From 10d8b4e861faedb734636a80dc4963392f1f82c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafael=20=C3=81vila=20de=20Esp=C3=ADndola?=
 <respindola@mozilla.com>
Date: Wed, 9 Mar 2011 15:05:22 -0500
Subject: [PATCH] Fix access to the rust stack.

---
 src/comp/back/x86.rs | 47 ++++++++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/src/comp/back/x86.rs b/src/comp/back/x86.rs
index 04f5d5af904..b9ba24c6e27 100644
--- a/src/comp/back/x86.rs
+++ b/src/comp/back/x86.rs
@@ -25,22 +25,39 @@ fn restore_callee_saves() -> vec[str] {
             "popl  %ebp");
 }
 
-fn load_esp_from_rust_sp() -> vec[str] {
+fn load_esp_from_rust_sp_first_arg() -> vec[str] {
     ret vec("movl  " + wstr(abi.task_field_rust_sp) + "(%ecx), %esp");
 }
 
-fn load_esp_from_runtime_sp() -> vec[str] {
+fn load_esp_from_runtime_sp_first_arg() -> vec[str] {
     ret vec("movl  " + wstr(abi.task_field_runtime_sp) + "(%ecx), %esp");
 }
 
-fn store_esp_to_rust_sp() -> vec[str] {
+fn store_esp_to_rust_sp_first_arg() -> vec[str] {
     ret vec("movl  %esp, " + wstr(abi.task_field_rust_sp) + "(%ecx)");
 }
 
-fn store_esp_to_runtime_sp() -> vec[str] {
+fn store_esp_to_runtime_sp_first_arg() -> vec[str] {
     ret vec("movl  %esp, " + wstr(abi.task_field_runtime_sp) + "(%ecx)");
 }
 
+fn load_esp_from_rust_sp_second_arg() -> vec[str] {
+    ret vec("movl  " + wstr(abi.task_field_rust_sp) + "(%edx), %esp");
+}
+
+fn load_esp_from_runtime_sp_second_arg() -> vec[str] {
+    ret vec("movl  " + wstr(abi.task_field_runtime_sp) + "(%edx), %esp");
+}
+
+fn store_esp_to_rust_sp_second_arg() -> vec[str] {
+    ret vec("movl  %esp, " + wstr(abi.task_field_rust_sp) + "(%edx)");
+}
+
+fn store_esp_to_runtime_sp_second_arg() -> vec[str] {
+    ret vec("movl  %esp, " + wstr(abi.task_field_runtime_sp) + "(%edx)");
+}
+
+
 /*
  * This is a bit of glue-code. It should be emitted once per
  * compilation unit.
@@ -61,8 +78,8 @@ fn store_esp_to_runtime_sp() -> vec[str] {
 fn rust_activate_glue() -> vec[str] {
     ret vec("movl  4(%esp), %ecx    # ecx = rust_task")
         + save_callee_saves()
-        + store_esp_to_runtime_sp()
-        + load_esp_from_rust_sp()
+        + store_esp_to_runtime_sp_first_arg()
+        + load_esp_from_rust_sp_first_arg()
 
         /*
          * There are two paths we can arrive at this code from:
@@ -154,10 +171,10 @@ fn rust_activate_glue() -> vec[str] {
 
 fn rust_yield_glue() -> vec[str] {
     ret vec("movl  0(%esp), %ecx    # ecx = rust_task")
-        + load_esp_from_rust_sp()
+        + load_esp_from_rust_sp_first_arg()
         + save_callee_saves()
-        + store_esp_to_rust_sp()
-        + load_esp_from_runtime_sp()
+        + store_esp_to_rust_sp_first_arg()
+        + load_esp_from_runtime_sp_first_arg()
         + restore_callee_saves()
         + vec("ret");
 }
@@ -192,19 +209,19 @@ fn upcall_glue(int n_args) -> vec[str] {
 
         + vec("movl  %esp, %ebp     # ebp = rust_sp")
 
-        + store_esp_to_rust_sp()
-        + load_esp_from_runtime_sp()
+        + store_esp_to_rust_sp_second_arg()
+        + load_esp_from_runtime_sp_second_arg()
 
         + vec("subl  $" + wstr(n_args + 1) + ", %esp   # esp -= args",
               "andl  $~0xf, %esp    # align esp down")
 
         + _vec.init_fn[str](carg, (n_args + 1) as uint)
 
-        +  vec("movl  %edx, %edi     # save task from ecx to edi",
-               "call  *%ecx          # call *%edx",
-               "movl  %edi, %edx     # restore edi-saved task to ecx")
+        +  vec("movl  %edx, %edi     # save task from edx to edi",
+               "call  *%ecx          # call *%ecx",
+               "movl  %edi, %edx     # restore edi-saved task to edx")
 
-        + load_esp_from_rust_sp()
+        + load_esp_from_rust_sp_second_arg()
         + restore_callee_saves()
         + vec("ret");