This adds a flag to CONSTRUCTOR nodes indicating that for
clobbers this marks the end-of-life of storage as opposed to
just ending the lifetime of the object that occupied it.
The dangling pointer diagnostics uses CLOBBERs but is confused
by those emitted by the C++ frontend for example which emits
them for the second purpose at the start of CTORs. The issue
is also appearant for aarch64 in PR104092.
Distinguishing the two cases is also necessary for the PR90348 fix.
Since I'm going to add another flag I added an enum clobber_flags
and a defaulted argument to build_clobber plus a convenient way to
query the enum from the CTOR tree and specify it for gimple_clobber_p.
Since 'CLOBBER' is already taken and I needed a name for the unspecified
clobber we have now I used 'CLOBBER_UNDEF'.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
I'll push tomorrow if there are no further comments based on Jeffs
earlier OK.
Richard.
2022-02-03 Richard Biener <rguent...@suse.de>
PR middle-end/90348
PR middle-end/104092
gcc/
* tree-core.h (clobber_kind): New enum.
(tree_base::u::bits::address_space): Document use in CONSTRUCTORs.
* tree.h (CLOBBER_KIND): Add.
(build_clobber): Add clobber kind argument, defaulted to
CLOBBER_UNDEF.
* gimple.h (gimple_clobber_p): New overload with specified kind.
* tree-streamer-in.cc (streamer_read_tree_bitfields): Stream
CLOBBER_KIND.
* tree-streamer-out.cc (streamer_write_tree_bitfields):
Likewise.
* tree-pretty-print.cc (dump_generic_node): Mark EOL CLOBBERs.
* gimplify.c (gimplify_bind_expr): Build storage end-of-life clobbers
with CLOBBER_EOL.
(gimplify_target_expr): Likewise.
* tree-inline.cc (expand_call_inline): Likewise.
* tree-ssa-ccp.cc (insert_clobber_before_stack_restore): Likewise.
* gimple-ssa-warn-access.cc (pass_waccess::check_stmt): Only treat
CLOBBER_EOL clobbers as ending lifetime of storage.
gcc/lto/
* lto-common.cc (compare_tree_sccs_1): Compare CLOBBER_KIND.
gcc/testsuite/
* gcc.dg/pr87052.c: Adjust.
---
gcc/gimple-ssa-warn-access.cc | 3 ++-
gcc/gimple.h | 9 +++++++++
gcc/gimplify.cc | 4 ++--
gcc/lto/lto-common.cc | 5 ++++-
gcc/testsuite/gcc.dg/pr87052.c | 2 +-
gcc/tree-core.h | 12 +++++++++++-
gcc/tree-inline.cc | 4 ++--
gcc/tree-pretty-print.cc | 6 +++++-
gcc/tree-ssa-ccp.cc | 2 +-
gcc/tree-streamer-in.cc | 2 ++
gcc/tree-streamer-out.cc | 5 ++++-
gcc/tree.cc | 3 ++-
gcc/tree.h | 6 +++++-
13 files changed, 50 insertions(+), 13 deletions(-)
diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc
index ad5e2f4458e..2559ad1506a 100644
--- a/gcc/gimple-ssa-warn-access.cc
+++ b/gcc/gimple-ssa-warn-access.cc
@@ -4330,7 +4330,8 @@ is_auto_decl (tree x)
void
pass_waccess::check_stmt (gimple *stmt)
{
- if (m_check_dangling_p && gimple_clobber_p (stmt))
+ if (m_check_dangling_p
+ && gimple_clobber_p (stmt, CLOBBER_EOL))
{
/* Ignore clobber statemts in blocks with exceptional edges. */
basic_block bb = gimple_bb (stmt);
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 441d29a109a..77a5a07e9b5 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -2939,6 +2939,15 @@ gimple_clobber_p (const gimple *s)
&& TREE_CLOBBER_P (gimple_assign_rhs1 (s));
}
+/* Return true if S is a clobber statement. */
+
+static inline bool
+gimple_clobber_p (const gimple *s, enum clobber_kind kind)
+{
+ return gimple_clobber_p (s)
+ && CLOBBER_KIND (gimple_assign_rhs1 (s)) == kind;
+}
+
/* Return true if GS is a GIMPLE_CALL. */
static inline bool
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index cd4b61362b4..875b115d02d 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -1475,7 +1475,7 @@ gimplify_bind_expr (tree *expr_p, gimple_seq *pre_p)
&& !is_gimple_reg (t)
&& flag_stack_reuse != SR_NONE)
{
- tree clobber = build_clobber (TREE_TYPE (t));
+ tree clobber = build_clobber (TREE_TYPE (t), CLOBBER_EOL);
gimple *clobber_stmt;
clobber_stmt = gimple_build_assign (t, clobber);
gimple_set_location (clobber_stmt, end_locus);
@@ -6981,7 +6981,7 @@ gimplify_target_expr (tree *expr_p, gimple_seq *pre_p,
gimple_seq *post_p)
{
if (flag_stack_reuse == SR_ALL)
{
- tree clobber = build_clobber (TREE_TYPE (temp));
+ tree clobber = build_clobber (TREE_TYPE (temp), CLOBBER_EOL);
clobber = build2 (MODIFY_EXPR, TREE_TYPE (temp), temp, clobber);
gimple_push_cleanup (temp, clobber, false, pre_p, true);
}
diff --git a/gcc/lto/lto-common.cc b/gcc/lto/lto-common.cc
index 11fde671162..ca28586a1e8 100644
--- a/gcc/lto/lto-common.cc
+++ b/gcc/lto/lto-common.cc
@@ -1309,7 +1309,10 @@ compare_tree_sccs_1 (tree t1, tree t2, tree **map)
return false;
if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
- compare_values (CONSTRUCTOR_NELTS);
+ {
+ compare_values (CLOBBER_KIND);
+ compare_values (CONSTRUCTOR_NELTS);
+ }
if (CODE_CONTAINS_STRUCT (code, TS_IDENTIFIER))
if (IDENTIFIER_LENGTH (t1) != IDENTIFIER_LENGTH (t2)
diff --git a/gcc/testsuite/gcc.dg/pr87052.c b/gcc/testsuite/gcc.dg/pr87052.c
index 2affc480f4e..18e092c4674 100644
--- a/gcc/testsuite/gcc.dg/pr87052.c
+++ b/gcc/testsuite/gcc.dg/pr87052.c
@@ -38,4 +38,4 @@ void test (void)
{ dg-final { scan-tree-dump-times "c = \"\";" 1 "gimple" } }
{ dg-final { scan-tree-dump-times "d = { *};" 1 "gimple" } }
{ dg-final { scan-tree-dump-times "e = " 1 "gimple" } }
- { dg-final { scan-tree-dump-times "e = {CLOBBER}" 1 "gimple" } } */
+ { dg-final { scan-tree-dump-times "e = {CLOBBER\\(eol\\)}" 1 "gimple" } }
*/
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index e83669f20d8..bf2efa61330 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -963,6 +963,15 @@ enum annot_expr_kind {
annot_expr_kind_last
};
+/* The kind of a TREE_CLOBBER_P CONSTRUCTOR node. */
+enum clobber_kind {
+ /* Unspecified, this clobber acts as a store of an undefined value. */
+ CLOBBER_UNDEF,
+ /* This clobber ends the lifetime of the storage. */
+ CLOBBER_EOL,
+ CLOBBER_LAST
+};
+
/*---------------------------------------------------------------------------
Type definitions
---------------------------------------------------------------------------*/
@@ -1055,7 +1064,8 @@ struct GTY(()) tree_base {
/* This field is only used with TREE_TYPE nodes; the only reason it is
present in tree_base instead of tree_type is to save space. The size
- of the field must be large enough to hold addr_space_t values. */
+ of the field must be large enough to hold addr_space_t values.
+ For CONSTRUCTOR nodes this holds the clobber_kind enum. */
unsigned address_space : 8;
} bits;
diff --git a/gcc/tree-inline.cc b/gcc/tree-inline.cc
index 497aa667eb9..ca66a8266b1 100644
--- a/gcc/tree-inline.cc
+++ b/gcc/tree-inline.cc
@@ -5138,7 +5138,7 @@ expand_call_inline (basic_block bb, gimple *stmt,
copy_body_data *id,
&& !is_gimple_reg (*varp)
&& !(id->debug_map && id->debug_map->get (p)))
{
- tree clobber = build_clobber (TREE_TYPE (*varp));
+ tree clobber = build_clobber (TREE_TYPE (*varp), CLOBBER_EOL);
gimple *clobber_stmt;
clobber_stmt = gimple_build_assign (*varp, clobber);
gimple_set_location (clobber_stmt, gimple_location (stmt));
@@ -5207,7 +5207,7 @@ expand_call_inline (basic_block bb, gimple *stmt,
copy_body_data *id,
&& !is_gimple_reg (id->retvar)
&& !stmt_ends_bb_p (stmt))
{
- tree clobber = build_clobber (TREE_TYPE (id->retvar));
+ tree clobber = build_clobber (TREE_TYPE (id->retvar), CLOBBER_EOL);
gimple *clobber_stmt;
clobber_stmt = gimple_build_assign (id->retvar, clobber);
gimple_set_location (clobber_stmt, gimple_location (old_stmt));
diff --git a/gcc/tree-pretty-print.cc b/gcc/tree-pretty-print.cc
index 6130c307e9a..666b7a70ea2 100644
--- a/gcc/tree-pretty-print.cc
+++ b/gcc/tree-pretty-print.cc
@@ -2500,7 +2500,11 @@ dump_generic_node (pretty_printer *pp, tree node, int
spc, dump_flags_t flags,
}
pp_left_brace (pp);
if (TREE_CLOBBER_P (node))
- pp_string (pp, "CLOBBER");
+ {
+ pp_string (pp, "CLOBBER");
+ if (CLOBBER_KIND (node) == CLOBBER_EOL)
+ pp_string (pp, "(eol)");
+ }
else if (TREE_CODE (TREE_TYPE (node)) == RECORD_TYPE
|| TREE_CODE (TREE_TYPE (node)) == UNION_TYPE)
is_struct_init = true;
diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc
index 48683f04d49..9164efe3037 100644
--- a/gcc/tree-ssa-ccp.cc
+++ b/gcc/tree-ssa-ccp.cc
@@ -2505,7 +2505,7 @@ insert_clobber_before_stack_restore (tree saved_val, tree
var,
FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val)
if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE))
{
- clobber = build_clobber (TREE_TYPE (var));
+ clobber = build_clobber (TREE_TYPE (var), CLOBBER_EOL);
clobber_stmt = gimple_build_assign (var, clobber);
i = gsi_for_stmt (stmt);
diff --git a/gcc/tree-streamer-in.cc b/gcc/tree-streamer-in.cc
index 65cdf125a70..a35a810f4d1 100644
--- a/gcc/tree-streamer-in.cc
+++ b/gcc/tree-streamer-in.cc
@@ -559,6 +559,8 @@ streamer_read_tree_bitfields (class lto_input_block *ib,
if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
{
+ CLOBBER_KIND (expr)
+ = bp_unpack_enum (&bp, clobber_kind, CLOBBER_LAST);
unsigned HOST_WIDE_INT length = bp_unpack_var_len_unsigned (&bp);
if (length > 0)
vec_safe_grow (CONSTRUCTOR_ELTS (expr), length, true);
diff --git a/gcc/tree-streamer-out.cc b/gcc/tree-streamer-out.cc
index 783b94dd094..d39dc158a46 100644
--- a/gcc/tree-streamer-out.cc
+++ b/gcc/tree-streamer-out.cc
@@ -504,7 +504,10 @@ streamer_write_tree_bitfields (struct output_block *ob,
tree expr)
cl_optimization_stream_out (ob, &bp, TREE_OPTIMIZATION (expr));
if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
- bp_pack_var_len_unsigned (&bp, CONSTRUCTOR_NELTS (expr));
+ {
+ bp_pack_enum (&bp, clobber_kind, CLOBBER_LAST, CLOBBER_KIND (expr));
+ bp_pack_var_len_unsigned (&bp, CONSTRUCTOR_NELTS (expr));
+ }
if (CODE_CONTAINS_STRUCT (code, TS_TARGET_OPTION)
/* Don't stream these when passing things to a different target. */
diff --git a/gcc/tree.cc b/gcc/tree.cc
index 7ce4f242751..dfcdf6822f1 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -2311,10 +2311,11 @@ build_constructor_va (tree type, int nelts, ...)
/* Return a node of type TYPE for which TREE_CLOBBER_P is true. */
tree
-build_clobber (tree type)
+build_clobber (tree type, enum clobber_kind kind)
{
tree clobber = build_constructor (type, NULL);
TREE_THIS_VOLATILE (clobber) = true;
+ CLOBBER_KIND (clobber) = kind;
return clobber;
}
diff --git a/gcc/tree.h b/gcc/tree.h
index e2157d66d6c..95334b077da 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1155,6 +1155,10 @@ extern void omp_clause_range_check_failed (const_tree,
const char *, int,
#define TREE_CLOBBER_P(NODE) \
(TREE_CODE (NODE) == CONSTRUCTOR && TREE_THIS_VOLATILE (NODE))
+/* Return the clobber_kind of a CLOBBER CONSTRUCTOR. */
+#define CLOBBER_KIND(NODE) \
+ (CONSTRUCTOR_CHECK (NODE)->base.u.bits.address_space)
+
/* Define fields and accessors for some nodes that represent expressions. */
/* Nonzero if NODE is an empty statement (NOP_EXPR <0>). */
@@ -4559,7 +4563,7 @@ extern tree build_constructor_single (tree, tree, tree);
extern tree build_constructor_from_list (tree, tree);
extern tree build_constructor_from_vec (tree, const vec<tree, va_gc> *);
extern tree build_constructor_va (tree, int, ...);
-extern tree build_clobber (tree);
+extern tree build_clobber (tree, enum clobber_kind = CLOBBER_UNDEF);
extern tree build_real_from_int_cst (tree, const_tree);
extern tree build_real_from_wide (tree, const wide_int_ref &, signop);
extern tree build_complex (tree, tree, tree);
--
2.34.1
