Introduced pragmas for audited nullability regions.

Introduce the clang pragmas "assume_nonnull begin" and "assume_nonnull
end" in which we make default assumptions about the nullability of many
unannotated pointers:

  - Single-level pointers are inferred to __nonnull
  - NSError** in a (function or method) parameter list is inferred to
    NSError * __nullable * __nullable.
  - CFErrorRef * in a (function or method) parameter list is inferred
    to CFErrorRef __nullable * __nullable.
  - Other multi-level pointers are never inferred to anything.

Implements rdar://problem/19191042.

llvm-svn: 240156

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index e68fb7df8e8..1a35d32dedb 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -355,6 +355,17 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
     PragmaARCCFCodeAuditedLoc = SourceLocation();
   }
 
+  // Complain about reaching a true EOF within assume_nonnull.
+  // We don't want to complain about reaching the end of a macro
+  // instantiation or a _Pragma.
+  if (PragmaAssumeNonNullLoc.isValid() &&
+      !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
+    Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
+
+    // Recover by leaving immediately.
+    PragmaAssumeNonNullLoc = SourceLocation();
+  }
+
   // If this is a #include'd file, pop it off the include stack and continue
   // lexing the #includer file.
   if (!IncludeMacroStack.empty()) {