From 72ac67757015df21ca3469cdce0ed049120a7c4b Mon Sep 17 00:00:00 2001
From: inglorion <voodoo@inglorion.net>
Date: Sun, 17 Feb 2013 11:21:02 -0800
Subject: [PATCH] made variables in shared libraries work on i386

---
 lib/voodoo/generators/amd64_nasm_generator.rb |  5 +++++
 lib/voodoo/generators/i386_nasm_generator.rb  | 18 ++++++++++++++++++
 lib/voodoo/generators/nasm_generator.rb       |  2 +-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/voodoo/generators/amd64_nasm_generator.rb b/lib/voodoo/generators/amd64_nasm_generator.rb
index 9e9ff3d..309a448 100644
--- a/lib/voodoo/generators/amd64_nasm_generator.rb
+++ b/lib/voodoo/generators/amd64_nasm_generator.rb
@@ -294,6 +294,11 @@ module Voodoo
       end
     end
 
+    # Loads a symbol from the global offset table.
+    def load_symbol_from_got symbol, reg
+      "[rel #{symbol} wrt ..gotpc]"
+    end
+
     #
     # == Miscellaneous
     #
diff --git a/lib/voodoo/generators/i386_nasm_generator.rb b/lib/voodoo/generators/i386_nasm_generator.rb
index 57c8bfe..69b29cc 100644
--- a/lib/voodoo/generators/i386_nasm_generator.rb
+++ b/lib/voodoo/generators/i386_nasm_generator.rb
@@ -79,6 +79,7 @@ module Voodoo
       @TEMPORARIES = [:ebx]
       super params
       @saved_registers = []
+      in_section(:data) { emit "extern _GLOBAL_OFFSET_TABLE_\n" }
       @features.merge! \
         :'bits-per-word' => '32',
         :'byte-order' => 'little-endian',
@@ -111,6 +112,23 @@ module Voodoo
       end
     end
 
+    # Loads the address of the global offset table into the given register.
+    def load_got_address reg
+      lbl = gensym
+      emit "call #{lbl}\n"
+      emit "#{lbl}:\n"
+      emit "pop #{reg}\n"
+      emit "add #{reg}, _GLOBAL_OFFSET_TABLE_ + $$ - #{lbl} wrt ..gotpc\n"
+      reg
+    end
+
+    # Loads a symbol from the global offset table.
+    def load_symbol_from_got symbol, reg
+      load_got_address reg
+      emit "mov #{reg}, [#{reg} + #{symbol} wrt ..got]\n"
+      reg
+    end
+
     # If the nth local is stored in a register, returns that register.
     # Otherwise, returns the offset from the frame pointer.
     def local_offset_or_register n
diff --git a/lib/voodoo/generators/nasm_generator.rb b/lib/voodoo/generators/nasm_generator.rb
index bf46ed4..cb2a6a3 100644
--- a/lib/voodoo/generators/nasm_generator.rb
+++ b/lib/voodoo/generators/nasm_generator.rb
@@ -352,7 +352,7 @@ module Voodoo
       else
         # Assume global
         if @relocated_symbols.include? symbol
-          "[rel #{symbol} wrt ..gotpc]"
+          load_symbol_from_got symbol, reg
         else
           symbol
         end
-- 
2.11.4.GIT