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re PR c/3347 (Too large bitfields should be errors) 

2003-12-17  Neil Booth  <neil@daikokuya.co.uk>
            Joseph S. Myers  <jsm@polyomino.org.uk>

	PR c/3347
	* c-decl.c (enum_decl_context): Remove BITFIELD.
	(grokdeclarator): Take bit-field width as an input.
	Perform bit-field width validation with
	check_bitfield_type_and_width rather than waiting for
	finish_struct.
	(groktypename, groktypename_in_parm_context, start_decl,
	push_parm_decl, grokfield, start_function): Update calls to
	grokdeclarator.
	(check_bitfield_type_and_width): New function.
	(finish_struct): Move bit-field validation to grokdeclarator
	and check_bitfield_type_and_width.

testsuite:
	* gcc.dg/bitfld-8.c: New test.

From-SVN: r74725
parent 89843f8b
Showing with 129 additions and 81 deletions
gcc/ChangeLog
2003-12-17 Neil Booth <neil@daikokuya.co.uk>
Joseph S. Myers <jsm@polyomino.org.uk>
PR c/3347
* c-decl.c (enum_decl_context): Remove BITFIELD.
(grokdeclarator): Take bit-field width as an input.
Perform bit-field width validation with
check_bitfield_type_and_width rather than waiting for
finish_struct.
(groktypename, groktypename_in_parm_context, start_decl,
push_parm_decl, grokfield, start_function): Update calls to
grokdeclarator.
(check_bitfield_type_and_width): New function.
(finish_struct): Move bit-field validation to grokdeclarator
and check_bitfield_type_and_width.
2003-12-16 John David Anglin <dave.anglin@nrc-cnrc.gc.ca>
PR bootstrap/13386
......
gcc/c-decl.c
......@@ -61,7 +61,6 @@ enum decl_context
FUNCDEF, /* Function definition */
PARM, /* Declaration of parm before function body */
FIELD, /* Declaration inside struct or union */
BITFIELD, /* Likewise but with specified width */
TYPENAME}; /* Typename (inside cast or sizeof) */
......@@ -315,7 +314,7 @@ static void bind_label (tree, tree, struct c_scope *);
static void implicit_decl_warning (tree);
static tree lookup_tag (enum tree_code, tree, int);
static tree lookup_name_current_level (tree);
static tree grokdeclarator (tree, tree, enum decl_context, int);
static tree grokdeclarator (tree, tree, enum decl_context, int, tree *);
static tree grokparms (tree, int);
static void layout_array_type (tree);
static void store_parm_decls_newstyle (void);
......@@ -325,6 +324,7 @@ static void c_expand_body_1 (tree, int);
static tree any_external_decl (tree);
static void record_external_decl (tree);
static void warn_if_shadowing (tree, tree);
static void check_bitfield_type_and_width (tree *, tree *, const char *);
static void clone_underlying_type (tree);
static bool flexible_array_type_p (tree);
static hashval_t link_hash_hash (const void *);
......@@ -2540,7 +2540,8 @@ groktypename (tree typename)
split_specs_attrs (TREE_PURPOSE (typename), &specs, &attrs);
typename = grokdeclarator (TREE_VALUE (typename), specs, TYPENAME, 0);
typename = grokdeclarator (TREE_VALUE (typename), specs, TYPENAME, 0,
NULL);
/* Apply attributes. */
decl_attributes (&typename, attrs, 0);
......@@ -2557,7 +2558,7 @@ groktypename_in_parm_context (tree typename)
return typename;
return grokdeclarator (TREE_VALUE (typename),
TREE_PURPOSE (typename),
PARM, 0);
PARM, 0, NULL);
}
/* Decode a declarator in an ordinary declaration or data definition.
......@@ -2587,7 +2588,7 @@ start_decl (tree declarator, tree declspecs, int initialized, tree attributes)
deprecated_state = DEPRECATED_SUPPRESS;
decl = grokdeclarator (declarator, declspecs,
NORMAL, initialized);
NORMAL, initialized, NULL);
deprecated_state = DEPRECATED_NORMAL;
......@@ -3023,7 +3024,8 @@ push_parm_decl (tree parm)
immediate_size_expand = 0;
decl = grokdeclarator (TREE_VALUE (TREE_PURPOSE (parm)),
TREE_PURPOSE (TREE_PURPOSE (parm)), PARM, 0);
TREE_PURPOSE (TREE_PURPOSE (parm)),
PARM, 0, NULL);
decl_attributes (&decl, TREE_VALUE (parm), 0);
decl = pushdecl (decl);
......@@ -3218,6 +3220,80 @@ flexible_array_type_p (tree type)
}
}
/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME,
replacing with appropriate values if they are invalid. */
static void
check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name)
{
tree type_mv;
unsigned int max_width;
unsigned HOST_WIDE_INT w;
const char *name = orig_name ? orig_name: _("<anonymous>");
/* Necessary? */
STRIP_NOPS (*width);
/* Detect and ignore out of range field width and process valid
field widths. */
if (TREE_CODE (*width) != INTEGER_CST)
{
error ("bit-field `%s' width not an integer constant", name);
*width = integer_one_node;
}
else
{
constant_expression_warning (*width);
if (tree_int_cst_sgn (*width) < 0)
{
error ("negative width in bit-field `%s'", name);
*width = integer_one_node;
}
else if (integer_zerop (*width) && orig_name)
{
error ("zero width for bit-field `%s'", name);
*width = integer_one_node;
}
}
/* Detect invalid bit-field type. */
if (TREE_CODE (*type) != INTEGER_TYPE
&& TREE_CODE (*type) != BOOLEAN_TYPE
&& TREE_CODE (*type) != ENUMERAL_TYPE)
{
error ("bit-field `%s' has invalid type", name);
*type = unsigned_type_node;
}
type_mv = TYPE_MAIN_VARIANT (*type);
if (pedantic
&& type_mv != integer_type_node
&& type_mv != unsigned_type_node
&& type_mv != boolean_type_node
/* Accept an enum that's equivalent to int or unsigned int. */
&& (TREE_CODE (*type) != ENUMERAL_TYPE
|| TYPE_PRECISION (*type) != TYPE_PRECISION (integer_type_node)))
pedwarn ("type of bit-field `%s' is a GCC extension", name);
if (type_mv == boolean_type_node)
max_width = CHAR_TYPE_SIZE;
else
max_width = TYPE_PRECISION (*type);
if (0 < compare_tree_int (*width, max_width))
{
error ("width of `%s' exceeds its type", name);
w = max_width;
*width = build_int_2 (w, 0);
}
else
w = tree_low_cst (*width, 1);
if (TREE_CODE (*type) == ENUMERAL_TYPE
&& (w < min_precision (TYPE_MIN_VALUE (*type), TREE_UNSIGNED (*type))
|| w < min_precision (TYPE_MAX_VALUE (*type), TREE_UNSIGNED (*type))))
warning ("`%s' is narrower than values of its type", name);
}
/* Given declspecs and a declarator,
determine the name and type of the object declared
and construct a ..._DECL node for it.
......@@ -3237,8 +3313,9 @@ flexible_array_type_p (tree type)
TYPENAME if for a typename (in a cast or sizeof).
Don't make a DECL node; just return the ..._TYPE node.
FIELD for a struct or union field; make a FIELD_DECL.
BITFIELD for a field with specified width.
INITIALIZED is 1 if the decl has an initializer.
WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node
representing the width of the bit-field.
In the TYPENAME case, DECLARATOR is really an absolute declarator.
It may also be so in the PARM case, for a prototype where the
......@@ -3249,7 +3326,7 @@ flexible_array_type_p (tree type)
static tree
grokdeclarator (tree declarator, tree declspecs,
enum decl_context decl_context, int initialized)
enum decl_context decl_context, int initialized, tree *width)
{
int specbits = 0;
tree spec;
......@@ -3264,19 +3341,16 @@ grokdeclarator (tree declarator, tree declspecs,
int explicit_char = 0;
int defaulted_int = 0;
tree typedef_decl = 0;
const char *name;
const char *name, *orig_name;
tree typedef_type = 0;
int funcdef_flag = 0;
enum tree_code innermost_code = ERROR_MARK;
int bitfield = 0;
int size_varies = 0;
tree decl_attr = NULL_TREE;
tree array_ptr_quals = NULL_TREE;
int array_parm_static = 0;
tree returned_attrs = NULL_TREE;
if (decl_context == BITFIELD)
bitfield = 1, decl_context = FIELD;
bool bitfield = width != NULL;
if (decl_context == FUNCDEF)
funcdef_flag = 1, decl_context = NORMAL;
......@@ -3309,6 +3383,7 @@ grokdeclarator (tree declarator, tree declspecs,
default:
abort ();
}
orig_name = name;
if (name == 0)
name = "type name";
}
......@@ -3541,7 +3616,7 @@ grokdeclarator (tree declarator, tree declspecs,
}
/* Decide whether an integer type is signed or not.
Optionally treat bitfields as signed by default. */
Optionally treat bit-fields as signed by default. */
if (specbits & 1 << (int) RID_UNSIGNED
|| (bitfield && ! flag_signed_bitfields
&& (explicit_int || defaulted_int || explicit_char
......@@ -3613,6 +3688,10 @@ grokdeclarator (tree declarator, tree declspecs,
}
}
/* Check the type and width of a bit-field. */
if (bitfield)
check_bitfield_type_and_width (&type, width, orig_name);
/* Figure out the type qualifiers for the declaration. There are
two ways a declaration can become qualified. One is something
like `const int i' where the `const' is explicit. Another is
......@@ -4769,7 +4848,7 @@ start_struct (enum tree_code code, tree name)
/* Process the specs, declarator (NULL if omitted) and width (NULL if omitted)
of a structure component, returning a FIELD_DECL node.
WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node.
WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node.
This is done during the parsing of the struct declaration.
The FIELD_DECL nodes are chained together and the lot of them
......@@ -4824,7 +4903,8 @@ grokfield (tree declarator, tree declspecs, tree width)
}
}
value = grokdeclarator (declarator, declspecs, width ? BITFIELD : FIELD, 0);
value = grokdeclarator (declarator, declspecs, FIELD, 0,
width ? &width : NULL);
finish_decl (value, NULL_TREE, NULL_TREE);
DECL_INITIAL (value) = width;
......@@ -4971,72 +5051,12 @@ finish_struct (tree t, tree fieldlist, tree attributes)
error ("nested redefinition of `%s'",
IDENTIFIER_POINTER (TYPE_NAME (t)));
/* Detect invalid bit-field size. */
if (DECL_INITIAL (x))
STRIP_NOPS (DECL_INITIAL (x));
if (DECL_INITIAL (x))
{
if (TREE_CODE (DECL_INITIAL (x)) == INTEGER_CST)
constant_expression_warning (DECL_INITIAL (x));
else
{
error ("%Jbit-field '%D' width not an integer constant", x, x);
DECL_INITIAL (x) = NULL;
}
}
/* Detect invalid bit-field type. */
if (DECL_INITIAL (x)
&& TREE_CODE (TREE_TYPE (x)) != INTEGER_TYPE
&& TREE_CODE (TREE_TYPE (x)) != BOOLEAN_TYPE
&& TREE_CODE (TREE_TYPE (x)) != ENUMERAL_TYPE)
{
error ("%Jbit-field '%D' has invalid type", x, x);
DECL_INITIAL (x) = NULL;
}
if (DECL_INITIAL (x) && pedantic
&& TYPE_MAIN_VARIANT (TREE_TYPE (x)) != integer_type_node
&& TYPE_MAIN_VARIANT (TREE_TYPE (x)) != unsigned_type_node
&& TYPE_MAIN_VARIANT (TREE_TYPE (x)) != boolean_type_node
/* Accept an enum that's equivalent to int or unsigned int. */
&& !(TREE_CODE (TREE_TYPE (x)) == ENUMERAL_TYPE
&& (TYPE_PRECISION (TREE_TYPE (x))
== TYPE_PRECISION (integer_type_node))))
pedwarn ("%Jbit-field '%D' type invalid in ISO C", x, x);
/* Detect and ignore out of range field width and process valid
field widths. */
if (DECL_INITIAL (x))
{
int max_width
= (TYPE_MAIN_VARIANT (TREE_TYPE (x)) == boolean_type_node
? CHAR_TYPE_SIZE : TYPE_PRECISION (TREE_TYPE (x)));
if (tree_int_cst_sgn (DECL_INITIAL (x)) < 0)
error ("%Jnegative width in bit-field '%D'", x, x);
else if (0 < compare_tree_int (DECL_INITIAL (x), max_width))
pedwarn ("%Jwidth of '%D' exceeds its type", x, x);
else if (integer_zerop (DECL_INITIAL (x)) && DECL_NAME (x) != 0)
error ("%Jzero width for bit-field '%D'", x, x);
else
{
/* The test above has assured us that TREE_INT_CST_HIGH is 0. */
unsigned HOST_WIDE_INT width
= tree_low_cst (DECL_INITIAL (x), 1);
if (TREE_CODE (TREE_TYPE (x)) == ENUMERAL_TYPE
&& (width < min_precision (TYPE_MIN_VALUE (TREE_TYPE (x)),
TREE_UNSIGNED (TREE_TYPE (x)))
|| (width
< min_precision (TYPE_MAX_VALUE (TREE_TYPE (x)),
TREE_UNSIGNED (TREE_TYPE (x))))))
warning ("%J'%D' is narrower than values of its type", x, x);
DECL_SIZE (x) = bitsize_int (width);
DECL_BIT_FIELD (x) = 1;
SET_DECL_C_BIT_FIELD (x);
}
unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1);
DECL_SIZE (x) = bitsize_int (width);
DECL_BIT_FIELD (x) = 1;
SET_DECL_C_BIT_FIELD (x);
}
DECL_INITIAL (x) = 0;
......@@ -5461,7 +5481,7 @@ start_function (tree declspecs, tree declarator, tree attributes)
/* Don't expand any sizes in the return type of the function. */
immediate_size_expand = 0;
decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1);
decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1, NULL);
/* If the declarator is not suitable for a function definition,
cause a syntax error. */
......
gcc/testsuite/ChangeLog
2003-12-17 Joseph S. Myers <jsm@polyomino.org.uk>
PR c/3347
* gcc.dg/bitfld-8.c: New test.
2003-12-16 James Lemke <jim@wasabisystems.com>
* gcc.dg/arm-scd42-[123].c: New tests.
......
gcc/testsuite/gcc.dg/bitfld-8.c 0 → 100644
/* Test that too wide bit-fields are hard errors. PR c/3347. */
/* Origin: Joseph Myers <jsm@polyomino.org.uk>, from PR c/3347 */
/* { dg-do compile } */
/* { dg-options "" } */
struct { int i : 1999; } x; /* { dg-bogus "warning" "warning in place of error" } */
/* { dg-error "width" "bit-field too wide" { target *-*-* } 6 } */
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