1 files changed, 43 insertions, 0 deletions
diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index f1015e62eec..1a398fd8a77 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -1598,6 +1598,49 @@ bool Generic_GCC::GCCVersion::isOlderThan(int RHSMajor, int RHSMinor,
   return false;
 }
 
+/// \brief Parse a GCCVersion object out of a string of text.
+///
+/// This is the primary means of forming GCCVersion objects.
+/*static*/
+Generic_GCC::GCCVersion Generic_GCC::GCCVersion::Parse(StringRef VersionText) {
+  const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
+  std::pair<StringRef, StringRef> First = VersionText.split('.');
+  std::pair<StringRef, StringRef> Second = First.second.split('.');
+
+  GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
+  if (First.first.getAsInteger(10, GoodVersion.Major) || GoodVersion.Major < 0)
+    return BadVersion;
+  GoodVersion.MajorStr = First.first.str();
+  if (First.second.empty())
+    return GoodVersion;
+  if (Second.first.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
+    return BadVersion;
+  GoodVersion.MinorStr = Second.first.str();
+
+  // First look for a number prefix and parse that if present. Otherwise just
+  // stash the entire patch string in the suffix, and leave the number
+  // unspecified. This covers versions strings such as:
+  //   5        (handled above)
+  //   4.4
+  //   4.4.0
+  //   4.4.x
+  //   4.4.2-rc4
+  //   4.4.x-patched
+  // And retains any patch number it finds.
+  StringRef PatchText = GoodVersion.PatchSuffix = Second.second.str();
+  if (!PatchText.empty()) {
+    if (size_t EndNumber = PatchText.find_first_not_of("0123456789")) {
+      // Try to parse the number and any suffix.
+      if (PatchText.slice(0, EndNumber).getAsInteger(10, GoodVersion.Patch) ||
+          GoodVersion.Patch < 0)
+        return BadVersion;
+      GoodVersion.PatchSuffix = PatchText.substr(EndNumber);
+    }
+  }
+
+  return GoodVersion;
+}
+
 static llvm::StringRef getGCCToolchainDir(const ArgList &Args) {
   const Arg *A = Args.getLastArg(clang::driver::options::OPT_gcc_toolchain);
   if (A)