On Fri, Apr 03, 2020 at 03:02:58PM -0400, Jason Merrill via Gcc-patches wrote:
> > Or do we want a further wrapper, perhaps C++ FE only, that would do this
> > protected_set_expr_location_if_unset (stmt, locus)?
>
> That sounds good to me.
So like this if it passes bootstrap/regtest?
2020-04-03 Jakub Jelinek <ja...@redhat.com>
PR debug/94441
* tree-iterator.h (expr_single): Declare.
* tree-iterator.c (expr_single): New function.
* tree.h (protected_set_expr_location_if_unset): Declare.
* tree.c (protected_set_expr_location): Use expr_single.
(protected_set_expr_location_if_unset): New function.
* parser.c (cp_parser_omp_for_loop): Use
protected_set_expr_location_if_unset.
* cp-gimplify.c (genericize_if_stmt, genericize_cp_loop): Likewise.
* g++.dg/opt/pr94441.C: New test.
--- gcc/tree-iterator.h.jj 2020-04-02 12:53:41.556232418 +0200
+++ gcc/tree-iterator.h 2020-04-03 21:07:01.335933695 +0200
@@ -119,5 +119,6 @@ extern void append_to_statement_list (tr
extern void append_to_statement_list_force (tree, tree *);
extern tree expr_first (tree);
extern tree expr_last (tree);
+extern tree expr_single (tree);
#endif /* GCC_TREE_ITERATOR_H */
--- gcc/tree-iterator.c.jj 2020-04-02 12:53:41.555232434 +0200
+++ gcc/tree-iterator.c 2020-04-03 21:07:01.335933695 +0200
@@ -354,4 +354,45 @@ expr_last (tree expr)
return expr;
}
+/* If EXPR is a STATEMENT_LIST containing just DEBUG_BEGIN_STMTs and
+ a single other stmt, return that other stmt (recursively).
+ If it is a STATEMENT_LIST containing no non-DEBUG_BEGIN_STMTs or
+ multiple, return NULL_TREE.
+ Otherwise return EXPR. */
+
+tree
+expr_single (tree expr)
+{
+ if (expr == NULL_TREE)
+ return expr;
+
+ if (TREE_CODE (expr) == STATEMENT_LIST)
+ {
+ /* With -gstatement-frontiers we could have a STATEMENT_LIST with
+ DEBUG_BEGIN_STMT(s) and only a single other stmt, which with
+ -g wouldn't be present and we'd have that single other stmt
+ directly instead. */
+ struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr);
+ if (!n)
+ return NULL_TREE;
+ while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT)
+ {
+ n = n->next;
+ if (!n)
+ return NULL_TREE;
+ }
+ expr = n->stmt;
+ do
+ {
+ n = n->next;
+ if (!n)
+ return expr_single (expr);
+ }
+ while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT);
+ return NULL_TREE;
+ }
+
+ return expr;
+}
+
#include "gt-tree-iterator.h"
--- gcc/tree.h.jj 2020-01-31 19:18:02.643900799 +0100
+++ gcc/tree.h 2020-04-03 21:09:26.134805791 +0200
@@ -1203,6 +1203,7 @@ get_expr_source_range (tree expr)
}
extern void protected_set_expr_location (tree, location_t);
+extern void protected_set_expr_location_if_unset (tree, location_t);
extern tree maybe_wrap_with_location (tree, location_t);
--- gcc/tree.c.jj 2020-04-03 15:41:34.442645256 +0200
+++ gcc/tree.c 2020-04-03 21:08:57.422227740 +0200
@@ -5148,33 +5148,23 @@ protected_set_expr_location (tree t, loc
SET_EXPR_LOCATION (t, loc);
else if (t && TREE_CODE (t) == STATEMENT_LIST)
{
- /* With -gstatement-frontiers we could have a STATEMENT_LIST with
- DEBUG_BEGIN_STMT(s) and only a single other stmt, which with
- -g wouldn't be present and we'd have that single other stmt
- directly instead. */
- struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (t);
- if (!n)
- return;
- while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT)
- {
- n = n->next;
- if (!n)
- return;
- }
- tree t2 = n->stmt;
- do
- {
- n = n->next;
- if (!n)
- {
- protected_set_expr_location (t2, loc);
- return;
- }
- }
- while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT);
+ t = expr_single (t);
+ if (t && CAN_HAVE_LOCATION_P (t))
+ SET_EXPR_LOCATION (t, loc);
}
}
+/* Like PROTECTED_SET_EXPR_LOCATION, but only do that if T has
+ UNKNOWN_LOCATION. */
+
+void
+protected_set_expr_location_if_unset (tree t, location_t loc)
+{
+ t = expr_single (t);
+ if (t && !EXPR_HAS_LOCATION (t))
+ protected_set_expr_location (t, loc);
+}
+
/* Data used when collecting DECLs and TYPEs for language data removal. */
class free_lang_data_d
--- gcc/cp/parser.c.jj 2020-04-02 12:53:41.542232631 +0200
+++ gcc/cp/parser.c 2020-04-03 21:11:39.675843324 +0200
@@ -39149,8 +39149,7 @@ cp_parser_omp_for_loop (cp_parser *parse
incr = cp_parser_omp_for_incr (parser, real_decl);
else
incr = cp_parser_expression (parser);
- if (!EXPR_HAS_LOCATION (incr))
- protected_set_expr_location (incr, input_location);
+ protected_set_expr_location_if_unset (incr, input_location);
}
parse_close_paren:
--- gcc/cp/cp-gimplify.c.jj 2020-04-02 12:53:41.530232814 +0200
+++ gcc/cp/cp-gimplify.c 2020-04-03 21:10:51.707548245 +0200
@@ -226,8 +226,7 @@ genericize_if_stmt (tree *stmt_p)
stmt = else_;
else
stmt = build3 (COND_EXPR, void_type_node, cond, then_, else_);
- if (!EXPR_HAS_LOCATION (stmt))
- protected_set_expr_location (stmt, locus);
+ protected_set_expr_location_if_unset (stmt, locus);
*stmt_p = stmt;
}
@@ -248,8 +247,7 @@ genericize_cp_loop (tree *stmt_p, locati
tree stmt_list = NULL;
tree debug_begin = NULL;
- if (EXPR_LOCATION (incr) == UNKNOWN_LOCATION)
- protected_set_expr_location (incr, start_locus);
+ protected_set_expr_location_if_unset (incr, start_locus);
cp_walk_tree (&cond, cp_genericize_r, data, NULL);
cp_walk_tree (&incr, cp_genericize_r, data, NULL);
--- gcc/testsuite/g++.dg/opt/pr94441.C.jj 2020-04-03 21:07:01.346933532
+0200
+++ gcc/testsuite/g++.dg/opt/pr94441.C 2020-04-03 21:07:01.346933532 +0200
@@ -0,0 +1,16 @@
+// PR debug/94441
+// { dg-do compile }
+// { dg-options "-O3 -fno-forward-propagate --param=max-cse-insns=0
-flive-range-shrinkage -std=c++17 -fcompare-debug" }
+
+template <class,class> struct Same;
+template <class T> struct Same<T,T> {};
+
+auto f()
+{
+ if constexpr (sizeof(int)==3)
+ return 42;
+ else
+ return 42L;
+}
+
+Same<decltype(f()), long> s;
Jakub
