On 14.04.2022 14:40, Roger Pau Monné wrote: > On Tue, Apr 12, 2022 at 12:27:34PM +0200, Jan Beulich wrote: >> While future gas versions will allow line number information to be >> generated for all instances of .irp and alike [1][2], the same isn't >> true (nor immediately intended) for .macro [3]. Hence macros, when they >> do more than just invoke another macro or issue an individual insn, want >> to have .line directives (in header files also .file ones) in place. >> >> Signed-off-by: Jan Beulich <[email protected]> >> >> [1] >> https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=7992631e8c0b0e711fbaba991348ef6f6e583725 >> [2] >> https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=2ee1792bec225ea19c71095cee5a3a9ae6df7c59 >> [3] >> https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=6d1ace6861e999361b30d1bc27459ab8094e0d4a >> --- >> Using .file has the perhaps undesirable side effect of generating a fair >> amount of (all identical) STT_FILE entries in the symbol table. We also >> can't use the supposedly assembler-internal (and hence undocumented) >> .appfile anymore, as it was removed [4]. Note that .linefile (also >> internal/undocumented) as well as the "# <line> <file>" constructs the >> compiler emits, leading to .linefile insertion by the assembler, aren't >> of use anyway as these are processed and purged when processing .macro >> [3]. >> >> [4] >> https://sourceware.org/git?p=binutils-gdb.git;a=commitdiff;h=c39e89c3aaa3a6790f85e80f2da5022bc4bce38b >> >> --- a/xen/arch/x86/include/asm/spec_ctrl_asm.h >> +++ b/xen/arch/x86/include/asm/spec_ctrl_asm.h >> @@ -24,6 +24,8 @@ >> #include <asm/msr-index.h> >> #include <asm/spec_ctrl.h> >> >> +#define FILE_AND_LINE .file __FILE__; .line __LINE__ > > Seeing as this seems to get added to all macros below, I guess you did > consider (and discarded) introducing a preprocessor macro do to the > asm macro definitons: > > #define DECLARE_MACRO(n, ...) \ > .macro n __VA_ARGS__ \ > .file __FILE__; .line __LINE__
No, I didn't even consider that. I view such as too obfuscating - there's then e.g. no visual match with the .endm. Furthermore, as outlined in the description, I don't think this wants applying uniformly. There are macros which better don't have this added. Yet I also would prefer to not end up with a mix of .macro and DECLARE_MACRO(). Jan
