From 8fc56df0e0c40d645ae61f834448ccaa0263d727 Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Mon, 8 Jan 2018 15:58:30 +0000
Subject: [PATCH] Add utility function that expands an operation in-place with
 new words

---
 .../driver/shaders/spirv/spirv_editor.cpp     | 23 +++++++++++++++++++
 renderdoc/driver/shaders/spirv/spirv_editor.h |  4 +++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.cpp b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
index c91859173..eef62e533 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.cpp
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.cpp
@@ -439,6 +439,29 @@ SPIRVId SPIRVEditor::DeclareStructType(std::vector<uint32_t> members)
   AddType(SPIRVOperation(spv::OpTypeStruct, members));
   return typeId;
 }
+
+void SPIRVEditor::AddWord(SPIRVIterator entry, uint32_t word)
+{
+  if(!entry)
+    return;
+
+  // if it's just pointing at a SPIRVOperation, we can just push_back immediately
+  if(entry.words != &spirv)
+  {
+    entry.words->push_back(word);
+    return;
+  }
+
+  // add word
+  spirv.insert(spirv.begin() + entry.offset + entry.size(), word);
+
+  // fix up header
+  entry.word(0) = SPIRVOperation::MakeHeader(entry.opcode(), entry.size() + 1);
+
+  // update offsets
+  addWords(entry.offset + entry.size(), 1);
+}
+
 void SPIRVEditor::addWords(size_t offs, int32_t num)
 {
   // look through every section, any that are >= this point, adjust the offsets
diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.h b/renderdoc/driver/shaders/spirv/spirv_editor.h
index 47b9b13fd..3cea93739 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.h
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.h
@@ -153,7 +153,7 @@ private:
 
   std::vector<uint32_t>::const_iterator begin() const { return iter.it(); }
   std::vector<uint32_t>::const_iterator end() const { return iter.it() + size(); }
-  inline uint32_t MakeHeader(spv::Op op, size_t WordCount)
+  inline static uint32_t MakeHeader(spv::Op op, size_t WordCount)
   {
     return (uint32_t(op) & spv::OpCodeMask) | (uint16_t(WordCount) << spv::WordCountShift);
   }
@@ -315,6 +315,8 @@ public:
 
   SPIRVId MakeId();
 
+  void AddWord(SPIRVIterator entry, uint32_t word);
+
   void SetName(uint32_t id, const char *name);
   void AddDecoration(const SPIRVOperation &op);
   void AddType(const SPIRVOperation &op);