From 020daa9476b5a2c8bce553066b0121d39de151fe Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Sat, 12 Sep 2009 01:00:39 +0000
Subject: [PATCH] Stub out room for ARM APCS ABI implementation (and AAPCS_VFP,
 although you can't hit this via command line options yet).

llvm-svn: 81595
---
 clang/lib/CodeGen/TargetABIInfo.cpp     | 41 +++++++++++++++++++++++--
 clang/test/CodeGen/arm-apcs-arguments.c |  6 ++++
 2 files changed, 45 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/CodeGen/arm-apcs-arguments.c

diff --git a/clang/lib/CodeGen/TargetABIInfo.cpp b/clang/lib/CodeGen/TargetABIInfo.cpp
index 1ebad5dd5c24..c85504e64cc3 100644
--- a/clang/lib/CodeGen/TargetABIInfo.cpp
+++ b/clang/lib/CodeGen/TargetABIInfo.cpp
@@ -1327,6 +1327,22 @@ llvm::Value *PIC16ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
 namespace {
 
 class ARMABIInfo : public ABIInfo {
+public:
+  enum ABIKind {
+    APCS = 0,
+    AAPCS = 1,
+    AAPCS_VFP
+  };
+
+private:
+  ABIKind Kind;
+
+public:
+  ARMABIInfo(ABIKind _Kind) : Kind(_Kind) {}
+
+private:
+  ABIKind getABIKind() const { return Kind; }
+
   ABIArgInfo classifyReturnType(QualType RetTy,
                                 ASTContext &Context,
                                 llvm::LLVMContext &VMCOntext) const;
@@ -1352,6 +1368,21 @@ void ARMABIInfo::computeInfo(CGFunctionInfo &FI, ASTContext &Context,
        it != ie; ++it) {
     it->info = classifyArgumentType(it->type, Context, VMContext);
   }
+
+  // ARM always overrides the calling convention.
+  switch (getABIKind()) {
+  case APCS:
+    FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_APCS);
+    break;
+
+  case AAPCS:
+    FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS);
+    break;
+
+  case AAPCS_VFP:
+    FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS_VFP);
+    break;
+  }
 }
 
 ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty,
@@ -1544,8 +1575,14 @@ const ABIInfo &CodeGenTypes::getABIInfo() const {
 
   case llvm::Triple::arm:
   case llvm::Triple::thumb:
-    // FIXME: Support for OABI?
-    return *(TheABIInfo = new ARMABIInfo());
+    // FIXME: We should get this from the target, we also need a -target-abi
+    // because the user should have some control over this.
+    //
+    // FIXME: We want to know the float calling convention as well.
+    if (Triple.getOS() == llvm::Triple::Darwin)
+      return *(TheABIInfo = new ARMABIInfo(ARMABIInfo::APCS));
+
+    return *(TheABIInfo = new ARMABIInfo(ARMABIInfo::AAPCS));
 
   case llvm::Triple::pic16:
     return *(TheABIInfo = new PIC16ABIInfo());
diff --git a/clang/test/CodeGen/arm-apcs-arguments.c b/clang/test/CodeGen/arm-apcs-arguments.c
new file mode 100644
index 000000000000..f64680649049
--- /dev/null
+++ b/clang/test/CodeGen/arm-apcs-arguments.c
@@ -0,0 +1,6 @@
+// RUN: clang-cc -triple armv7-apple-darwin9 -emit-llvm -o - %s | FileCheck %s
+
+// CHECK: define arm_apcscc signext i8 @f0()
+char f0(void) {
+  return 0;
+}