From dfc17f75e81250f3dcf06938f164481a77a50d60 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Wed, 12 Aug 2009 06:19:40 +0000
Subject: [PATCH] add a couple of helpers to the Triple class for decoding the
 darwin version string.  This should help consolidate the variety of weird
 functions we have scattered around the codebase that do stuff like this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78792 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/Triple.h | 15 +++++++++
 lib/Support/Triple.cpp    | 65 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/include/llvm/ADT/Triple.h b/include/llvm/ADT/Triple.h
index 31cf8effc66..47f8b6e9416 100644
--- a/include/llvm/ADT/Triple.h
+++ b/include/llvm/ADT/Triple.h
@@ -158,6 +158,21 @@ public:
   /// if the environment component is present).
   StringRef getOSAndEnvironmentName() const;
 
+  
+  /// getDarwinNumber - Parse the 'darwin number' out of the specific target
+  /// triple.  For example, if we have darwin8.5 return 8,5,0.  If any entry is
+  /// not defined, return 0's.  This requires that the triple have an OSType of
+  /// darwin before it is called.
+  void getDarwinNumber(unsigned &Maj, unsigned &Min, unsigned &Revision) const;
+  
+  /// getDarwinMajorNumber - Return just the major version number, this is
+  /// specialized because it is a common query.
+  unsigned getDarwinMajorNumber() const {
+    unsigned Maj, Min, Rev;
+    getDarwinNumber(Maj, Min, Rev);
+    return Maj;
+  }
+  
   /// @}
   /// @name Mutators
   /// @{
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index 1cdaac0c2b1..7c028f4cf1b 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -209,6 +209,71 @@ StringRef Triple::getOSAndEnvironmentName() const {
   return Tmp.split('-').second;                      // Strip second component
 }
 
+static unsigned EatNumber(StringRef &Str) {
+  assert(!Str.empty() && Str[0] >= '0' && Str[0] <= '9' && "Not a number");
+  unsigned Result = Str[0]-'0';
+  
+  // Eat the digit.
+  Str = Str.substr(1);
+  
+  // Handle "darwin11".
+  if (Result == 1 && !Str.empty() && Str[0] >= '0' && Str[0] <= '9') {
+    Result = Result*10 + (Str[0] - '0');
+    // Eat the digit.
+    Str = Str.substr(1);
+  }
+  
+  return Result;
+}
+
+/// getDarwinNumber - Parse the 'darwin number' out of the specific target
+/// triple.  For example, if we have darwin8.5 return 8,5,0.  If any entry is
+/// not defined, return 0's.  This requires that the triple have an OSType of
+/// darwin before it is called.
+void Triple::getDarwinNumber(unsigned &Maj, unsigned &Min,
+                             unsigned &Revision) const {
+  assert(getOS() == Darwin && "Not a darwin target triple!");
+  StringRef OSName = getOSName();
+  assert(OSName.startswith("darwin") && "Unknown darwin target triple!");
+  
+  // Strip off "darwin".
+  OSName = OSName.substr(6);
+  
+  Maj = Min = Revision = 0;
+
+  if (OSName.empty() || OSName[0] < '0' || OSName[0] > '9')
+    return;
+
+  // The major version is the first digit.
+  Maj = EatNumber(OSName);
+  if (OSName.empty()) return;
+  
+  // Handle minor version: 10.4.9 -> darwin8.9.
+  if (OSName[0] != '.')
+    return;
+  
+  // Eat the '.'.
+  OSName = OSName.substr(1);
+
+  if (OSName.empty() || OSName[0] < '0' || OSName[0] > '9')
+    return;
+  
+  Min = EatNumber(OSName);
+  if (OSName.empty()) return;
+
+  // Handle revision darwin8.9.1
+  if (OSName[0] != '.')
+    return;
+  
+  // Eat the '.'.
+  OSName = OSName.substr(1);
+  
+  if (OSName.empty() || OSName[0] < '0' || OSName[0] > '9')
+    return;
+
+  Revision = EatNumber(OSName);
+}
+
 void Triple::setTriple(const Twine &Str) {
   Data = Str.str();
   Arch = InvalidArch;