commit 864bf89f69a1c51939534fac7c58e7f02a2b9fc2
author Jordan Rose <jordan_rose@apple.com> Mon Jun 18 08:39:55 2018 -0700
committer GitHub <noreply@github.com> Mon Jun 18 08:39:55 2018 -0700
tree 3a811097e268c7ca2312b4a026e510f21551b206
parent fb541adf9ec4e27d1f9a879bd7db782e70cefca1

[ClangImporter] Handle lookup tables with many entries (#17265)

In particular, there are frameworks with more than 65536 entries for
'init' as a base name.

I can't think of a test case for this besides actually adding such a
massive framework, but the assertions that were added here should
catch the issue in Debug builds if it ever comes up again. I'm going
to go harden everything else that uses this API next.

rdar://problem/40828315

lib/ClangImporter/SwiftLookupTable.cpp

diff --git a/lib/ClangImporter/SwiftLookupTable.cpp b/lib/ClangImporter/SwiftLookupTable.cpp
index 41fa398..c22a655 100644
--- a/lib/ClangImporter/SwiftLookupTable.cpp
+++ b/lib/ClangImporter/SwiftLookupTable.cpp
@@ -961,6 +961,7 @@
       if (key.Kind == DeclBaseName::Kind::Normal) {
         keyLength += key.Name.size(); // The name's length
       }
+      assert(keyLength == static_cast<uint16_t>(keyLength));
 
       // # of entries
       uint32_t dataLength = sizeof(uint16_t);
@@ -982,7 +983,7 @@
 
       endian::Writer<little> writer(out);
       writer.write<uint16_t>(keyLength);
-      writer.write<uint16_t>(dataLength);
+      writer.write<uint32_t>(dataLength);
       return { keyLength, dataLength };
     }
 
@@ -1067,10 +1068,12 @@
       uint32_t keyLength = 1;
       if (SwiftLookupTable::contextRequiresName(key.first))
         keyLength += key.second.size();
+      assert(keyLength == static_cast<uint16_t>(keyLength));
 
       // # of entries
       uint32_t dataLength =
         sizeof(uint16_t) + sizeof(uint64_t) * data.size();
+      assert(dataLength == static_cast<uint16_t>(dataLength));
 
       endian::Writer<little> writer(out);
       writer.write<uint16_t>(keyLength);
@@ -1226,7 +1229,7 @@
     static std::pair<unsigned, unsigned>
     ReadKeyDataLength(const uint8_t *&data) {
       unsigned keyLength = endian::readNext<uint16_t, little, unaligned>(data);
-      unsigned dataLength = endian::readNext<uint16_t, little, unaligned>(data);
+      unsigned dataLength = endian::readNext<uint32_t, little, unaligned>(data);
       return { keyLength, dataLength };
     }