[PATCH v5 1/2] asan: specify alignment for LASANPC labels

[Ilya Leoshkevich <iii@linux.ibm.com>]

gcc/ChangeLog:

2020-06-30  Ilya Leoshkevich  <iii@linux.ibm.com>

	* asan.cc (asan_emit_stack_protection): Use CODE_LABEL_BOUNDARY.
	* defaults.h (CODE_LABEL_BOUNDARY): New macro.
	* doc/tm.texi: Document CODE_LABEL_BOUNDARY.
	* doc/tm.texi.in: Likewise.
---
 gcc/asan.cc        | 1 +
 gcc/defaults.h     | 5 +++++
 gcc/doc/tm.texi    | 4 ++++
 gcc/doc/tm.texi.in | 4 ++++
 4 files changed, 14 insertions(+)

diff --git a/gcc/asan.cc b/gcc/asan.cc
index 8276f12cc69..62f50ee769b 100644
--- a/gcc/asan.cc
+++ b/gcc/asan.cc
@@ -1960,6 +1960,7 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
   DECL_INITIAL (decl) = decl;
   TREE_ASM_WRITTEN (decl) = 1;
   TREE_ASM_WRITTEN (id) = 1;
+  SET_DECL_ALIGN (decl, CODE_LABEL_BOUNDARY);
   emit_move_insn (mem, expand_normal (build_fold_addr_expr (decl)));
   shadow_base = expand_binop (Pmode, lshr_optab, base,
 			      gen_int_shift_amount (Pmode, ASAN_SHADOW_SHIFT),
diff --git a/gcc/defaults.h b/gcc/defaults.h
index 953605c1627..52a471cf08e 100644
--- a/gcc/defaults.h
+++ b/gcc/defaults.h
@@ -1455,4 +1455,9 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 typedef TARGET_UNIT target_unit;
 #endif
 
+/* Alignment required for a code label, in bits.  */
+#ifndef CODE_LABEL_BOUNDARY
+#define CODE_LABEL_BOUNDARY BITS_PER_UNIT
+#endif
+
 #endif  /* ! GCC_DEFAULTS_H */
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 858bfb80cec..cc588ee23b5 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -1075,6 +1075,10 @@ to a value equal to or larger than @code{STACK_BOUNDARY}.
 Alignment required for a function entry point, in bits.
 @end defmac
 
+@defmac CODE_LABEL_BOUNDARY
+Alignment required for a code label, in bits.
+@end defmac
+
 @defmac BIGGEST_ALIGNMENT
 Biggest alignment that any data type can require on this machine, in
 bits.  Note that this is not the biggest alignment that is supported,
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 21b849ea32a..a0b725b0685 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -971,6 +971,10 @@ to a value equal to or larger than @code{STACK_BOUNDARY}.
 Alignment required for a function entry point, in bits.
 @end defmac
 
+@defmac CODE_LABEL_BOUNDARY
+Alignment required for a code label, in bits.
+@end defmac
+
 @defmac BIGGEST_ALIGNMENT
 Biggest alignment that any data type can require on this machine, in
 bits.  Note that this is not the biggest alignment that is supported,
-- 
2.37.2