[AST] NFC: Try to static_assert that ExtInfo and TypeBase agree

Author: davezarzycki

include/swift/AST/Types.h

@@ -289,7 +289,7 @@ class alignas(1 << TypeAlignInBits) TypeBase {
 
     /// Extra information which affects how the function is called, like
     /// regparm and the calling convention.
-    unsigned ExtInfo : 7;
+    unsigned ExtInfo : 7; enum { NumExtInfoBits = 7 };
   };
   enum { NumAnyFunctionTypeBits = NumTypeBaseBits + 7 };
   static_assert(NumAnyFunctionTypeBits <= 32, "fits in an unsigned");
@@ -316,7 +316,7 @@ class alignas(1 << TypeAlignInBits) TypeBase {
 
   struct SILFunctionTypeBitfields {
     unsigned : NumTypeBaseBits;
-    unsigned ExtInfo : 6;
+    unsigned ExtInfo : 6; enum { NumExtInfoBits = 6 };
     unsigned CalleeConvention : 3;
     unsigned HasErrorResult : 1;
     unsigned CoroutineKind : 2;
@@ -2392,20 +2392,21 @@ class AnyFunctionType : public TypeBase {
   /// \brief A class which abstracts out some details necessary for
   /// making a call.
   class ExtInfo {
-    // NOTE: If bits are added or removed, then TypeBase::AnyFunctionTypeBits
-    // must be updated to match.
-
+    // If bits are added or removed, then TypeBase::AnyFunctionTypeBits
+    // and NumMaskBits must be updated, and they must match.
+    //
     //   |representation|isAutoClosure|noEscape|throws|
     //   |    0 .. 3    |      4      |    5   |   6  |
     //
     enum : unsigned {
-      RepresentationMask     = 0x0F,
-      AutoClosureMask        = 0x10,
-      NoEscapeMask           = 0x20,
-      ThrowsMask             = 0x40,
+      RepresentationMask     = 0xF << 0,
+      AutoClosureMask        = 1 << 4,
+      NoEscapeMask           = 1 << 5,
+      ThrowsMask             = 1 << 6,
+      NumMaskBits            = 7
     };
 
-    unsigned Bits;
+    unsigned Bits; // Naturally sized for speed.
 
     ExtInfo(unsigned Bits) : Bits(Bits) {}
 
@@ -2505,7 +2506,7 @@ class AnyFunctionType : public TypeBase {
         return ExtInfo(Bits & ~ThrowsMask);
     }
 
-    uint16_t getFuncAttrKey() const {
+    unsigned getFuncAttrKey() const {
       return Bits;
     }
 
@@ -2539,7 +2540,11 @@ class AnyFunctionType : public TypeBase {
   : TypeBase(Kind, CanTypeContext, properties), Input(Input), Output(Output),
     NumParams(NumParams) {
     AnyFunctionTypeBits.ExtInfo = Info.Bits;
+    // The use of both assert() and static_assert() is intentional.
     assert(AnyFunctionTypeBits.ExtInfo == Info.Bits && "Bits were dropped!");
+    static_assert(ExtInfo::NumMaskBits ==
+                  AnyFunctionTypeBitfields::NumExtInfoBits,
+                 "ExtInfo and AnyFunctionTypeBitfields must agree on bit size");
   }
 
 public:
@@ -3249,19 +3254,20 @@ class SILFunctionType final : public TypeBase, public llvm::FoldingSetNode,
   /// \brief A class which abstracts out some details necessary for
   /// making a call.
   class ExtInfo {
-    // NOTE: If bits are added or removed, then TypeBase::SILFunctionTypeBits
-    // must be updated to match.
+    // If bits are added or removed, then TypeBase::SILFunctionTypeBits
+    // and NumMaskBits must be updated, and they must match.
 
     //   |representation|pseudogeneric| noescape |
     //   |    0 .. 3    |      4      |     5    |
     //
     enum : unsigned {
-      RepresentationMask = 0x0F,
-      PseudogenericMask  = 0x10,
-      NoEscapeMask       = 0x20,
+      RepresentationMask = 0xF << 0,
+      PseudogenericMask  = 1 << 4,
+      NoEscapeMask       = 1 << 5,
+      NumMaskBits        = 6
     };
 
-    unsigned Bits;
+    unsigned Bits; // Naturally sized for speed.
 
     ExtInfo(unsigned Bits) : Bits(Bits) {}
 
@@ -3364,7 +3370,7 @@ class SILFunctionType final : public TypeBase, public llvm::FoldingSetNode,
         return ExtInfo(Bits & ~NoEscapeMask);
     }
 
-    uint16_t getFuncAttrKey() const {
+    unsigned getFuncAttrKey() const {
       return Bits;
     }
 

lib/AST/ASTContext.cpp

@@ -3869,7 +3869,11 @@ SILFunctionType::SILFunctionType(GenericSignature *genericSig, ExtInfo ext,
 
   SILFunctionTypeBits.HasErrorResult = errorResult.hasValue();
   SILFunctionTypeBits.ExtInfo = ext.Bits;
+  // The use of both assert() and static_assert() below is intentional.
   assert(SILFunctionTypeBits.ExtInfo == ext.Bits && "Bits were dropped!");
+  static_assert(ExtInfo::NumMaskBits ==
+                SILFunctionTypeBitfields::NumExtInfoBits,
+                "ExtInfo and SILFunctionTypeBitfields must agree on bit size");
   SILFunctionTypeBits.CoroutineKind = unsigned(coroutineKind);
   NumParameters = params.size();
   if (coroutineKind == SILCoroutineKind::None) {