Thread Safety: Added basic argument parsing for all new attributes.

This patch special cases the parser for thread safety attributes so that all
attribute arguments are put in the argument list (instead of a special
parameter) since arguments may not otherwise resolve correctly without two-token
lookahead.

This patch also adds checks to make sure that attribute arguments are
lockable objects.

llvm-svn: 137130

1 files changed, 80 insertions, 0 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 1e318fe66e2..2a95ecc7c72 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -19,6 +19,7 @@
 #include "clang/Sema/PrettyDeclStackTrace.h"
 #include "RAIIObjectsForParser.h"
 #include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/StringSwitch.h"
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -121,6 +122,10 @@ void Parser::ParseGNUAttributes(ParsedAttributes &attrs,
       // Availability attributes have their own grammar.
       if (AttrName->isStr("availability"))
         ParseAvailabilityAttribute(*AttrName, AttrNameLoc, attrs, endLoc);
+      // Thread safety attributes fit into the FIXME case above, so we
+      // just parse the arguments as a list of expressions
+      else if (IsThreadSafetyAttribute(AttrName->getName()))
+        ParseThreadSafetyAttribute(*AttrName, AttrNameLoc, attrs, endLoc);
       // check if we have a "parameterized" attribute
       else if (Tok.is(tok::l_paren)) {
         ConsumeParen(); // ignore the left paren loc for now
@@ -650,6 +655,81 @@ void Parser::ParseAvailabilityAttribute(IdentifierInfo &Availability,
                UnavailableLoc, false, false);
 }
 
+/// \brief Wrapper around a case statement checking if AttrName is
+/// one of the thread safety attributes
+bool Parser::IsThreadSafetyAttribute(llvm::StringRef AttrName){
+  return llvm::StringSwitch<bool>(AttrName)
+      .Case("guarded_by", true)
+      .Case("guarded_var", true)
+      .Case("pt_guarded_by", true)
+      .Case("pt_guarded_var", true)
+      .Case("lockable", true)
+      .Case("scoped_lockable", true)
+      .Case("no_thread_safety_analysis", true)
+      .Case("acquired_after", true)
+      .Case("acquired_before", true)
+      .Case("exclusive_lock_function", true)
+      .Case("shared_lock_function", true)
+      .Case("exclusive_trylock_function", true)
+      .Case("shared_trylock_function", true)
+      .Case("unlock_function", true)
+      .Case("lock_returned", true)
+      .Case("locks_excluded", true)
+      .Case("exclusive_locks_required", true)
+      .Case("shared_locks_required", true)
+      .Default(false);
+}
+
+/// \brief Parse the contents of thread safety attributes. These
+/// should always be parsed as an expression list.
+///
+/// We need to special case the parsing due to the fact that if the first token
+/// of the first argument is an identifier, the main parse loop will store
+/// that token as a "parameter" and the rest of
+/// the arguments will be added to a list of "arguments". However,
+/// subsequent tokens in the first argument are lost. We instead parse each
+/// argument as an expression and add all arguments to the list of "arguments".
+/// In future, we will take advantage of this special case to also
+/// deal with some argument scoping issues here (for example, referring to a
+/// function parameter in the attribute on that function).
+void Parser::ParseThreadSafetyAttribute(IdentifierInfo &AttrName,
+                                        SourceLocation AttrNameLoc,
+                                        ParsedAttributes &Attrs,
+                                        SourceLocation *EndLoc) {
+
+  if (Tok.is(tok::l_paren)) {
+    SourceLocation LeftParenLoc = Tok.getLocation();
+    ConsumeParen(); // ignore the left paren loc for now
+
+    ExprVector ArgExprs(Actions);
+    bool ArgExprsOk = true;
+
+    // now parse the list of expressions
+    while (1) {
+      ExprResult ArgExpr(ParseAssignmentExpression());
+      if (ArgExpr.isInvalid()) {
+        ArgExprsOk = false;
+        MatchRHSPunctuation(tok::r_paren, LeftParenLoc);
+        break;
+      } else {
+        ArgExprs.push_back(ArgExpr.release());
+      }
+      if (Tok.isNot(tok::comma))
+        break;
+      ConsumeToken(); // Eat the comma, move to the next argument
+    }
+    // Match the ')'.
+    if (ArgExprsOk && Tok.is(tok::r_paren)) {
+      ConsumeParen(); // ignore the right paren loc for now
+      Attrs.addNew(&AttrName, AttrNameLoc, 0, AttrNameLoc, 0, SourceLocation(),
+                   ArgExprs.take(), ArgExprs.size());
+    }
+  } else {
+    Attrs.addNew(&AttrName, AttrNameLoc, 0, AttrNameLoc,
+                 0, SourceLocation(), 0, 0);
+  }
+}
+
 void Parser::DiagnoseProhibitedAttributes(ParsedAttributesWithRange &attrs) {
   Diag(attrs.Range.getBegin(), diag::err_attributes_not_allowed)
     << attrs.Range;