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, 9 insertions, 0 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 43def2b32c5..33ce7992281 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1575,6 +1575,15 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     PragmaARCCFCodeAuditedLoc = SourceLocation();
   }
 
+  // Complain about attempts to #include files in an assume-nonnull pragma.
+  if (PragmaAssumeNonNullLoc.isValid()) {
+    Diag(HashLoc, diag::err_pp_include_in_assume_nonnull);
+    Diag(PragmaAssumeNonNullLoc, diag::note_pragma_entered_here);
+
+    // Immediately leave the pragma.
+    PragmaAssumeNonNullLoc = SourceLocation();
+  }
+
   if (HeaderInfo.HasIncludeAliasMap()) {
     // Map the filename with the brackets still attached.  If the name doesn't 
     // map to anything, fall back on the filename we've already gotten the