE is not set there either. The missing DECL_BY_REFERENCE on cloned_parm causes incorrect debug info to be generated. This patch fixes the problem by copying DECL_BY_REFERENCE in update_cloned_parm. Bootstrapped and reg-tested on x86_64. 2018-07-31 Tom de Vries PR debug/86687 * optimize.c (update_cloned_parm): Copy DECL_BY_REFERENCE. * g++.dg/guality/pr86687.C: New test. From-SVN: r263164 --- gcc/cp/ChangeLog | 5 +++++ gcc/cp/optimize.c | 2 ++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/guality/pr86687.C | 28 ++++++++++++++++++++++++++ 4 files changed, 40 insertions(+) create mode 100644 gcc/testsuite/g++.dg/guality/pr86687.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index bf6ce9761ac..503d8b4a433 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,8 @@ +2018-07-31 Tom de Vries + + PR debug/86687 + * optimize.c (update_cloned_parm): Copy DECL_BY_REFERENCE. + 2018-07-31 Jakub Jelinek P1008R1 - prohibit aggregates with user-declared constructors diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c index 0e9b84ed8a4..3923a5fc6c4 100644 --- a/gcc/cp/optimize.c +++ b/gcc/cp/optimize.c @@ -46,6 +46,8 @@ update_cloned_parm (tree parm, tree cloned_parm, bool first) /* We may have taken its address. */ TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm); + DECL_BY_REFERENCE (cloned_parm) = DECL_BY_REFERENCE (parm); + /* The definition might have different constness. */ TREE_READONLY (cloned_parm) = TREE_READONLY (parm); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 90fb9c19a40..2cc69735ff5 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2018-07-31 Tom de Vries + + PR debug/86687 + * g++.dg/guality/pr86687.C: New test. + 2018-07-31 Jakub Jelinek P1008R1 - prohibit aggregates with user-declared constructors diff --git a/gcc/testsuite/g++.dg/guality/pr86687.C b/gcc/testsuite/g++.dg/guality/pr86687.C new file mode 100644 index 00000000000..140a6fce596 --- /dev/null +++ b/gcc/testsuite/g++.dg/guality/pr86687.C @@ -0,0 +1,28 @@ +// PR debug/86687 +// { dg-do run } +// { dg-options "-g" } + +class string { +public: + string (int p) { this->p = p ; } + string (const string &s) { this->p = s.p; } + + int p; +}; + +class foo { +public: + foo (string dir_hint) { + p = dir_hint.p; // { dg-final { gdb-test . "dir_hint.p" 3 } } + } + + int p; +}; + +int +main (void) +{ + string s = 3; + foo bar(s); + return !(bar.p == 3); +} -- 2.30.2