Re: [PATCH] coverage: update gcov info for newer versions of gcc

[Jan Beulich <jbeulich@xxxxxxxx>]

On 02.09.2023 17:11, Javi Merino wrote:
> --- a/xen/common/coverage/Makefile
> +++ b/xen/common/coverage/Makefile
> @@ -5,7 +5,9 @@ obj-y += $(call cc-ifversion,-lt,0407, \
>               gcc_3_4.o, $(call cc-ifversion,-lt,0409, \
>               gcc_4_7.o, $(call cc-ifversion,-lt,0500, \
>               gcc_4_9.o, $(call cc-ifversion,-lt,0700, \
> -             gcc_5.o, gcc_7.o))))
> +             gcc_5.o, $(call cc-ifversion,-lt,1000, \
> +             gcc_7.o,  $(call cc-ifversion,-lt,1200, \
> +             gcc_10.o, gcc_12.o))))))

This is getting unwieldy, so I think we ought to try to limit the number
of different files we have. Already gcc_4_9.c and gcc_7.c specify the
same GCOV_COUNTERS and differ only in the version checks (which could be
combined). Therefore ...

> --- /dev/null
> +++ b/xen/common/coverage/gcc_10.c
> @@ -0,0 +1,31 @@
> +/*
> + *  This code provides functions to handle gcc's profiling data format
> + *  introduced with gcc 10.
> + *
> + *  For a better understanding, refer to gcc source:
> + *  gcc/gcov-io.h
> + *  libgcc/libgcov.c
> + *
> + *  Uses gcc-internal data definitions.
> + */
> +
> +#include "gcov.h"
> +
> +#if GCC_VERSION < 100000 || GCC_VERSION > 120000
> +#error "Wrong version of GCC used to compile gcov"
> +#endif
> +
> +#define GCOV_COUNTERS 8
> +#define GCOV_UNIT_SIZE 1
> +
> +#include "gcc_4_7.c"

... this could simply re-use gcc_4_7.c directly, with just the version
check there suitably tweaked.

> --- a/xen/common/coverage/gcc_4_7.c
> +++ b/xen/common/coverage/gcc_4_7.c
> @@ -27,6 +27,7 @@
>  #  error "Wrong version of GCC used to compile gcov"
>  # endif
>  #define GCOV_COUNTERS 8
> +#define GCOV_UNIT_SIZE 1
>  #endif

If further this became a separate #ifdef, ...

> --- a/xen/common/coverage/gcc_4_9.c
> +++ b/xen/common/coverage/gcc_4_9.c
> @@ -19,6 +19,7 @@
>  #endif
>  
>  #define GCOV_COUNTERS 9
> +#define GCOV_UNIT_SIZE 1
>  
>  #include "gcc_4_7.c"
>  
> --- a/xen/common/coverage/gcc_5.c
> +++ b/xen/common/coverage/gcc_5.c
> @@ -19,6 +19,7 @@
>  #endif
>  
>  #define GCOV_COUNTERS 10
> +#define GCOV_UNIT_SIZE 1
>  
>  #include "gcc_4_7.c"
>  

... touching these two files could be avoided altogether.

Henry - afaict this was submitted after the feature submission deadline,
so you may want to consider giving it an exception.

Jan