https://gcc.gnu.org/g:bb49b6e4f55891d0d8b596845118f40df6ae72a5
commit r15-945-gbb49b6e4f55891d0d8b596845118f40df6ae72a5
Author: Qing Zhao <qing.z...@oracle.com>
Date: Tue May 28 18:34:09 2024 +0000
Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
Including the following changes:
* The definition of the new internal function .ACCESS_WITH_SIZE
in internal-fn.def.
* C FE converts every reference to a FAM with a "counted_by" attribute
to a call to the internal function .ACCESS_WITH_SIZE.
(build_component_ref in c_typeck.cc)
This includes the case when the object is statically allocated and
initialized.
In order to make this working, the routine digest_init in c-typeck.cc
is updated to fold calls to .ACCESS_WITH_SIZE to its first argument
when require_constant is TRUE.
However, for the reference inside "offsetof", the "counted_by" attribute
is
ignored since it's not useful at all.
(c_parser_postfix_expression in c/c-parser.cc)
In addtion to "offsetof", for the reference inside operator "typeof" and
"alignof", we ignore counted_by attribute too.
When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE,
replace the call with its first argument.
* Convert every call to .ACCESS_WITH_SIZE to its first argument.
(expand_ACCESS_WITH_SIZE in internal-fn.cc)
* Provide the utility routines to check the call is .ACCESS_WITH_SIZE and
get the reference from the call to .ACCESS_WITH_SIZE.
(is_access_with_size_p and get_ref_from_access_with_size in tree.cc)
gcc/c/ChangeLog:
* c-parser.cc (c_parser_postfix_expression): Ignore the counted-by
attribute when build_component_ref inside offsetof operator.
* c-tree.h (build_component_ref): Add one more parameter.
* c-typeck.cc (build_counted_by_ref): New function.
(build_access_with_size_for_counted_by): New function.
(build_component_ref): Check the counted-by attribute and build
call to .ACCESS_WITH_SIZE.
(build_unary_op): When building ADDR_EXPR for
.ACCESS_WITH_SIZE, use its first argument.
(lvalue_p): Accept call to .ACCESS_WITH_SIZE.
(digest_init): Fold call to .ACCESS_WITH_SIZE to its first
argument when require_constant is TRUE.
gcc/ChangeLog:
* internal-fn.cc (expand_ACCESS_WITH_SIZE): New function.
* internal-fn.def (ACCESS_WITH_SIZE): New internal function.
* tree.cc (is_access_with_size_p): New function.
(get_ref_from_access_with_size): New function.
* tree.h (is_access_with_size_p): New prototype.
(get_ref_from_access_with_size): New prototype.
gcc/testsuite/ChangeLog:
* gcc.dg/flex-array-counted-by-2.c: New test.
Diff:
---
gcc/c/c-parser.cc | 10 +-
gcc/c/c-tree.h | 2 +-
gcc/c/c-typeck.cc | 142 ++++++++++++++++++++++++-
gcc/internal-fn.cc | 34 ++++++
gcc/internal-fn.def | 5 +
gcc/testsuite/gcc.dg/flex-array-counted-by-2.c | 112 +++++++++++++++++++
gcc/tree.cc | 22 ++++
gcc/tree.h | 8 ++
8 files changed, 328 insertions(+), 7 deletions(-)
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 00f8bf4376e..2d9e9c0969f 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -10848,9 +10848,12 @@ c_parser_postfix_expression (c_parser *parser)
if (c_parser_next_token_is (parser, CPP_NAME))
{
c_token *comp_tok = c_parser_peek_token (parser);
+ /* Ignore the counted_by attribute for reference inside
+ offsetof since the information is not useful at all. */
offsetof_ref
= build_component_ref (loc, offsetof_ref, comp_tok->value,
- comp_tok->location, UNKNOWN_LOCATION);
+ comp_tok->location, UNKNOWN_LOCATION,
+ false);
c_parser_consume_token (parser);
while (c_parser_next_token_is (parser, CPP_DOT)
|| c_parser_next_token_is (parser,
@@ -10877,11 +10880,14 @@ c_parser_postfix_expression (c_parser *parser)
break;
}
c_token *comp_tok = c_parser_peek_token (parser);
+ /* Ignore the counted_by attribute for reference inside
+ offsetof since the information is not useful. */
offsetof_ref
= build_component_ref (loc, offsetof_ref,
comp_tok->value,
comp_tok->location,
- UNKNOWN_LOCATION);
+ UNKNOWN_LOCATION,
+ false);
c_parser_consume_token (parser);
}
else
diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
index 531a7e8742e..56a33b8156c 100644
--- a/gcc/c/c-tree.h
+++ b/gcc/c/c-tree.h
@@ -779,7 +779,7 @@ extern void mark_exp_read (tree);
extern tree composite_type (tree, tree);
extern tree lookup_field (const_tree, tree);
extern tree build_component_ref (location_t, tree, tree, location_t,
- location_t);
+ location_t, bool = true);
extern tree build_array_ref (location_t, tree, tree);
extern tree build_omp_array_section (location_t, tree, tree, tree);
extern tree build_external_ref (location_t, tree, bool, tree *);
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 80ed59998b7..268c3ddbe14 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -2652,15 +2652,116 @@ should_suggest_deref_p (tree datum_type)
return false;
}
+/* For a SUBDATUM field of a structure or union DATUM, generate a REF to
+ the object that represents its counted_by per the attribute counted_by
+ attached to this field if it's a flexible array member field, otherwise
+ return NULL_TREE.
+ Set COUNTED_BY_TYPE to the TYPE of the counted_by field.
+ For example, if:
+
+ struct P {
+ int k;
+ int x[] __attribute__ ((counted_by (k)));
+ } *p;
+
+ for:
+ p->x
+
+ the ref to the object that represents its element count will be:
+
+ &(p->k)
+
+*/
+static tree
+build_counted_by_ref (tree datum, tree subdatum, tree *counted_by_type)
+{
+ tree type = TREE_TYPE (datum);
+ if (!c_flexible_array_member_type_p (TREE_TYPE (subdatum)))
+ return NULL_TREE;
+
+ tree attr_counted_by = lookup_attribute ("counted_by",
+ DECL_ATTRIBUTES (subdatum));
+ tree counted_by_ref = NULL_TREE;
+ *counted_by_type = NULL_TREE;
+ if (attr_counted_by)
+ {
+ tree field_id = TREE_VALUE (TREE_VALUE (attr_counted_by));
+ counted_by_ref
+ = build_component_ref (UNKNOWN_LOCATION,
+ datum, field_id,
+ UNKNOWN_LOCATION, UNKNOWN_LOCATION);
+ counted_by_ref = build_fold_addr_expr (counted_by_ref);
+
+ /* Get the TYPE of the counted_by field. */
+ tree counted_by_field = lookup_field (type, field_id);
+ gcc_assert (counted_by_field);
+
+ do
+ {
+ *counted_by_type = TREE_TYPE (TREE_VALUE (counted_by_field));
+ counted_by_field = TREE_CHAIN (counted_by_field);
+ }
+ while (counted_by_field);
+ }
+ return counted_by_ref;
+}
+
+/* Given a COMPONENT_REF REF with the location LOC, the corresponding
+ COUNTED_BY_REF, and the COUNTED_BY_TYPE, generate an INDIRECT_REF
+ to a call to the internal function .ACCESS_WITH_SIZE.
+
+ REF
+
+ to:
+
+ (*.ACCESS_WITH_SIZE (REF, COUNTED_BY_REF, 1, (TYPE_OF_SIZE)0, -1))
+
+ NOTE: The return type of this function is the POINTER type pointing
+ to the original flexible array type.
+ Then the type of the INDIRECT_REF is the original flexible array type.
+
+ The type of the first argument of this function is a POINTER type
+ to the original flexible array type.
+
+ The 4th argument of the call is a constant 0 with the TYPE of the
+ object pointed by COUNTED_BY_REF.
+
+ */
+static tree
+build_access_with_size_for_counted_by (location_t loc, tree ref,
+ tree counted_by_ref,
+ tree counted_by_type)
+{
+ gcc_assert (c_flexible_array_member_type_p (TREE_TYPE (ref)));
+ /* The result type of the call is a pointer to the flexible array type. */
+ tree result_type = build_pointer_type (TREE_TYPE (ref));
+
+ tree call
+ = build_call_expr_internal_loc (loc, IFN_ACCESS_WITH_SIZE,
+ result_type, 5,
+ array_to_pointer_conversion (loc, ref),
+ counted_by_ref,
+ build_int_cst (integer_type_node, 1),
+ build_int_cst (counted_by_type, 0),
+ build_int_cst (integer_type_node, -1));
+ /* Wrap the call with an INDIRECT_REF with the flexible array type. */
+ call = build1 (INDIRECT_REF, TREE_TYPE (ref), call);
+ SET_EXPR_LOCATION (call, loc);
+ return call;
+}
+
/* Make an expression to refer to the COMPONENT field of structure or
union value DATUM. COMPONENT is an IDENTIFIER_NODE. LOC is the
location of the COMPONENT_REF. COMPONENT_LOC is the location
of COMPONENT. ARROW_LOC is the location of the first -> operand if
- it is from -> operator. */
+ it is from -> operator.
+ If HANDLE_COUNTED_BY is true, check the counted_by attribute and generate
+ a call to .ACCESS_WITH_SIZE. Otherwise, ignore the attribute. */
tree
build_component_ref (location_t loc, tree datum, tree component,
- location_t component_loc, location_t arrow_loc)
+ location_t component_loc, location_t arrow_loc,
+ bool handle_counted_by)
{
tree type = TREE_TYPE (datum);
enum tree_code code = TREE_CODE (type);
@@ -2732,7 +2833,13 @@ build_component_ref (location_t loc, tree datum, tree
component,
int quals;
tree subtype;
bool use_datum_quals;
-
+ tree counted_by_type = NULL_TREE;
+ /* Do not handle counted_by when in typeof and alignof operator. */
+ handle_counted_by = handle_counted_by && !in_typeof && !in_alignof;
+ tree counted_by_ref = handle_counted_by
+ ? build_counted_by_ref (datum, subdatum,
+ &counted_by_type)
+ : NULL_TREE;
if (TREE_TYPE (subdatum) == error_mark_node)
return error_mark_node;
@@ -2751,6 +2858,12 @@ build_component_ref (location_t loc, tree datum, tree
component,
ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
NULL_TREE);
SET_EXPR_LOCATION (ref, loc);
+
+ if (counted_by_ref)
+ ref = build_access_with_size_for_counted_by (loc, ref,
+ counted_by_ref,
+ counted_by_type);
+
if (TREE_READONLY (subdatum)
|| (use_datum_quals && TREE_READONLY (datum)))
TREE_READONLY (ref) = 1;
@@ -5155,7 +5268,11 @@ build_unary_op (location_t location, enum tree_code
code, tree xarg,
goto return_build_unary_op;
}
- /* Ordinary case; arg is a COMPONENT_REF or a decl. */
+ /* Ordinary case; arg is a COMPONENT_REF or a decl, or a call to
+ .ACCESS_WITH_SIZE. */
+ if (is_access_with_size_p (arg))
+ arg = TREE_OPERAND (TREE_OPERAND (CALL_EXPR_ARG (arg, 0), 0), 0);
+
argtype = TREE_TYPE (arg);
/* If the lvalue is const or volatile, merge that into the type
@@ -5306,6 +5423,9 @@ lvalue_p (const_tree ref)
case BIND_EXPR:
return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
+ case CALL_EXPR:
+ return is_access_with_size_p (ref);
+
default:
return false;
}
@@ -8593,6 +8713,20 @@ digest_init (location_t init_loc, tree type, tree init,
tree origtype,
STRIP_TYPE_NOPS (inside_init);
+ /* If require_constant is TRUE, when the initializer is a call to
+ .ACCESS_WITH_SIZE, use the first argument as the initializer.
+ For example:
+ y = (char *) .ACCESS_WITH_SIZE ((char *) &static_annotated.c,...)
+ will be converted to
+ y = &static_annotated.c. */
+
+ if (require_constant
+ && TREE_CODE (inside_init) == NOP_EXPR
+ && TREE_CODE (TREE_OPERAND (inside_init, 0)) == CALL_EXPR
+ && is_access_with_size_p (TREE_OPERAND (inside_init, 0)))
+ inside_init
+ = get_ref_from_access_with_size (TREE_OPERAND (inside_init, 0));
+
if (!c_in_omp_for)
{
if (TREE_CODE (inside_init) == EXCESS_PRECISION_EXPR)
diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
index 9c09026793f..eb2c4cd5904 100644
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -3438,6 +3438,40 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
}
}
+/* Expand the IFN_ACCESS_WITH_SIZE function:
+ ACCESS_WITH_SIZE (REF_TO_OBJ, REF_TO_SIZE, CLASS_OF_SIZE,
+ TYPE_OF_SIZE, ACCESS_MODE)
+ which returns the REF_TO_OBJ same as the 1st argument;
+
+ 1st argument REF_TO_OBJ: The reference to the object;
+ 2nd argument REF_TO_SIZE: The reference to the size of the object,
+ 3rd argument CLASS_OF_SIZE: The size referenced by the REF_TO_SIZE
represents
+ 0: the number of bytes.
+ 1: the number of the elements of the object type;
+ 4th argument TYPE_OF_SIZE: A constant 0 with its TYPE being the same as the
TYPE
+ of the object referenced by REF_TO_SIZE
+ 5th argument ACCESS_MODE:
+ -1: Unknown access semantics
+ 0: none
+ 1: read_only
+ 2: write_only
+ 3: read_write
+
+ Both the return type and the type of the first argument of this
+ function have been converted from the incomplete array type to
+ the corresponding pointer type.
+
+ For each call to a .ACCESS_WITH_SIZE, replace it with its 1st argument. */
+
+static void
+expand_ACCESS_WITH_SIZE (internal_fn, gcall *stmt)
+{
+ tree lhs = gimple_call_lhs (stmt);
+ tree ref_to_obj = gimple_call_arg (stmt, 0);
+ if (lhs)
+ expand_assignment (lhs, ref_to_obj, false);
+}
+
/* The size of an OpenACC compute dimension. */
static void
diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
index 25badbb86e5..8de1fa882e9 100644
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -512,6 +512,11 @@ DEF_INTERNAL_FN (PHI, 0, NULL)
automatic variable. */
DEF_INTERNAL_FN (DEFERRED_INIT, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
+/* A function to associate the access size and access mode information
+ with the corresponding reference to an object. It only reads from the
+ 2nd argument. */
+DEF_INTERNAL_FN (ACCESS_WITH_SIZE, ECF_PURE | ECF_LEAF | ECF_NOTHROW, NULL)
+
/* DIM_SIZE and DIM_POS return the size of a particular compute
dimension and the executing thread's position within that
dimension. DIM_POS is pure (and not const) so that it isn't
diff --git a/gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
b/gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
new file mode 100644
index 00000000000..d4899a63af3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
@@ -0,0 +1,112 @@
+/* Test the code generation for the new attribute counted_by.
+ And also the offsetof operator on such array. */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-original" } */
+
+#include <stdlib.h>
+
+struct annotated {
+ int b;
+ char c[] __attribute__ ((counted_by (b)));
+} *array_annotated;
+
+static struct annotated static_annotated = { sizeof "hello", "hello" };
+static char *y = static_annotated.c;
+
+struct flex {
+ int b;
+ char c[];
+};
+
+struct nested_annotated {
+ struct {
+ union {
+ int b;
+ float f;
+ };
+ int n;
+ };
+ char c[] __attribute__ ((counted_by (b)));
+} *array_nested_annotated;
+
+static struct nested_annotated nested_static_annotated
+ = { sizeof "hello1", 0, "hello1" };
+static char *nested_y = nested_static_annotated.c;
+
+struct nested_flex {
+ struct {
+ union {
+ int b;
+ float f;
+ };
+ int n;
+ };
+ char c[];
+};
+
+void __attribute__((__noinline__)) setup (int normal_count, int attr_count)
+{
+ array_annotated
+ = (struct annotated *)malloc (sizeof (struct annotated)
+ + attr_count * sizeof (char));
+ array_annotated->b = attr_count;
+
+ array_nested_annotated
+ = (struct nested_annotated *)malloc (sizeof (struct nested_annotated)
+ + attr_count * sizeof (char));
+ array_nested_annotated->b = attr_count;
+
+ return;
+}
+
+void __attribute__((__noinline__)) test (char a, char b)
+{
+ if (__builtin_offsetof (struct annotated, c[0])
+ != __builtin_offsetof (struct flex, c[0]))
+ abort ();
+ if (__builtin_offsetof (struct annotated, c[1])
+ != __builtin_offsetof (struct flex, c[1]))
+ abort ();
+ if (__builtin_offsetof (struct nested_annotated, c[0])
+ != __builtin_offsetof (struct nested_flex, c[0]))
+ abort ();
+ if (__builtin_offsetof (struct nested_annotated, c[1])
+ != __builtin_offsetof (struct nested_flex, c[1]))
+ abort ();
+
+ if (__builtin_types_compatible_p (typeof (array_annotated->c),
+ typeof (&(array_annotated->c)[0])))
+ abort ();
+ if (__builtin_types_compatible_p (typeof (array_nested_annotated->c),
+ typeof (&(array_nested_annotated->c)[0])))
+ abort ();
+
+ if (__alignof (array_annotated->c) != __alignof (char))
+ abort ();
+ if (__alignof (array_nested_annotated->c) != __alignof (char))
+ abort ();
+
+ if ((unsigned long) array_annotated->c != (unsigned long)
&array_annotated->c)
+ abort ();
+ if ((unsigned long) array_nested_annotated->c
+ != (unsigned long) &array_nested_annotated->c)
+ abort ();
+
+ array_annotated->c[2] = a;
+ array_nested_annotated->c[3] = b;
+
+ if (y[2] != 'l') abort ();
+ if (nested_y[4] !='o') abort ();
+
+}
+
+int main(int argc, char *argv[])
+{
+ setup (10,10);
+ test ('A', 'B');
+ if (array_annotated->c[2] != 'A') abort ();
+ if (array_nested_annotated->c[3] != 'B') abort ();
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "ACCESS_WITH_SIZE" 8 "original" } } */
diff --git a/gcc/tree.cc b/gcc/tree.cc
index 6564b002dc1..01572fe70f7 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -13405,6 +13405,28 @@ component_ref_size (tree ref, special_array_member
*sam /* = NULL */)
? NULL_TREE : size_zero_node);
}
+/* Return true if the given node CALL is a call to a .ACCESS_WITH_SIZE
+ function. */
+bool
+is_access_with_size_p (const_tree call)
+{
+ if (TREE_CODE (call) != CALL_EXPR)
+ return false;
+ if (CALL_EXPR_IFN (call) == IFN_ACCESS_WITH_SIZE)
+ return true;
+ return false;
+}
+
+/* Get the corresponding reference from the call to a .ACCESS_WITH_SIZE.
+ * i.e the first argument of this call. Return NULL_TREE otherwise. */
+tree
+get_ref_from_access_with_size (tree call)
+{
+ if (is_access_with_size_p (call))
+ return CALL_EXPR_ARG (call, 0);
+ return NULL_TREE;
+}
+
/* Return the machine mode of T. For vectors, returns the mode of the
inner type. The main use case is to feed the result to HONOR_NANS,
avoiding the BLKmode that a direct TYPE_MODE (T) might return. */
diff --git a/gcc/tree.h b/gcc/tree.h
index ee2aae332a4..60488564118 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -5772,6 +5772,14 @@ extern special_array_member component_ref_sam_type
(tree);
cannot be determined. */
extern tree component_ref_size (tree, special_array_member * = NULL);
+/* Return true if the given node is a call to a .ACCESS_WITH_SIZE
+ function. */
+extern bool is_access_with_size_p (const_tree);
+
+/* Get the corresponding reference from the call to a .ACCESS_WITH_SIZE,
+ * i.e. the first argument of this call. Return NULL_TREE otherwise. */
+extern tree get_ref_from_access_with_size (tree);
+
extern int tree_map_base_eq (const void *, const void *);
extern unsigned int tree_map_base_hash (const void *);
extern bool tree_map_base_marked_p (const void *);
