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C++ PATCH for c++/68464 (ICE with constexpr and delayed folding)
- From: Jason Merrill <jason at redhat dot com>
- To: gcc-patches List <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 7 Dec 2015 14:32:14 -0500
- Subject: C++ PATCH for c++/68464 (ICE with constexpr and delayed folding)
- Authentication-results: sourceware.org; auth=none
This testcase was failing because the NRV optimization changing VAR_DECL
to RESULT_DECL was confusing the constexpr code. Fixed by moving
delayed folding to below NRV modifications. I also needed to move the
pre-genericize plugin earlier so that folding doesn't break the
expression ranges plugin.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 95e8cb9f98c39a7e198ce95e0cb3ba1e57de959c
Author: Jason Merrill <jason@redhat.com>
Date: Mon Dec 7 13:26:33 2015 -0500
PR c++/68464
* cp-gimplify.c (cp_fold): Don't assume X has TREE_TYPE.
(cp_genericize): Don't do cp_fold_r here.
(cp_fold_function): New.
* cp-tree.h: Declare it.
* decl.c (finish_function): Call it and the pre-genericize plugin
before NRV processing.
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 177e271..373c9e1 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -991,6 +991,15 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data)
return NULL;
}
+/* Fold ALL the trees! FIXME we should be able to remove this, but
+ apparently that still causes optimization regressions. */
+
+void
+cp_fold_function (tree fndecl)
+{
+ cp_walk_tree (&DECL_SAVED_TREE (fndecl), cp_fold_r, NULL, NULL);
+}
+
/* Perform any pre-gimplification lowering of C++ front end trees to
GENERIC. */
@@ -1475,10 +1484,6 @@ cp_genericize (tree fndecl)
{
tree t;
- /* Fold ALL the trees! FIXME we should be able to remove this, but
- apparently that still causes optimization regressions. */
- cp_walk_tree (&DECL_SAVED_TREE (fndecl), cp_fold_r, NULL, NULL);
-
/* Fix up the types of parms passed by invisible reference. */
for (t = DECL_ARGUMENTS (fndecl); t; t = DECL_CHAIN (t))
if (TREE_ADDRESSABLE (TREE_TYPE (t)))
@@ -1936,11 +1941,11 @@ cp_fold (tree x)
location_t loc;
bool rval_ops = true;
- if (!x || error_operand_p (x))
+ if (!x || x == error_mark_node)
return x;
if (processing_template_decl
- || (EXPR_P (x) && !TREE_TYPE (x)))
+ || (EXPR_P (x) && (!TREE_TYPE (x) || TREE_TYPE (x) == error_mark_node)))
return x;
/* Don't bother to cache DECLs or constants. */
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 1b2563d..6190f4e 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6812,6 +6812,7 @@ extern tree cxx_omp_clause_dtor (tree, tree);
extern void cxx_omp_finish_clause (tree, gimple_seq *);
extern bool cxx_omp_privatize_by_reference (const_tree);
extern bool cxx_omp_disregard_value_expr (tree, bool);
+extern void cp_fold_function (tree);
extern tree cp_fully_fold (tree);
/* in name-lookup.c */
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 0af7bd4..62636c9 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -14580,6 +14580,14 @@ finish_function (int flags)
the NRV transformation. */
maybe_save_function_definition (fndecl);
+ /* Invoke the pre-genericize plugin before we start munging things. */
+ if (!processing_template_decl)
+ invoke_plugin_callbacks (PLUGIN_PRE_GENERICIZE, fndecl);
+
+ /* Perform delayed folding before NRV transformation. */
+ if (!processing_template_decl)
+ cp_fold_function (fndecl);
+
/* Set up the named return value optimization, if we can. Candidate
variables are selected in check_return_expr. */
if (current_function_return_value)
@@ -14686,7 +14694,6 @@ finish_function (int flags)
if (!processing_template_decl)
{
struct language_function *f = DECL_SAVED_FUNCTION_DATA (fndecl);
- invoke_plugin_callbacks (PLUGIN_PRE_GENERICIZE, fndecl);
cp_genericize (fndecl);
/* Clear out the bits we don't need. */
f->x_current_class_ptr = NULL;