From c8041e7d3700fe30ec9d0a1541a7d5850b456611 Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Sun, 6 Jan 2013 16:07:45 -0500
Subject: [PATCH] add signext/zeroext attributes to small integer ccall
 arguments. fixes #978

---
 src/ccall.cpp   | 24 +++++++++++++++++++++++-
 src/codegen.cpp |  1 +
 test/ccall.jl   |  2 +-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/ccall.cpp b/src/ccall.cpp
index 02363d82e232d..ddbb29fe0ec80 100644
--- a/src/ccall.cpp
+++ b/src/ccall.cpp
@@ -260,6 +260,8 @@ static Value *julia_to_native(Type *ty, jl_value_t *jt, Value *jv,
                               false);
 }
 
+static jl_value_t *jl_signed_type=NULL;
+
 // --- code generator for ccall itself ---
 
 // ccall(pointer, rettype, (argtypes...), args...)
@@ -368,12 +370,31 @@ static Value *emit_ccall(jl_value_t **args, size_t nargs, jl_codectx_t *ctx)
     size_t i;
     bool haspointers = false;
     bool isVa = false;
-    for(i=0; i < jl_tuple_len(tt); i++) {
+    size_t nargt = jl_tuple_len(tt);
+    std::vector<AttributeWithIndex> attrs;
+    for(i=0; i < nargt; i++) {
         jl_value_t *tti = jl_tupleref(tt,i);
         if (jl_is_seq_type(tti)) {
             isVa = true;
             tti = jl_tparam0(tti);
         }
+        if (jl_is_bits_type(tti)) {
+            // see pull req #978. need to annotate signext/zeroext for
+            // small integer arguments.
+            jl_bits_type_t *bt = (jl_bits_type_t*)tti;
+            if (bt->nbits < 32) {
+                if (jl_signed_type == NULL) {
+                    jl_signed_type = jl_get_global(jl_core_module,jl_symbol("Signed"));
+                }
+                Attributes::AttrVal av;
+                if (jl_signed_type && jl_subtype(tti, jl_signed_type, 0))
+                    av = Attributes::SExt;
+                else
+                    av = Attributes::ZExt;
+                attrs.push_back(AttributeWithIndex::get(getGlobalContext(), i+1,
+                                                        ArrayRef<Attributes::AttrVal>(&av, 1)));
+            }
+        }
         Type *t = julia_type_to_llvm(tti);
         if (t == NULL) {
             JL_GC_POP();
@@ -524,6 +545,7 @@ static Value *emit_ccall(jl_value_t **args, size_t nargs, jl_codectx_t *ctx)
                                        ArrayRef<Value*>(&argvals[0],(nargs-3)/2));
     if (cc != CallingConv::C)
         ((CallInst*)result)->setCallingConv(cc);
+    ((CallInst*)result)->setAttributes(AttrListPtr::get(getGlobalContext(), ArrayRef<AttributeWithIndex>(attrs)));
 
     // restore temp argument area stack pointer
     if (haspointers) {
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 9346563258fa5..380272055d721 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -11,6 +11,7 @@
 #include "llvm/Intrinsics.h"
 #include "llvm/PassManager.h"
 #include "llvm/Analysis/Verifier.h"
+#include "llvm/Attributes.h"
 #if defined(LLVM_VERSION_MAJOR) && LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 2 
 #include "llvm/DebugInfo.h"
 #include "llvm/DIBuilder.h"
diff --git a/test/ccall.jl b/test/ccall.jl
index a61ab82fda162..49351a5a6b4aa 100644
--- a/test/ccall.jl
+++ b/test/ccall.jl
@@ -1,3 +1,3 @@
-ccall_test_func(x) = ccall((:testUcharX, "./libccalltest"), Int32, (Int8,), x)
+ccall_test_func(x) = ccall((:testUcharX, "./libccalltest"), Int32, (Uint8,), x)
 @assert ccall_test_func(3) == 1
 @assert ccall_test_func(259) == 1