QUnicodeTables: pack Properties struct

GCC doesn't like the sequence

   : 5
   : 5
   : 8
   : 6
   : 8

and inserts a :6 padding between the :5 and the :8 and a :2 padding
between the :6 and the :8, growing the bitfield by 8 bits of embedded
padding and another byte to bring the struct back to sizeof % 2 == 0.

Fix by reshuffling the elements and adding a static_assert for the
next round.

Saves ~5KiB in QtCore executable size.

Change-Id: I4758a6f48ba389abc2aee92f60997d42ebb0e5b8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/util/unicode/main.cpp b/util/unicode/main.cpp
index 84231c6277..16f9e4be66 100644
--- a/util/unicode/main.cpp
+++ b/util/unicode/main.cpp
@@ -814,8 +814,8 @@ static const char *property_string =
     "#endif\n"
     "    ushort graphemeBreakClass  : 5; /* 5 used */\n"
     "    ushort wordBreakClass      : 5; /* 5 used */\n"
-    "    ushort sentenceBreakClass  : 8; /* 4 used */\n"
     "    ushort lineBreakClass      : 6; /* 6 used */\n"
+    "    ushort sentenceBreakClass  : 8; /* 4 used */\n"
     "    ushort script              : 8;\n"
     "};\n\n"
     "Q_CORE_EXPORT const Properties * QT_FASTCALL properties(uint ucs4) noexcept;\n"
@@ -874,6 +874,9 @@ static const char *methods =
 
 static const int SizeOfPropertiesStruct = 20;
 
+static const QByteArray sizeOfPropertiesStructCheck =
+        "Q_STATIC_ASSERT(sizeof(Properties) == " + QByteArray::number(SizeOfPropertiesStruct) + ");\n\n";
+
 struct PropertyFlags {
     bool operator==(const PropertyFlags &o) const {
         return (combiningClass == o.combiningClass
@@ -2502,16 +2505,16 @@ static QByteArray createPropertyInfo()
         out += ", ";
 //     "        ushort graphemeBreakClass  : 5; /* 5 used */\n"
 //     "        ushort wordBreakClass      : 5; /* 5 used */\n"
-//     "        ushort sentenceBreakClass  : 8; /* 4 used */\n"
 //     "        ushort lineBreakClass      : 6; /* 6 used */\n"
         out += QByteArray::number( p.graphemeBreakClass );
         out += ", ";
         out += QByteArray::number( p.wordBreakClass );
         out += ", ";
-        out += QByteArray::number( p.sentenceBreakClass );
-        out += ", ";
         out += QByteArray::number( p.lineBreakClass );
         out += ", ";
+//     "        ushort sentenceBreakClass  : 8; /* 4 used */\n"
+        out += QByteArray::number( p.sentenceBreakClass );
+        out += ", ";
 //     "        ushort script              : 8;\n"
         out += QByteArray::number( p.script );
         out += " },";
@@ -3129,6 +3132,7 @@ int main(int, char **)
     f.write("#define UNICODE_DATA_VERSION " DATA_VERSION_STR "\n\n");
     f.write("namespace QUnicodeTables {\n\n");
     f.write(property_string);
+    f.write(sizeOfPropertiesStructCheck);
     f.write(grapheme_break_class_string);
     f.write(word_break_class_string);
     f.write(sentence_break_class_string);