From 061dadbc618b3e50e3c2aa41c2a08846ab367a4b Mon Sep 17 00:00:00 2001
From: Sepalani <sepalani@hotmail.fr>
Date: Sat, 28 Jan 2017 03:28:28 +0000
Subject: [PATCH] HLE: SVR4 VAList struct added

---
 Source/Core/Core/HLE/HLE_VarArgs.cpp | 50 ++++++++++++++++++++++++++++
 Source/Core/Core/HLE/HLE_VarArgs.h   | 35 ++++++++++++++++++-
 2 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/Source/Core/Core/HLE/HLE_VarArgs.cpp b/Source/Core/Core/HLE/HLE_VarArgs.cpp
index 27ac6f7bf2..1b9b14e760 100644
--- a/Source/Core/Core/HLE/HLE_VarArgs.cpp
+++ b/Source/Core/Core/HLE/HLE_VarArgs.cpp
@@ -4,6 +4,8 @@
 
 #include "Core/HLE/HLE_VarArgs.h"
 
+#include "Common/Logging/Log.h"
+
 HLE::SystemVABI::VAList::~VAList() = default;
 
 u32 HLE::SystemVABI::VAList::GetGPR(u32 gpr) const
@@ -15,3 +17,51 @@ double HLE::SystemVABI::VAList::GetFPR(u32 fpr) const
 {
   return rPS0(fpr);
 }
+
+HLE::SystemVABI::VAListStruct::VAListStruct(u32 address)
+    : VAList(0), m_va_list{PowerPC::HostRead_U8(address), PowerPC::HostRead_U8(address + 1),
+                           PowerPC::HostRead_U32(address + 4), PowerPC::HostRead_U32(address + 8)},
+      m_address(address), m_has_fpr_area(GetCRBit(6) == 1)
+{
+  m_stack = m_va_list.overflow_arg_area;
+  m_gpr += m_va_list.gpr;
+  m_fpr += m_va_list.fpr;
+}
+
+u32 HLE::SystemVABI::VAListStruct::GetGPRArea() const
+{
+  return m_va_list.reg_save_area;
+}
+
+u32 HLE::SystemVABI::VAListStruct::GetFPRArea() const
+{
+  return GetGPRArea() + 4 * 8;
+}
+
+u32 HLE::SystemVABI::VAListStruct::GetGPR(u32 gpr) const
+{
+  if (gpr < 3 || gpr > 10)
+  {
+    ERROR_LOG(OSHLE, "VAListStruct at %08x doesn't have GPR%d!", m_address, gpr);
+    return 0;
+  }
+  const u32 gpr_address = Common::AlignUp(GetGPRArea() + 4 * (gpr - 3), 4);
+  return PowerPC::HostRead_U32(gpr_address);
+}
+
+double HLE::SystemVABI::VAListStruct::GetFPR(u32 fpr) const
+{
+  double value = 0.0;
+
+  if (!m_has_fpr_area || fpr < 1 || fpr > 8)
+  {
+    ERROR_LOG(OSHLE, "VAListStruct at %08x doesn't have FPR%d!", m_address, fpr);
+  }
+  else
+  {
+    const u32 fpr_address = Common::AlignUp(GetFPRArea() + 8 * (fpr - 1), 8);
+    const u64 integral = PowerPC::HostRead_U64(fpr_address);
+    std::memcpy(&value, &integral, sizeof(double));
+  }
+  return value;
+}
diff --git a/Source/Core/Core/HLE/HLE_VarArgs.h b/Source/Core/Core/HLE/HLE_VarArgs.h
index a76ae76fe3..3c72c1f05e 100644
--- a/Source/Core/Core/HLE/HLE_VarArgs.h
+++ b/Source/Core/Core/HLE/HLE_VarArgs.h
@@ -130,15 +130,48 @@ public:
     return static_cast<T>(GetArg<T>());
   }
 
-private:
+protected:
   u32 m_gpr = 3;
   u32 m_fpr = 1;
   const u32 m_gpr_max = 10;
   const u32 m_fpr_max = 8;
   u32 m_stack;
 
+private:
   virtual u32 GetGPR(u32 gpr) const;
   virtual double GetFPR(u32 fpr) const;
 };
+
+// See System V ABI (SVR4) for more details
+//  -> 6-6 Required Routines
+//  -> 3-21 Variable Argument Lists
+//
+// Source:
+// http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
+class VAListStruct : public VAList
+{
+public:
+  explicit VAListStruct(u32 address);
+  ~VAListStruct() = default;
+
+private:
+  struct svr4_va_list
+  {
+    u8 gpr;
+    u8 fpr;
+    u32 overflow_arg_area;
+    u32 reg_save_area;
+  };
+  const svr4_va_list m_va_list;
+  const u32 m_address;
+  const bool m_has_fpr_area;
+
+  u32 GetGPRArea() const;
+  u32 GetFPRArea() const;
+
+  u32 GetGPR(u32 gpr) const override;
+  double GetFPR(u32 fpr) const override;
+};
+
 }  // namespace SystemVABI
 }  // namespace HLE