Altera Nios II C2H Compiler - Manual (Page 126)

7–2 9.1 Altera Corporation
Nios II C2H Compiler User Guide November 2009
Language
■ Escape character sequences in character constants are supported if
they are used as string literals rather than character constants.
The following declaration is supported because it employs a string
literal:
char *newline = "\n";
The following declaration is not supported because it employs a
character constant:
char newline = '\n';
■ Composite concatenation is not supported in initialization
statements.
The C2H Compiler does not support the initialization statement
which concatenates two strings, such as the following:
char s[] = "this" " string";
The following declaration is supported:
char s[] = "this string";
Bit-Field Declarations (Section 6.7.2.1)
Structs are supported; however, bit-field declarations used in packed
structs are not supported.
For example, the following packed struct defining a 3-bit field is not
supported:
struct my_struct
{
unsigned int tbits:3;
} ms;
ms.tbits = 0xFF;
You can use a mask of appropriate length to identify the significant bits:
struct my_struct
{
unsigned int tbits;
} ms;
ms.tbits = 0xFF & 7;