From ba2280c5c705fceb31443a57bb6bed96c3e5be7e Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Mon, 9 Apr 2018 11:58:53 +0100
Subject: [PATCH] Apply extra sort to SPDB file list to put entry file first.
 Closes #950

* This isn't 100% reliable but it seems reasonably consistent that while
  the first file in the streams isn't always the entry file, the first
  name of a file in the list of names which map to files is. So we
  re-sort by the list of names.
---
 .../driver/shaders/dxbc/dxbc_inspect.cpp      | 27 ++++++++++
 .../driver/shaders/dxbc/dxbc_reflect.cpp      | 50 +------------------
 2 files changed, 29 insertions(+), 48 deletions(-)

diff --git a/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp b/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
index 8a9a72da1..2a4caec7f 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_inspect.cpp
@@ -24,6 +24,7 @@
  ******************************************************************************/
 
 #include "dxbc_inspect.h"
+#include <algorithm>
 #include "api/app/renderdoc_app.h"
 #include "common/common.h"
 #include "serialise/serialiser.h"
@@ -2527,6 +2528,32 @@ SPDBChunk::SPDBChunk(void *chunk)
 
   delete[] pages;
 
+  // Sort files according to the order they come in the Names array, this seems to be more reliable
+  // about placing the main file first.
+  std::sort(Files.begin(), Files.end(), [&Names](const std::pair<std::string, std::string> &a,
+                                                 const std::pair<std::string, std::string> &b) {
+    // any entries that aren't found in Names at all (like @cmdline that we add) will be sorted to
+    // the end.
+    size_t aIdx = ~0U, bIdx = ~0U;
+
+    size_t i = 0;
+    for(auto it = Names.begin(); it != Names.end(); ++it)
+    {
+      if(it->second == a.first)
+        aIdx = i;
+      if(it->second == b.first)
+        bIdx = i;
+
+      i++;
+    }
+
+    // if neither were found, sort by filename
+    if(aIdx == bIdx)
+      return a.first < b.first;
+
+    return aIdx < bIdx;
+  });
+
   m_HasDebugInfo = true;
 }
 
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_reflect.cpp b/renderdoc/driver/shaders/dxbc/dxbc_reflect.cpp
index 29df72929..8eb483d6d 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_reflect.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_reflect.cpp
@@ -239,54 +239,8 @@ void MakeShaderReflection(DXBC::DXBCFile *dxbc, ShaderReflection *refl,
     if(entry.empty())
       entry = "main";
 
-    // sort the file with the entry point to the start. We don't have to do anything if there's only
-    // one file.
-    // This isn't a perfect search - it will match entry_point() anywhere in the file, even if it's
-    // in a comment or disabled preprocessor definition. This is just best-effort
-    if(refl->debugInfo.files.count() > 1)
-    {
-      // search from 0 up. If we find a match, we swap it into [0]. If we don't find a match then
-      // we can't rearrange anything. This is a no-op for 0 since it's already in first place, but
-      // since our search isn't perfect we might have multiple matches with some being false
-      // positives, and so we want to bias towards leaving [0] in place.
-      for(size_t i = 0; i < refl->debugInfo.files.size(); i++)
-      {
-        const char *c = strstr(refl->debugInfo.files[i].contents.c_str(), entry.c_str());
-        const char *end = refl->debugInfo.files[i].contents.end();
-
-        // no substring match? continue
-        if(c == NULL)
-          continue;
-
-        // if we did get a substring match, ensure there's whitespace preceeding it.
-        if(c == entry.c_str() || !isspace((int)*(c - 1)))
-          continue;
-
-        // skip past the entry point. Then skip any whitespace
-        c += entry.size();
-
-        // check for EOF.
-        if(c >= end)
-          continue;
-
-        while(c < end && isspace(*c))
-          c++;
-
-        if(c >= end)
-          continue;
-
-        // if there's an open bracket next, we found a entry_point( which we count as the
-        // declaration.
-        if(*c == '(')
-        {
-          // only do anything if we're looking at a later file
-          if(i > 0)
-            std::swap(refl->debugInfo.files[0], refl->debugInfo.files[i]);
-
-          break;
-        }
-      }
-    }
+    // assume the debug info put the file with the entry point at the start. SDBG seems to do this
+    // by default, and SPDB has an extra sorting step that probably maybe possibly does this.
   }
 
   refl->encoding = ShaderEncoding::DXBC;