From 0aca1c30c691bcf8fbe9d112210cad3052e22708 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Wed, 30 Apr 2014 06:14:25 +0000
Subject: [PATCH] ARM: print COFF function header for Windows on ARM

Emit the COFF header when printing out the function.  This is important as the
header contains two important pieces of information: the storage class for the
symbol and the symbol type information.  This bit of information is required for
the linker to correctly identify the type of symbol that it is dealing with.

llvm-svn: 207613
---
 llvm/lib/Target/ARM/ARMAsmPrinter.cpp       | 24 ++++++++++-
 llvm/test/MC/ARM/coff-function-type-info.ll | 45 +++++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/MC/ARM/coff-function-type-info.ll

diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index 451189786701..f101053708c5 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -44,6 +44,7 @@
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/ARMBuildAttributes.h"
+#include "llvm/Support/COFF.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ELF.h"
@@ -97,7 +98,28 @@ bool ARMAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   AFI = MF.getInfo<ARMFunctionInfo>();
   MCP = MF.getConstantPool();
 
-  return AsmPrinter::runOnMachineFunction(MF);
+  SetupMachineFunction(MF);
+
+  if (Subtarget->isTargetCOFF()) {
+    bool Internal = MF.getFunction()->hasInternalLinkage();
+    COFF::SymbolStorageClass Scl = Internal ? COFF::IMAGE_SYM_CLASS_STATIC
+                                            : COFF::IMAGE_SYM_CLASS_EXTERNAL;
+    int Type = COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT;
+
+    OutStreamer.BeginCOFFSymbolDef(CurrentFnSym);
+    OutStreamer.EmitCOFFSymbolStorageClass(Scl);
+    OutStreamer.EmitCOFFSymbolType(Type);
+    OutStreamer.EndCOFFSymbolDef();
+  }
+
+  // Have common code print out the function header with linkage info etc.
+  EmitFunctionHeader();
+
+  // Emit the rest of the function body.
+  EmitFunctionBody();
+
+  // We didn't modify anything.
+  return false;
 }
 
 void ARMAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
diff --git a/llvm/test/MC/ARM/coff-function-type-info.ll b/llvm/test/MC/ARM/coff-function-type-info.ll
new file mode 100644
index 000000000000..a9f7c186b630
--- /dev/null
+++ b/llvm/test/MC/ARM/coff-function-type-info.ll
@@ -0,0 +1,45 @@
+; RUN: llc -mtriple thumbv7-windows-itanium -filetype asm -o - %s \
+; RUN:    | FileCheck %s -check-prefix CHECK-ASM
+
+; RUN: llc -mtriple thumbv7-windows-itanium -filetype obj -o - %s \
+; RUN:    | llvm-readobj -t | FileCheck %s -check-prefix CHECK-OBJECT
+
+define arm_aapcs_vfpcc void @external() {
+entry:
+  ret void
+}
+
+; CHECK-ASM: .def external
+; CHECK-ASM:   .scl 2
+; CHECK-ASM:   .type 32
+; CHECK-ASM: .endef
+; CHECK-ASM: .globl external
+
+define internal arm_aapcs_vfpcc void @internal() {
+entry:
+  ret void
+}
+
+; CHECK-ASM: .def internal
+; CHECK-ASM:    .scl 3
+; CHECK-ASM:    .type 32
+; CHECK-ASM: .endef
+; CHECK-ASM-NOT: .globl internal
+
+; CHECK-OBJECT: Symbol {
+; CHECK-OBJECT:   Name: external
+; CHECK-OBJECT:   Section: .text
+; CHECK-OBJECT:   BaseType: Null
+; CHECK-OBJECT:   ComplexType: Function
+; CHECK-OBJECT:   StorageClass: External
+; CHECK-OBJECT:   AuxSymbolCount: 0
+; CHECK-OBJECT: }
+; CHECK-OBJECT: Symbol {
+; CHECK-OBJECT:   Name: internal
+; CHECK-OBJECT:   Section: .text
+; CHECK-OBJECT:   BaseType: Null
+; CHECK-OBJECT:   ComplexType: Function
+; CHECK-OBJECT:   StorageClass: Static
+; CHECK-OBJECT:   AuxSymbolCount: 0
+; CHECK-OBJECT: }
+