From 6944f6f7281dfa04c500e517e1660c7abd265d01 Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Fri, 9 Feb 2018 12:17:40 +0000
Subject: [PATCH] Don't allow direct == or != on SPIRVIterator, use <

* The reason is if comparing directly against the end of a section, we
  could skip over it if the section ends in a nop and the next section
  starts in a nop. Instead < will always work as expected.
---
 renderdoc/driver/shaders/spirv/spirv_editor.cpp |  2 +-
 renderdoc/driver/shaders/spirv/spirv_editor.h   |  8 +++-----
 renderdoc/driver/vulkan/vk_postvs.cpp           | 10 +++++-----
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.cpp b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
index 610289b45..3ec465721 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.cpp
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
@@ -325,7 +325,7 @@ SPIRVIterator SPIRVEditor::GetEntry(SPIRVId id)
   SPIRVIterator it(spirv, entryPointSection.startOffset);
   SPIRVIterator end(spirv, entryPointSection.endOffset);
 
-  while(it && it != end)
+  while(it && it < end)
   {
     if(it.word(2) == id)
       return it;
diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.h b/renderdoc/driver/shaders/spirv/spirv_editor.h
index beebec7c9..2d2471468 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.h
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.h
@@ -77,11 +77,9 @@ public:
 
     return *this;
   }
-  bool operator==(const SPIRVIterator &it) const
-  {
-    return words == it.words && offset == it.offset;
-  }
-  bool operator!=(const SPIRVIterator &it) const { return !(*this == it); }
+  bool operator==(const SPIRVIterator &it) const = delete;
+  bool operator!=(const SPIRVIterator &it) const = delete;
+  bool operator<(const SPIRVIterator &it) const { return words == it.words && offset < it.offset; }
   // utility functions
   explicit operator bool() const { return words != NULL && offset < words->size(); }
   uint32_t &operator*() { return cur(); }
diff --git a/renderdoc/driver/vulkan/vk_postvs.cpp b/renderdoc/driver/vulkan/vk_postvs.cpp
index 49e24d91e..b57390488 100644
--- a/renderdoc/driver/vulkan/vk_postvs.cpp
+++ b/renderdoc/driver/vulkan/vk_postvs.cpp
@@ -49,7 +49,7 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
 
   descSet = 0;
 
-  for(SPIRVIterator it = editor.BeginDecorations(), end = editor.EndDecorations(); it != end; ++it)
+  for(SPIRVIterator it = editor.BeginDecorations(), end = editor.EndDecorations(); it < end; ++it)
   {
     // we will use the descriptor set immediately after the last set statically used by the shader.
     // This means we don't have to worry about if the descriptor set layout declares more sets which
@@ -103,7 +103,7 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
   std::map<SPIRVId, SPIRVId> typeReplacements;
 
   // rewrite any inputs and outputs to be private storage class
-  for(SPIRVIterator it = editor.BeginTypes(), end = editor.EndTypes(); it != end; ++it)
+  for(SPIRVIterator it = editor.BeginTypes(), end = editor.EndTypes(); it < end; ++it)
   {
     // rewrite any input/output variables to private, and build up inputs/outputs list
     if(it.opcode() == spv::OpTypePointer)
@@ -246,7 +246,7 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
   }
 
   // detect builtin inputs or outputs, and remove builtin decorations
-  for(SPIRVIterator it = editor.BeginDecorations(), end = editor.EndDecorations(); it != end; ++it)
+  for(SPIRVIterator it = editor.BeginDecorations(), end = editor.EndDecorations(); it < end; ++it)
   {
     // remove any builtin decorations
     if(it.opcode() == spv::OpDecorate && it.word(2) == spv::DecorationBuiltIn)
@@ -335,7 +335,7 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
 
   RDCASSERT(entryID);
 
-  for(SPIRVIterator it = editor.BeginDebug(), end2 = editor.EndDebug(); it != end2; ++it)
+  for(SPIRVIterator it = editor.BeginDebug(), end2 = editor.EndDebug(); it < end2; ++it)
   {
     if(it.opcode() == spv::OpName &&
        (inputs.find(it.word(1)) != inputs.end() || outputs.find(it.word(1)) != outputs.end()))
@@ -659,7 +659,7 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
     ++it;
   }
 
-  for(SPIRVIterator end = editor.EndEntries(); it != end; ++it)
+  for(SPIRVIterator end = editor.EndEntries(); it < end; ++it)
     editor.Remove(it);
 
   editor.AddOperation(