Add new code migrator support for migrating existing Objective-C code to use

the new Objective-C NSArray/NSDictionary/NSNumber literal syntax.

This introduces a new library, libEdit, which provides a new way to support
migration of code that improves on the original ARC migrator.  We now believe
that most of its functionality can be refactored into the existing libraries,
and thus this new library may shortly disappear.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152141 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 87 insertions, 7 deletions

diff --git a/lib/ARCMigrate/TransRetainReleaseDealloc.cpp b/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
index 7bb7b5eeea..15669ac973 100644
--- a/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
+++ b/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
@@ -21,6 +21,8 @@
 #include "Internals.h"
 #include "clang/Sema/SemaDiagnostic.h"
 #include "clang/AST/ParentMap.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/SourceManager.h"
 
 using namespace clang;
 using namespace arcmt;
@@ -128,27 +130,105 @@ public:
     Transaction Trans(Pass.TA);
     clearDiagnostics(rec->getExprLoc());
 
-    if (E->getMethodFamily() == OMF_release &&
-        isRemovable(E) && isInAtFinally(E)) {
+    ObjCMessageExpr *Msg = E;
+    Expr *RecContainer = Msg;
+    SourceRange RecRange = rec->getSourceRange();
+    checkForGCDOrXPC(Msg, RecContainer, rec, RecRange);
+
+    if (Msg->getMethodFamily() == OMF_release &&
+        isRemovable(RecContainer) && isInAtFinally(RecContainer)) {
       // Change the -release to "receiver = nil" in a finally to avoid a leak
       // when an exception is thrown.
-      Pass.TA.replace(E->getSourceRange(), rec->getSourceRange());
+      Pass.TA.replace(RecContainer->getSourceRange(), RecRange);
       std::string str = " = ";
       str += getNilString(Pass.Ctx);
-      Pass.TA.insertAfterToken(rec->getLocEnd(), str);
+      Pass.TA.insertAfterToken(RecRange.getEnd(), str);
       return true;
     }
 
-    if (!hasSideEffects(E, Pass.Ctx)) {
-      if (tryRemoving(E))
+    if (!hasSideEffects(rec, Pass.Ctx)) {
+      if (tryRemoving(RecContainer))
         return true;
     }
-    Pass.TA.replace(E->getSourceRange(), rec->getSourceRange());
+    Pass.TA.replace(RecContainer->getSourceRange(), RecRange);
 
     return true;
   }
 
 private:
+  /// \brief Check if the retain/release is due to a GCD/XPC macro that are
+  /// defined as:
+  ///
+  /// #define dispatch_retain(object) ({ dispatch_object_t _o = (object); _dispatch_object_validate(_o); (void)[_o retain]; })
+  /// #define dispatch_release(object) ({ dispatch_object_t _o = (object); _dispatch_object_validate(_o); [_o release]; })
+  /// #define xpc_retain(object) ({ xpc_object_t _o = (object); _xpc_object_validate(_o); [_o retain]; })
+  /// #define xpc_release(object) ({ xpc_object_t _o = (object); _xpc_object_validate(_o); [_o release]; })
+  ///
+  /// and return the top container which is the StmtExpr and the macro argument
+  /// expression.
+  void checkForGCDOrXPC(ObjCMessageExpr *Msg, Expr *&RecContainer,
+                        Expr *&Rec, SourceRange &RecRange) {
+    SourceLocation Loc = Msg->getExprLoc();
+    if (!Loc.isMacroID())
+      return;
+    SourceManager &SM = Pass.Ctx.getSourceManager();
+    StringRef MacroName = Lexer::getImmediateMacroName(Loc, SM,
+                                                     Pass.Ctx.getLangOptions());
+    bool isGCDOrXPC = llvm::StringSwitch<bool>(MacroName)
+        .Case("dispatch_retain", true)
+        .Case("dispatch_release", true)
+        .Case("xpc_retain", true)
+        .Case("xpc_release", true)
+        .Default(false);
+    if (!isGCDOrXPC)
+      return;
+
+    StmtExpr *StmtE = 0;
+    Stmt *S = Msg;
+    while (S) {
+      if (StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
+        StmtE = SE;
+        break;
+      }
+      S = StmtMap->getParent(S);
+    }
+
+    if (!StmtE)
+      return;
+
+    Stmt::child_range StmtExprChild = StmtE->children();
+    if (!StmtExprChild)
+      return;
+    CompoundStmt *CompS = dyn_cast_or_null<CompoundStmt>(*StmtExprChild);
+    if (!CompS)
+      return;
+
+    Stmt::child_range CompStmtChild = CompS->children();
+    if (!CompStmtChild)
+      return;
+    DeclStmt *DeclS = dyn_cast_or_null<DeclStmt>(*CompStmtChild);
+    if (!DeclS)
+      return;
+    if (!DeclS->isSingleDecl())
+      return;
+    VarDecl *VD = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl());
+    if (!VD)
+      return;
+    Expr *Init = VD->getInit();
+    if (!Init)
+      return;
+
+    RecContainer = StmtE;
+    Rec = Init->IgnoreParenImpCasts();
+    if (ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Rec))
+      Rec = EWC->getSubExpr()->IgnoreParenImpCasts();
+    RecRange = Rec->getSourceRange();
+    if (SM.isMacroArgExpansion(RecRange.getBegin()))
+      RecRange.setBegin(SM.getImmediateSpellingLoc(RecRange.getBegin()));
+    if (SM.isMacroArgExpansion(RecRange.getEnd()))
+      RecRange.setEnd(SM.getImmediateSpellingLoc(RecRange.getEnd()));
+  }
+
   void clearDiagnostics(SourceLocation loc) const {
     Pass.TA.clearDiagnostic(diag::err_arc_illegal_explicit_message,
                             diag::err_unavailable,