commit cfaa5525b8eea6c5f7767010e04e323f76bed1ab
author David Majnemer <david.majnemer@gmail.com> Sat Jul 20 07:15:15 2013 +0000
committer David Majnemer <david.majnemer@gmail.com> Sat Jul 20 07:15:15 2013 +0000
tree 8077c07be7e5570fdbcd8f3061d956cc5cd002e9
parent 03bf10dc4f245a17ee4f702461cba5120cc4d09b

DiagnosticIDs: Forbid Diag ID from being valid

Diag ID is used throughout clang as a sentinel id meaning "this is an
invalid diagnostic id."  Confusingly, Diag ID maps to a valid, usable,
diagnostic id.  Instead, start diagnostic ids at ID one.

Incidently, remove an unused element from StaticDiagInfo.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186760 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Basic/DiagnosticIDs.cpp

diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index a703876..e96d509 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -15,8 +15,8 @@
 #include "clang/Basic/AllDiagnostics.h"
 #include "clang/Basic/DiagnosticCategories.h"
 #include "clang/Basic/SourceManager.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <map>
 using namespace clang;
@@ -83,11 +83,9 @@
 #include "clang/Basic/DiagnosticSemaKinds.inc"
 #include "clang/Basic/DiagnosticAnalysisKinds.inc"
 #undef DIAG
-  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
 };
 
-static const unsigned StaticDiagInfoSize =
-  llvm::array_lengthof(StaticDiagInfo)-1;
+static const unsigned StaticDiagInfoSize = llvm::array_lengthof(StaticDiagInfo);
 
 /// GetDiagInfo - Return the StaticDiagInfoRec entry for the specified DiagID,
 /// or null if the ID is invalid.
@@ -106,7 +104,7 @@
 
   // Out of bounds diag. Can't be in the table.
   using namespace diag;
-  if (DiagID >= DIAG_UPPER_LIMIT)
+  if (DiagID >= DIAG_UPPER_LIMIT || DiagID <= DIAG_START_COMMON)
     return 0;
 
   // Compute the index of the requested diagnostic in the static table.
@@ -118,8 +116,7 @@
   // This is cheaper than a binary search on the table as it doesn't touch
   // memory at all.
   unsigned Offset = 0;
-  unsigned ID = DiagID;
-#define DIAG_START_COMMON 0 // Sentinel value.
+  unsigned ID = DiagID - DIAG_START_COMMON - 1;
 #define CATEGORY(NAME, PREV) \
   if (DiagID > DIAG_START_##NAME) { \
     Offset += NUM_BUILTIN_##PREV##_DIAGNOSTICS - DIAG_START_##PREV - 1; \
@@ -135,7 +132,6 @@
 CATEGORY(SEMA, COMMENT)
 CATEGORY(ANALYSIS, SEMA)
 #undef CATEGORY
-#undef DIAG_START_COMMON
 
   // Avoid out of bounds reads.
   if (ID + Offset >= StaticDiagInfoSize)