From 06381d0ac641d7644c90f75fddebc151acaed8c2 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Mon, 5 Mar 2018 09:28:15 -0500 Subject: [PATCH] PR c++/84686 - missing volatile loads. * cvt.c (convert_to_void): Call maybe_undo_parenthesized_ref. From-SVN: r258246 --- gcc/cp/ChangeLog | 5 +++++ gcc/cp/cvt.c | 2 ++ gcc/testsuite/g++.dg/tree-ssa/volatile2.C | 20 ++++++++++++++++++++ 3 files changed, 27 insertions(+) create mode 100644 gcc/testsuite/g++.dg/tree-ssa/volatile2.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index ab5a911f44ff..763a6947ec25 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,8 @@ +2018-03-03 Jason Merrill + + PR c++/84686 - missing volatile loads. + * cvt.c (convert_to_void): Call maybe_undo_parenthesized_ref. + 2018-03-02 Jason Merrill PR c++/84489 - dependent default template argument diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c index 0d1048cd7fe4..43fcff9854ea 100644 --- a/gcc/cp/cvt.c +++ b/gcc/cp/cvt.c @@ -932,6 +932,8 @@ convert_to_void (tree expr, impl_conv_void implicit, tsubst_flags_t complain) || TREE_TYPE (expr) == error_mark_node) return error_mark_node; + expr = maybe_undo_parenthesized_ref (expr); + if (implicit == ICV_CAST) mark_exp_read (expr); else diff --git a/gcc/testsuite/g++.dg/tree-ssa/volatile2.C b/gcc/testsuite/g++.dg/tree-ssa/volatile2.C new file mode 100644 index 000000000000..bec604424776 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/volatile2.C @@ -0,0 +1,20 @@ +// PR c++/84686 +// { dg-additional-options -fdump-tree-gimple } +// { dg-final { scan-tree-dump-times "= i" 10 "gimple" } } + +volatile int i; + +int main() +{ + i; //evaluated (a load is performed) + (i); //unevaluated => the load shall be performed + + (void)i; //evaluated (a load is performed) + (void)(i); //unevaluated => the load shall be performed + + (void)i; //evaluated (a load is performed) + (void)(i); //unevaluated => the load shall be performed + + (i,i); // the two subexpression are evaluated + ((i),(i)); // no evaluation, => two loads shall happen +} -- 2.47.2