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Diffstat (limited to 'gcc/extend.texi')
| -rw-r--r-- | gcc/extend.texi | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/gcc/extend.texi b/gcc/extend.texi index 573b36cd331..0d88bdf175e 100644 --- a/gcc/extend.texi +++ b/gcc/extend.texi @@ -886,12 +886,25 @@ struct line @{ @} @end example -In standard C, you would have to give @code{contents} a length of 1, which +In ISO C89, you would have to give @code{contents} a length of 1, which means either you waste space or complicate the argument to @code{malloc}. -Static initialization of the zero-length array is not allowed. A -warning will be generated for each initializer attempting to initialize -the zero-length array. +In ISO C99, you would use a @dfn{flexible array member}, which uses a +slightly different syntax: leave out the @code{0} and write +@code{contents[]}. + +GCC allows static initialization of the zero-length array if +the structure is not nested inside another structure. I.e. + +@example +/* Legal. */ +struct line x = @{ 4, @{ 'g', 'o', 'o', 'd' @} @}; + +/* Illegal. */ +struct bar @{ + struct line a; +@} y = @{ @{ 3, @{ 'b', 'a', 'd' @} @} @}; +@end example @node Variable Length @section Arrays of Variable Length |
