From a468414748da8fc96e2b14fb298d2bbc2d772a05 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Tue, 19 Jul 2022 12:53:34 +0200
Subject: [PATCH] ARM64: Allow building with unwinding disabled.

(cherry-picked from commit 5677985dc1f19cf0a67112f4365c7fb79237fa16)

Prior to this patch, the LuaJIT build with the
`-DLUAJIT_NO_UNWIND=1` option enabled failed because of linker
relocation errors related to dwarf-specific code. This patch
disables emission of the `.eh_frame` section for builds without
unwinding to solve the issue.

The `LUAJIT_NO_UNWIND` build option is added to CMakeLists.txt.
This patch adds this build flavor to our exotic builds workflow.

Maxim Kokryashkin:
* added the description for the problem

Part of tarantool/tarantool#9145
---
 CMakeLists.txt    | 5 +++++
 src/vm_arm64.dasc | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7ef10f2f6f..7f5e2afb6a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -202,6 +202,11 @@ if(LUAJIT_DISABLE_UNWIND_JIT)
   AppendFlags(TARGET_C_FLAGS -DLUAJIT_DISABLE_UNWIND_JIT)
 endif()
 
+option(LUAJIT_NO_UNWIND "Disable external unwinding.")
+if(LUAJIT_NO_UNWIND)
+  AppendFlags(TARGET_C_FLAGS -DLUAJIT_NO_UNWIND)
+endif()
+
 # Disable memory profiler.
 option(LUAJIT_DISABLE_MEMPROF "LuaJIT memory profiler support" OFF)
 if(LUAJIT_DISABLE_MEMPROF)
diff --git a/src/vm_arm64.dasc b/src/vm_arm64.dasc
index 0a12b5b781..1cf1ea519e 100644
--- a/src/vm_arm64.dasc
+++ b/src/vm_arm64.dasc
@@ -3915,6 +3915,7 @@ static void emit_asm_debug(BuildCtx *ctx)
 	"\t.align 3\n"
 	".LEFDE1:\n\n", (int)ctx->codesz - fcofs);
 #endif
+#if !LJ_NO_UNWIND
     fprintf(ctx->fp, "\t.section .eh_frame,\"a\",%%progbits\n");
     fprintf(ctx->fp,
 	".Lframe1:\n"
@@ -3982,6 +3983,7 @@ static void emit_asm_debug(BuildCtx *ctx)
 	"\t.byte 0x94\n\t.uleb128 4\n"		/* offset x20 */
 	"\t.align 3\n"
 	".LEFDE3:\n\n", (int)ctx->codesz - fcofs);
+#endif
 #endif
     break;
 #if !LJ_NO_UNWIND