Define the last scalar offset instead of hard coding it

Author: Azoy

stdlib/public/stubs/Unicode/Apple/ScalarPropsData.h

@@ -7420,6 +7420,8 @@ static const __swift_uint32_t _swift_stdlib_word_indices[12866] = {
   0x13139,
 };
 
+#define NAMES_LAST_SCALAR_OFFSET 215884
+
 static const __swift_uint8_t _swift_stdlib_names[215884] = {
   0xFF, 0xA3, 0x2, 0xFF, 0x76, 0x2, 0x2B, 0xFF, 0x36, 0x2, 0x2B, 0x1D, 0x1, 0xFF, 0x1B, 0x5, 0x1,
   0xFF, 0x28, 0x6, 0x1, 0xFF, 0x74, 0x4, 0xFF, 0x45, 0x4, 0x27, 0xFF, 0xB7, 0x1, 0x25, 0xFF, 0xB7,

stdlib/public/stubs/Unicode/Common/ScalarPropsData.h

@@ -7391,6 +7391,8 @@ static const __swift_uint32_t _swift_stdlib_word_indices[12866] = {
   0x130FC, 0x130FE, 0x13103, 0x13108, 0x1310D, 0x13111, 0x1311A, 0x13127, 0x1312B, 0x13131, 0x1313A,
 };
 
+#define NAMES_LAST_SCALAR_OFFSET 215884
+
 static const __swift_uint8_t _swift_stdlib_names[215884] = {
   0xFF, 0xA7, 0x2, 0xFF, 0x77, 0x2, 0x2B, 0xFF, 0x3A, 0x2, 0x2B, 0x1D, 0x1, 0xFF, 0xDD, 0x4, 0x1,
   0xFF, 0x7C, 0x6, 0x1, 0xFF, 0x9F, 0x4, 0xFF, 0x46, 0x4, 0x27, 0xFF, 0xB6, 0x1, 0x25, 0xFF, 0xB6,

stdlib/public/stubs/Unicode/UnicodeScalarProps.cpp

@@ -252,11 +252,8 @@ __swift_intptr_t _swift_stdlib_getScalarName(__swift_uint32_t scalar,
     }
   } else {
     // This is the last element in the array which represents the last scalar
-    // name that Unicode defines (excluding variation selectors). This is
-    // U+E007F at the moment whose name is 'CANCEL TAG'. We add 4 because
-    // 'CANCEL' is found outside the byte area for words, but tag does.
-    // The resulting word indices look like this: [..., 0xFF, _, _, 0xXX];
-    nextScalarOffset = scalarOffset + 4;
+    // name that Unicode defines (excluding variation selectors).
+    nextScalarOffset = NAMES_LAST_SCALAR_OFFSET;
   }
 
   auto nameSize = nextScalarOffset - scalarOffset;

utils/gen-unicode-data/Sources/GenScalarProps/Names.swift

@@ -160,7 +160,7 @@ func emitScalarNames(
   }
 
   result += """
-  #define NAMES_SCALARS_MAX_INDEX \(scalars.count - 1)
+  #define NAMES_LAST_SCALAR_OFFSET \(nameBytes.count)
   
   
   """
@@ -204,6 +204,12 @@ func emitScalars(
     }
   }
 
+  result += """
+  #define NAMES_SCALARS_MAX_INDEX \(scalars.count - 1)
+  
+  
+  """
+  
   emitCollection(scalars, name: "_swift_stdlib_names_scalars", into: &result)
 
   return scalarSetIndices