Re: [PATCH bpf-next] selftests/bpf: move struct definitions out of function params

sdf@xxxxxxxxxx · Wed, 21 Dec 2022 11:07:37 -0800

On 12/20, James Hilliard wrote:
Anonymous structs can't be declared inside function parameter
definitions in current c standards, however clang doesn't detect this
condition currently while GCC does.

Details: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108189

Fixes errors like:
progs/btf_dump_test_case_bitfields.c:85:7: error: anonymous struct  
declared inside parameter list will not be visible outside of this  
definition or declaration [-Werror]
    85 | int f(struct {
       |       ^~~~~~

Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>

Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>

Looking at the referenced thread, seems like it requires at lest C23
and I doubt default clang is using that; so seems fine to be pedantic
here and move the definitions out.

---
  .../bpf/progs/btf_dump_test_case_bitfields.c  |  9 ++++--
  .../progs/btf_dump_test_case_namespacing.c    | 10 ++++---
  .../bpf/progs/btf_dump_test_case_packing.c    | 10 ++++---
  .../bpf/progs/btf_dump_test_case_padding.c    | 10 ++++---
  .../bpf/progs/btf_dump_test_case_syntax.c     | 30 +++++++++++++------
  5 files changed, 46 insertions(+), 23 deletions(-)

diff --git  
a/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c  
b/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c
index e01690618e1e..c75f6bd06a49 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c
@@ -82,11 +82,16 @@ struct bitfield_flushed {
  	long b: 16;
  };

-int f(struct {
+/* ----- START-EXPECTED-OUTPUT ----- */
+struct root_struct {
  	struct bitfields_only_mixed_types _1;
  	struct bitfield_mixed_with_others _2;
  	struct bitfield_flushed _3;
-} *_)
+};
+
+/* ------ END-EXPECTED-OUTPUT ------ */
+
+int f(struct root_struct *_)
  {
  	return 0;
  }
diff --git  
a/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c  
b/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c
index 92a4ad428710..d7cf2a8487c9 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_namespacing.c
@@ -49,9 +49,7 @@ typedef int Y;

  typedef int Z;

-/*------ END-EXPECTED-OUTPUT ------ */
-
-int f(struct {
+struct root_struct {
  	struct S _1;
  	S _2;
  	union U _3;
@@ -67,7 +65,11 @@ int f(struct {
  	X xx;
  	Y yy;
  	Z zz;
-} *_)
+};
+
+/*------ END-EXPECTED-OUTPUT ------ */
+
+int f(struct root_struct *_)
  {
  	return 0;
  }
diff --git  
a/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c  
b/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c
index 7998f27df7dd..e039ceb50c43 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c
@@ -132,9 +132,7 @@ struct outer_packed_struct {
  	struct nested_packed_struct b;
  } __attribute__((packed));

-/* ------ END-EXPECTED-OUTPUT ------ */
-
-int f(struct {
+struct root_struct {
  	struct packed_trailing_space _1;
  	struct non_packed_trailing_space _2;
  	struct packed_fields _3;
@@ -147,7 +145,11 @@ int f(struct {
  	struct usb_host_endpoint _10;
  	struct outer_nonpacked_struct _11;
  	struct outer_packed_struct _12;
-} *_)
+};
+
+/* ------ END-EXPECTED-OUTPUT ------ */
+
+int f(struct root_struct *_)
  {
  	return 0;
  }
diff --git  
a/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c  
b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
index 79276fbe454a..2ca46ad8d66a 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c
@@ -220,9 +220,7 @@ struct outer_mixed_but_unpacked {
  	struct nested_packed b2;
  };

-/* ------ END-EXPECTED-OUTPUT ------ */
-
-int f(struct {
+struct root_struct {
  	struct padded_implicitly _1;
  	struct padded_explicitly _2;
  	struct padded_a_lot _3;
@@ -243,7 +241,11 @@ int f(struct {
  	struct ib_wc _201;
  	struct acpi_object_method _202;
  	struct outer_mixed_but_unpacked _203;
-} *_)
+} __attribute__((packed));
+
+/* ------ END-EXPECTED-OUTPUT ------ */
+
+int f(struct root_struct *_)
  {
  	return 0;
  }
diff --git  
a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c  
b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
index 26fffb02ed10..3e31df7cecc6 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
@@ -104,24 +104,24 @@ typedef void (*printf_fn_t)(const char *, ...);
   *   typedef const fn_output_inner_t fn_ptr_arr2_t[5];
   */
  /* ----- START-EXPECTED-OUTPUT ----- */
-typedef char * const * (*fn_ptr2_t)(struct {
-	int a;
-}, int (*)(int));
+struct struct_a;
+
+typedef char * const * (*fn_ptr2_t)(struct struct_a, int (*)(int));
+
+struct struct_c;
+
+struct struct_h;

  typedef struct {
  	int a;
-	void (*b)(int, struct {
-		int c;
-	}, union {
+	void (*b)(int, struct struct_c, union {
  		char d;
  		int e[5];
  	});
  } (*fn_complex_t)(union {
  	void *f;
  	char g[16];
-}, struct {
-	int h;
-});
+}, struct struct_h);

  typedef void (* (*signal_t)(int, void (*)(int)))(int);

@@ -272,6 +272,18 @@ struct root_struct {
  	struct float_struct _15;
  };

+struct struct_a {
+	int a;
+};
+
+struct struct_h {
+	int h;
+};
+
+struct struct_c {
+	int c;
+};
+
  /* ------ END-EXPECTED-OUTPUT ------ */

  int f(struct root_struct *s)
--
2.34.1







