Commit 0b58b80e authored by Artem Dergachev's avatar Artem Dergachev
Browse files

[analyzer] Fix Objective-C accessor body farms after 2073dd2d. 

Fix a canonicalization problem for the newly added property accessor stubs that
was causing a wrong decl to be used for 'self' in the accessor's body farm.

Fix a crash when constructing a body farm for accessors of a property
that is declared and @synthesize'd in different (but related) interfaces.

Differential Revision: https://reviews.llvm.org/D70158
parent bbc8662d

clang/lib/Analysis/BodyFarm.cpp

+51 −40
Original line number Diff line number Diff line
@@ -737,9 +737,23 @@ static const ObjCIvarDecl *findBackingIvar(const ObjCPropertyDecl *Prop) { 
}



static Stmt *createObjCPropertyGetter(ASTContext &Ctx,

                                      const ObjCPropertyDecl *Prop) {

                                      const ObjCMethodDecl *MD) {

    // First, find the backing ivar.

  const ObjCIvarDecl *IVar = findBackingIvar(Prop);

  const ObjCIvarDecl *IVar = nullptr;



  // Property accessor stubs sometimes do not correspond to any property.

  if (MD->isSynthesizedAccessorStub()) {

    const ObjCInterfaceDecl *IntD = MD->getClassInterface();

    const ObjCImplementationDecl *ImpD = IntD->getImplementation();

    for (const auto *V: ImpD->ivars()) {

      if (V->getName() == MD->getSelector().getNameForSlot(0))

        IVar = V;

    }

  }



  if (!IVar) {

    const ObjCPropertyDecl *Prop = MD->findPropertyDecl();

    IVar = findBackingIvar(Prop);

    if (!IVar)

      return nullptr;
@@ -775,12 +789,13 @@ static Stmt *createObjCPropertyGetter(ASTContext &Ctx, 
    if (!IVar->getType()->isObjCLifetimeType() &&

        !IVar->getType().isTriviallyCopyableType(Ctx))

      return nullptr;

  }



  // Generate our body:

  //   return self->_ivar;

  ASTMaker M(Ctx);



  const VarDecl *selfVar = Prop->getGetterMethodDecl()->getSelfDecl();

  const VarDecl *selfVar = MD->getSelfDecl();

  if (!selfVar)

    return nullptr;
@@ -791,7 +806,7 @@ static Stmt *createObjCPropertyGetter(ASTContext &Ctx, 
        selfVar->getType()),

      IVar);



  if (!Prop->getType()->isReferenceType())

  if (!MD->getReturnType()->isReferenceType())

    loadedIVar = M.makeLvalueToRvalue(loadedIVar, IVar->getType());



  return M.makeReturn(loadedIVar);
@@ -814,10 +829,6 @@ Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) { 
    return Val.getValue();

  Val = nullptr;



  const ObjCPropertyDecl *Prop = D->findPropertyDecl();

  if (!Prop)

    return nullptr;



  // For now, we only synthesize getters.

  // Synthesizing setters would cause false negatives in the

  // RetainCountChecker because the method body would bind the parameter
@@ -840,7 +851,7 @@ Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) { 
        return nullptr;

    }



  Val = createObjCPropertyGetter(C, Prop);

  Val = createObjCPropertyGetter(C, D);



  return Val.getValue();

}

clang/lib/StaticAnalyzer/Core/CallEvent.cpp

+2 −0
Original line number Diff line number Diff line
@@ -1309,6 +1309,8 @@ RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const { 
        }



        const ObjCMethodDecl *MD = Val.getValue();

        if (MD && !MD->hasBody())

          MD = MD->getCanonicalDecl();

        if (CanBeSubClassed)

          return RuntimeDefinition(MD, Receiver);

        else

clang/test/Analysis/Inputs/expected-plists/nullability-notes.m.plist

+59 −23
Original line number Diff line number Diff line
@@ -16,12 +16,46 @@ 
        <key>start</key>

         <array>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>31</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>31</integer>

           <key>col</key><integer>33</integer>

           <key>file</key><integer>0</integer>

          </dict>

         </array>

        <key>end</key>

         <array>

          <dict>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>10</integer>

           <key>file</key><integer>0</integer>

          </dict>

         </array>

       </dict>

      </array>

    </dict>

    <dict>

     <key>kind</key><string>control</string>

     <key>edges</key>

      <array>

       <dict>

        <key>start</key>

         <array>

          <dict>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>10</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -29,12 +63,12 @@ 
        <key>end</key>

         <array>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>22</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>22</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -46,7 +80,7 @@ 
     <key>kind</key><string>event</string>

     <key>location</key>

     <dict>

      <key>line</key><integer>16</integer>

      <key>line</key><integer>33</integer>

      <key>col</key><integer>22</integer>

      <key>file</key><integer>0</integer>

     </dict>
@@ -54,12 +88,12 @@ 
     <array>

       <array>

        <dict>

         <key>line</key><integer>16</integer>

         <key>line</key><integer>33</integer>

         <key>col</key><integer>22</integer>

         <key>file</key><integer>0</integer>

        </dict>

        <dict>

         <key>line</key><integer>16</integer>

         <key>line</key><integer>33</integer>

         <key>col</key><integer>22</integer>

         <key>file</key><integer>0</integer>

        </dict>
@@ -79,12 +113,12 @@ 
        <key>start</key>

         <array>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>22</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>22</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -92,12 +126,12 @@ 
        <key>end</key>

         <array>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>10</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -113,12 +147,12 @@ 
        <key>start</key>

         <array>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>16</integer>

           <key>line</key><integer>33</integer>

           <key>col</key><integer>10</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -126,12 +160,12 @@ 
        <key>end</key>

         <array>

          <dict>

           <key>line</key><integer>17</integer>

           <key>line</key><integer>36</integer>

           <key>col</key><integer>3</integer>

           <key>file</key><integer>0</integer>

          </dict>

          <dict>

           <key>line</key><integer>17</integer>

           <key>line</key><integer>36</integer>

           <key>col</key><integer>14</integer>

           <key>file</key><integer>0</integer>

          </dict>
@@ -143,7 +177,7 @@ 
     <key>kind</key><string>event</string>

     <key>location</key>

     <dict>

      <key>line</key><integer>17</integer>

      <key>line</key><integer>36</integer>

      <key>col</key><integer>3</integer>

      <key>file</key><integer>0</integer>

     </dict>
@@ -151,12 +185,12 @@ 
     <array>

       <array>

        <dict>

         <key>line</key><integer>17</integer>

         <key>line</key><integer>36</integer>

         <key>col</key><integer>16</integer>

         <key>file</key><integer>0</integer>

        </dict>

        <dict>

         <key>line</key><integer>17</integer>

         <key>line</key><integer>36</integer>

         <key>col</key><integer>16</integer>

         <key>file</key><integer>0</integer>

        </dict>
@@ -177,10 +211,10 @@ 
   <key>issue_hash_content_of_line_in_context</key><string>ff735bea0eb12d4d172b139143c32365</string>

  <key>issue_context_kind</key><string>Objective-C method</string>

  <key>issue_context</key><string>method</string>

  <key>issue_hash_function_offset</key><string>3</string>

  <key>issue_hash_function_offset</key><string>6</string>

  <key>location</key>

  <dict>

   <key>line</key><integer>17</integer>

   <key>line</key><integer>36</integer>

   <key>col</key><integer>3</integer>

   <key>file</key><integer>0</integer>

  </dict>
@@ -188,9 +222,11 @@ 
  <dict>

   <key>0</key>

   <array>

    <integer>14</integer>

    <integer>16</integer>

    <integer>17</integer>

    <integer>26</integer>

    <integer>30</integer>

    <integer>31</integer>

    <integer>33</integer>

    <integer>36</integer>

   </array>

  </dict>

  </dict>

clang/test/Analysis/nullability-notes.m

+22 −3
Original line number Diff line number Diff line 
// RUN: %clang_analyze_cc1 -fblocks -analyzer-checker=core,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,nullability.NullableDereferenced -analyzer-output=text -verify %s

// RUN: %clang_analyze_cc1 -fblocks -analyzer-checker=core,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,nullability.NullableDereferenced -analyzer-output=plist -o %t.plist %s

// RUN: %normalize_plist <%t.plist | diff -ub %S/Inputs/expected-plists/nullability-notes.m.plist -

// RUN: %clang_analyze_cc1 -fblocks -analyzer-checker=core \

// RUN:   -analyzer-checker=nullability.NullPassedToNonnull \

// RUN:   -analyzer-checker=nullability.NullReturnedFromNonnull \

// RUN:   -analyzer-checker=nullability.NullablePassedToNonnull \

// RUN:   -analyzer-checker=nullability.NullableReturnedFromNonnull \

// RUN:   -analyzer-checker=nullability.NullableDereferenced \

// RUN:   -analyzer-checker=debug.ExprInspection \

// RUN:   -analyzer-output=text -verify %s

// RUN: %clang_analyze_cc1 -fblocks -analyzer-checker=core \

// RUN:   -analyzer-checker=nullability.NullPassedToNonnull \

// RUN:   -analyzer-checker=nullability.NullReturnedFromNonnull \

// RUN:   -analyzer-checker=nullability.NullablePassedToNonnull \

// RUN:   -analyzer-checker=nullability.NullableReturnedFromNonnull \

// RUN:   -analyzer-checker=nullability.NullableDereferenced \

// RUN:   -analyzer-output=plist -o %t.plist %s

// RUN: %normalize_plist <%t.plist \

// RUN:   | diff -ub %S/Inputs/expected-plists/nullability-notes.m.plist -



void clang_analyzer_warnOnDeadSymbol(id);



#include "Inputs/system-header-simulator-for-nullability.h"
@@ -12,8 +28,11 @@ void takesNonnull(NSObject *_Nonnull y); 
@end;

@implementation ClassWithProperties

-(void) method {

  clang_analyzer_warnOnDeadSymbol(self);

  // no-crash

  NSObject *x = self.x; // expected-note{{Nullability 'nullable' is inferred}}

                        // expected-warning@-1{{SYMBOL DEAD}}

                        // expected-note@-2   {{SYMBOL DEAD}}

  takesNonnull(x); // expected-warning{{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}

                   // expected-note@-1{{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}

}

clang/test/Analysis/properties.m

+47 −0
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 


void clang_analyzer_eval(int);



#define nil ((id)0)



typedef const void * CFTypeRef;

extern CFTypeRef CFRetain(CFTypeRef cf);

void CFRelease(CFTypeRef cf);
@@ -1040,3 +1042,48 @@ void testNoCrashWhenAccessPropertyAndThereAreNoDirectBindingsAtAll() { 
	clang_analyzer_eval(self.still_no_custom_accessor == self.still_no_custom_accessor); // expected-warning{{TRUE}}

}

@end



@interface Shadowed

@property (assign) NSObject *o;

- (NSObject *)getShadowedIvar;

- (void)clearShadowedIvar;

- (NSObject *)getShadowedProp;

- (void)clearShadowedProp;

@end



@implementation Shadowed

- (NSObject *)getShadowedIvar {

  return self->_o;

}

- (void)clearShadowedIvar {

  self->_o = nil;

}

- (NSObject *)getShadowedProp {

  return self.o;

}

- (void)clearShadowedProp {

  self.o = nil;

}

@end



@interface Shadowing : Shadowed

@end



@implementation Shadowing

// Property 'o' is declared in the superclass but synthesized here.

// This creates a separate ivar that shadows the superclass's ivar,

// but the old ivar is still accessible from the methods of the superclass.

// The old property, however, is not accessible with the property syntax

// even from the superclass methods.

@synthesize o;



-(void)testPropertyShadowing {

  NSObject *oo = self.o;

  clang_analyzer_eval(self.o == oo); // expected-warning{{TRUE}}

  clang_analyzer_eval([self getShadowedIvar] == oo); // expected-warning{{UNKNOWN}}

  [self clearShadowedIvar];

  clang_analyzer_eval(self.o == oo); // expected-warning{{TRUE}}

  clang_analyzer_eval([self getShadowedIvar] == oo); // expected-warning{{UNKNOWN}}

  clang_analyzer_eval([self getShadowedIvar] == nil); // expected-warning{{TRUE}}

}

@end