Hi!
The following testcase ICEs starting with the r14-4229 PR111529
change which moved ANNOTATE_EXPR handling from tsubst_expr to
tsubst_copy_and_build.
ANNOTATE_EXPR is only allowed in the IL to wrap a loop condition,
and the loop condition of while/for loops can be a COMPOUND_EXPR
with DECL_EXPR in the first operand and the corresponding VAR_DECL
in the second, as created by finish_cond
else if (!empty_expr_stmt_p (cond))
expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), cond, expr);
Since then Patrick reworked the instantiation, so that we have now
tsubst_stmt and tsubst_expr and ANNOTATE_EXPR ended up in the latter,
while only tsubst_stmt can handle DECL_EXPR.
Now, the reason why the while/for loops with variable declaration
in the condition works in templates without the pragmas (i.e. without
ANNOTATE_EXPR) is that both the FOR_STMT and WHILE_STMT handling uses
RECUR aka tsubst_stmt in handling of the *_COND operand:
case FOR_STMT:
stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
RECUR (FOR_INIT_STMT (t));
finish_init_stmt (stmt);
tmp = RECUR (FOR_COND (t));
finish_for_cond (tmp, stmt, false, 0, false);
and
case WHILE_STMT:
stmt = begin_while_stmt ();
tmp = RECUR (WHILE_COND (t));
finish_while_stmt_cond (tmp, stmt, false, 0, false);
Therefore, it will handle DECL_EXPR embedded in COMPOUND_EXPR of the
{WHILE,FOR}_COND just fine.
But if that COMPOUND_EXPR with DECL_EXPR is wrapped with one or more
ANNOTATE_EXPRs, because ANNOTATE_EXPR is now done solely in tsubst_expr
and uses RECUR there (i.e. tsubst_expr), it will ICE on DECL_EXPR in there.
Here are 2 possible fixes for this.
The first one keeps ANNOTATE_EXPR handling in tsubst_expr but uses
tsubst_stmt for the first operand.
The second one moves ANNOTATE_EXPR handling to tsubst_stmt (and uses
tsubst_expr for the second/third operand (it could just RECUR too if you
prefer that)).
Yet another possibility could be to duplicate the ANNOTATE_EXPR handling
from tsubst_expr to tsubst_stmt, where both would just RECUR on its
operands, so if one arrives to ANNOTATE_EXPR from tsubst_stmt, it will
tsubst_stmt recursively, if from tsubst_expr (when?) then it would handle
it using tsubst_expr.
So far just lightly tested (but g++.dg/ext/unroll-4.C and the new test
both pass with both versions of the patch), what do you prefer? I'd like
to avoid testing too many variants...
2024-04-10 Jakub Jelinek <ja...@redhat.com>
PR c++/114409
* pt.cc (tsubst_expr) <case ANNOTATE_EXPR>: Use tsubst_stmt rather
than tsubst_expr aka RECUR on op1.
* g++.dg/ext/pr114409-2.C: New test.
--- gcc/cp/pt.cc.jj 2024-04-09 09:29:04.721521726 +0200
+++ gcc/cp/pt.cc 2024-04-10 14:38:43.591554947 +0200
@@ -21774,7 +21774,10 @@ tsubst_expr (tree t, tree args, tsubst_f
case ANNOTATE_EXPR:
{
- op1 = RECUR (TREE_OPERAND (t, 0));
+ /* ANNOTATE_EXPR should only appear in WHILE_COND, DO_COND or
+ FOR_COND expressions, which are tsubsted using tsubst_stmt
+ rather than tsubst_expr and can contain DECL_EXPRs. */
+ op1 = tsubst_stmt (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op2 = RECUR (TREE_OPERAND (t, 1));
tree op3 = RECUR (TREE_OPERAND (t, 2));
if (TREE_CODE (op2) == INTEGER_CST
--- gcc/testsuite/g++.dg/ext/pr114409-2.C.jj 2024-04-10 14:35:19.693300552
+0200
+++ gcc/testsuite/g++.dg/ext/pr114409-2.C 2024-04-10 14:35:13.513383766
+0200
@@ -0,0 +1,36 @@
+// PR c++/114409
+// { dg-do compile }
+// { dg-options "-O2" }
+
+template <typename T>
+T
+foo (T)
+{
+ static T t;
+ return 42 - ++t;
+}
+
+template <typename T>
+void
+bar (T x)
+{
+ #pragma GCC novector
+ while (T y = foo (x))
+ ++y;
+}
+
+template <typename T>
+void
+baz (T x)
+{
+ #pragma GCC novector
+ for (; T y = foo (x); )
+ ++y;
+}
+
+void
+qux ()
+{
+ bar (0);
+ baz (0);
+}
Jakub
2024-04-10 Jakub Jelinek <ja...@redhat.com>
PR c++/114409
* pt.cc (tsubst_expr) <case ANNOTATE_EXPR>: Move to ...
(tsubst_stmt) <case ANNOTATE_EXPR>: ... here. Use tsubst_expr
instead of RECUR for the last 2 arguments.
* g++.dg/ext/pr114409-2.C: New test.
--- gcc/cp/pt.cc.jj 2024-04-09 09:29:04.721521726 +0200
+++ gcc/cp/pt.cc 2024-04-10 14:45:25.527142692 +0200
@@ -19433,6 +19433,23 @@ tsubst_stmt (tree t, tree args, tsubst_f
case PREDICT_EXPR:
RETURN (add_stmt (copy_node (t)));
+ case ANNOTATE_EXPR:
+ {
+ /* Although ANNOTATE_EXPR is an expression, it can only appear in
+ WHILE_COND, DO_COND or FOR_COND expressions, which are tsubsted
+ using tsubst_stmt rather than tsubst_expr and can contain
+ DECL_EXPRs. */
+ tree op1 = RECUR (TREE_OPERAND (t, 0));
+ tree op2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl);
+ tree op3 = tsubst_expr (TREE_OPERAND (t, 2), args, complain, in_decl);
+ if (TREE_CODE (op2) == INTEGER_CST
+ && wi::to_widest (op2) == (int) annot_expr_unroll_kind)
+ op3 = cp_check_pragma_unroll (EXPR_LOCATION (TREE_OPERAND (t, 2)),
+ op3);
+ RETURN (build3_loc (EXPR_LOCATION (t), ANNOTATE_EXPR,
+ TREE_TYPE (op1), op1, op2, op3));
+ }
+
default:
gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
@@ -21772,19 +21789,6 @@ tsubst_expr (tree t, tree args, tsubst_f
RETURN (op);
}
- case ANNOTATE_EXPR:
- {
- op1 = RECUR (TREE_OPERAND (t, 0));
- tree op2 = RECUR (TREE_OPERAND (t, 1));
- tree op3 = RECUR (TREE_OPERAND (t, 2));
- if (TREE_CODE (op2) == INTEGER_CST
- && wi::to_widest (op2) == (int) annot_expr_unroll_kind)
- op3 = cp_check_pragma_unroll (EXPR_LOCATION (TREE_OPERAND (t, 2)),
- op3);
- RETURN (build3_loc (EXPR_LOCATION (t), ANNOTATE_EXPR,
- TREE_TYPE (op1), op1, op2, op3));
- }
-
default:
/* Handle Objective-C++ constructs, if appropriate. */
if (tree subst = objcp_tsubst_expr (t, args, complain, in_decl))
--- gcc/testsuite/g++.dg/ext/pr114409-2.C.jj 2024-04-10 14:35:19.693300552
+0200
+++ gcc/testsuite/g++.dg/ext/pr114409-2.C 2024-04-10 14:35:13.513383766
+0200
@@ -0,0 +1,36 @@
+// PR c++/114409
+// { dg-do compile }
+// { dg-options "-O2" }
+
+template <typename T>
+T
+foo (T)
+{
+ static T t;
+ return 42 - ++t;
+}
+
+template <typename T>
+void
+bar (T x)
+{
+ #pragma GCC novector
+ while (T y = foo (x))
+ ++y;
+}
+
+template <typename T>
+void
+baz (T x)
+{
+ #pragma GCC novector
+ for (; T y = foo (x); )
+ ++y;
+}
+
+void
+qux ()
+{
+ bar (0);
+ baz (0);
+}
