Add some support for diagnosing possibly mismatched constraint, type size and

modifiers. (From an idea by Eric...)
<rdar://problem/12284092>

llvm-svn: 166647

1 files changed, 23 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index ba96185f72d..960a2858e41 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -3315,6 +3315,29 @@ public:
     }
     return R;
   }
+  virtual bool validateConstraintModifier(StringRef Constraint,
+                                          const char Modifier,
+                                          unsigned Size) const {
+    // Strip off constraint modifiers.
+    while (Constraint[0] == '=' ||
+           Constraint[0] == '+' ||
+           Constraint[0] == '&')
+      Constraint = Constraint.substr(1);
+
+    switch (Constraint[0]) {
+    default: break;
+    case 'r': {
+      switch (Modifier) {
+      default: return Size == 32;
+      case 'q':
+        // A register of size 32 cannot fit a vector type.
+        return false;
+      }
+    }
+    }
+
+    return true;
+  }
   virtual const char *getClobbers() const {
     // FIXME: Is this really right?
     return "";