Restructure how the driver communicates information about the

target Objective-C runtime down to the frontend:  break this
down into a single target runtime kind and version, and compute
all the relevant information from that.  This makes it
relatively painless to add support for new runtimes to the
compiler.  Make the new -cc1 flag, -fobjc-runtime=blah-x.y.z,
available at the driver level as a better and more general
alternative to -fgnu-runtime and -fnext-runtime.  This new
concept of an Objective-C runtime also encompasses what we
were previously separating out as the "Objective-C ABI", so
fragile vs. non-fragile runtimes are now really modelled as
different kinds of runtime, paving the way for better overall
differentiation.

As a sort of special case, continue to accept the -cc1 flag
-fobjc-runtime-has-weak, as a sop to PLCompatibilityWeak.

I won't go so far as to say "no functionality change", even
ignoring the new driver flag, but subtle changes in driver
semantics are almost certainly not intended.

llvm-svn: 158793

1 files changed, 52 insertions, 0 deletions

diff --git a/clang/lib/Basic/VersionTuple.cpp b/clang/lib/Basic/VersionTuple.cpp
index 77aad39cbf2..4f479d00d6c 100644
--- a/clang/lib/Basic/VersionTuple.cpp
+++ b/clang/lib/Basic/VersionTuple.cpp
@@ -34,3 +34,55 @@ raw_ostream& clang::operator<<(raw_ostream &Out,
     Out << '.' << *Subminor;
   return Out;
 }
+
+static bool parseInt(StringRef &input, unsigned &value) {
+  assert(value == 0);
+  if (input.empty()) return true;
+
+  char next = input[0];
+  input = input.substr(1);
+  if (next < '0' || next > '9') return true;
+  value = (unsigned) (next - '0');
+
+  while (!input.empty()) {
+    next = input[0];
+    if (next < '0' || next > '9') return false;
+    input = input.substr(1);
+    value = value * 10 + (unsigned) (next - '0');
+  }
+
+  return false;
+}
+
+bool VersionTuple::tryParse(StringRef input) {
+  unsigned major = 0, minor = 0, micro = 0;
+
+  // Parse the major version, [0-9]+
+  if (parseInt(input, major)) return true;
+
+  if (input.empty()) {
+    *this = VersionTuple(major);
+    return false;
+  }
+
+  // If we're not done, parse the minor version, \.[0-9]+
+  if (input[0] != '.') return true;
+  input = input.substr(1);
+  if (parseInt(input, minor)) return true;
+
+  if (input.empty()) {
+    *this = VersionTuple(major, minor);
+    return false;
+  }
+
+  // If we're not done, parse the micro version, \.[0-9]+
+  if (input[0] != '.') return true;
+  input = input.substr(1);
+  if (parseInt(input, micro)) return true;
+
+  // If we have characters left over, it's an error.
+  if (!input.empty()) return true;
+
+  *this = VersionTuple(major, minor, micro);
+  return false;
+}