Re: [Qemu-devel] [PATCH] multiboot: make tests work with clang

[Philippe Mathieu-Daudé]

Hi Anatol,

Next time use 'v2' for an updated patch (for the automated tracking 
tools), also no need to link it to the previous Message-Id it looks more 
messy and can get lost.

On 08/23/2017 09:01 PM, Anatol Pomozov wrote:
>   * clang 3.8 enables SSE even for 32bit code. Generate code for pentium
>     CPU to make sure no new instructions are used.
>   * add memset() implementation. Clang implements array zeroing in
>     print_num() via memset() function call.
> ---
>   tests/multiboot/Makefile    | 2 +-
>   tests/multiboot/libc.c      | 9 +++++++++
>   tests/multiboot/libc.h      | 2 ++
>   tests/multiboot/run_test.sh | 1 +
>   4 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/tests/multiboot/Makefile b/tests/multiboot/Makefile
> index 856e76682a..2e015409dc 100644
> --- a/tests/multiboot/Makefile
> +++ b/tests/multiboot/Makefile
> @@ -1,5 +1,5 @@
>   CC=gcc
> -CCFLAGS=-m32 -Wall -Wextra -Werror -fno-stack-protector -nostdinc -fno-builtin
> +CCFLAGS=-m32 -Wall -Wextra -Werror -fno-stack-protector -nostdinc -fno-builtin 
> -march=pentium

Now that I remark it, I think -ffreestanding is a better flag to 
multiboot than -fno-builtin.

>   ASFLAGS=-m32
>   
>   LD=ld
> diff --git a/tests/multiboot/libc.c b/tests/multiboot/libc.c
> index 6df9bda96d..512fccd7fa 100644
> --- a/tests/multiboot/libc.c
> +++ b/tests/multiboot/libc.c
> @@ -33,6 +33,15 @@ void* memcpy(void *dest, const void *src, int n)
>   
>       return dest;
>   }
> +void *memset(void *s, int c, size_t n)
> +{
> +    size_t i;
> +    char *d = s;
> +    for (i = 0; i < n; i++) {
> +        *d++ = c;
> +    }
> +    return s;
> +}
>   
>   static void print_char(char c)
>   {
> diff --git a/tests/multiboot/libc.h b/tests/multiboot/libc.h
> index 04c9922c27..44b71350dd 100644
> --- a/tests/multiboot/libc.h
> +++ b/tests/multiboot/libc.h
> @@ -36,6 +36,7 @@ typedef signed short int16_t;
>   typedef signed char int8_t;
>   
>   typedef uint32_t uintptr_t;
> +typedef uint32_t size_t;
>   

I'd also add here:

_Static_assert(sizeof(void *) == sizeof(uint32_t), "Expecting a 32-bit 
arch");

Anyway:
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

>   
>   /* stdarg.h */
> @@ -58,5 +59,6 @@ static inline void outb(uint16_t port, uint8_t data)
>   
>   void printf(const char *fmt, ...);
>   void* memcpy(void *dest, const void *src, int n);
> +void *memset(void *s, int c, size_t n);
>   
>   #endif
> diff --git a/tests/multiboot/run_test.sh b/tests/multiboot/run_test.sh
> index f04e35cbf0..38dcfef42c 100755
> --- a/tests/multiboot/run_test.sh
> +++ b/tests/multiboot/run_test.sh
> @@ -29,6 +29,7 @@ run_qemu() {
>       printf %b "\n\n=== Running test case: $kernel $* ===\n\n" >> test.log
>   
>       $QEMU \
> +        -cpu pentium \
>           -kernel $kernel \
>           -display none \
>           -device isa-debugcon,chardev=stdio \