diff -aur cmake-3.1.0.orig/Source/cmGlobalXCodeGenerator.cxx cmake-3.1.0/Source/cmGlobalXCodeGenerator.cxx
--- cmake-3.1.0.orig/Source/cmGlobalXCodeGenerator.cxx	2015-10-15 09:31:13.000000000 -0500
+++ cmake-3.1.0/Source/cmGlobalXCodeGenerator.cxx	2015-10-15 11:37:37.000000000 -0500
@@ -1455,8 +1455,11 @@
 //----------------------------------------------------------------------------
 // This function removes each occurrence of the flag and returns the last one
 // (i.e., the dominant flag in GCC)
+// If an argument is longer than ignore_longer_than, then it will be ignored
+// and not removed.
 std::string cmGlobalXCodeGenerator::ExtractFlag(const char* flag,
-                                                std::string& flags)
+                                                std::string& flags,
+                                                unsigned int ignore_longer_than)
 {
   std::string retFlag;
   std::string::size_type lastOccurancePos = flags.rfind(flag);
@@ -1467,16 +1470,25 @@
     std::string::size_type pos = lastOccurancePos;
     if(pos == 0 || flags[pos-1]==' ')
       {
-      while(pos < flags.size() && flags[pos] != ' ')
+      // determine the argument's length and ignore if the argument is to long
+      std::string::size_type tpos = pos;
+      while(tpos < flags.size() && flags[tpos] != ' ')
         {
-        if(!saved)
+        tpos++;
+        }
+      if ((tpos - pos) <= ignore_longer_than)
+        {
+        while(pos < flags.size() && flags[pos] != ' ')
           {
-          retFlag += flags[pos];
+          if(!saved)
+            {
+            retFlag += flags[pos];
+            }
+          flags[pos] = ' ';
+          pos++;
           }
-        flags[pos] = ' ';
-        pos++;
+        saved = true;
         }
-      saved = true;
       }
     //decrement lastOccurancePos while making sure we don't loop around
     //and become a very large positive number since size_type is unsigned
@@ -2140,7 +2152,7 @@
     buildSettings->AddAttribute("HEADER_SEARCH_PATHS",
                                 dirs.CreateList());
     }
-  std::string oflagc = this->ExtractFlag("-O", cflags);
+  std::string oflagc = this->ExtractFlag("-O", cflags, 3);
   char optLevel[2];
   optLevel[0] = '0';
   optLevel[1] = 0;
@@ -2152,7 +2164,7 @@
     {
     optLevel[0] = '1';
     }
-  std::string oflag = this->ExtractFlag("-O", flags);
+  std::string oflag = this->ExtractFlag("-O", flags, 3);
   if(oflag.size() == 3)
     {
     optLevel[0] = oflag[2];
diff -aur cmake-3.1.0.orig/Source/cmGlobalXCodeGenerator.h cmake-3.1.0/Source/cmGlobalXCodeGenerator.h
--- cmake-3.1.0.orig/Source/cmGlobalXCodeGenerator.h	2014-12-15 14:07:43.000000000 -0600
+++ cmake-3.1.0/Source/cmGlobalXCodeGenerator.h	2015-10-15 11:30:42.000000000 -0500
@@ -148,7 +148,8 @@
   void CreateBuildSettings(cmTarget& target,
                            cmXCodeObject* buildSettings,
                            const std::string& buildType);
-  std::string ExtractFlag(const char* flag, std::string& flags);
+  std::string ExtractFlag(const char* flag, std::string& flags,
+                          unsigned int ignore_longer_than = 256);
   // delete all objects in the this->XCodeObjects vector.
   void ClearXCodeObjects();
   void CreateXCodeObjects(cmLocalGenerator* root,

From 99ca3254e4886155c20de54761dc9c2ca64fdf89 Mon Sep 17 00:00:00 2001
From: Davy Durham <ddurham@bomgar.com>
Date: Thu, 15 Oct 2015 12:04:43 -0500
Subject: [PATCH] Fixed an issue where the Xcode generated was clobbering
 "-O..." flags that aren't optimization flags

---
 Source/cmGlobalXCodeGenerator.cxx | 28 ++++++++++++++++++++--------
 Source/cmGlobalXCodeGenerator.h   |  3 ++-
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 6291796..8d361ec 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -1580,8 +1580,11 @@ void cmGlobalXCodeGenerator::CreateCustomCommands(cmXCodeObject* buildPhases,
 //----------------------------------------------------------------------------
 // This function removes each occurrence of the flag and returns the last one
 // (i.e., the dominant flag in GCC)
+// If an argument is longer than ignore_longer_than, then it will be ignored
+// and not removed.
 std::string cmGlobalXCodeGenerator::ExtractFlag(const char* flag,
-                                                std::string& flags)
+                                                std::string& flags,
+                                                unsigned int ignore_longer_than)
 {
   std::string retFlag;
   std::string::size_type lastOccurancePos = flags.rfind(flag);
@@ -1592,16 +1595,25 @@ std::string cmGlobalXCodeGenerator::ExtractFlag(const char* flag,
     std::string::size_type pos = lastOccurancePos;
     if(pos == 0 || flags[pos-1]==' ')
       {
-      while(pos < flags.size() && flags[pos] != ' ')
+      // determine the argument's length and ignore if the argument is to long
+      std::string::size_type tpos = pos;
+      while(tpos < flags.size() && flags[tpos] != ' ')
         {
-        if(!saved)
+        tpos++;
+        }
+      if ((tpos - pos) <= ignore_longer_than)
+        {
+        while(pos < flags.size() && flags[pos] != ' ')
           {
-          retFlag += flags[pos];
+          if(!saved)
+            {
+            retFlag += flags[pos];
+            }
+          flags[pos] = ' ';
+          pos++;
           }
-        flags[pos] = ' ';
-        pos++;
+        saved = true;
         }
-      saved = true;
       }
     //decrement lastOccurancePos while making sure we don't loop around
     //and become a very large positive number since size_type is unsigned
@@ -2237,7 +2249,7 @@ void cmGlobalXCodeGenerator::CreateBuildSettings(cmTarget& target,
     {
     std::string& flags = cflags[*li];
     std::string& gflag = gflags[*li];
-    std::string oflag = this->ExtractFlag("-O", flags);
+    std::string oflagc = this->ExtractFlag("-O", cflags, 3);
     if(oflag.size() == 3)
       {
       optLevel[0] = oflag[2];
diff --git a/Source/cmGlobalXCodeGenerator.h b/Source/cmGlobalXCodeGenerator.h
index 9daf0ab..aa6260f 100644
--- a/Source/cmGlobalXCodeGenerator.h
+++ b/Source/cmGlobalXCodeGenerator.h
@@ -150,7 +150,8 @@ private:
   void CreateBuildSettings(cmTarget& target,
                            cmXCodeObject* buildSettings,
                            const std::string& buildType);
-  std::string ExtractFlag(const char* flag, std::string& flags);
+  std::string ExtractFlag(const char* flag, std::string& flags,
+                          unsigned int ignore_longer_than = 256);
   void SortXCodeObjects();
   // delete all objects in the this->XCodeObjects vector.
   void ClearXCodeObjects();
-- 
1.8.5.2 (Apple Git-48)