Add support for GCC's '__auto_type' extension, per the GCC manual:

https://gcc.gnu.org/onlinedocs/gcc/Typeof.html

Differences from the GCC extension:
 * __auto_type is also permitted in C++ (but only in places where
   it could appear in C), allowing its use in headers that might
   be shared across C and C++, or used from C++98
 * __auto_type can be combined with a declarator, as with C++ auto
   (for instance, "__auto_type *p")
 * multiple variables can be declared in a single __auto_type
   declaration, with the C++ semantics (the deduced type must be
   the same in each case)

This patch also adds a missing restriction on applying typeof to
a bit-field, which GCC has historically rejected in C (due to
lack of clarity as to whether the operand should be promoted).
The same restriction also applies to __auto_type in C (in both
GCC and Clang).

This also fixes PR25449.

Patch by Nicholas Allegra!

llvm-svn: 252690

1 files changed, 2 insertions, 2 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 32656037921..fa84b94b082 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5413,9 +5413,9 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
 
   case TYPE_AUTO: {
     QualType Deduced = readType(*Loc.F, Record, Idx);
-    bool IsDecltypeAuto = Record[Idx++];
+    AutoTypeKeyword Keyword = (AutoTypeKeyword)Record[Idx++];
     bool IsDependent = Deduced.isNull() ? Record[Idx++] : false;
-    return Context.getAutoType(Deduced, IsDecltypeAuto, IsDependent);
+    return Context.getAutoType(Deduced, Keyword, IsDependent);
   }
 
   case TYPE_RECORD: {