* Re: [PATCH PING] unreviewed tree-slimming patches
2011-05-26 14:00 ` Jason Merrill
2011-05-26 14:34 ` Nathan Froyd
@ 2011-05-27 4:54 ` Nathan Froyd
2011-05-27 8:14 ` Jason Merrill
1 sibling, 1 reply; 12+ messages in thread
From: Nathan Froyd @ 2011-05-27 4:54 UTC (permalink / raw)
To: Jason Merrill; +Cc: gcc-patches
On Thu, May 26, 2011 at 09:39:30AM -0400, Jason Merrill wrote:
> On 05/25/2011 10:21 PM, Nathan Froyd wrote:
> >An alternative solution would be to initialize cur_stmt_list somewhere with an
> >actual 1-element VEC;
>
> Or just push NULL onto the stack and let append_to_statement_list_1
> allocate the VEC?
>
> >the check in add_stmt would then be unnecessary, as we'd
> >always be assured of having someplace in the stack to store it. I don't trust
> >myself to write a patch like that tonight; I'll twiddle with that tomorrow.
>
> Right, that's what I was thinking about. I think we should only
> need to do this once per function.
Sigh, I am an idiot. It appears that we always have something pushed by
the time add_stmt is called. (I ran into problems implementing the
above approach, as I wound up with [ NULL_TREE, <tree> ] and that gave
pop_stmt heartburn.) I can't recall why I added the check in the first
place; it might have been because I ran into problems in the C FE and
blindly assumed I needed the same fix in the C++ FE.
Below is a revised patch with the dubious code taken out of add_stmt and
an assert added. Bootstrap/testing in progress on
x86_64-unknown-linux-gnu, but we've built libstdc++ a couple of times,
so I don't anticipate any surprises. OK to commit?
-Nathan
gcc/
* c-decl.c (c_push_function_context): Copy the current statement
list stack.
(add_stmt): Check building_stmt_list_p and push_stmt if necessary.
(finish_struct): Call building_stmt_list_p instead of checking
cur_stmt_list.
* c-parser.c (c_parser_postfix_expression): Likewise.
* c-typeck.c (c_end_compound_stmt): Likewise.
* print-tree.c (print_node) [STATEMENT_LIST]: Don't print TREE_CHAIN.
* tree-iterator.c (stmt_list_cache): Change to a VEC.
(alloc_stmt_list): Adjust for stmt_list_cache's new type.
(free_stmt_list): Likewise.
* tree.h (struct tree_statement_list): Include typed_tree instead
of tree_common.
* tree.c (initialize_tree_contains_struct): Mark TS_STATEMENT_LIST
as TS_TYPED instead of TS_COMMON.
gcc/c-family/
* c-common.h (struct stmt_tree_s) [x_cur_stmt_list]: Change to a VEC.
(stmt_list_stack): Define.
(cur_stmt_list): Adjust for new type of x_cur_stmt_list.
* c-semantics.c (push_stmt_list, pop_stmt_list): Likewise.
gcc/cp/
* cp-tree.h (building_stmt_tree): Delete.
* decl.c (save_function_data): Tweak initializer for x_cur_stmt_list.
(build_aggr_init_full_exprs): Call building_stmt_list_p
instead of building_stmt_tree.
(initialize_local_var): Likewise.
(finish_function): Likewise.
* decl2.c (finish_anon_union): Likewise.
* init.c (begin_init_stmts): Likewise.
(finish_init_stmts): Likewise.
(expand_aggr_init_1): Likewise.
* name-lookup.c (do_local_using_decl): Likewise.
(do_namespace_alias): Likewise.
(do_using_directive): Likewise.
(cp_emit_debug_info_for_using): Likewise.
* semantics.c (add_stmt): Assert that stmt_list_stack is non-empty.
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index a7cc965..1d43126 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -552,6 +552,8 @@ add_stmt (tree t)
/* Add T to the statement-tree. Non-side-effect statements need to be
recorded during statement expressions. */
+ if (!building_stmt_list_p ())
+ push_stmt_list ();
append_to_statement_list_force (t, &cur_stmt_list);
return t;
@@ -7188,7 +7190,7 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
/* If we're inside a function proper, i.e. not file-scope and not still
parsing parameters, then arrange for the size of a variable sized type
to be bound now. */
- if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE))
+ if (building_stmt_list_p () && variably_modified_type_p (t, NULL_TREE))
add_stmt (build_stmt (loc,
DECL_EXPR, build_decl (loc, TYPE_DECL, NULL, t)));
@@ -8424,6 +8426,8 @@ c_push_function_context (void)
cfun->language = p;
p->base.x_stmt_tree = c_stmt_tree;
+ c_stmt_tree.x_cur_stmt_list
+ = VEC_copy (tree, gc, c_stmt_tree.x_cur_stmt_list);
p->x_break_label = c_break_label;
p->x_cont_label = c_cont_label;
p->x_switch_stack = c_switch_stack;
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 65f8ad1..1b658b1 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -452,8 +452,8 @@ typedef enum ref_operator {
/* Information about a statement tree. */
struct GTY(()) stmt_tree_s {
- /* The current statement list being collected. */
- tree x_cur_stmt_list;
+ /* A stack of statement lists being collected. */
+ VEC(tree,gc) *x_cur_stmt_list;
/* In C++, Nonzero if we should treat statements as full
expressions. In particular, this variable is no-zero if at the
@@ -483,11 +483,17 @@ struct GTY(()) c_language_function {
struct stmt_tree_s x_stmt_tree;
};
+#define stmt_list_stack (current_stmt_tree ()->x_cur_stmt_list)
+
/* When building a statement-tree, this is the current statement list
- being collected. It's TREE_CHAIN is a back-pointer to the previous
- statement list. */
+ being collected. We define it in this convoluted way, rather than
+ using VEC_last, because it must be an lvalue. */
+
+#define cur_stmt_list \
+ (*(VEC_address (tree, stmt_list_stack) \
+ + VEC_length (tree, stmt_list_stack) - 1))
-#define cur_stmt_list (current_stmt_tree ()->x_cur_stmt_list)
+#define building_stmt_list_p() (!VEC_empty (tree, stmt_list_stack))
/* Language-specific hooks. */
diff --git a/gcc/c-family/c-semantics.c b/gcc/c-family/c-semantics.c
index a5bd9ba..cb0f2be 100644
--- a/gcc/c-family/c-semantics.c
+++ b/gcc/c-family/c-semantics.c
@@ -38,8 +38,7 @@ push_stmt_list (void)
{
tree t;
t = alloc_stmt_list ();
- TREE_CHAIN (t) = cur_stmt_list;
- cur_stmt_list = t;
+ VEC_safe_push (tree, gc, stmt_list_stack, t);
return t;
}
@@ -48,21 +47,23 @@ push_stmt_list (void)
tree
pop_stmt_list (tree t)
{
- tree u = cur_stmt_list, chain;
+ tree u = NULL_TREE;
/* Pop statement lists until we reach the target level. The extra
nestings will be due to outstanding cleanups. */
while (1)
{
- chain = TREE_CHAIN (u);
- TREE_CHAIN (u) = NULL_TREE;
- if (chain)
- STATEMENT_LIST_HAS_LABEL (chain) |= STATEMENT_LIST_HAS_LABEL (u);
+ u = VEC_pop (tree, stmt_list_stack);
+ if (!VEC_empty (tree, stmt_list_stack))
+ {
+ tree x = VEC_last (tree, stmt_list_stack);
+ STATEMENT_LIST_HAS_LABEL (x) |= STATEMENT_LIST_HAS_LABEL (u);
+ }
if (t == u)
break;
- u = chain;
}
- cur_stmt_list = chain;
+
+ gcc_assert (u != NULL_TREE);
/* If the statement list is completely empty, just return it. This is
just as good small as build_empty_stmt, with the advantage that
diff --git a/gcc/c-parser.c b/gcc/c-parser.c
index cb70bed..65966a9 100644
--- a/gcc/c-parser.c
+++ b/gcc/c-parser.c
@@ -6126,7 +6126,7 @@ c_parser_postfix_expression (c_parser *parser)
c_parser_consume_token (parser);
brace_loc = c_parser_peek_token (parser)->location;
c_parser_consume_token (parser);
- if (cur_stmt_list == NULL)
+ if (!building_stmt_list_p ())
{
error_at (loc, "braced-group within expression allowed "
"only inside a function");
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index e609611..a451606 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -9293,7 +9293,7 @@ c_end_compound_stmt (location_t loc, tree stmt, bool do_scope)
do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
STATEMENT_LISTs merge, and thus we can lose track of what statement
was really last. */
- if (cur_stmt_list
+ if (building_stmt_list_p ()
&& STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
&& TREE_CODE (stmt) != BIND_EXPR)
{
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index ada01fb..6b0bd2b 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -293,10 +293,6 @@ typedef struct ptrmem_cst * ptrmem_cst_t;
#define same_type_p(TYPE1, TYPE2) \
comptypes ((TYPE1), (TYPE2), COMPARE_STRICT)
-/* Nonzero if we are presently building a statement tree, rather
- than expanding each statement as we encounter it. */
-#define building_stmt_tree() (cur_stmt_list != NULL_TREE)
-
/* Returns nonzero iff NODE is a declaration for the global function
`main'. */
#define DECL_MAIN_P(NODE) \
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index a956dbb..2ae937b 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5352,13 +5352,13 @@ build_aggr_init_full_exprs (tree decl, tree init, int flags)
{
int saved_stmts_are_full_exprs_p = 0;
- if (building_stmt_tree ())
+ if (building_stmt_list_p ())
{
saved_stmts_are_full_exprs_p = stmts_are_full_exprs_p ();
current_stmt_tree ()->stmts_are_full_exprs_p = 1;
}
init = build_aggr_init (decl, init, flags, tf_warning_or_error);
- if (building_stmt_tree ())
+ if (building_stmt_list_p ())
current_stmt_tree ()->stmts_are_full_exprs_p =
saved_stmts_are_full_exprs_p;
return init;
@@ -5751,7 +5751,7 @@ initialize_local_var (tree decl, tree init)
if (cleanup && TREE_CODE (type) != ARRAY_TYPE)
wrap_temporary_cleanups (init, cleanup);
- gcc_assert (building_stmt_tree ());
+ gcc_assert (building_stmt_list_p ());
saved_stmts_are_full_exprs_p = stmts_are_full_exprs_p ();
current_stmt_tree ()->stmts_are_full_exprs_p = 1;
finish_expr_stmt (init);
@@ -12918,7 +12918,7 @@ save_function_data (tree decl)
DECL_SAVED_FUNCTION_DATA (decl) = f;
/* Clear out the bits we don't need. */
- f->base.x_stmt_tree.x_cur_stmt_list = NULL_TREE;
+ f->base.x_stmt_tree.x_cur_stmt_list = NULL;
f->bindings = NULL;
f->x_local_names = NULL;
}
@@ -13163,7 +13163,7 @@ finish_function (int flags)
This caused &foo to be of type ptr-to-const-function
which then got a warning when stored in a ptr-to-function variable. */
- gcc_assert (building_stmt_tree ());
+ gcc_assert (building_stmt_list_p ());
/* The current function is being defined, so its DECL_INITIAL should
be set, and unless there's a multiple definition, it should be
error_mark_node. */
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 91a6644..9005f7e 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -1437,7 +1437,7 @@ finish_anon_union (tree anon_union_decl)
}
pushdecl (anon_union_decl);
- if (building_stmt_tree ()
+ if (building_stmt_list_p ()
&& at_function_scope_p ())
add_decl_expr (anon_union_decl);
else if (!processing_template_decl)
diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index 6336dd7..d92dacc 100644
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -61,7 +61,7 @@ static int diagnose_uninitialized_cst_or_ref_member_1 (tree, tree, bool, bool);
static bool
begin_init_stmts (tree *stmt_expr_p, tree *compound_stmt_p)
{
- bool is_global = !building_stmt_tree ();
+ bool is_global = !building_stmt_list_p ();
*stmt_expr_p = begin_stmt_expr ();
*compound_stmt_p = begin_compound_stmt (BCS_NO_SCOPE);
@@ -79,7 +79,7 @@ finish_init_stmts (bool is_global, tree stmt_expr, tree compound_stmt)
stmt_expr = finish_stmt_expr (stmt_expr, true);
- gcc_assert (!building_stmt_tree () == is_global);
+ gcc_assert (!building_stmt_list_p () == is_global);
return stmt_expr;
}
@@ -1552,7 +1552,7 @@ expand_aggr_init_1 (tree binfo, tree true_exp, tree exp, tree init, int flags,
tree type = TREE_TYPE (exp);
gcc_assert (init != error_mark_node && type != error_mark_node);
- gcc_assert (building_stmt_tree ());
+ gcc_assert (building_stmt_list_p ());
/* Use a function returning the desired type to initialize EXP for us.
If the function is a constructor, and its first argument is
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 3d07ff6..0e762fd 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -2475,7 +2475,7 @@ do_local_using_decl (tree decl, tree scope, tree name)
if (decl == NULL_TREE)
return;
- if (building_stmt_tree ()
+ if (building_stmt_list_p ()
&& at_function_scope_p ())
add_decl_expr (decl);
@@ -3570,7 +3570,7 @@ do_namespace_alias (tree alias, tree name_space)
pushdecl (alias);
/* Emit debug info for namespace alias. */
- if (!building_stmt_tree ())
+ if (!building_stmt_list_p ())
(*debug_hooks->global_decl) (alias);
}
@@ -3718,7 +3718,7 @@ do_using_directive (tree name_space)
gcc_assert (TREE_CODE (name_space) == NAMESPACE_DECL);
- if (building_stmt_tree ())
+ if (building_stmt_list_p ())
add_stmt (build_stmt (input_location, USING_STMT, name_space));
name_space = ORIGINAL_NAMESPACE (name_space);
@@ -5890,7 +5890,7 @@ cp_emit_debug_info_for_using (tree t, tree context)
for (t = OVL_CURRENT (t); t; t = OVL_NEXT (t))
if (TREE_CODE (t) != TEMPLATE_DECL)
{
- if (building_stmt_tree ())
+ if (building_stmt_list_p ())
add_stmt (build_stmt (input_location, USING_STMT, t));
else
(*debug_hooks->imported_module_or_decl) (t, NULL_TREE, context, false);
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 7833d76..557bf4c 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -393,6 +393,7 @@ add_stmt (tree t)
/* Add T to the statement-tree. Non-side-effect statements need to be
recorded during statement expressions. */
+ gcc_checking_assert (!VEC_empty (tree, stmt_list_stack));
append_to_statement_list_force (t, &cur_stmt_list);
return t;
diff --git a/gcc/print-tree.c b/gcc/print-tree.c
index 58c9613..1a1e33f 100644
--- a/gcc/print-tree.c
+++ b/gcc/print-tree.c
@@ -911,7 +911,6 @@ print_node (FILE *file, const char *prefix, tree node, int indent)
print_node (file, "stmt", tsi_stmt (i), indent + 4);
}
}
- print_node (file, "chain", TREE_CHAIN (node), indent + 4);
break;
case BLOCK:
diff --git a/gcc/tree-iterator.c b/gcc/tree-iterator.c
index 05764da..44b6bed 100644
--- a/gcc/tree-iterator.c
+++ b/gcc/tree-iterator.c
@@ -31,17 +31,16 @@ along with GCC; see the file COPYING3. If not see
/* This is a cache of STATEMENT_LIST nodes. We create and destroy them
fairly often during gimplification. */
-static GTY ((deletable (""))) tree stmt_list_cache;
+static GTY ((deletable (""))) VEC(tree,gc) *stmt_list_cache;
tree
alloc_stmt_list (void)
{
- tree list = stmt_list_cache;
- if (list)
+ tree list;
+ if (!VEC_empty (tree, stmt_list_cache))
{
- stmt_list_cache = TREE_CHAIN (list);
- gcc_assert (stmt_list_cache != list);
- memset (list, 0, sizeof(struct tree_common));
+ list = VEC_pop (tree, stmt_list_cache);
+ memset (list, 0, sizeof(struct tree_base));
TREE_SET_CODE (list, STATEMENT_LIST);
}
else
@@ -55,11 +54,7 @@ free_stmt_list (tree t)
{
gcc_assert (!STATEMENT_LIST_HEAD (t));
gcc_assert (!STATEMENT_LIST_TAIL (t));
- /* If this triggers, it's a sign that the same list is being freed
- twice. */
- gcc_assert (t != stmt_list_cache || stmt_list_cache == NULL);
- TREE_CHAIN (t) = stmt_list_cache;
- stmt_list_cache = t;
+ VEC_safe_push (tree, gc, stmt_list_cache, t);
}
/* A subroutine of append_to_statement_list{,_force}. T is not NULL. */
diff --git a/gcc/tree.c b/gcc/tree.c
index 178873c..85c0516 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -383,6 +383,7 @@ initialize_tree_contains_struct (void)
case TS_CONSTRUCTOR:
case TS_EXP:
case TS_IDENTIFIER:
+ case TS_STATEMENT_LIST:
MARK_TS_TYPED (code);
break;
@@ -391,7 +392,6 @@ initialize_tree_contains_struct (void)
case TS_LIST:
case TS_VEC:
case TS_BINFO:
- case TS_STATEMENT_LIST:
case TS_OMP_CLAUSE:
case TS_OPTIMIZATION:
case TS_TARGET_OPTION:
diff --git a/gcc/tree.h b/gcc/tree.h
index e214b12..f63764a 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3556,7 +3556,7 @@ struct GTY ((chain_next ("%h.next"), chain_prev ("%h.prev"))) tree_statement_lis
struct GTY(()) tree_statement_list
{
- struct tree_common common;
+ struct tree_typed typed;
struct tree_statement_list_node *head;
struct tree_statement_list_node *tail;
};
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