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<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal">I’m trying to enable Uefi firmware clang build which is to switch gcc to clang as the firmware default CC compiler, and I have some troubles to handle the X64 library variable arguments parsing with __attribute__((ms_abi)) calling convention.
I hope to implement my own va_list macros, e.g. va_start, va_arg, va_end, va_copy, and I see the Stdarg.h define the va_list as __builtin_va_list, but I don’t know how clang define the __builtin_va_list for X64 architecture. Where can I find it?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>I thought the __builtin_va_list might be the char * and I defined the va_list macros as below, but they does not work. <o:p></o:p></p>
<p class="MsoNormal">typedef CHAR8 *VA_LIST;<o:p></o:p></p>
<p class="MsoNormal">#define VA_START(Marker, Parameter) (Marker = (VA_LIST) ((UINTN) & (Parameter) + _INT_SIZE_OF (Parameter)))<o:p></o:p></p>
<p class="MsoNormal">#define VA_ARG(Marker, TYPE) (*(TYPE *) ((Marker += _INT_SIZE_OF (TYPE)) - _INT_SIZE_OF (TYPE)))<o:p></o:p></p>
<p class="MsoNormal">#define VA_END(Marker) (Marker = (VA_LIST) 0)<o:p></o:p></p>
<p class="MsoNormal">#define VA_COPY(Dest, Start) ((void)((Dest) = (Start)))<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>I also tried directly use the _builtin functions as below, the result is better, but still cannot completely work if the library function have very long variable arguments. <o:p></o:p></p>
<p class="MsoNormal">typedef __builtin_va_list VA_LIST;<o:p></o:p></p>
<p class="MsoNormal">#define VA_START(Marker, Parameter) __builtin_va_start (Marker, Parameter)<o:p></o:p></p>
<p class="MsoNormal">#define VA_ARG(Marker, TYPE) ((sizeof (TYPE) < sizeof (UINTN)) ? (TYPE)(__builtin_va_arg (Marker, UINTN)) : (TYPE)(__builtin_va_arg (Marker, TYPE)))<o:p></o:p></p>
<p class="MsoNormal">#define VA_END(Marker) __builtin_va_end (Marker)<o:p></o:p></p>
<p class="MsoNormal">#define VA_COPY(Dest, Start) __builtin_va_copy (Dest, Start)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any suggestion is appreciated!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Arial",sans-serif">Steven Shi</span></b><b><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Arial",sans-serif">SSG\STO\UEFI Firmware</span></b><b><span style="font-size:12.0pt;font-family:"Arial",sans-serif"><o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></b></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">Tel: +86 021-61166522<o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:9.0pt;font-family:"Arial",sans-serif">iNet: 821-6522<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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