[PATCH] Predefine __STRICT_ALIGN__ if STRICT_ALIGNMENT

[YunQiang Su <syq@gcc.gnu.org>]

Arm32 predefines __ARM_FEATURE_UNALIGNED if -mno-unaligned-access,
and RISC-V predefines __riscv_misaligned_avoid, while other ports
that support -mstrict-align/-mno-unaligned-access don't have such
macro, and these backend macros are only avaiable for c-family.
Note: Arm64 always predefine __ARM_FEATURE_UNALIGNED: See #111555.

Let's add a generic one.

__STRICT_ALIGN__ is used instead of __STRICT_ALIGNMENT__, due to that
the later is used by some softwares, such as lzo2, syslinux etc.

gcc
	* cppbuiltin.cc: Predefine __STRICT_ALIGNMENT__ if
	STRICT_ALIGNMENT.
---
 gcc/cppbuiltin.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/cppbuiltin.cc b/gcc/cppbuiltin.cc
index c4bfc2917dc..d32efdf9a07 100644
--- a/gcc/cppbuiltin.cc
+++ b/gcc/cppbuiltin.cc
@@ -123,6 +123,9 @@ define_builtin_macros_for_compilation_flags (cpp_reader *pfile)
 
   cpp_define_formatted (pfile, "__FINITE_MATH_ONLY__=%d",
 			flag_finite_math_only);
+
+  if (STRICT_ALIGNMENT)
+    cpp_define (pfile, "__STRICT_ALIGNMENT__");
 }
 
 
-- 
2.39.2