From 9da72a62eca3e4226480110e660357ec687ee2dd Mon Sep 17 00:00:00 2001
From: Evgeny Karpov <evgeny.karpov@microsoft.com>
Date: Fri, 7 Jun 2024 16:55:23 +0200
Subject: [PATCH] aarch64: Add debugging information

This patch enables DWARF and allows compilation with debugging
information by using "gcc -g". The unwind info is disabled for
the moment and will be revisited after SEH implementation for
the target.

gcc/ChangeLog:

	* config/aarch64/aarch64.cc (TARGET_ASM_UNALIGNED_HI_OP):
	Enable DWARF.
	(TARGET_ASM_UNALIGNED_SI_OP): Likewise.
	(TARGET_ASM_UNALIGNED_DI_OP): Likewise.
	* config/aarch64/cygming.h (DWARF2_DEBUGGING_INFO): Likewise.
	(PREFERRED_DEBUGGING_TYPE): Likewise.
	(DWARF2_UNWIND_INFO): Likewise.
	(ASM_OUTPUT_DWARF_OFFSET): Likewise.
---
 gcc/config/aarch64/aarch64.cc |  9 ++++++++
 gcc/config/aarch64/cygming.h  | 39 ++++++++++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index f0672420aed..d90134009a4 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -31131,6 +31131,15 @@ aarch64_run_selftests (void)
 #undef TARGET_ASM_ALIGNED_SI_OP
 #define TARGET_ASM_ALIGNED_SI_OP "\t.word\t"
 
+#if TARGET_PECOFF
+#undef TARGET_ASM_UNALIGNED_HI_OP
+#define TARGET_ASM_UNALIGNED_HI_OP TARGET_ASM_ALIGNED_HI_OP
+#undef TARGET_ASM_UNALIGNED_SI_OP
+#define TARGET_ASM_UNALIGNED_SI_OP TARGET_ASM_ALIGNED_SI_OP
+#undef TARGET_ASM_UNALIGNED_DI_OP
+#define TARGET_ASM_UNALIGNED_DI_OP TARGET_ASM_ALIGNED_DI_OP
+#endif
+
 #undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
 #define TARGET_ASM_CAN_OUTPUT_MI_THUNK \
   hook_bool_const_tree_hwi_hwi_const_tree_true
diff --git a/gcc/config/aarch64/cygming.h b/gcc/config/aarch64/cygming.h
index bd6078023e3..e4ceab82b9e 100644
--- a/gcc/config/aarch64/cygming.h
+++ b/gcc/config/aarch64/cygming.h
@@ -21,8 +21,13 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_AARCH64_CYGMING_H
 #define GCC_AARCH64_CYGMING_H
 
+#define DWARF2_DEBUGGING_INFO 1
+
 #undef PREFERRED_DEBUGGING_TYPE
-#define PREFERRED_DEBUGGING_TYPE DINFO_TYPE_NONE
+#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
+
+#undef DWARF2_UNWIND_INFO
+#define DWARF2_UNWIND_INFO 0
 
 #define FASTCALL_PREFIX '@'
 
@@ -75,6 +80,38 @@ still needed for compilation.  */
 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
   mingw_pe_declare_function_type (FILE, XSTR (FUN, 0), 1)
 
+/* Use section relative relocations for debugging offsets.  Unlike
+   other targets that fake this by putting the section VMA at 0, PE
+   won't allow it.  */
+#define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, OFFSET, SECTION) \
+  do {								\
+    switch (SIZE)						\
+      {								\
+      case 4:							\
+	fputs ("\t.secrel32\t", FILE);				\
+	assemble_name (FILE, LABEL);				\
+	if ((OFFSET) != 0)					\
+	  fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC,		\
+		   (HOST_WIDE_INT) (OFFSET));			\
+	break;							\
+      case 8:							\
+	/* This is a hack.  There is no 64-bit section relative	\
+	   relocation.  However, the COFF format also does not	\
+	   support 64-bit file offsets; 64-bit applications are	\
+	   limited to 32-bits of code+data in any one module.	\
+	   Fake the 64-bit offset by zero-extending it.  */	\
+	fputs ("\t.secrel32\t", FILE);				\
+	assemble_name (FILE, LABEL);				\
+	if ((OFFSET) != 0)					\
+	  fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC,		\
+		   (HOST_WIDE_INT) (OFFSET));			\
+	fputs ("\n\t.long\t0", FILE);				\
+	break;							\
+      default:							\
+	gcc_unreachable ();					\
+      }								\
+  } while (0)
+
 #define TARGET_OS_CPP_BUILTINS()					\
   do									\
     {									\