[llvm-branch-commits] [clang] 5b08e49 - [analyzer] NFC: Store the pointee/referenced type for dynamic type tracking.

[Hans Wennborg via llvm-branch-commits]

Author: Adam Balogh
Date: 2020-08-28T11:32:08+02:00
New Revision: 5b08e498cd35b05a937d6afd5cc20bde90822a29

URL: https://github.com/llvm/llvm-project/commit/5b08e498cd35b05a937d6afd5cc20bde90822a29
DIFF: https://github.com/llvm/llvm-project/commit/5b08e498cd35b05a937d6afd5cc20bde90822a29.diff

LOG: [analyzer] NFC: Store the pointee/referenced type for dynamic type tracking.

The successfulness of a dynamic cast depends only on the C++ class, not the pointer or reference. Thus if *A is a *B, then &A is a &B,
const *A is a const *B etc. This patch changes DynamicCastInfo to store
and check the cast between the unqualified pointed/referenced types.
It also removes e.g. SubstTemplateTypeParmType from both the pointer
and the pointed type.

Differential Revision: https://reviews.llvm.org/D85752

(cherry picked from commit 5a9e7789396e7618c1407aafc329e00584437a2f)

Added: 
    

Modified: 
    clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
    clang/lib/StaticAnalyzer/Core/DynamicType.cpp
    clang/test/Analysis/cast-value-state-dump.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
index 1ef70b650414..3d1721f04875 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
@@ -106,7 +106,7 @@ static const NoteTag *getNoteTag(CheckerContext &C,
                                  QualType CastToTy, const Expr *Object,
                                  bool CastSucceeds, bool IsKnownCast) {
   std::string CastToName =
-      CastInfo ? CastInfo->to()->getPointeeCXXRecordDecl()->getNameAsString()
+      CastInfo ? CastInfo->to()->getAsCXXRecordDecl()->getNameAsString()
                : CastToTy->getPointeeCXXRecordDecl()->getNameAsString();
   Object = Object->IgnoreParenImpCasts();
 

diff  --git a/clang/lib/StaticAnalyzer/Core/DynamicType.cpp b/clang/lib/StaticAnalyzer/Core/DynamicType.cpp
index e9b64fd79614..9ed915aafcab 100644
--- a/clang/lib/StaticAnalyzer/Core/DynamicType.cpp
+++ b/clang/lib/StaticAnalyzer/Core/DynamicType.cpp
@@ -65,6 +65,13 @@ const DynamicTypeInfo *getRawDynamicTypeInfo(ProgramStateRef State,
   return State->get<DynamicTypeMap>(MR);
 }
 
+static void unbox(QualType &Ty) {
+  // FIXME: Why are we being fed references to pointers in the first place?
+  while (Ty->isReferenceType() || Ty->isPointerType())
+    Ty = Ty->getPointeeType();
+  Ty = Ty.getCanonicalType().getUnqualifiedType();
+}
+
 const DynamicCastInfo *getDynamicCastInfo(ProgramStateRef State,
                                           const MemRegion *MR,
                                           QualType CastFromTy,
@@ -73,6 +80,9 @@ const DynamicCastInfo *getDynamicCastInfo(ProgramStateRef State,
   if (!Lookup)
     return nullptr;
 
+  unbox(CastFromTy);
+  unbox(CastToTy);
+
   for (const DynamicCastInfo &Cast : *Lookup)
     if (Cast.equals(CastFromTy, CastToTy))
       return &Cast;
@@ -112,6 +122,9 @@ ProgramStateRef setDynamicTypeAndCastInfo(ProgramStateRef State,
     State = State->set<DynamicTypeMap>(MR, CastToTy);
   }
 
+  unbox(CastFromTy);
+  unbox(CastToTy);
+
   DynamicCastInfo::CastResult ResultKind =
       CastSucceeds ? DynamicCastInfo::CastResult::Success
                    : DynamicCastInfo::CastResult::Failure;

diff  --git a/clang/test/Analysis/cast-value-state-dump.cpp b/clang/test/Analysis/cast-value-state-dump.cpp
index 3dffb78767cf..3e6a40cf1319 100644
--- a/clang/test/Analysis/cast-value-state-dump.cpp
+++ b/clang/test/Analysis/cast-value-state-dump.cpp
@@ -35,8 +35,8 @@ void evalNonNullParamNonNullReturn(const Shape *S) {
   // CHECK-NEXT: ],
   // CHECK-NEXT: "dynamic_casts": [
   // CHECK:        { "region": "SymRegion{reg_$0<const struct clang::Shape * S>}", "casts": [
-  // CHECK-NEXT:     { "from": "const struct clang::Shape *", "to": "const class clang::Circle *", "kind": "success" },
-  // CHECK-NEXT:     { "from": "const struct clang::Shape *", "to": "const class clang::Square *", "kind": "fail" }
+  // CHECK-NEXT:     { "from": "struct clang::Shape", "to": "class clang::Circle", "kind": "success" },
+  // CHECK-NEXT:     { "from": "struct clang::Shape", "to": "class clang::Square", "kind": "fail" }
   // CHECK-NEXT:   ] }
 
   (void)(1 / !C);