Reorder and shrink size of NameLen field in diagnostic group table. Shaves ~4K from clang binary.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189445 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 7 insertions, 5 deletions

diff --git a/tools/diagtool/DiagnosticNames.h b/tools/diagtool/DiagnosticNames.h
index dd5381f028..957a1818e8 100644
--- a/tools/diagtool/DiagnosticNames.h
+++ b/tools/diagtool/DiagnosticNames.h
@@ -35,11 +35,8 @@ namespace diagtool {
 
 
   struct GroupRecord {
-    // Be safe with the size of 'NameLen' because we don't statically check if
-    // the size will fit in the field; the struct size won't decrease with a
-    // shorter type anyway.
-    size_t NameLen;
     const char *NameStr;
+    uint16_t NameLen;
     uint16_t Members;
     uint16_t SubGroups;
 
diff --git a/tools/diagtool/TreeView.cpp b/tools/diagtool/TreeView.cpp
index 6298179030..10809c1d8d 100644
--- a/tools/diagtool/TreeView.cpp
+++ b/tools/diagtool/TreeView.cpp
@@ -94,7 +94,12 @@ static int showGroup(llvm::raw_ostream &out, StringRef RootGroup,
                      bool FlagsOnly) {
   ArrayRef<GroupRecord> AllGroups = getDiagnosticGroups();
 
-  GroupRecord Key = { RootGroup.size(), RootGroup.data(), 0, 0 };
+  if (RootGroup.size() > UINT16_MAX) {
+    llvm::errs() << "No such diagnostic group exists\n";
+    return 1;
+  }
+
+  GroupRecord Key = { RootGroup.data(), (uint16_t)RootGroup.size(), 0, 0 };
   const GroupRecord *Found =
     std::lower_bound(AllGroups.begin(), AllGroups.end(), Key);