diff mbox series

[RFC,3/4] multilib_header_wrapper.h: support musl

Message ID 20261029113829.2806167-4-mark.yang@lge.com
State New
Headers show
Series musl multilib: loader path and headers | expand

Commit Message

mark.yang Oct. 29, 2026, 11:38 a.m. UTC 
From: "mark.yang" <mark.yang@lge.com>

Pick the -32/-64 variant on musl from the musl headers in the sysroot,
or from __SIZEOF_POINTER__ when both variants are there. glibc multilib
is unchanged.

This brings back __MHWORDSIZE, dropped in 3a6ba47ede. musl defines
__WORDSIZE in sys/reg.h and sys/user.h, and a wrapper included after
them would redefine it. The first wrapper in a translation unit sets
it as follows:

1. Already defined: used as is. SWIG has no __has_include, so musl
   recipes that run it over wrapped headers pass -D__MHWORDSIZE=<bits>.
2. Only bits/alltypes-32.h or only bits/alltypes-64.h: 32 or 64.
   This is a recipe sysroot, which has one musl variant.
3. bits/alltypes.h with both variants: __SIZEOF_POINTER__ * 8.
   This is an SDK sysroot.
4. Otherwise: __WORDSIZE from bits/wordsize.h, as before.

musl installs bits/alltypes-32.h or -64.h now that its bits headers
are wrapped.

bpf needs no __bpf__ check. 6d8c7e3426 removed the old one, which
set 64. A lib32 recipe that builds eBPF with clang -target bpf gets
8-byte pointers, so the pointer size alone would pick the -64.h
headers. Its sysroot has only the -32.h ones, and rule 2 picks those.

Signed-off-by: mark.yang <mark.yang@lge.com>
---
 scripts/multilib_header_wrapper.h | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/scripts/multilib_header_wrapper.h b/scripts/multilib_header_wrapper.h
index 88f3193812..cb7ebb8c10 100644
--- a/scripts/multilib_header_wrapper.h
+++ b/scripts/multilib_header_wrapper.h
@@ -5,9 +5,23 @@ 
  * 
  */
 
-#include <bits/wordsize.h>
+#ifndef __MHWORDSIZE
+# if defined(__has_include)
+#  if __has_include(<bits/alltypes-32.h>) && !__has_include(<bits/alltypes-64.h>)
+#   define __MHWORDSIZE 32				/* musl, 32-bit only */
+#  elif __has_include(<bits/alltypes-64.h>) && !__has_include(<bits/alltypes-32.h>)
+#   define __MHWORDSIZE 64				/* musl, 64-bit only */
+#  elif __has_include(<bits/alltypes.h>)
+#   define __MHWORDSIZE (__SIZEOF_POINTER__ * 8)	/* musl, both (SDK) */
+#  endif
+# endif
+# ifndef __MHWORDSIZE
+#  include <bits/wordsize.h>				/* glibc */
+#  define __MHWORDSIZE __WORDSIZE
+# endif
+#endif
 
-#if __WORDSIZE == 32
+#if __MHWORDSIZE == 32
 
 #ifdef _MIPS_SIM
 
@@ -23,9 +37,9 @@ 
 #include <ENTER_HEADER_FILENAME_HERE-32.h>
 #endif
 
-#elif __WORDSIZE == 64
+#elif __MHWORDSIZE == 64
 #include <ENTER_HEADER_FILENAME_HERE-64.h>
 #else
 #error "Unknown __WORDSIZE detected"
-#endif /* matches #if __WORDSIZE == 32 */
+#endif /* matches #if __MHWORDSIZE == 32 */