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I think we now handle conformant arrays in structures correctly - the

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test cases pass
This commit is contained in:
Andrew Tridgell -
parent 2cc354bd82
commit 22e1502350
4 changed files with 155 additions and 19 deletions
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78
source/build/pidl/NOTES.txt Normal file
View File

@ -0,0 +1,78 @@
FIXED ARRAY
-----------
A fixed array looks like this:
typedef struct {
long s[4];
} Struct1;
the NDR representation looks just like 4 separate long
declarations. The array size is not encoded on the wire.
CONFORMANT ARRAYS
-----------------
A conformant array is one with that ends in [*] or []. The strange
things about conformant arrays are:
* they can only appear as the last element of a structure
* the array size appears before the structure itself on the wire.
So, in this example:
typedef struct {
long abc;
long count;
long foo;
[size_is(count)] long s[*];
} Struct1;
it appears like this:
[size_is] [abc] [count] [foo] [s...]
the first [size_is] field is the allocation size of the array, and
occurs before the array elements and even before the structure
alignment.
Note that size_is() can refer to a constant, but that doesn't change
the wire representation. It does not make the array a fixed array.
midl.exe would write the above array as the following C header:
typedef struct {
long abc;
long count;
long foo;
long s[1];
} Struct1;
VARYING ARRAYS
--------------
A varying array looks like this:
typedef struct {
long abc;
long count;
long foo;
[size_is(count)] long *s;
} Struct1;
This will look like this on the wire:
[abc] [count] [foo] [PTR_s] [count] [s...]
VALIDATOR
---------
We need to write an IDL validator, so we know that we are writing
valid IDL. Right now the compiler sails on regardless in many cases
even if the IDL is invalid (for example, I don't check that conformant
arrays are always the last element in any structure). There are dozens
of rules that should be checked.

8
source/build/pidl/header.pm
View File

@ -59,13 +59,13 @@ sub HeaderElement($)
$res .= "*";
}
}
if (defined $element->{ARRAY_LEN} &&
$element->{ARRAY_LEN} eq "*") {
if (defined $element->{ARRAY_LEN} && $element->{ARRAY_LEN} eq "*") {
# conformant arrays are ugly! I choose to implement them with
# pointers instead of the [1] method
$res .= "*";
}
$res .= "$element->{NAME}";
if (defined $element->{ARRAY_LEN} &&
$element->{ARRAY_LEN} ne "*") {
if (defined $element->{ARRAY_LEN} && $element->{ARRAY_LEN} ne "*") {
$res .= "[$element->{ARRAY_LEN}]";
}
$res .= ";\n";

5
source/build/pidl/idl.gram
View File

@ -76,7 +76,10 @@ base_element: property_list(s?) type pointer(s?) identifier array_len(?)
}}
| <error>
array_len: '[' <commit> constant ']'
array_len:
'[]'
{ "*" }
| '[' <commit> constant ']'
{ $item{constant} }
| <error?>

83
source/build/pidl/parser.pm
View File

@ -81,16 +81,18 @@ sub ParseArrayPush($$)
my $e = shift;
my $var_prefix = shift;
my $size = find_size_var($e, util::array_size($e));
my $const = "";
if (util::is_constant($size)) {
$const = "_const";
if (defined $e->{CONFORMANT_SIZE}) {
# the conformant size has already been pushed
} elsif (!util::is_constant($size)) {
# we need to emit the array size
$res .= "\t\tNDR_CHECK(ndr_push_uint32(ndr, $size));\n";
}
if (util::is_scalar_type($e->{TYPE})) {
$res .= "\t\tNDR_CHECK(ndr_push$const\_array_$e->{TYPE}(ndr, $var_prefix$e->{NAME}, $size));\n";
$res .= "\t\tNDR_CHECK(ndr_push_array_$e->{TYPE}(ndr, $var_prefix$e->{NAME}, $size));\n";
} else {
$res .= "\t\tNDR_CHECK(ndr_push$const\_array(ndr, ndr_flags, $var_prefix$e->{NAME}, sizeof($var_prefix$e->{NAME}\[0]), $size, (ndr_push_flags_fn_t)ndr_push_$e->{TYPE}));\n";
$res .= "\t\tNDR_CHECK(ndr_push_array(ndr, ndr_flags, $var_prefix$e->{NAME}, sizeof($var_prefix$e->{NAME}\[0]), $size, (ndr_push_flags_fn_t)ndr_push_$e->{TYPE}));\n";
}
}
@ -116,19 +118,39 @@ sub ParseArrayPull($$)
my $e = shift;
my $var_prefix = shift;
my $size = find_size_var($e, util::array_size($e));
my $const = "";
my $alloc_size = $size;
if (util::is_constant($size)) {
$const = "_const";
# if this is a conformant array then we use that size to allocate, and make sure
# we allocate enough to pull the elements
if (defined $e->{CONFORMANT_SIZE}) {
$alloc_size = $e->{CONFORMANT_SIZE};
$res .= "\tif ($size > $alloc_size) {\n";
$res .= "\t\treturn ndr_pull_error(ndr, NDR_ERR_CONFORMANT_SIZE, \"Bad conformant size %u should be %u\", $alloc_size, $size);\n";
$res .= "\t}\n";
} elsif (!util::is_constant($size)) {
# non fixed arrays encode the size just before the array
$res .= "\t{\n";
$res .= "\t\tuint32 _array_size;\n";
$res .= "\t\tNDR_CHECK(ndr_pull_uint32(ndr, &_array_size));\n";
$res .= "\t\tif ($size > _array_size) {\n";
$res .= "\t\t\treturn ndr_pull_error(ndr, NDR_ERR_ARRAY_SIZE, \"Bad array size %u should be %u\", _array_size, $size);\n";
$res .= "\t\t}\n";
$res .= "\t}\n";
}
if (util::need_alloc($e) && !util::is_constant($size)) {
$res .= "\t\tNDR_ALLOC_N_SIZE(ndr, $var_prefix$e->{NAME}, $size, sizeof($var_prefix$e->{NAME}\[0]));\n";
$res .= "\t\tNDR_ALLOC_N_SIZE(ndr, $var_prefix$e->{NAME}, $alloc_size, sizeof($var_prefix$e->{NAME}\[0]));\n";
}
if (util::has_property($e, "length_is")) {
die "we don't handle varying arrays yet";
}
if (util::is_scalar_type($e->{TYPE})) {
$res .= "\t\tNDR_CHECK(ndr_pull$const\_array_$e->{TYPE}(ndr, $var_prefix$e->{NAME}, $size));\n";
$res .= "\t\tNDR_CHECK(ndr_pull_array_$e->{TYPE}(ndr, $var_prefix$e->{NAME}, $size));\n";
} else {
$res .= "\t\tNDR_CHECK(ndr_pull$const\_array(ndr, ndr_flags, (void **)$var_prefix$e->{NAME}, sizeof($var_prefix$e->{NAME}\[0]), $size, (ndr_pull_flags_fn_t)ndr_pull_$e->{TYPE}));\n";
$res .= "\t\tNDR_CHECK(ndr_pull_array(ndr, ndr_flags, (void **)$var_prefix$e->{NAME}, sizeof($var_prefix$e->{NAME}\[0]), $size, (ndr_pull_flags_fn_t)ndr_pull_$e->{TYPE}));\n";
}
}
@ -191,7 +213,7 @@ sub ParseElementPullSwitch($$$$)
$res .= "\t{ uint16 _level;\n";
$res .= "\tNDR_CHECK(ndr_pull_$e->{TYPE}(ndr, $ndr_flags, &_level, $cprefix$var_prefix$e->{NAME}));\n";
$res .= "\tif (_level != $switch_var) return NT_STATUS_INVALID_LEVEL;\n";
$res .= "\tif (_level != $switch_var) return ndr_pull_error(ndr, NDR_ERR_BAD_SWITCH, \"Bad switch value %u in $e->{NAME}\");\n";
$res .= "\t}\n";
}
@ -322,6 +344,7 @@ sub ParseStructPush($)
{
my($struct) = shift;
my($struct_len);
my $conform_e;
if (! defined $struct->{ELEMENTS}) {
return;
@ -341,6 +364,19 @@ sub ParseStructPush($)
$res .= "\tndr_push_save(ndr, &_save1);\n";
}
# see if the structure contains a conformant array. If it
# does, then it must be the last element of the structure, and
# we need to push the conformant length early, as it fits on
# the wire before the structure (and even before the structure
# alignment)
my $e = $struct->{ELEMENTS}[-1];
if (defined $e->{ARRAY_LEN} && $e->{ARRAY_LEN} eq "*") {
my $size = find_size_var($e, util::array_size($e));
$e->{CONFORMANT_SIZE} = $size;
$conform_e = $e;
$res .= "\tNDR_CHECK(ndr_push_uint32(ndr, $size));\n";
}
my $align = struct_alignment($struct);
$res .= "\tNDR_CHECK(ndr_push_align(ndr, $align));\n";
@ -394,11 +430,24 @@ sub ParseStructPull($)
{
my($struct) = shift;
my($struct_len);
my $conform_e;
if (! defined $struct->{ELEMENTS}) {
return;
}
# see if the structure contains a conformant array. If it
# does, then it must be the last element of the structure, and
# we need to pull the conformant length early, as it fits on
# the wire before the structure (and even before the structure
# alignment)
my $e = $struct->{ELEMENTS}[-1];
if (defined $e->{ARRAY_LEN} && $e->{ARRAY_LEN} eq "*") {
$conform_e = $e;
$res .= "\tuint32 _conformant_size;\n";
$conform_e->{CONFORMANT_SIZE} = "_conformant_size";
}
# declare any internal pointers we need
foreach my $e (@{$struct->{ELEMENTS}}) {
$e->{PARENT} = $struct;
@ -426,6 +475,10 @@ sub ParseStructPull($)
$res .= "\tndr_pull_save(ndr, &_save);\n";
}
if (defined $conform_e) {
$res .= "\tNDR_CHECK(ndr_pull_uint32(ndr, &$conform_e->{CONFORMANT_SIZE}));\n";
}
my $align = struct_alignment($struct);
$res .= "\tNDR_CHECK(ndr_pull_align(ndr, $align));\n";
@ -490,7 +543,8 @@ sub ParseUnionPull($)
ParseElementPullScalar($el->{DATA}, "r->", "NDR_SCALARS");
$res .= "\tbreak;\n\n";
}
$res .= "\tdefault:\n\t\treturn NT_STATUS_INVALID_LEVEL;\n";
$res .= "\tdefault:\n";
$res .= "\t\treturn ndr_pull_error(ndr, NDR_ERR_BAD_SWITCH, \"Bad switch value %u in $e->{NAME}\", *level);\n";
$res .= "\t}\n";
$res .= "buffers:\n";
$res .= "\tif (!(ndr_flags & NDR_BUFFERS)) goto done;\n";
@ -500,7 +554,8 @@ sub ParseUnionPull($)
ParseElementPullBuffer($el->{DATA}, "r->", "NDR_BUFFERS");
$res .= "\tbreak;\n\n";
}
$res .= "\tdefault:\n\t\treturn NT_STATUS_INVALID_LEVEL;\n";
$res .= "\tdefault:\n";
$res .= "\t\treturn ndr_pull_error(ndr, NDR_ERR_BAD_SWITCH, \"Bad switch value %u in $e->{NAME}\", *level);\n";
$res .= "\t}\n";
$res .= "done:\n";
}