From 3e42bc55db0c3ffba5ee7085529944934be2993d Mon Sep 17 00:00:00 2001
From: Bob Wilson <bob.wilson@apple.com>
Date: Tue, 20 Sep 2011 22:00:38 +0000
Subject: [PATCH] For i386 kext fallback to llvm-gcc, search paths for several
 Darwin versions.

This replaces the hack to read UNAME_RELEASE from the environment when
identifying the OS version on Darwin, and it's more flexible.  It's also
horribly ugly, but at least this consolidates the ugliness to touch less of
the code so that it will be easier to rip out later.

llvm-svn: 140187
---
 clang/lib/Driver/ToolChains.cpp | 16 +++++++++++-----
 clang/lib/Driver/ToolChains.h   |  3 +++
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index 5ed9dc897032..92c3ec9539ba 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -276,8 +276,6 @@ Tool &Darwin::SelectTool(const Compilation &C, const JobAction &JA,
 DarwinClang::DarwinClang(const HostInfo &Host, const llvm::Triple& Triple)
   : Darwin(Host, Triple)
 {
-  std::string UsrPrefix = "llvm-gcc-4.2/";
-
   getProgramPaths().push_back(getDriver().getInstalledDir());
   if (getDriver().getInstalledDir() != getDriver().Dir)
     getProgramPaths().push_back(getDriver().Dir);
@@ -290,16 +288,24 @@ DarwinClang::DarwinClang(const HostInfo &Host, const llvm::Triple& Triple)
   // For fallback, we need to know how to find the GCC cc1 executables, so we
   // also add the GCC libexec paths. This is legacy code that can be removed
   // once fallback is no longer useful.
+  AddGCCLibexecPath(DarwinVersion[0]);
+  AddGCCLibexecPath(DarwinVersion[0] - 2);
+  AddGCCLibexecPath(DarwinVersion[0] - 1);
+  AddGCCLibexecPath(DarwinVersion[0] + 1);
+  AddGCCLibexecPath(DarwinVersion[0] + 2);
+}
+
+void DarwinClang::AddGCCLibexecPath(unsigned darwinVersion) {
   std::string ToolChainDir = "i686-apple-darwin";
-  ToolChainDir += llvm::utostr(DarwinVersion[0]);
+  ToolChainDir += llvm::utostr(darwinVersion);
   ToolChainDir += "/4.2.1";
 
   std::string Path = getDriver().Dir;
-  Path += "/../" + UsrPrefix + "libexec/gcc/";
+  Path += "/../llvm-gcc-4.2/libexec/gcc/";
   Path += ToolChainDir;
   getProgramPaths().push_back(Path);
 
-  Path = "/usr/" + UsrPrefix + "libexec/gcc/";
+  Path = "/usr/llvm-gcc-4.2/libexec/gcc/";
   Path += ToolChainDir;
   getProgramPaths().push_back(Path);
 }
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index c7771170b838..c9ff3a0473d1 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -262,6 +262,9 @@ public:
 
 /// DarwinClang - The Darwin toolchain used by Clang.
 class LLVM_LIBRARY_VISIBILITY DarwinClang : public Darwin {
+private:
+  void AddGCCLibexecPath(unsigned darwinVersion);
+
 public:
   DarwinClang(const HostInfo &Host, const llvm::Triple& Triple);