Recent gas versions generate minimalistic Dwarf debug info for items annotated as functions and having their sizes specified [1]. Furthermore generating live patches wants items properly annotated. "Borrow" Arm's END() and (remotely) derive other annotation infrastructure from Linux'es, for all architectures to use.
Signed-off-by: Jan Beulich <jbeul...@suse.com> [1] https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=591cc9fbbfd6d51131c0f1d4a92e7893edcc7a28 --- v3: New, generalized from earlier x86-only version. LAST() (now LASTARG()) moved to macros.h. --- TBD: What to set CODE_ALIGN to by default? Or should we requires arch-es to define that in all cases? TBD: {CODE,DATA}_ALIGN are byte granular, such that a value of 0 can be specified (in case this has some special meaning on an arch; conceivably it could mean to use some kind of arch default). We may not strictly need that, and hence we could also make these power-of -2 values (using .p2align). Note that we can't use ALIGN() (in place of SYM_ALIGN()) as long as we still have ALIGN. Note further that FUNC()'s etc "algn" parameter is intended to allow for only no or a single argument. If we wanted to also make the fill value customizable per call site, the constructs would need re-doing to some degree. --- /dev/null +++ b/xen/include/xen/linkage.h @@ -0,0 +1,56 @@ +#ifndef __LINKAGE_H__ +#define __LINKAGE_H__ + +#ifdef __ASSEMBLY__ + +#include <xen/macros.h> + +#ifndef CODE_ALIGN +# define CODE_ALIGN ?? +#endif +#ifndef CODE_FILL +# define CODE_FILL ~0 +#endif + +#ifndef DATA_ALIGN +# define DATA_ALIGN 0 +#endif +#ifndef DATA_FILL +# define DATA_FILL ~0 +#endif + +#define SYM_ALIGN(algn...) .balign algn + +#define SYM_L_GLOBAL(name) .globl name +#define SYM_L_WEAK(name) .weak name +#define SYM_L_LOCAL(name) /* nothing */ + +#define SYM_T_FUNC STT_FUNC +#define SYM_T_DATA STT_OBJECT +#define SYM_T_NONE STT_NOTYPE + +#define SYM(name, typ, linkage, algn...) \ + .type name, SYM_T_ ## typ; \ + SYM_L_ ## linkage(name); \ + SYM_ALIGN(algn); \ + name: + +#define END(name) .size name, . - name + +#define FUNC(name, algn...) \ + SYM(name, FUNC, GLOBAL, LASTARG(CODE_ALIGN, ## algn), CODE_FILL) +#define LABEL(name, algn...) \ + SYM(name, NONE, GLOBAL, LASTARG(CODE_ALIGN, ## algn), CODE_FILL) +#define DATA(name, algn...) \ + SYM(name, DATA, GLOBAL, LASTARG(DATA_ALIGN, ## algn), DATA_FILL) + +#define FUNC_LOCAL(name, algn...) \ + SYM(name, FUNC, LOCAL, LASTARG(CODE_ALIGN, ## algn), CODE_FILL) +#define LABEL_LOCAL(name, algn...) \ + SYM(name, NONE, LOCAL, LASTARG(CODE_ALIGN, ## algn), CODE_FILL) +#define DATA_LOCAL(name, algn...) \ + SYM(name, DATA, LOCAL, LASTARG(DATA_ALIGN, ## algn), DATA_FILL) + +#endif /* __ASSEMBLY__ */ + +#endif /* __LINKAGE_H__ */ --- a/xen/include/xen/macros.h +++ b/xen/include/xen/macros.h @@ -15,6 +15,15 @@ #define count_args(args...) \ count_args_(., ## args, 8, 7, 6, 5, 4, 3, 2, 1, 0) +#define ARG1_(x, y...) (x) +#define ARG2_(x, y...) ARG1_(y) +#define ARG3_(x, y...) ARG2_(y) +#define ARG4_(x, y...) ARG3_(y) + +#define ARG__(nr) ARG ## nr ## _ +#define ARG_(nr) ARG__(nr) +#define LASTARG(x, y...) ARG_(count_args(x, ## y))(x, ## y) + /* Indirect macros required for expanded argument pasting. */ #define PASTE_(a, b) a ## b #define PASTE(a, b) PASTE_(a, b)
