Merge pull request #24 from apple/api-notes-noescape

[API Notes] Add support for parameters, 'noescape' attribute <rdar://problem/27256643>

Author: DougGregor

include/clang/APINotes/Types.h

@@ -268,7 +268,6 @@ class VariableInfo : public CommonEntityInfo {
     Nullable = static_cast<unsigned>(kind);
   }
 
-
   friend bool operator==(const VariableInfo &lhs, const VariableInfo &rhs) {
     return static_cast<const CommonEntityInfo &>(lhs) == rhs &&
            lhs.NullabilityAudited == rhs.NullabilityAudited &&
@@ -279,6 +278,13 @@ class VariableInfo : public CommonEntityInfo {
     return !(lhs == rhs);
   }
 
+  friend VariableInfo &operator|=(VariableInfo &lhs,
+                                  const VariableInfo &rhs) {
+    static_cast<CommonEntityInfo &>(lhs) |= rhs;
+    if (!lhs.NullabilityAudited && rhs.NullabilityAudited)
+      lhs.setNullabilityAudited(*rhs.getNullability());
+    return lhs;
+  }
 };
 
 /// Describes API notes data for an Objective-C property.
@@ -300,6 +306,34 @@ class ObjCPropertyInfo : public VariableInfo {
   }
 };
 
+/// Describes a function or method parameter.
+class ParamInfo : public VariableInfo {
+  /// Whether the this parameter has the 'noescape' attribute.
+  unsigned NoEscape : 1;
+
+public:
+  ParamInfo() : VariableInfo(), NoEscape(false) { }
+
+  bool isNoEscape() const { return NoEscape; }
+  void setNoEscape(bool noescape) { NoEscape = noescape; }
+
+  friend ParamInfo &operator|=(ParamInfo &lhs, const ParamInfo &rhs) {
+    static_cast<VariableInfo &>(lhs) |= rhs;
+    if (!lhs.NoEscape && rhs.NoEscape)
+      lhs.NoEscape = true;
+    return lhs;
+  }
+
+  friend bool operator==(const ParamInfo &lhs, const ParamInfo &rhs) {
+    return static_cast<const VariableInfo &>(lhs) == rhs &&
+           lhs.NoEscape == rhs.NoEscape;
+  }
+
+  friend bool operator!=(const ParamInfo &lhs, const ParamInfo &rhs) {
+    return !(lhs == rhs);
+  }
+};
+
 /// A temporary reference to an Objective-C selector, suitable for
 /// referencing selector data on the stack.
 ///
@@ -333,6 +367,9 @@ class FunctionInfo : public CommonEntityInfo {
   //  of the parameters.
   uint64_t NullabilityPayload = 0;
 
+  /// The function parameters.
+  std::vector<ParamInfo> Params;
+
   FunctionInfo()
     : CommonEntityInfo(),
       NullabilityAudited(false),

lib/APINotes/APINotesFormat.h

@@ -35,7 +35,7 @@ const uint16_t VERSION_MAJOR = 0;
 /// API notes file minor version number.
 ///
 /// When the format changes IN ANY WAY, this number should be incremented.
-const uint16_t VERSION_MINOR = 12;  // SwiftPrivate
+const uint16_t VERSION_MINOR = 13;  // Function/method parameters
 
 using IdentifierID = Fixnum<31>;
 using IdentifierIDField = BCVBR<16>;

lib/APINotes/APINotesReader.cpp

@@ -228,6 +228,22 @@ namespace {
       = endian::readNext<uint8_t, little, unaligned>(data);
     info.NullabilityPayload
       = endian::readNext<uint64_t, little, unaligned>(data);
+
+    unsigned numParams = endian::readNext<uint16_t, little, unaligned>(data);
+    while (numParams > 0) {
+      uint8_t payload = endian::readNext<uint8_t, little, unaligned>(data);
+
+      ParamInfo pi;
+      uint8_t nullabilityValue = payload & 0x3; payload >>= 2;
+      if (payload & 0x01)
+        pi.setNullabilityAudited(static_cast<NullabilityKind>(nullabilityValue));
+      payload >>= 1;
+      pi.setNoEscape(payload & 0x01);
+      payload >>= 1; assert(payload == 0 && "Bad API notes");
+
+      info.Params.push_back(pi);
+      --numParams;
+    }
   }
 
   /// Used to deserialize the on-disk Objective-C method table.

lib/APINotes/APINotesWriter.cpp

@@ -494,7 +494,8 @@ namespace {
   /// Retrieve the serialized size of the given FunctionInfo, for use in
   /// on-disk hash tables.
   static unsigned getFunctionInfoSize(const FunctionInfo &info) {
-    return 2 + sizeof(uint64_t) + getCommonEntityInfoSize(info);
+    return 2 + sizeof(uint64_t) + getCommonEntityInfoSize(info) + 
+           2 + info.Params.size() * 1;
   }
 
   /// Emit a serialized representation of the function information.
@@ -505,6 +506,20 @@ namespace {
     writer.write<uint8_t>(info.NullabilityAudited);
     writer.write<uint8_t>(info.NumAdjustedNullable);
     writer.write<uint64_t>(info.NullabilityPayload);
+
+    // Parameters.
+    writer.write<uint16_t>(info.Params.size());
+    for (const auto &pi : info.Params) {
+      uint8_t payload = pi.isNoEscape();
+
+      auto nullability = pi.getNullability();
+      payload = (payload << 1) | nullability.hasValue();
+
+      payload = payload << 2;
+      if (nullability)
+        payload |= static_cast<uint8_t>(*nullability);
+      writer.write<uint8_t>(payload);
+    }
   }
 
   /// Used to serialize the on-disk Objective-C method table.

lib/APINotes/APINotesYAMLCompiler.cpp

@@ -166,9 +166,17 @@ namespace {
     NullabilityKind::NonNull;
   typedef std::vector<clang::NullabilityKind> NullabilitySeq;
 
+  struct Param {
+    unsigned Position;
+    bool NoEscape = false;
+    llvm::Optional<NullabilityKind> Nullability;
+  };
+  typedef std::vector<Param> ParamsSeq;
+
   struct Method {
     StringRef Selector;
     MethodKind Kind;
+    ParamsSeq Params;
     NullabilitySeq Nullability;
     llvm::Optional<NullabilityKind> NullabilityOfRet;
     AvailabilityItem Availability;
@@ -205,6 +213,7 @@ namespace {
 
   struct Function {
     StringRef Name;
+    ParamsSeq Params;
     NullabilitySeq Nullability;
     llvm::Optional<NullabilityKind> NullabilityOfRet;
     AvailabilityItem Availability;
@@ -272,6 +281,7 @@ namespace {
 LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR(clang::NullabilityKind)
 LLVM_YAML_IS_SEQUENCE_VECTOR(Method)
 LLVM_YAML_IS_SEQUENCE_VECTOR(Property)
+LLVM_YAML_IS_SEQUENCE_VECTOR(Param)
 LLVM_YAML_IS_SEQUENCE_VECTOR(Class)
 LLVM_YAML_IS_SEQUENCE_VECTOR(Function)
 LLVM_YAML_IS_SEQUENCE_VECTOR(GlobalVariable)
@@ -322,6 +332,16 @@ namespace llvm {
       }
     };
 
+    template <>
+    struct MappingTraits<Param> {
+      static void mapping(IO &io, Param& p) {
+        io.mapRequired("Position",        p.Position);
+        io.mapOptional("Nullability",     p.Nullability, 
+                                          AbsentNullability);
+        io.mapOptional("NoEscape",        p.NoEscape);
+      }
+    };
+
     template <>
     struct MappingTraits<Property> {
       static void mapping(IO &io, Property& p) {
@@ -340,6 +360,7 @@ namespace llvm {
       static void mapping(IO &io, Method& m) {
         io.mapRequired("Selector",        m.Selector);
         io.mapRequired("MethodKind",      m.Kind);
+        io.mapOptional("Parameters",      m.Params);
         io.mapOptional("Nullability",     m.Nullability);
         io.mapOptional("NullabilityOfRet",  m.NullabilityOfRet,
                                             AbsentNullability);
@@ -374,6 +395,7 @@ namespace llvm {
     struct MappingTraits<Function> {
       static void mapping(IO &io, Function& f) {
         io.mapRequired("Name",             f.Name);
+        io.mapOptional("Parameters",       f.Params);
         io.mapOptional("Nullability",      f.Nullability);
         io.mapOptional("NullabilityOfRet", f.NullabilityOfRet,
                                            AbsentNullability);
@@ -527,6 +549,20 @@ namespace {
       return false;
     }
 
+    void convertParams(const ParamsSeq &params, FunctionInfo &outInfo) {
+      for (const auto &p : params) {
+        ParamInfo pi;
+        if (p.Nullability)
+          pi.setNullabilityAudited(*p.Nullability);
+        pi.setNoEscape(p.NoEscape);
+
+        while (outInfo.Params.size() <= p.Position) {
+          outInfo.Params.push_back(ParamInfo());
+        }
+        outInfo.Params[p.Position] |= pi;
+      }
+    }
+
     void convertNullability(const NullabilitySeq &nullability,
                             Optional<NullabilityKind> nullabilityOfRet,
                             FunctionInfo &outInfo,
@@ -610,6 +646,9 @@ namespace {
       if (meth.FactoryAsInit != FactoryAsInitKind::Infer)
         mInfo.setFactoryAsInitKind(meth.FactoryAsInit);
 
+      // Translate parameter information.
+      convertParams(meth.Params, mInfo);
+
       // Translate nullability info.
       convertNullability(meth.Nullability, meth.NullabilityOfRet,
                          mInfo, meth.Selector);
@@ -744,6 +783,7 @@ namespace {
         convertAvailability(function.Availability, info, function.Name);
         info.SwiftPrivate = function.SwiftPrivate;
         info.SwiftName = function.SwiftName;
+        convertParams(function.Params, info);
         convertNullability(function.Nullability,
                            function.NullabilityOfRet,
                            info, function.Name);
@@ -924,6 +964,19 @@ namespace {
       }
     }
 
+    /// Map parameter information for a function.
+    void handleParameters(ParamsSeq &params,
+                          const FunctionInfo &info) {
+      unsigned position = 0;
+      for (const auto &pi: info.Params) {
+        Param p;
+        p.Position = position++;
+        p.Nullability = pi.getNullability();
+        p.NoEscape = pi.isNoEscape();
+        params.push_back(p);
+      }
+    }
+
     /// Map nullability information for a function.
     void handleNullability(NullabilitySeq &nullability,
                            llvm::Optional<NullabilityKind> &nullabilityOfRet,
@@ -967,6 +1020,7 @@ namespace {
       method.Kind = isInstanceMethod ? MethodKind::Instance : MethodKind::Class;
 
       handleCommon(method, info);
+      handleParameters(method.Params, info);
       handleNullability(method.Nullability, method.NullabilityOfRet, info,
                         selector.count(':'));
       method.FactoryAsInit = info.getFactoryAsInitKind();
@@ -1003,6 +1057,7 @@ namespace {
       Function function;
       function.Name = name;
       handleCommon(function, info);
+      handleParameters(function.Params, info);
       if (info.NumAdjustedNullable > 0)
         handleNullability(function.Nullability, function.NullabilityOfRet,
                           info, info.NumAdjustedNullable-1);

lib/Sema/SemaAPINotes.cpp

@@ -175,18 +175,27 @@ static void ProcessAPINotes(Sema &S, Decl *D,
   ProcessAPINotes(S, D, static_cast<const api_notes::CommonEntityInfo &>(Info));
 }
 
+/// Process API notes for a parameter.
+static void ProcessAPINotes(Sema &S, ParmVarDecl *D,
+                            const api_notes::ParamInfo &Info) {
+  // noescape
+  if (Info.isNoEscape() && !D->getAttr<NoEscapeAttr>())
+    D->addAttr(NoEscapeAttr::CreateImplicit(S.Context));
+
+  // Handle common entity information.
+  ProcessAPINotes(S, D, static_cast<const api_notes::VariableInfo &>(Info));
+}
+
 /// Process API notes for a global variable.
 static void ProcessAPINotes(Sema &S, VarDecl *D,
                             const api_notes::GlobalVariableInfo &Info) {
-
   // Handle common entity information.
   ProcessAPINotes(S, D, static_cast<const api_notes::VariableInfo &>(Info));
 }
 
 /// Process API notes for an Objective-C property.
 static void ProcessAPINotes(Sema &S, ObjCPropertyDecl *D,
                             const api_notes::ObjCPropertyInfo &Info) {
-
   // Handle common entity information.
   ProcessAPINotes(S, D, static_cast<const api_notes::VariableInfo &>(Info));
 }
@@ -207,26 +216,31 @@ static void ProcessAPINotes(Sema &S, FunctionOrMethod AnyFunc,
     D = MD;
   }
 
-  // Nullability.
+  // Nullability of return type.
   if (Info.NullabilityAudited) {
-    // Return type.
     applyNullability(S, D, Info.getReturnTypeInfo());
+  }
 
-    // Parameters.
-    unsigned NumParams;
+  // Parameters.
+  unsigned NumParams;
+  if (FD)
+    NumParams = FD->getNumParams();
+  else
+    NumParams = MD->param_size();
+  
+  for (unsigned I = 0; I != NumParams; ++I) {
+    ParmVarDecl *Param;
     if (FD)
-      NumParams = FD->getNumParams();
+      Param = FD->getParamDecl(I);
     else
-      NumParams = MD->param_size();
-
-    for (unsigned I = 0; I != NumParams; ++I) {
-      ParmVarDecl *Param;
-      if (FD)
-        Param = FD->getParamDecl(I);
-      else
-        Param = MD->param_begin()[I];
-
+      Param = MD->param_begin()[I];
+    
+    // Nullability.
+    if (Info.NullabilityAudited)
       applyNullability(S, Param, Info.getParamTypeInfo(I));
+
+    if (I < Info.Params.size()) {
+      ProcessAPINotes(S, Param, Info.Params[I]);
     }
   }
 

test/APINotes/Inputs/APINotes/HeaderLib.apinotes

@@ -9,6 +9,13 @@ Functions:
   - Name: do_something_with_pointers
     NullabilityOfRet: O
     Nullability: [ N, O ]
+  - Name: take_pointer_and_int
+    Parameters:
+      - Position: 0
+        Nullability: N
+        NoEscape: true
+      - Position: 1
+        NoEscape: true
 
 Globals:
   - Name: global_int

test/APINotes/Inputs/Headers/HeaderLib.h

@@ -13,4 +13,6 @@ void do_something_with_pointers(int *ptr1, int *ptr2);
 typedef int unavailable_typedef;
 struct unavailable_struct { int x, y, z; };
 
+void take_pointer_and_int(int *ptr1, int value);
+
 #endif

test/APINotes/Inputs/roundtrip.apinotes

@@ -67,6 +67,13 @@ Classes:
         SwiftName:       ''
       - Selector:        'addSubview:positioned:relativeTo:'
         MethodKind:      Instance
+        Parameters:      
+          - Position:        0
+            NoEscape:        false
+          - Position:        1
+            NoEscape:        false
+          - Position:        2
+            NoEscape:        true
         Nullability:     [ N, N, O ]
         NullabilityOfRet: N
         Availability:    available

test/APINotes/nullability.c

@@ -8,6 +8,7 @@ int main() {
   int i = 0;
   do_something_with_pointers(&i, 0);
   do_something_with_pointers(0, &i); // expected-warning{{null passed to a callee that requires a non-null argument}}
+  take_pointer_and_int(0, 0); // expected-warning{{null passed to a callee that requires a non-null argument}}
 
   float *fp = global_int; // expected-warning{{incompatible pointer types initializing 'float *' with an expression of type 'int * _Nonnull'}}
   return 0;