clang complains:
asm_newscn.c:48:22: error: field 'pattern' with variable sized type 'struct
FillPattern' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct FillPattern pattern;
^
Fix by using a union instead. Define the second union member to be a
char array 1 byte larger than struct FillPattern. This should be legal
according to 6.7.9:
If an object that has static or thread storage duration is not
initialized explicitly, then ... if it is a union, the first named
member is initialized (recursively) according to these rules, and
any padding is initialized to zero bits.
Signed-off-by: Ilya Leoshkevich <[email protected]>
---
libasm/asm_newscn.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/libasm/asm_newscn.c b/libasm/asm_newscn.c
index d258d969..f28c40f9 100644
--- a/libasm/asm_newscn.c
+++ b/libasm/asm_newscn.c
@@ -41,19 +41,25 @@
/* Memory for the default pattern. The type uses a flexible array
- which does work well with a static initializer. So we play some
- dirty tricks here. */
-static const struct
+ which does work well with a static initializer. Work around this by
+ wrapping it in a union, whose second member is a char array 1 byte larger
+ than struct FillPattern. According to 6.7.9, this does what we need:
+
+ If an object that has static or thread storage duration is not
+ initialized explicitly, then ... if it is a union, the first named
+ member is initialized (recursively) according to these rules, and
+ any padding is initialized to zero bits. */
+
+static const union
{
struct FillPattern pattern;
- char zero;
+ char zeroes[sizeof(struct FillPattern) + 1];
} xdefault_pattern =
{
.pattern =
{
.len = 1
},
- .zero = '\0'
};
const struct FillPattern *__libasm_default_pattern = &xdefault_pattern.pattern;
--
2.39.1
