On 12/12/17 11:24, Zenith432 wrote: > Below is an amended patch. > > I changed the wording in the notes a little to exclude a non-variadic > function using VA_START, and to remind that VA_COPY should also be > paired with VA_END. > > Also, if GCC gets its VA_COPY repaired, documentation may change to > allow to using VA_COPY > inside non-EFIAPI as well. > --- > > This is to resolve bug 457. > https://bugzilla.tianocore.org/show_bug.cgi?id=457 > > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Zenith432 <zenith432 at users.sourceforge.net> > --- > MdePkg/Include/Base.h | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h > index 02140a5a..4fd5161f 100644 > --- a/MdePkg/Include/Base.h > +++ b/MdePkg/Include/Base.h > @@ -552,21 +552,24 @@ struct _LIST_ENTRY { > #define BASE_8EB 0x8000000000000000ULL > > // > -// Support for variable length argument lists using the ANSI standard. > +// Support for variable argument lists in freestanding edk2 modules. > // > -// Since we are using the ANSI standard we used the standard naming and > -// did not follow the coding convention > +// For modules that use the ISO C library interfaces for variable > +// argument lists, refer to "StdLib/Include/stdarg.h". > // > // VA_LIST - typedef for argument list. > // VA_START (VA_LIST Marker, argument before the ...) - Init Marker > for use. > // VA_END (VA_LIST Marker) - Clear Marker > -// VA_ARG (VA_LIST Marker, var arg size) - Use Marker to get an > argument from > -// the ... list. You must know the size and pass it in this macro. > +// VA_ARG (VA_LIST Marker, var arg type) - Use Marker to get an > argument from > +// the ... list. You must know the type and pass it in this macro. > Type > +// must be compatible with the type of the actual next argument (as > promoted > +// according to the default argument promotions.) > // VA_COPY (VA_LIST Dest, VA_LIST Start) - Initialize Dest as a copy > of Start. > // > -// example: > +// Example: > // > // UINTN > +// EFIAPI > // ExampleVarArg ( > // IN UINTN NumberOfArgs, > // ... > @@ -582,15 +585,21 @@ struct _LIST_ENTRY { > // VA_START (Marker, NumberOfArgs); > // for (Index = 0, Result = 0; Index < NumberOfArgs; Index++) { > // // > -// // The ... list is a series of UINTN values, so average them up. > +// // The ... list is a series of UINTN values, so sum them up. > // // > // Result += VA_ARG (Marker, UINTN); > // } > // > // VA_END (Marker); > -// return Result > +// return Result; > // } > // > +// Notes: > +// - Functions that call VA_START() / VA_END() must have a variable > +// argument list and must be declared EFIAPI. > +// - Functions that call VA_COPY() / VA_END() must be declared EFIAPI. > +// - Functions that only use VA_LIST and VA_ARG() need not be EFIAPI. > +// > > /** > Return the size of argument that has been aligned to sizeof (UINTN).
Reviewed-by: Laszlo Ersek <ler...@redhat.com> (Liming, I can help with applying this patch, if you want that.) Thanks! Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
