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

1 files changed, 65 insertions, 0 deletions

diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index 1cdaac0c2b..7c028f4cf1 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;