[PATCH] Skip VLA structure field tests when compiling with clang

[PATCH] Skip VLA structure field tests when compiling with clang

[Gary Benson]

Hi all,

Clang fails to compile gdb.base/vla-datatypes.c with the following
error: fields must have a constant size: 'variable length array in
structure' extension will never be supported.  This patch adds
preprocessor contitionals to vla-datatypes.c to not compile any code
defining or using use VLA structure fields when compiling with clang,
and modifies vla-datatypes.exp to skip all tests that require the
omitted code as appropriate.

Checked on Fedora 31 x86_64, GCC and clang.  Ok to commit?

Cheers,
Gary

--
gdb/testsuite/ChangeLog:

	* gdb.base/vla-datatypes.c (vla_factory): Wrap sections defining
	and using VLA structure fields with "#if !defined(__clang__)".
	* gdb.base/vla-datatypes.exp: Skip VLA structure field tests if
	compiling with clang.
---
 gdb/testsuite/ChangeLog                  |  7 +++++
 gdb/testsuite/gdb.base/vla-datatypes.c   |  8 ++++++
 gdb/testsuite/gdb.base/vla-datatypes.exp | 47 ++++++++++++++++++++------------
 3 files changed, 44 insertions(+), 18 deletions(-)

diff --git a/gdb/testsuite/gdb.base/vla-datatypes.c b/gdb/testsuite/gdb.base/vla-datatypes.c
index 682319f..ce383a1 100644
--- a/gdb/testsuite/gdb.base/vla-datatypes.c
+++ b/gdb/testsuite/gdb.base/vla-datatypes.c
@@ -46,6 +46,9 @@ struct foo
   BAR             bar_vla[n];
   int i;
 
+  /* Clang says it will never support variable length arrays in
+     structures.  */
+#if !defined(__clang__)
   struct vla_struct
   {
     int something;
@@ -89,6 +92,7 @@ struct foo
   vla_struct_typedef_struct_member_object.something = n * 2;
   vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
   vla_struct_typedef_union_member_object.vla_object.something = n + 1;
+#endif /* !defined(__clang__) */
   for (i = 0; i < n; i++)
     {
       int_vla[i] = i*2;
@@ -104,6 +108,7 @@ struct foo
       foo_vla[i].a = i*2;
       bar_vla[i].x = i*2;
       bar_vla[i].y.a = i*2;
+#if !defined(__clang__)
       vla_struct_object.vla_field[i] = i*2;
       vla_union_object.vla_field[i] = i*2;
       inner_vla_struct_object.vla_field[i] = i*2;
@@ -111,6 +116,7 @@ struct foo
 	= i * 3;
       vla_struct_typedef_union_member_object.vla_object.vla_field[i]
 	= i * 3 - 1;
+#endif /* !defined(__clang__) */
     }
 
   size_t int_size        = sizeof(int_vla);     /* vlas_filled */
@@ -124,9 +130,11 @@ struct foo
   size_t uchar_size      = sizeof(unsigned_char_vla);
   size_t foo_size        = sizeof(foo_vla);
   size_t bar_size        = sizeof(bar_vla);
+#if !defined(__clang__)
   size_t vla_struct_object_size = sizeof(vla_struct_object);
   size_t vla_union_object_size = sizeof(vla_union_object);
   size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
+#endif /* !defined(__clang__) */
 
   return;                                 /* break_end_of_vla_factory */
 }
diff --git a/gdb/testsuite/gdb.base/vla-datatypes.exp b/gdb/testsuite/gdb.base/vla-datatypes.exp
index e8d8457..2924475 100644
--- a/gdb/testsuite/gdb.base/vla-datatypes.exp
+++ b/gdb/testsuite/gdb.base/vla-datatypes.exp
@@ -15,6 +15,9 @@
 
 standard_testfile
 
+# Clang says it will never support variable length arrays in structures.
+set is_clang [test_compiler_info clang*]
+
 if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
     return -1
 }
@@ -41,14 +44,16 @@ gdb_test "print foo_vla" \
          "\\\{\\\{a = 0\\\}, \\\{a = 2\\\}, \\\{a = 4\\\}, \\\{a = 6\\\}, \\\{a = 8\\\}\\\}"
 gdb_test "print bar_vla" \
          "\\\{\\\{x = 0, y = \\\{a = 0\\\}\\\}, \\\{x = 2, y = \\\{a = 2\\\}\\\}, \\\{x = 4, y = \\\{a = 4\\\}\\\}, \\\{x = 6, y = \\\{a = 6\\\}\\\}, \\\{x = 8, y = \\\{a = 8\\\}\\\}\\\}"
-gdb_test "print vla_struct_object" \
-    "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
-gdb_test "print vla_union_object" \
-    "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
-gdb_test "print vla_struct_typedef_struct_member_object" \
-    "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
-gdb_test "print vla_struct_typedef_union_member_object" \
-    "\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
+if {!$is_clang} {
+    gdb_test "print vla_struct_object" \
+	"\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
+    gdb_test "print vla_union_object" \
+	"\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
+    gdb_test "print vla_struct_typedef_struct_member_object" \
+	"\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
+    gdb_test "print vla_struct_typedef_union_member_object" \
+	"\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
+}
 
 # Check whatis of VLA's.
 gdb_test "whatis int_vla" "type = int \\\[5\\\]"
@@ -65,8 +70,10 @@ gdb_test "whatis unsigned_short_vla" \
 gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]"
 gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]"
 gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]"
-gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
-gdb_test "whatis vla_union_object" "type = union vla_union"
+if {!$is_clang} {
+    gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
+    gdb_test "whatis vla_union_object" "type = union vla_union"
+}
 
 # Check ptype of VLA's.
 gdb_test "ptype int_vla" "type = int \\\[5\\\]"
@@ -82,10 +89,12 @@ gdb_test "ptype unsigned_char_vla" "type = unsigned char \\\[5\\\]"
 gdb_test "ptype foo_vla" "type = struct foo {\r\n\\s+int a;\r\n} \\\[5\\\]"
 gdb_test "ptype bar_vla" \
          "type = struct bar {\r\n\\s+int x;\r\n\\s+struct foo y;\r\n} \\\[5\\\]"
-gdb_test "ptype vla_struct_object" \
-    "type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
-gdb_test "ptype vla_union_object" \
-    "type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
+if {!$is_clang} {
+    gdb_test "ptype vla_struct_object" \
+	"type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
+    gdb_test "ptype vla_union_object" \
+	"type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
+}
 
 # Check the size of the VLA's.
 gdb_breakpoint [gdb_get_line_number "break_end_of_vla_factory"]
@@ -109,10 +118,12 @@ gdb_test "print uchar_size == sizeof(unsigned_char_vla)" " = 1" \
          "size of unsigned_char_vla"
 gdb_test "print foo_size == sizeof(foo_vla)" " = 1" "size of foo_vla"
 gdb_test "print bar_size == sizeof(bar_vla)" " = 1" "size of bar_vla"
-gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
-    " = 1" "size of vla_struct_object"
-gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
-    " = 1" "size of vla_union_object"
+if {!$is_clang} {
+    gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
+	" = 1" "size of vla_struct_object"
+    gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
+	" = 1" "size of vla_union_object"
+}
 
 # Check side effects for sizeof argument.
 set sizeof_int [get_sizeof "int" 4]
-- 
1.8.3.1

Re: [PATCH] Skip VLA structure field tests when compiling with clang

[Luis Machado]

Hi,

As a general comment (for this and other patches like this), I think the 
preprocessor blocks intermixed with the test code make it harder to 
follow and update the test.

If clang claims it will never support a particular feature, then maybe 
we should have a separate testcase clang can actually run and skip this 
entire test if the compiler is clang?

Or maybe separate the bits clang doesn't support and put it into a 
separate test that clang-compiled hosts should skip?

On 6/30/20 8:12 AM, Gary Benson via Gdb-patches wrote:
> Hi all,
> 
> Clang fails to compile gdb.base/vla-datatypes.c with the following
> error: fields must have a constant size: 'variable length array in
> structure' extension will never be supported.  This patch adds
> preprocessor contitionals to vla-datatypes.c to not compile any code
> defining or using use VLA structure fields when compiling with clang,
> and modifies vla-datatypes.exp to skip all tests that require the
> omitted code as appropriate.
> 
> Checked on Fedora 31 x86_64, GCC and clang.  Ok to commit?
> 
> Cheers,
> Gary
> 
> --
> gdb/testsuite/ChangeLog:
> 
> 	* gdb.base/vla-datatypes.c (vla_factory): Wrap sections defining
> 	and using VLA structure fields with "#if !defined(__clang__)".
> 	* gdb.base/vla-datatypes.exp: Skip VLA structure field tests if
> 	compiling with clang.
> ---
>   gdb/testsuite/ChangeLog                  |  7 +++++
>   gdb/testsuite/gdb.base/vla-datatypes.c   |  8 ++++++
>   gdb/testsuite/gdb.base/vla-datatypes.exp | 47 ++++++++++++++++++++------------
>   3 files changed, 44 insertions(+), 18 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.base/vla-datatypes.c b/gdb/testsuite/gdb.base/vla-datatypes.c
> index 682319f..ce383a1 100644
> --- a/gdb/testsuite/gdb.base/vla-datatypes.c
> +++ b/gdb/testsuite/gdb.base/vla-datatypes.c
> @@ -46,6 +46,9 @@ struct foo
>     BAR             bar_vla[n];
>     int i;
>   
> +  /* Clang says it will never support variable length arrays in
> +     structures.  */
> +#if !defined(__clang__)
>     struct vla_struct
>     {
>       int something;
> @@ -89,6 +92,7 @@ struct foo
>     vla_struct_typedef_struct_member_object.something = n * 2;
>     vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
>     vla_struct_typedef_union_member_object.vla_object.something = n + 1;
> +#endif /* !defined(__clang__) */
>     for (i = 0; i < n; i++)
>       {
>         int_vla[i] = i*2;
> @@ -104,6 +108,7 @@ struct foo
>         foo_vla[i].a = i*2;
>         bar_vla[i].x = i*2;
>         bar_vla[i].y.a = i*2;
> +#if !defined(__clang__)
>         vla_struct_object.vla_field[i] = i*2;
>         vla_union_object.vla_field[i] = i*2;
>         inner_vla_struct_object.vla_field[i] = i*2;
> @@ -111,6 +116,7 @@ struct foo
>   	= i * 3;
>         vla_struct_typedef_union_member_object.vla_object.vla_field[i]
>   	= i * 3 - 1;
> +#endif /* !defined(__clang__) */
>       }
>   
>     size_t int_size        = sizeof(int_vla);     /* vlas_filled */
> @@ -124,9 +130,11 @@ struct foo
>     size_t uchar_size      = sizeof(unsigned_char_vla);
>     size_t foo_size        = sizeof(foo_vla);
>     size_t bar_size        = sizeof(bar_vla);
> +#if !defined(__clang__)
>     size_t vla_struct_object_size = sizeof(vla_struct_object);
>     size_t vla_union_object_size = sizeof(vla_union_object);
>     size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
> +#endif /* !defined(__clang__) */
>   
>     return;                                 /* break_end_of_vla_factory */
>   }
> diff --git a/gdb/testsuite/gdb.base/vla-datatypes.exp b/gdb/testsuite/gdb.base/vla-datatypes.exp
> index e8d8457..2924475 100644
> --- a/gdb/testsuite/gdb.base/vla-datatypes.exp
> +++ b/gdb/testsuite/gdb.base/vla-datatypes.exp
> @@ -15,6 +15,9 @@
>   
>   standard_testfile
>   
> +# Clang says it will never support variable length arrays in structures.
> +set is_clang [test_compiler_info clang*]
> +
>   if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
>       return -1
>   }
> @@ -41,14 +44,16 @@ gdb_test "print foo_vla" \
>            "\\\{\\\{a = 0\\\}, \\\{a = 2\\\}, \\\{a = 4\\\}, \\\{a = 6\\\}, \\\{a = 8\\\}\\\}"
>   gdb_test "print bar_vla" \
>            "\\\{\\\{x = 0, y = \\\{a = 0\\\}\\\}, \\\{x = 2, y = \\\{a = 2\\\}\\\}, \\\{x = 4, y = \\\{a = 4\\\}\\\}, \\\{x = 6, y = \\\{a = 6\\\}\\\}, \\\{x = 8, y = \\\{a = 8\\\}\\\}\\\}"
> -gdb_test "print vla_struct_object" \
> -    "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> -gdb_test "print vla_union_object" \
> -    "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> -gdb_test "print vla_struct_typedef_struct_member_object" \
> -    "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
> -gdb_test "print vla_struct_typedef_union_member_object" \
> -    "\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
> +if {!$is_clang} {
> +    gdb_test "print vla_struct_object" \
> +	"\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> +    gdb_test "print vla_union_object" \
> +	"\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> +    gdb_test "print vla_struct_typedef_struct_member_object" \
> +	"\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
> +    gdb_test "print vla_struct_typedef_union_member_object" \
> +	"\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
> +}
>   
>   # Check whatis of VLA's.
>   gdb_test "whatis int_vla" "type = int \\\[5\\\]"
> @@ -65,8 +70,10 @@ gdb_test "whatis unsigned_short_vla" \
>   gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]"
>   gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]"
>   gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]"
> -gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
> -gdb_test "whatis vla_union_object" "type = union vla_union"
> +if {!$is_clang} {
> +    gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
> +    gdb_test "whatis vla_union_object" "type = union vla_union"
> +}
>   
>   # Check ptype of VLA's.
>   gdb_test "ptype int_vla" "type = int \\\[5\\\]"
> @@ -82,10 +89,12 @@ gdb_test "ptype unsigned_char_vla" "type = unsigned char \\\[5\\\]"
>   gdb_test "ptype foo_vla" "type = struct foo {\r\n\\s+int a;\r\n} \\\[5\\\]"
>   gdb_test "ptype bar_vla" \
>            "type = struct bar {\r\n\\s+int x;\r\n\\s+struct foo y;\r\n} \\\[5\\\]"
> -gdb_test "ptype vla_struct_object" \
> -    "type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
> -gdb_test "ptype vla_union_object" \
> -    "type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
> +if {!$is_clang} {
> +    gdb_test "ptype vla_struct_object" \
> +	"type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
> +    gdb_test "ptype vla_union_object" \
> +	"type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
> +}
>   
>   # Check the size of the VLA's.
>   gdb_breakpoint [gdb_get_line_number "break_end_of_vla_factory"]
> @@ -109,10 +118,12 @@ gdb_test "print uchar_size == sizeof(unsigned_char_vla)" " = 1" \
>            "size of unsigned_char_vla"
>   gdb_test "print foo_size == sizeof(foo_vla)" " = 1" "size of foo_vla"
>   gdb_test "print bar_size == sizeof(bar_vla)" " = 1" "size of bar_vla"
> -gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
> -    " = 1" "size of vla_struct_object"
> -gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
> -    " = 1" "size of vla_union_object"
> +if {!$is_clang} {
> +    gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
> +	" = 1" "size of vla_struct_object"
> +    gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
> +	" = 1" "size of vla_union_object"
> +}
>   
>   # Check side effects for sizeof argument.
>   set sizeof_int [get_sizeof "int" 4]
> 

[PATCH v2] Skip VLA structure field tests when compiling with clang

[Gary Benson]

Hi Luis,

Luis Machado wrote:
> As a general comment (for this and other patches like this), I think
> the preprocessor blocks intermixed with the test code make it harder
> to follow and update the test.
>
> If clang claims it will never support a particular feature, then
> maybe we should ... separate the bits clang doesn't support and put
> it into a separate test that clang-compiled hosts should skip?

Thanks for the review.  I've made that change, the updated patch is
below.  I checked it on Fedora 31 x86_64, GCC and clang.  Is it ok to
commit?

Cheers
Gary

--
Clang fails to compile gdb.base/vla-datatypes.c with the following
error: fields must have a constant size: 'variable length array in
structure' extension will never be supported.  This patch factors
the affected tests out into a new testcase, vla-struct-fields.{exp,c},
which is skipped when the testcase is compiled using clang,

gdb/testsuite/ChangeLog:

	* gdb.base/vla-datatypes.c (vla_factory): Factor out sections
	defining and using VLA structure fields into...
	* gdb.base/vla-struct-fields.c: New file.
	* gdb.base/vla-datatypes.exp: Factor out VLA structure field
	tests into...
	* gdb.base/vla-struct-fields.exp: New file.
---
 gdb/testsuite/ChangeLog                      |   9 +++
 gdb/testsuite/gdb.base/vla-datatypes.c       |  53 --------------
 gdb/testsuite/gdb.base/vla-datatypes.exp     |  24 -------
 gdb/testsuite/gdb.base/vla-struct-fields.c   | 104 +++++++++++++++++++++++++++
 gdb/testsuite/gdb.base/vla-struct-fields.exp |  67 +++++++++++++++++
 5 files changed, 180 insertions(+), 77 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/vla-struct-fields.c
 create mode 100644 gdb/testsuite/gdb.base/vla-struct-fields.exp

diff --git a/gdb/testsuite/gdb.base/vla-datatypes.c b/gdb/testsuite/gdb.base/vla-datatypes.c
index 682319f..d8b835a 100644
--- a/gdb/testsuite/gdb.base/vla-datatypes.c
+++ b/gdb/testsuite/gdb.base/vla-datatypes.c
@@ -46,49 +46,6 @@ struct foo
   BAR             bar_vla[n];
   int i;
 
-  struct vla_struct
-  {
-    int something;
-    int vla_field[n];
-  };
-  /* Define a typedef for a VLA structure.  */
-  typedef struct vla_struct vla_struct_typedef;
-  vla_struct_typedef vla_struct_object;
-
-  struct inner_vla_struct
-  {
-    int something;
-    int vla_field[n];
-    int after;
-  } inner_vla_struct_object;
-
-  /* Define a structure which uses a typedef for the VLA field
-     to make sure that GDB creates the proper type for this field,
-     preventing a possible assertion failure (see gdb/21356).  */
-  struct vla_struct_typedef_struct_member
-  {
-    int something;
-    vla_struct_typedef vla_object;
-  } vla_struct_typedef_struct_member_object;
-
-  union vla_union
-  {
-    int vla_field[n];
-  } vla_union_object;
-
-  /* Like vla_struct_typedef_struct_member but a union type.  */
-  union vla_struct_typedef_union_member
-  {
-    int something;
-    vla_struct_typedef vla_object;
-  } vla_struct_typedef_union_member_object;
-
-  vla_struct_object.something = n;
-  inner_vla_struct_object.something = n;
-  inner_vla_struct_object.after = n;
-  vla_struct_typedef_struct_member_object.something = n * 2;
-  vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
-  vla_struct_typedef_union_member_object.vla_object.something = n + 1;
   for (i = 0; i < n; i++)
     {
       int_vla[i] = i*2;
@@ -104,13 +61,6 @@ struct foo
       foo_vla[i].a = i*2;
       bar_vla[i].x = i*2;
       bar_vla[i].y.a = i*2;
-      vla_struct_object.vla_field[i] = i*2;
-      vla_union_object.vla_field[i] = i*2;
-      inner_vla_struct_object.vla_field[i] = i*2;
-      vla_struct_typedef_struct_member_object.vla_object.vla_field[i]
-	= i * 3;
-      vla_struct_typedef_union_member_object.vla_object.vla_field[i]
-	= i * 3 - 1;
     }
 
   size_t int_size        = sizeof(int_vla);     /* vlas_filled */
@@ -124,9 +74,6 @@ struct foo
   size_t uchar_size      = sizeof(unsigned_char_vla);
   size_t foo_size        = sizeof(foo_vla);
   size_t bar_size        = sizeof(bar_vla);
-  size_t vla_struct_object_size = sizeof(vla_struct_object);
-  size_t vla_union_object_size = sizeof(vla_union_object);
-  size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
 
   return;                                 /* break_end_of_vla_factory */
 }
diff --git a/gdb/testsuite/gdb.base/vla-datatypes.exp b/gdb/testsuite/gdb.base/vla-datatypes.exp
index e8d8457..201f051 100644
--- a/gdb/testsuite/gdb.base/vla-datatypes.exp
+++ b/gdb/testsuite/gdb.base/vla-datatypes.exp
@@ -41,14 +41,6 @@ gdb_test "print foo_vla" \
          "\\\{\\\{a = 0\\\}, \\\{a = 2\\\}, \\\{a = 4\\\}, \\\{a = 6\\\}, \\\{a = 8\\\}\\\}"
 gdb_test "print bar_vla" \
          "\\\{\\\{x = 0, y = \\\{a = 0\\\}\\\}, \\\{x = 2, y = \\\{a = 2\\\}\\\}, \\\{x = 4, y = \\\{a = 4\\\}\\\}, \\\{x = 6, y = \\\{a = 6\\\}\\\}, \\\{x = 8, y = \\\{a = 8\\\}\\\}\\\}"
-gdb_test "print vla_struct_object" \
-    "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
-gdb_test "print vla_union_object" \
-    "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
-gdb_test "print vla_struct_typedef_struct_member_object" \
-    "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
-gdb_test "print vla_struct_typedef_union_member_object" \
-    "\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
 
 # Check whatis of VLA's.
 gdb_test "whatis int_vla" "type = int \\\[5\\\]"
@@ -65,8 +57,6 @@ gdb_test "whatis unsigned_short_vla" \
 gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]"
 gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]"
 gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]"
-gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
-gdb_test "whatis vla_union_object" "type = union vla_union"
 
 # Check ptype of VLA's.
 gdb_test "ptype int_vla" "type = int \\\[5\\\]"
@@ -82,10 +72,6 @@ gdb_test "ptype unsigned_char_vla" "type = unsigned char \\\[5\\\]"
 gdb_test "ptype foo_vla" "type = struct foo {\r\n\\s+int a;\r\n} \\\[5\\\]"
 gdb_test "ptype bar_vla" \
          "type = struct bar {\r\n\\s+int x;\r\n\\s+struct foo y;\r\n} \\\[5\\\]"
-gdb_test "ptype vla_struct_object" \
-    "type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
-gdb_test "ptype vla_union_object" \
-    "type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
 
 # Check the size of the VLA's.
 gdb_breakpoint [gdb_get_line_number "break_end_of_vla_factory"]
@@ -109,10 +95,6 @@ gdb_test "print uchar_size == sizeof(unsigned_char_vla)" " = 1" \
          "size of unsigned_char_vla"
 gdb_test "print foo_size == sizeof(foo_vla)" " = 1" "size of foo_vla"
 gdb_test "print bar_size == sizeof(bar_vla)" " = 1" "size of bar_vla"
-gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
-    " = 1" "size of vla_struct_object"
-gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
-    " = 1" "size of vla_union_object"
 
 # Check side effects for sizeof argument.
 set sizeof_int [get_sizeof "int" 4]
@@ -130,9 +112,3 @@ gdb_test "print int_vla\[0\]" " = 42" \
 gdb_test "whatis ++int_vla\[0\]" "type = int"
 gdb_test "print int_vla\[0\]" " = 42" \
          "print int_vla\[0\] - whatis no side effects"
-
-# Fails due to incorrect debugging information generated by GCC.
-setup_xfail "*-*-*"
-gdb_test \
-    "print inner_vla_struct_object_size == sizeof(inner_vla_struct_object)" \
-    " = 1" "size of inner_vla_struct_object"
diff --git a/gdb/testsuite/gdb.base/vla-struct-fields.c b/gdb/testsuite/gdb.base/vla-struct-fields.c
new file mode 100644
index 0000000..ef236a7
--- /dev/null
+++ b/gdb/testsuite/gdb.base/vla-struct-fields.c
@@ -0,0 +1,104 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2014-2020 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <stddef.h>
+#define SIZE 5
+
+struct foo
+{
+  int a;
+};
+
+typedef struct bar
+{
+  int x;
+  struct foo y;
+} BAR;
+
+void
+vla_factory (int n)
+{
+  struct vla_struct
+  {
+    int something;
+    int vla_field[n];
+  };
+  /* Define a typedef for a VLA structure.  */
+  typedef struct vla_struct vla_struct_typedef;
+  vla_struct_typedef vla_struct_object;
+
+  struct inner_vla_struct
+  {
+    int something;
+    int vla_field[n];
+    int after;
+  } inner_vla_struct_object;
+
+  /* Define a structure which uses a typedef for the VLA field
+     to make sure that GDB creates the proper type for this field,
+     preventing a possible assertion failure (see gdb/21356).  */
+  struct vla_struct_typedef_struct_member
+  {
+    int something;
+    vla_struct_typedef vla_object;
+  } vla_struct_typedef_struct_member_object;
+
+  union vla_union
+  {
+    int vla_field[n];
+  } vla_union_object;
+
+  /* Like vla_struct_typedef_struct_member but a union type.  */
+  union vla_struct_typedef_union_member
+  {
+    int something;
+    vla_struct_typedef vla_object;
+  } vla_struct_typedef_union_member_object;
+  int i;
+
+  vla_struct_object.something = n;
+  inner_vla_struct_object.something = n;
+  inner_vla_struct_object.after = n;
+  vla_struct_typedef_struct_member_object.something = n * 2;
+  vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
+  vla_struct_typedef_union_member_object.vla_object.something = n + 1;
+
+  for (i = 0; i < n; i++)
+    {
+      vla_struct_object.vla_field[i] = i*2;
+      vla_union_object.vla_field[i] = i*2;
+      inner_vla_struct_object.vla_field[i] = i*2;
+      vla_struct_typedef_struct_member_object.vla_object.vla_field[i]
+	= i * 3;
+      vla_struct_typedef_union_member_object.vla_object.vla_field[i]
+	= i * 3 - 1;
+    }
+
+  size_t vla_struct_object_size
+    = sizeof(vla_struct_object);          /* vlas_filled */
+  size_t vla_union_object_size = sizeof(vla_union_object);
+  size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
+
+  return;                                 /* break_end_of_vla_factory */
+}
+
+int
+main (void)
+{
+  vla_factory(SIZE);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/vla-struct-fields.exp b/gdb/testsuite/gdb.base/vla-struct-fields.exp
new file mode 100644
index 0000000..150a328
--- /dev/null
+++ b/gdb/testsuite/gdb.base/vla-struct-fields.exp
@@ -0,0 +1,67 @@
+# Copyright 2014-2020 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile
+
+# Clang says it will never support variable length arrays in structures.
+if {[test_compiler_info clang*]} {
+    unsupported "compiler does not variable length arrays in structure"
+    return
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
+    return -1
+}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint [gdb_get_line_number "vlas_filled"]
+gdb_continue_to_breakpoint "vlas_filled"
+
+# Check the values of VLA's.
+gdb_test "print vla_struct_object" \
+    "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
+gdb_test "print vla_union_object" \
+    "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
+gdb_test "print vla_struct_typedef_struct_member_object" \
+    "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
+gdb_test "print vla_struct_typedef_union_member_object" \
+    "\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
+
+# Check whatis of VLA's.
+gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
+gdb_test "whatis vla_union_object" "type = union vla_union"
+
+# Check ptype of VLA's.
+gdb_test "ptype vla_struct_object" \
+    "type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
+gdb_test "ptype vla_union_object" \
+    "type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
+
+# Check the size of the VLA's.
+gdb_breakpoint [gdb_get_line_number "break_end_of_vla_factory"]
+gdb_continue_to_breakpoint "break_end_of_vla_factory"
+gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
+    " = 1" "size of vla_struct_object"
+gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
+    " = 1" "size of vla_union_object"
+
+# Fails due to incorrect debugging information generated by GCC.
+setup_xfail "*-*-*"
+gdb_test \
+    "print inner_vla_struct_object_size == sizeof(inner_vla_struct_object)" \
+    " = 1" "size of inner_vla_struct_object"
-- 
1.8.3.1

Re: [PATCH v2] Skip VLA structure field tests when compiling with clang

[Luis Machado]

Hi Gary,

On 7/8/20 12:46 PM, Gary Benson wrote:
> Hi Luis,
> 
> Luis Machado wrote:
>> As a general comment (for this and other patches like this), I think
>> the preprocessor blocks intermixed with the test code make it harder
>> to follow and update the test.
>>
>> If clang claims it will never support a particular feature, then
>> maybe we should ... separate the bits clang doesn't support and put
>> it into a separate test that clang-compiled hosts should skip?
> 
> Thanks for the review.  I've made that change, the updated patch is
> below.  I checked it on Fedora 31 x86_64, GCC and clang.  Is it ok to
> commit?

Thanks. That looks cleaner. Just a gotcha below...

> 
> Cheers
> Gary
> 
> --
> Clang fails to compile gdb.base/vla-datatypes.c with the following
> error: fields must have a constant size: 'variable length array in
> structure' extension will never be supported.  This patch factors
> the affected tests out into a new testcase, vla-struct-fields.{exp,c},
> which is skipped when the testcase is compiled using clang,
> 
> gdb/testsuite/ChangeLog:
> 
> 	* gdb.base/vla-datatypes.c (vla_factory): Factor out sections
> 	defining and using VLA structure fields into...
> 	* gdb.base/vla-struct-fields.c: New file.
> 	* gdb.base/vla-datatypes.exp: Factor out VLA structure field
> 	tests into...
> 	* gdb.base/vla-struct-fields.exp: New file.
> ---
>   gdb/testsuite/ChangeLog                      |   9 +++
>   gdb/testsuite/gdb.base/vla-datatypes.c       |  53 --------------
>   gdb/testsuite/gdb.base/vla-datatypes.exp     |  24 -------
>   gdb/testsuite/gdb.base/vla-struct-fields.c   | 104 +++++++++++++++++++++++++++
>   gdb/testsuite/gdb.base/vla-struct-fields.exp |  67 +++++++++++++++++
>   5 files changed, 180 insertions(+), 77 deletions(-)
>   create mode 100644 gdb/testsuite/gdb.base/vla-struct-fields.c
>   create mode 100644 gdb/testsuite/gdb.base/vla-struct-fields.exp
> 
> diff --git a/gdb/testsuite/gdb.base/vla-datatypes.c b/gdb/testsuite/gdb.base/vla-datatypes.c
> index 682319f..d8b835a 100644
> --- a/gdb/testsuite/gdb.base/vla-datatypes.c
> +++ b/gdb/testsuite/gdb.base/vla-datatypes.c
> @@ -46,49 +46,6 @@ struct foo
>     BAR             bar_vla[n];
>     int i;
>   
> -  struct vla_struct
> -  {
> -    int something;
> -    int vla_field[n];
> -  };
> -  /* Define a typedef for a VLA structure.  */
> -  typedef struct vla_struct vla_struct_typedef;
> -  vla_struct_typedef vla_struct_object;
> -
> -  struct inner_vla_struct
> -  {
> -    int something;
> -    int vla_field[n];
> -    int after;
> -  } inner_vla_struct_object;
> -
> -  /* Define a structure which uses a typedef for the VLA field
> -     to make sure that GDB creates the proper type for this field,
> -     preventing a possible assertion failure (see gdb/21356).  */
> -  struct vla_struct_typedef_struct_member
> -  {
> -    int something;
> -    vla_struct_typedef vla_object;
> -  } vla_struct_typedef_struct_member_object;
> -
> -  union vla_union
> -  {
> -    int vla_field[n];
> -  } vla_union_object;
> -
> -  /* Like vla_struct_typedef_struct_member but a union type.  */
> -  union vla_struct_typedef_union_member
> -  {
> -    int something;
> -    vla_struct_typedef vla_object;
> -  } vla_struct_typedef_union_member_object;
> -
> -  vla_struct_object.something = n;
> -  inner_vla_struct_object.something = n;
> -  inner_vla_struct_object.after = n;
> -  vla_struct_typedef_struct_member_object.something = n * 2;
> -  vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
> -  vla_struct_typedef_union_member_object.vla_object.something = n + 1;
>     for (i = 0; i < n; i++)
>       {
>         int_vla[i] = i*2;
> @@ -104,13 +61,6 @@ struct foo
>         foo_vla[i].a = i*2;
>         bar_vla[i].x = i*2;
>         bar_vla[i].y.a = i*2;
> -      vla_struct_object.vla_field[i] = i*2;
> -      vla_union_object.vla_field[i] = i*2;
> -      inner_vla_struct_object.vla_field[i] = i*2;
> -      vla_struct_typedef_struct_member_object.vla_object.vla_field[i]
> -	= i * 3;
> -      vla_struct_typedef_union_member_object.vla_object.vla_field[i]
> -	= i * 3 - 1;
>       }
>   
>     size_t int_size        = sizeof(int_vla);     /* vlas_filled */
> @@ -124,9 +74,6 @@ struct foo
>     size_t uchar_size      = sizeof(unsigned_char_vla);
>     size_t foo_size        = sizeof(foo_vla);
>     size_t bar_size        = sizeof(bar_vla);
> -  size_t vla_struct_object_size = sizeof(vla_struct_object);
> -  size_t vla_union_object_size = sizeof(vla_union_object);
> -  size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
>   
>     return;                                 /* break_end_of_vla_factory */
>   }
> diff --git a/gdb/testsuite/gdb.base/vla-datatypes.exp b/gdb/testsuite/gdb.base/vla-datatypes.exp
> index e8d8457..201f051 100644
> --- a/gdb/testsuite/gdb.base/vla-datatypes.exp
> +++ b/gdb/testsuite/gdb.base/vla-datatypes.exp
> @@ -41,14 +41,6 @@ gdb_test "print foo_vla" \
>            "\\\{\\\{a = 0\\\}, \\\{a = 2\\\}, \\\{a = 4\\\}, \\\{a = 6\\\}, \\\{a = 8\\\}\\\}"
>   gdb_test "print bar_vla" \
>            "\\\{\\\{x = 0, y = \\\{a = 0\\\}\\\}, \\\{x = 2, y = \\\{a = 2\\\}\\\}, \\\{x = 4, y = \\\{a = 4\\\}\\\}, \\\{x = 6, y = \\\{a = 6\\\}\\\}, \\\{x = 8, y = \\\{a = 8\\\}\\\}\\\}"
> -gdb_test "print vla_struct_object" \
> -    "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> -gdb_test "print vla_union_object" \
> -    "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
> -gdb_test "print vla_struct_typedef_struct_member_object" \
> -    "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
> -gdb_test "print vla_struct_typedef_union_member_object" \
> -    "\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
>   
>   # Check whatis of VLA's.
>   gdb_test "whatis int_vla" "type = int \\\[5\\\]"
> @@ -65,8 +57,6 @@ gdb_test "whatis unsigned_short_vla" \
>   gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]"
>   gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]"
>   gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]"
> -gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
> -gdb_test "whatis vla_union_object" "type = union vla_union"
>   
>   # Check ptype of VLA's.
>   gdb_test "ptype int_vla" "type = int \\\[5\\\]"
> @@ -82,10 +72,6 @@ gdb_test "ptype unsigned_char_vla" "type = unsigned char \\\[5\\\]"
>   gdb_test "ptype foo_vla" "type = struct foo {\r\n\\s+int a;\r\n} \\\[5\\\]"
>   gdb_test "ptype bar_vla" \
>            "type = struct bar {\r\n\\s+int x;\r\n\\s+struct foo y;\r\n} \\\[5\\\]"
> -gdb_test "ptype vla_struct_object" \
> -    "type = struct vla_struct {\r\n\\s+int something;\r\n\\s+int vla_field\\\[5\\\];\r\n}"
> -gdb_test "ptype vla_union_object" \
> -    "type = union vla_union {\r\n\\s+int vla_field\\\[5\\\];\r\n}"
>   
>   # Check the size of the VLA's.
>   gdb_breakpoint [gdb_get_line_number "break_end_of_vla_factory"]
> @@ -109,10 +95,6 @@ gdb_test "print uchar_size == sizeof(unsigned_char_vla)" " = 1" \
>            "size of unsigned_char_vla"
>   gdb_test "print foo_size == sizeof(foo_vla)" " = 1" "size of foo_vla"
>   gdb_test "print bar_size == sizeof(bar_vla)" " = 1" "size of bar_vla"
> -gdb_test "print vla_struct_object_size == sizeof(vla_struct_object)" \
> -    " = 1" "size of vla_struct_object"
> -gdb_test "print vla_union_object_size == sizeof(vla_union_object)" \
> -    " = 1" "size of vla_union_object"
>   
>   # Check side effects for sizeof argument.
>   set sizeof_int [get_sizeof "int" 4]
> @@ -130,9 +112,3 @@ gdb_test "print int_vla\[0\]" " = 42" \
>   gdb_test "whatis ++int_vla\[0\]" "type = int"
>   gdb_test "print int_vla\[0\]" " = 42" \
>            "print int_vla\[0\] - whatis no side effects"
> -
> -# Fails due to incorrect debugging information generated by GCC.
> -setup_xfail "*-*-*"
> -gdb_test \
> -    "print inner_vla_struct_object_size == sizeof(inner_vla_struct_object)" \
> -    " = 1" "size of inner_vla_struct_object"
> diff --git a/gdb/testsuite/gdb.base/vla-struct-fields.c b/gdb/testsuite/gdb.base/vla-struct-fields.c
> new file mode 100644
> index 0000000..ef236a7
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/vla-struct-fields.c
> @@ -0,0 +1,104 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> +   Copyright 2014-2020 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +#include <stddef.h>
> +#define SIZE 5
> +
> +struct foo
> +{
> +  int a;
> +};
> +
> +typedef struct bar
> +{
> +  int x;
> +  struct foo y;
> +} BAR;
> +
> +void
> +vla_factory (int n)
> +{
> +  struct vla_struct
> +  {
> +    int something;
> +    int vla_field[n];
> +  };
> +  /* Define a typedef for a VLA structure.  */
> +  typedef struct vla_struct vla_struct_typedef;
> +  vla_struct_typedef vla_struct_object;
> +
> +  struct inner_vla_struct
> +  {
> +    int something;
> +    int vla_field[n];
> +    int after;
> +  } inner_vla_struct_object;
> +
> +  /* Define a structure which uses a typedef for the VLA field
> +     to make sure that GDB creates the proper type for this field,
> +     preventing a possible assertion failure (see gdb/21356).  */
> +  struct vla_struct_typedef_struct_member
> +  {
> +    int something;
> +    vla_struct_typedef vla_object;
> +  } vla_struct_typedef_struct_member_object;
> +
> +  union vla_union
> +  {
> +    int vla_field[n];
> +  } vla_union_object;
> +
> +  /* Like vla_struct_typedef_struct_member but a union type.  */
> +  union vla_struct_typedef_union_member
> +  {
> +    int something;
> +    vla_struct_typedef vla_object;
> +  } vla_struct_typedef_union_member_object;
> +  int i;
> +
> +  vla_struct_object.something = n;
> +  inner_vla_struct_object.something = n;
> +  inner_vla_struct_object.after = n;
> +  vla_struct_typedef_struct_member_object.something = n * 2;
> +  vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
> +  vla_struct_typedef_union_member_object.vla_object.something = n + 1;
> +
> +  for (i = 0; i < n; i++)
> +    {
> +      vla_struct_object.vla_field[i] = i*2;
> +      vla_union_object.vla_field[i] = i*2;
> +      inner_vla_struct_object.vla_field[i] = i*2;
> +      vla_struct_typedef_struct_member_object.vla_object.vla_field[i]
> +	= i * 3;
> +      vla_struct_typedef_union_member_object.vla_object.vla_field[i]
> +	= i * 3 - 1;
> +    }
> +
> +  size_t vla_struct_object_size
> +    = sizeof(vla_struct_object);          /* vlas_filled */
> +  size_t vla_union_object_size = sizeof(vla_union_object);
> +  size_t inner_vla_struct_object_size = sizeof(inner_vla_struct_object);
> +
> +  return;                                 /* break_end_of_vla_factory */
> +}
> +
> +int
> +main (void)
> +{
> +  vla_factory(SIZE);
> +  return 0;
> +}
> diff --git a/gdb/testsuite/gdb.base/vla-struct-fields.exp b/gdb/testsuite/gdb.base/vla-struct-fields.exp
> new file mode 100644
> index 0000000..150a328
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/vla-struct-fields.exp
> @@ -0,0 +1,67 @@
> +# Copyright 2014-2020 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +standard_testfile
> +
> +# Clang says it will never support variable length arrays in structures.
> +if {[test_compiler_info clang*]} {
> +    unsupported "compiler does not variable length arrays in structure"

                                       ^^^ support?

Otherwise this looks good to me. Can't approve a commit though.

Re: [PATCH v2] Skip VLA structure field tests when compiling with clang

[Gary Benson]

Luis Machado wrote:
> Hi Gary,
> 
> On 7/8/20 12:46 PM, Gary Benson wrote:
> > Hi Luis,
> > 
> > Luis Machado wrote:
> > > As a general comment (for this and other patches like this), I
> > > think the preprocessor blocks intermixed with the test code make
> > > it harder to follow and update the test.
> > > 
> > > If clang claims it will never support a particular feature, then
> > > maybe we should ... separate the bits clang doesn't support and
> > > put it into a separate test that clang-compiled hosts should
> > > skip?
> > 
> > Thanks for the review.  I've made that change, the updated patch
> > is below.  I checked it on Fedora 31 x86_64, GCC and clang.  Is it
> > ok to commit?
> 
> Thanks. That looks cleaner. Just a gotcha below...
> 
[snip]
> > +
> > +# Clang says it will never support variable length arrays in structures.
> > +if {[test_compiler_info clang*]} {
> > +    unsupported "compiler does not variable length arrays in structure"
> 
>                                       ^^^ support?
> 
> Otherwise this looks good to me. Can't approve a commit though.

Good catch.  Thanks for your review, I've fixed this in my tree.

Cheers,
Gary

-- 
Gary Benson - he / him / his
Principal Software Engineer, Red Hat

Re: [PATCH v2] Skip VLA structure field tests when compiling with clang

[Pedro Alves]

On 7/10/20 1:00 PM, Gary Benson via Gdb-patches wrote:

>>> +# Clang says it will never support variable length arrays in structures.
>>> +if {[test_compiler_info clang*]} {
>>> +    unsupported "compiler does not variable length arrays in structure"
>>
>>                                       ^^^ support?
>>
>> Otherwise this looks good to me. Can't approve a commit though.
> 
> Good catch.  Thanks for your review, I've fixed this in my tree.

This is OK with that fixed.

Thanks,
Pedro Alves

Re: [PATCH v2] Skip VLA structure field tests when compiling with clang

[Gary Benson]

Pedro Alves wrote:
> On 7/10/20 1:00 PM, Gary Benson via Gdb-patches wrote:
> > > > +# Clang says it will never support variable length arrays in structures.
> > > > +if {[test_compiler_info clang*]} {
> > > > +    unsupported "compiler does not variable length arrays in structure"
> > >
> > >                                       ^^^ support?
> > >
> > > Otherwise this looks good to me. Can't approve a commit though.
> > 
> > Good catch.  Thanks for your review, I've fixed this in my tree.
> 
> This is OK with that fixed.

Thanks, I've pushed it.

Cheers,
Gary

-- 
Gary Benson - he / him / his
Principal Software Engineer, Red Hat