Port to Tiny C on x86-64

This allows Emacs to build on Ubuntu 21.10 x86-64 with
‘./configure --without-modules CC=tcc’.
* configure.ac (GC_SETJMP_WORKS):
Accept __x86_64__ as an alias for __amd64__.
* src/lisp.h (alignas): Provide a no-op substitute.

diff --git a/configure.ac b/configure.ac
index c36dffde84c5a2323ad6d88486d2c090f5de1d2a..0c23b60805bded5dde187527a4a0fc7d5e25e702 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -5426,6 +5426,7 @@ case $opsys in
 #if defined __i386__ || defined __sparc__ || defined __mc68000__ \
   || defined __alpha__ || defined __mips__ || defined __s390__ \
   || defined __arm__ || defined __powerpc__ || defined __amd64__ \
+  || defined __x86_64__ \
   || defined __ia64__ || defined __sh__
 /* ok */
 #else

diff --git a/src/lisp.h b/src/lisp.h
index 242156bbcb84a24ccd3674b7f311fe52691a1b0a..d44ab55453bdd598c43fcf6d5820dc546974f027 100644 (file)
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -259,6 +259,11 @@ DEFINE_GDB_SYMBOL_BEGIN (EMACS_INT, VALMASK)
 # define VALMASK (USE_LSB_TAG ? - (1 << GCTYPEBITS) : VAL_MAX)
 DEFINE_GDB_SYMBOL_END (VALMASK)
 
+/* Ignore 'alignas' on compilers lacking it.  */
+#if !defined alignas && !defined __alignas_is_defined
+# define alignas(a)
+#endif
+
 /* Minimum alignment requirement for Lisp objects, imposed by the
    internal representation of tagged pointers.  It is 2**GCTYPEBITS if
    USE_LSB_TAG, 1 otherwise.  It must be a literal integer constant,