[analyzer] Improve dereferenced expression tracking for MemberExpr with a dot and non-reference base

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179734 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 278 insertions, 0 deletions

diff --git a/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp b/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
index 7a0d370b81..9cf39d1e96 100644
--- a/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ b/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -61,6 +61,10 @@ const Expr *bugreporter::getDerefExpr(const Stmt *S) {
     else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
       if (ME->isArrow() || isDeclRefExprToReference(ME->getBase())) {
         return ME->getBase()->IgnoreParenCasts();
+      } else {
+        // If we have a member expr with a dot, the base must have been
+        // dereferenced.
+        return getDerefExpr(ME->getBase());
       }
     }
     else if (const ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E)) {
diff --git a/test/Analysis/inlining/path-notes.cpp b/test/Analysis/inlining/path-notes.cpp
index 01af5313b1..b090b68fd6 100644
--- a/test/Analysis/inlining/path-notes.cpp
+++ b/test/Analysis/inlining/path-notes.cpp
@@ -222,6 +222,28 @@ void test(Derived d) {
             // expected-note@-1 {{Dereference of null pointer (loaded from field 'x')}}
 }
 
+struct Owner {
+	struct Wrapper {
+		int x;
+	};
+	Wrapper *arr;
+	void testGetDerefExprOnMemberExprWithADot();
+};
+
+void Owner::testGetDerefExprOnMemberExprWithADot() {
+	if (arr)  // expected-note {{Assuming pointer value is null}}
+            // expected-note@-1 {{Taking false branch}}
+	  ;
+	arr[1].x = 1; //expected-warning {{Dereference of null pointer}}
+                //expected-note@-1 {{Dereference of null pointer}}
+}
+
+void testGetDerefExprOnMemberExprWithADot() {
+  Owner::Wrapper *arr; // expected-note {{'arr' declared without an initial value}}
+	arr[2].x = 1; // expected-warning {{Dereference of undefined pointer value}}
+                // expected-note@-1 {{Dereference of undefined pointer value}}
+}
+
 // CHECK:  <key>diagnostics</key>
 // CHECK-NEXT:  <array>
 // CHECK-NEXT:   <dict>
@@ -3937,4 +3959,256 @@ void test(Derived d) {
 // CHECK-NEXT:    <key>file</key><integer>0</integer>
 // CHECK-NEXT:   </dict>
 // CHECK-NEXT:   </dict>
+// CHECK-NEXT:   <dict>
+// CHECK-NEXT:    <key>path</key>
+// CHECK-NEXT:    <array>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>control</string>
+// CHECK-NEXT:      <key>edges</key>
+// CHECK-NEXT:       <array>
+// CHECK-NEXT:        <dict>
+// CHECK-NEXT:         <key>start</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>2</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>3</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:         <key>end</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>6</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>8</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:        </dict>
+// CHECK-NEXT:       </array>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>event</string>
+// CHECK-NEXT:      <key>location</key>
+// CHECK-NEXT:      <dict>
+// CHECK-NEXT:       <key>line</key><integer>234</integer>
+// CHECK-NEXT:       <key>col</key><integer>6</integer>
+// CHECK-NEXT:       <key>file</key><integer>0</integer>
+// CHECK-NEXT:      </dict>
+// CHECK-NEXT:      <key>ranges</key>
+// CHECK-NEXT:      <array>
+// CHECK-NEXT:        <array>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>234</integer>
+// CHECK-NEXT:          <key>col</key><integer>6</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>234</integer>
+// CHECK-NEXT:          <key>col</key><integer>8</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:        </array>
+// CHECK-NEXT:      </array>
+// CHECK-NEXT:      <key>depth</key><integer>0</integer>
+// CHECK-NEXT:      <key>extended_message</key>
+// CHECK-NEXT:      <string>Assuming pointer value is null</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>Assuming pointer value is null</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>control</string>
+// CHECK-NEXT:      <key>edges</key>
+// CHECK-NEXT:       <array>
+// CHECK-NEXT:        <dict>
+// CHECK-NEXT:         <key>start</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>6</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>234</integer>
+// CHECK-NEXT:            <key>col</key><integer>8</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:         <key>end</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>237</integer>
+// CHECK-NEXT:            <key>col</key><integer>2</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>237</integer>
+// CHECK-NEXT:            <key>col</key><integer>4</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:        </dict>
+// CHECK-NEXT:       </array>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>event</string>
+// CHECK-NEXT:      <key>location</key>
+// CHECK-NEXT:      <dict>
+// CHECK-NEXT:       <key>line</key><integer>237</integer>
+// CHECK-NEXT:       <key>col</key><integer>2</integer>
+// CHECK-NEXT:       <key>file</key><integer>0</integer>
+// CHECK-NEXT:      </dict>
+// CHECK-NEXT:      <key>ranges</key>
+// CHECK-NEXT:      <array>
+// CHECK-NEXT:        <array>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>237</integer>
+// CHECK-NEXT:          <key>col</key><integer>2</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>237</integer>
+// CHECK-NEXT:          <key>col</key><integer>13</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:        </array>
+// CHECK-NEXT:      </array>
+// CHECK-NEXT:      <key>depth</key><integer>0</integer>
+// CHECK-NEXT:      <key>extended_message</key>
+// CHECK-NEXT:      <string>Dereference of null pointer</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>Dereference of null pointer</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:    </array>
+// CHECK-NEXT:    <key>description</key><string>Dereference of null pointer</string>
+// CHECK-NEXT:    <key>category</key><string>Logic error</string>
+// CHECK-NEXT:    <key>type</key><string>Dereference of null pointer</string>
+// CHECK-NEXT:   <key>issue_context_kind</key><string>C++ method</string>
+// CHECK-NEXT:   <key>issue_context</key><string>testGetDerefExprOnMemberExprWithADot</string>
+// CHECK-NEXT:   <key>issue_hash</key><string>4</string>
+// CHECK-NEXT:   <key>location</key>
+// CHECK-NEXT:   <dict>
+// CHECK-NEXT:    <key>line</key><integer>237</integer>
+// CHECK-NEXT:    <key>col</key><integer>2</integer>
+// CHECK-NEXT:    <key>file</key><integer>0</integer>
+// CHECK-NEXT:   </dict>
+// CHECK-NEXT:   </dict>
+// CHECK-NEXT:   <dict>
+// CHECK-NEXT:    <key>path</key>
+// CHECK-NEXT:    <array>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>event</string>
+// CHECK-NEXT:      <key>location</key>
+// CHECK-NEXT:      <dict>
+// CHECK-NEXT:       <key>line</key><integer>242</integer>
+// CHECK-NEXT:       <key>col</key><integer>3</integer>
+// CHECK-NEXT:       <key>file</key><integer>0</integer>
+// CHECK-NEXT:      </dict>
+// CHECK-NEXT:      <key>ranges</key>
+// CHECK-NEXT:      <array>
+// CHECK-NEXT:        <array>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>242</integer>
+// CHECK-NEXT:          <key>col</key><integer>3</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>242</integer>
+// CHECK-NEXT:          <key>col</key><integer>21</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:        </array>
+// CHECK-NEXT:      </array>
+// CHECK-NEXT:      <key>depth</key><integer>0</integer>
+// CHECK-NEXT:      <key>extended_message</key>
+// CHECK-NEXT:      <string>&apos;arr&apos; declared without an initial value</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>&apos;arr&apos; declared without an initial value</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>control</string>
+// CHECK-NEXT:      <key>edges</key>
+// CHECK-NEXT:       <array>
+// CHECK-NEXT:        <dict>
+// CHECK-NEXT:         <key>start</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>242</integer>
+// CHECK-NEXT:            <key>col</key><integer>3</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>242</integer>
+// CHECK-NEXT:            <key>col</key><integer>7</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:         <key>end</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>243</integer>
+// CHECK-NEXT:            <key>col</key><integer>2</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>243</integer>
+// CHECK-NEXT:            <key>col</key><integer>4</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:        </dict>
+// CHECK-NEXT:       </array>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>event</string>
+// CHECK-NEXT:      <key>location</key>
+// CHECK-NEXT:      <dict>
+// CHECK-NEXT:       <key>line</key><integer>243</integer>
+// CHECK-NEXT:       <key>col</key><integer>2</integer>
+// CHECK-NEXT:       <key>file</key><integer>0</integer>
+// CHECK-NEXT:      </dict>
+// CHECK-NEXT:      <key>ranges</key>
+// CHECK-NEXT:      <array>
+// CHECK-NEXT:        <array>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>243</integer>
+// CHECK-NEXT:          <key>col</key><integer>2</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>243</integer>
+// CHECK-NEXT:          <key>col</key><integer>13</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:        </array>
+// CHECK-NEXT:      </array>
+// CHECK-NEXT:      <key>depth</key><integer>0</integer>
+// CHECK-NEXT:      <key>extended_message</key>
+// CHECK-NEXT:      <string>Dereference of undefined pointer value</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>Dereference of undefined pointer value</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:    </array>
+// CHECK-NEXT:    <key>description</key><string>Dereference of undefined pointer value</string>
+// CHECK-NEXT:    <key>category</key><string>Logic error</string>
+// CHECK-NEXT:    <key>type</key><string>Dereference of undefined pointer value</string>
+// CHECK-NEXT:   <key>issue_context_kind</key><string>function</string>
+// CHECK-NEXT:   <key>issue_context</key><string>testGetDerefExprOnMemberExprWithADot</string>
+// CHECK-NEXT:   <key>issue_hash</key><string>2</string>
+// CHECK-NEXT:   <key>location</key>
+// CHECK-NEXT:   <dict>
+// CHECK-NEXT:    <key>line</key><integer>243</integer>
+// CHECK-NEXT:    <key>col</key><integer>2</integer>
+// CHECK-NEXT:    <key>file</key><integer>0</integer>
+// CHECK-NEXT:   </dict>
+// CHECK-NEXT:   </dict>
 // CHECK-NEXT:  </array>