12:25 p.m.
For API parameters that are pointers and must not be NULL, add the
appropriate GCC annotations.
Reviewed-by: Laszlo Ersek <lersek(a)redhat.com>
---
generator/C.ml | 59 +++++++++++++++++++++++++++++++++++--
tests/errors-connect-null.c | 4 +++
2 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/generator/C.ml b/generator/C.ml
index 66498a7d88..6e4538fd34 100644
--- a/generator/C.ml
+++ b/generator/C.ml
@@ -107,6 +107,28 @@ let
| UInt64 n -> [n]
| UIntPtr n -> [n]
+(* Map function arguments to __attribute__((nonnull)) annotations.
+ * Because a single arg may map to multiple C parameters this
+ * returns a list. Note: true => add attribute nonnull.
+ *)
+let arg_attr_nonnull =
+ function
+ (* BytesIn/Out are passed using a non-null pointer, and size_t *)
+ | BytesIn _ | BytesOut _
+ | BytesPersistIn _ | BytesPersistOut _ -> [ true; false ]
+ (* sockaddr is also non-null pointer, and length *)
+ | SockAddrAndLen (n, len) -> [ true; false ]
+ (* strings should be marked as non-null *)
+ | Path _ | String _ -> [ true ]
+ (* list of strings should be marked as non-null *)
+ | StringList n -> [ true ]
+ (* numeric and other non-pointer types are not able to be null *)
+ | Bool _ | Closure _ | Enum _ | Fd _ | Flags _
+ | Int _ | Int64 _ | SizeT _
+ | UInt _ | UInt32 _ | UInt64 _ | UIntPtr _ -> [ false ]
+
+let optarg_attr_nonnull (OClosure _ | OFlags _) = [ false ]
+
let rec print_arg_list ?(wrap = false) ?maxcol ?handle ?types ?(parens = true)
?closure_style args optargs =
if parens then pr "(";
@@ -216,7 +238,21 @@ let
let print_fndecl ?wrap ?closure_style name args optargs ret =
pr "extern ";
print_call ?wrap ?closure_style name args optargs ret;
- pr ";\n"
+
+ (* Output __attribute__((nonnull)) for the function parameters:
+ * eg. struct nbd_handle *, int, char *
+ * => [ true, false, true ]
+ * => LIBNBD_ATTRIBUTE_NONNULL((1,3))
+ * => __attribute__((nonnull,(1,3)))
+ *)
+ let nns : bool list =
+ [ true ] (* struct nbd_handle * *)
+ @ List.flatten (List.map arg_attr_nonnull args)
+ @ List.flatten (List.map optarg_attr_nonnull optargs) in
+ let nns = List.mapi (fun i b -> (i+1, b)) nns in
+ let nns = filter_map (fun (i, b) -> if b then Some i else None) nns in
+ let nns : string list = List.map string_of_int nns in
+ pr "\n LIBNBD_ATTRIBUTE_NONNULL((%s));\n" (String.concat ","
nns)
let rec print_cbarg_list ?(wrap = false) ?maxcol ?types ?(parens = true)
cbargs =
@@ -349,6 +385,19 @@ let
pr "extern \"C\" {\n";
pr "#endif\n";
pr "\n";
+ pr "#if defined(__GNUC__)\n";
+ pr "#define LIBNBD_GCC_VERSION \\\n";
+ pr " (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)\n";
+ pr "#endif\n";
+ pr "\n";
+ pr "#ifndef LIBNBD_ATTRIBUTE_NONNULL\n";
+ pr "#if defined(__GNUC__) && LIBNBD_GCC_VERSION >= 120000 /* gcc >=
12.0 */\n";
+ pr "#define LIBNBD_ATTRIBUTE_NONNULL(s) __attribute__((__nonnull__ s))\n";
+ pr "#else\n";
+ pr "#define LIBNBD_ATTRIBUTE_NONNULL(s)\n";
+ pr "#endif\n";
+ pr "#endif /* ! defined LIBNBD_ATTRIBUTE_NONNULL */\n";
+ pr "\n";
pr "struct nbd_handle;\n";
pr "\n";
List.iter (
@@ -382,7 +431,7 @@ let
pr "extern struct nbd_handle *nbd_create (void);\n";
pr "#define LIBNBD_HAVE_NBD_CREATE 1\n";
pr "\n";
- pr "extern void nbd_close (struct nbd_handle *h);\n";
+ pr "extern void nbd_close (struct nbd_handle *h); /* h can be NULL */\n";
pr "#define LIBNBD_HAVE_NBD_CLOSE 1\n";
pr "\n";
pr "extern const char *nbd_get_error (void);\n";
@@ -770,6 +819,12 @@ let
pr "\n";
pr "#include <pthread.h>\n";
pr "\n";
+ pr "/* GCC will remove NULL checks from this file for any parameter\n";
+ pr " * annotated with attribute((nonnull)). See RHBZ#1041336. To\n";
+ pr " * avoid this, disable the attribute when including libnbd.h.\n";
+ pr " */\n";
+ pr "#define LIBNBD_ATTRIBUTE_NONNULL(s)\n";
+ pr "\n";
pr "#include \"libnbd.h\"\n";
pr "#include \"internal.h\"\n";
pr "\n";
diff --git a/tests/errors-connect-null.c b/tests/errors-connect-null.c
index 27b21f0f8f..b975181afb 100644
--- a/tests/errors-connect-null.c
+++ b/tests/errors-connect-null.c
@@ -27,6 +27,10 @@
#include <string.h>
#include <errno.h>
+/* GCC will warn that we are passing NULL (or worse), so to do this
+ * test we must remove the header file attribute.
+ */
+#define LIBNBD_ATTRIBUTE_NONNULL(s)
#include <libnbd.h>
static char *progname;
--
2.37.0.rc2