From c428a156b8e659a884d4867e52c49534125dc72f Mon Sep 17 00:00:00 2001

From: Mark Shinwell <mshinwell@gmail.com>

Date: Wed, 13 Sep 2017 10:23:16 +0100

Subject: [PATCH 12/12] AArch64 GOT fixed

---

 Changes                    |  4 ++++

 asmcomp/arm64/emit.mlp     | 15 +++++++++++++--

 asmcomp/arm64/selection.ml |  4 ++--

 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/Changes b/Changes

index e8dbd42e2..b84a1f30e 100644

--- a/Changes

+++ b/Changes

@@ -150,6 +150,10 @@ OCaml 4.05.0 (13 Jul 2017):

   (Hannes Mehnert, Guillaume Bury,

    review by Daniel Bünzli, Gabriel Scherer, Damien Doligez)

+- GPR#1330: when generating dynamically-linkable code on AArch64, always

+  reference symbols (even locally-defined ones) through the GOT.

+  (Mark Shinwell, review by Xavier Leroy)

+

 ### Standard library:

 - MPR#6975, GPR#902: Truncate function added to stdlib Buffer module

diff --git a/asmcomp/arm64/emit.mlp b/asmcomp/arm64/emit.mlp

index f75646e12..729096c57 100644

--- a/asmcomp/arm64/emit.mlp

+++ b/asmcomp/arm64/emit.mlp

@@ -114,6 +114,7 @@ let emit_addressing addr r =

   | Iindexed ofs ->

       `[{emit_reg r}, #{emit_int ofs}]`

   | Ibased(s, ofs) ->

+      assert (not !Clflags.dlcode);  (* see selection.ml *)

       `[{emit_reg r}, #:lo12:{emit_symbol_offset s ofs}]`

 (* Record live pointers at call points *)

@@ -323,7 +324,7 @@ let emit_literals() =

 (* Emit code to load the address of a symbol *)

 let emit_load_symbol_addr dst s =

-  if (not !Clflags.dlcode) || Compilenv.symbol_in_current_unit s then begin

+  if not !Clflags.dlcode then begin

     `	adrp	{emit_reg dst}, {emit_symbol s}\n`;

     `	add	{emit_reg dst}, {emit_reg dst}, #:lo12:{emit_symbol s}\n`

   end else begin

@@ -609,6 +610,7 @@ let emit_instr i =

           match addr with

           | Iindexed _ -> i.arg.(0)

           | Ibased(s, ofs) ->

+              assert (not !Clflags.dlcode);  (* see selection.ml *)

               `	adrp	{emit_reg reg_tmp1}, {emit_symbol_offset s ofs}\n`;

               reg_tmp1 in

         begin match size with

@@ -636,6 +638,7 @@ let emit_instr i =

           match addr with

           | Iindexed _ -> i.arg.(1)

           | Ibased(s, ofs) ->

+              assert (not !Clflags.dlcode);

               `	adrp	{emit_reg reg_tmp1}, {emit_symbol_offset s ofs}\n`;

               reg_tmp1 in

         begin match size with

@@ -924,7 +927,15 @@ let fundecl fundecl =

 let emit_item = function

   | Cglobal_symbol s -> `	.globl	{emit_symbol s}\n`;

-  | Cdefine_symbol s -> `{emit_symbol s}:\n`

+  | Cdefine_symbol s ->

+    if !Clflags.dlcode then begin

+      (* GOT relocations against non-global symbols don't seem to work

+         properly: GOT entries are not created for the symbols and the

+         relocations evaluate to random other GOT entries.  For the moment

+         force all symbols to be global. *)

+      `	.globl	{emit_symbol s}\n`;

+    end;

+    `{emit_symbol s}:\n`

   | Cint8 n -> `	.byte	{emit_int n}\n`

   | Cint16 n -> `	.short	{emit_int n}\n`

   | Cint32 n -> `	.long	{emit_nativeint n}\n`

diff --git a/asmcomp/arm64/selection.ml b/asmcomp/arm64/selection.ml

index d8ea7f83b..b714d0032 100644

--- a/asmcomp/arm64/selection.ml

+++ b/asmcomp/arm64/selection.ml

@@ -82,8 +82,8 @@ let inline_ops =

   [ "sqrt"; "caml_bswap16_direct"; "caml_int32_direct_bswap";

     "caml_int64_direct_bswap"; "caml_nativeint_direct_bswap" ]

-let use_direct_addressing symb =

-  (not !Clflags.dlcode) || Compilenv.symbol_in_current_unit symb

+let use_direct_addressing _symb =

+  not !Clflags.dlcode

 (* Instruction selection *)

-- 

2.13.2