[cfe-commits] r91044 - in /cfe/trunk: lib/Sema/SemaDecl.cpp test/SemaCXX/array-bound-merge.cpp

[Eli Friedman]

Author: efriedma
Date: Thu Dec 10 02:54:47 2009
New Revision: 91044

URL: http://llvm.org/viewvc/llvm-project?rev=91044&view=rev
Log:
Fix for PR5515: allow "merging" array bounds both forwards and backwards.


Added:
    cfe/trunk/test/SemaCXX/array-bound-merge.cpp
Modified:
    cfe/trunk/lib/Sema/SemaDecl.cpp

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=91044&r1=91043&r2=91044&view=diff

==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu Dec 10 02:54:47 2009
@@ -1090,10 +1090,11 @@
   if (getLangOptions().CPlusPlus) {
     if (Context.hasSameType(New->getType(), Old->getType()))
       MergedT = New->getType();
-    // C++ [basic.types]p7:
-    //   [...] The declared type of an array object might be an array of
-    //   unknown size and therefore be incomplete at one point in a
-    //   translation unit and complete later on; [...]
+    // C++ [basic.link]p10:
+    //   [...] the types specified by all declarations referring to a given
+    //   object or function shall be identical, except that declarations for an
+    //   array object can specify array types that differ by the presence or
+    //   absence of a major array bound (8.3.4).
     else if (Old->getType()->isIncompleteArrayType() &&
              New->getType()->isArrayType()) {
       CanQual<ArrayType> OldArray
@@ -1102,6 +1103,14 @@
         = Context.getCanonicalType(New->getType())->getAs<ArrayType>();
       if (OldArray->getElementType() == NewArray->getElementType())
         MergedT = New->getType();
+    } else if (Old->getType()->isArrayType() &&
+             New->getType()->isIncompleteArrayType()) {
+      CanQual<ArrayType> OldArray
+        = Context.getCanonicalType(Old->getType())->getAs<ArrayType>();
+      CanQual<ArrayType> NewArray
+        = Context.getCanonicalType(New->getType())->getAs<ArrayType>();
+      if (OldArray->getElementType() == NewArray->getElementType())
+        MergedT = Old->getType();
     }
   } else {
     MergedT = Context.mergeTypes(New->getType(), Old->getType());

Added: cfe/trunk/test/SemaCXX/array-bound-merge.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/array-bound-merge.cpp?rev=91044&view=auto

==============================================================================
--- cfe/trunk/test/SemaCXX/array-bound-merge.cpp (added)
+++ cfe/trunk/test/SemaCXX/array-bound-merge.cpp Thu Dec 10 02:54:47 2009
@@ -0,0 +1,9 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+// PR5515
+
+extern int a[];
+int a[10];
+extern int b[10];
+int b[];
+extern int c[1];
+int c[] = {1,2}; // expected-error {{excess elements in array initializer}}