1 files changed, 364 insertions, 0 deletions
diff --git a/lib/ARCMigrate/TransProperties.cpp b/lib/ARCMigrate/TransProperties.cpp
new file mode 100644
index 000000000000..872c95e1a444
--- /dev/null
+++ b/lib/ARCMigrate/TransProperties.cpp
@@ -0,0 +1,364 @@
+//===--- TransProperties.cpp - Tranformations to ARC mode -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// rewriteProperties:
+//
+// - Adds strong/weak/unsafe_unretained ownership specifier to properties that
+//   are missing one.
+// - Migrates properties from (retain) to (strong) and (assign) to
+//   (unsafe_unretained/weak).
+// - If a property is synthesized, adds the ownership specifier in the ivar
+//   backing the property.
+//
+//  @interface Foo : NSObject {
+//      NSObject *x;
+//  }
+//  @property (assign) id x;
+//  @end
+// ---->
+//  @interface Foo : NSObject {
+//      NSObject *__weak x;
+//  }
+//  @property (weak) id x;
+//  @end
+//
+//===----------------------------------------------------------------------===//
+
+#include "Transforms.h"
+#include "Internals.h"
+#include "clang/Sema/SemaDiagnostic.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include <map>
+
+using namespace clang;
+using namespace arcmt;
+using namespace trans;
+using llvm::StringRef;
+
+namespace {
+
+class PropertiesRewriter {
+  MigrationPass &Pass;
+
+  struct PropData {
+    ObjCPropertyDecl *PropD;
+    ObjCIvarDecl *IvarD;
+    ObjCPropertyImplDecl *ImplD;
+
+    PropData(ObjCPropertyDecl *propD) : PropD(propD), IvarD(0), ImplD(0) { }
+  };
+
+  typedef llvm::SmallVector<PropData, 2> PropsTy;
+  typedef std::map<unsigned, PropsTy> AtPropDeclsTy;
+  AtPropDeclsTy AtProps;
+
+public:
+  PropertiesRewriter(MigrationPass &pass) : Pass(pass) { }
+
+  void doTransform(ObjCImplementationDecl *D) {
+    ObjCInterfaceDecl *iface = D->getClassInterface();
+    if (!iface)
+      return;
+
+    for (ObjCInterfaceDecl::prop_iterator
+           propI = iface->prop_begin(),
+           propE = iface->prop_end(); propI != propE; ++propI) {
+      if (propI->getAtLoc().isInvalid())
+        continue;
+      PropsTy &props = AtProps[propI->getAtLoc().getRawEncoding()];
+      props.push_back(*propI);
+    }
+
+    typedef DeclContext::specific_decl_iterator<ObjCPropertyImplDecl>
+        prop_impl_iterator;
+    for (prop_impl_iterator
+           I = prop_impl_iterator(D->decls_begin()),
+           E = prop_impl_iterator(D->decls_end()); I != E; ++I) {
+      ObjCPropertyImplDecl *implD = *I;
+      if (implD->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
+        continue;
+      ObjCPropertyDecl *propD = implD->getPropertyDecl();
+      if (!propD || propD->isInvalidDecl())
+        continue;
+      ObjCIvarDecl *ivarD = implD->getPropertyIvarDecl();
+      if (!ivarD || ivarD->isInvalidDecl())
+        continue;
+      unsigned rawAtLoc = propD->getAtLoc().getRawEncoding();
+      AtPropDeclsTy::iterator findAtLoc = AtProps.find(rawAtLoc);
+      if (findAtLoc == AtProps.end())
+        continue;
+      
+      PropsTy &props = findAtLoc->second;
+      for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I) {
+        if (I->PropD == propD) {
+          I->IvarD = ivarD;
+          I->ImplD = implD;
+          break;
+        }
+      }
+    }
+
+    for (AtPropDeclsTy::iterator
+           I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
+      SourceLocation atLoc = SourceLocation::getFromRawEncoding(I->first);
+      PropsTy &props = I->second;
+      QualType ty = getPropertyType(props);
+      if (!ty->isObjCRetainableType())
+        continue;
+      if (hasIvarWithExplicitOwnership(props))
+        continue;
+      
+      Transaction Trans(Pass.TA);
+      rewriteProperty(props, atLoc);
+    }
+  }
+
+private:
+  void rewriteProperty(PropsTy &props, SourceLocation atLoc) const {
+    ObjCPropertyDecl::PropertyAttributeKind propAttrs = getPropertyAttrs(props);
+    
+    if (propAttrs & (ObjCPropertyDecl::OBJC_PR_copy |
+                     ObjCPropertyDecl::OBJC_PR_unsafe_unretained |
+                     ObjCPropertyDecl::OBJC_PR_strong |
+                     ObjCPropertyDecl::OBJC_PR_weak))
+      return;
+
+    if (propAttrs & ObjCPropertyDecl::OBJC_PR_retain) {
+      rewriteAttribute("retain", "strong", atLoc);
+      return;
+    }
+
+    if (propAttrs & ObjCPropertyDecl::OBJC_PR_assign)
+      return rewriteAssign(props, atLoc);
+
+    return maybeAddWeakOrUnsafeUnretainedAttr(props, atLoc);
+  }
+
+  void rewriteAssign(PropsTy &props, SourceLocation atLoc) const {
+    bool canUseWeak = canApplyWeak(Pass.Ctx, getPropertyType(props));
+
+    bool rewroteAttr = rewriteAttribute("assign",
+                                     canUseWeak ? "weak" : "unsafe_unretained",
+                                         atLoc);
+    if (!rewroteAttr)
+      canUseWeak = false;
+
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I) {
+      if (isUserDeclared(I->IvarD))
+        Pass.TA.insert(I->IvarD->getLocation(),
+                       canUseWeak ? "__weak " : "__unsafe_unretained ");
+      if (I->ImplD)
+        Pass.TA.clearDiagnostic(diag::err_arc_assign_property_ownership,
+                                I->ImplD->getLocation());
+    }
+  }
+
+  void maybeAddWeakOrUnsafeUnretainedAttr(PropsTy &props,
+                                          SourceLocation atLoc) const {
+    ObjCPropertyDecl::PropertyAttributeKind propAttrs = getPropertyAttrs(props);
+    if ((propAttrs & ObjCPropertyDecl::OBJC_PR_readonly) &&
+        hasNoBackingIvars(props))
+      return;
+
+    bool canUseWeak = canApplyWeak(Pass.Ctx, getPropertyType(props));
+    bool addedAttr = addAttribute(canUseWeak ? "weak" : "unsafe_unretained",
+                                  atLoc);
+    if (!addedAttr)
+      canUseWeak = false;
+
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I) {
+      if (isUserDeclared(I->IvarD))
+        Pass.TA.insert(I->IvarD->getLocation(),
+                       canUseWeak ? "__weak " : "__unsafe_unretained ");
+      if (I->ImplD) {
+        Pass.TA.clearDiagnostic(diag::err_arc_assign_property_ownership,
+                                I->ImplD->getLocation());
+        Pass.TA.clearDiagnostic(
+                           diag::err_arc_objc_property_default_assign_on_object,
+                           I->ImplD->getLocation());
+      }
+    }
+  }
+
+  bool rewriteAttribute(llvm::StringRef fromAttr, llvm::StringRef toAttr,
+                        SourceLocation atLoc) const {
+    if (atLoc.isMacroID())
+      return false;
+
+    SourceManager &SM = Pass.Ctx.getSourceManager();
+
+    // Break down the source location.
+    std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(atLoc);
+
+    // Try to load the file buffer.
+    bool invalidTemp = false;
+    llvm::StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
+    if (invalidTemp)
+      return false;
+
+    const char *tokenBegin = file.data() + locInfo.second;
+
+    // Lex from the start of the given location.
+    Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
+                Pass.Ctx.getLangOptions(),
+                file.begin(), tokenBegin, file.end());
+    Token tok;
+    lexer.LexFromRawLexer(tok);
+    if (tok.isNot(tok::at)) return false;
+    lexer.LexFromRawLexer(tok);
+    if (tok.isNot(tok::raw_identifier)) return false;
+    if (llvm::StringRef(tok.getRawIdentifierData(), tok.getLength())
+          != "property")
+      return false;
+    lexer.LexFromRawLexer(tok);
+    if (tok.isNot(tok::l_paren)) return false;
+    
+    lexer.LexFromRawLexer(tok);
+    if (tok.is(tok::r_paren))
+      return false;
+
+    while (1) {
+      if (tok.isNot(tok::raw_identifier)) return false;
+      llvm::StringRef ident(tok.getRawIdentifierData(), tok.getLength());
+      if (ident == fromAttr) {
+        Pass.TA.replaceText(tok.getLocation(), fromAttr, toAttr);
+        return true;
+      }
+
+      do {
+        lexer.LexFromRawLexer(tok);
+      } while (tok.isNot(tok::comma) && tok.isNot(tok::r_paren));
+      if (tok.is(tok::r_paren))
+        break;
+      lexer.LexFromRawLexer(tok);
+    }
+
+    return false;
+  }
+
+  bool addAttribute(llvm::StringRef attr, SourceLocation atLoc) const {
+    if (atLoc.isMacroID())
+      return false;
+
+    SourceManager &SM = Pass.Ctx.getSourceManager();
+
+    // Break down the source location.
+    std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(atLoc);
+
+    // Try to load the file buffer.
+    bool invalidTemp = false;
+    llvm::StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
+    if (invalidTemp)
+      return false;
+
+    const char *tokenBegin = file.data() + locInfo.second;
+
+    // Lex from the start of the given location.
+    Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
+                Pass.Ctx.getLangOptions(),
+                file.begin(), tokenBegin, file.end());
+    Token tok;
+    lexer.LexFromRawLexer(tok);
+    if (tok.isNot(tok::at)) return false;
+    lexer.LexFromRawLexer(tok);
+    if (tok.isNot(tok::raw_identifier)) return false;
+    if (llvm::StringRef(tok.getRawIdentifierData(), tok.getLength())
+          != "property")
+      return false;
+    lexer.LexFromRawLexer(tok);
+
+    if (tok.isNot(tok::l_paren)) {
+      Pass.TA.insert(tok.getLocation(), std::string("(") + attr.str() + ") ");
+      return true;
+    }
+    
+    lexer.LexFromRawLexer(tok);
+    if (tok.is(tok::r_paren)) {
+      Pass.TA.insert(tok.getLocation(), attr);
+      return true;
+    }
+
+    if (tok.isNot(tok::raw_identifier)) return false;
+
+    Pass.TA.insert(tok.getLocation(), std::string(attr) + ", ");
+    return true;
+  }
+
+  bool hasIvarWithExplicitOwnership(PropsTy &props) const {
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I) {
+      if (isUserDeclared(I->IvarD)) {
+        if (isa<AttributedType>(I->IvarD->getType()))
+          return true;
+        if (I->IvarD->getType().getLocalQualifiers().getObjCLifetime()
+              != Qualifiers::OCL_Strong)
+          return true;
+      }
+    }
+
+    return false;    
+  }
+
+  bool hasNoBackingIvars(PropsTy &props) const {
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I)
+      if (I->IvarD)
+        return false;
+
+    return true;
+  }
+
+  bool isUserDeclared(ObjCIvarDecl *ivarD) const {
+    return ivarD && !ivarD->getSynthesize();
+  }
+
+  QualType getPropertyType(PropsTy &props) const {
+    assert(!props.empty());
+    QualType ty = props[0].PropD->getType();
+
+#ifndef NDEBUG
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I)
+      assert(ty == I->PropD->getType());
+#endif
+
+    return ty;
+  }
+
+  ObjCPropertyDecl::PropertyAttributeKind
+  getPropertyAttrs(PropsTy &props) const {
+    assert(!props.empty());
+    ObjCPropertyDecl::PropertyAttributeKind
+      attrs = props[0].PropD->getPropertyAttributesAsWritten();
+
+#ifndef NDEBUG
+    for (PropsTy::iterator I = props.begin(), E = props.end(); I != E; ++I)
+      assert(attrs == I->PropD->getPropertyAttributesAsWritten());
+#endif
+
+    return attrs;
+  }
+};
+
+class ImplementationChecker :
+                             public RecursiveASTVisitor<ImplementationChecker> {
+  MigrationPass &Pass;
+
+public:
+  ImplementationChecker(MigrationPass &pass) : Pass(pass) { }
+
+  bool TraverseObjCImplementationDecl(ObjCImplementationDecl *D) {
+    PropertiesRewriter(Pass).doTransform(D);
+    return true;
+  }
+};
+
+} // anonymous namespace
+
+void trans::rewriteProperties(MigrationPass &pass) {
+  ImplementationChecker(pass).TraverseDecl(pass.Ctx.getTranslationUnitDecl());
+}