commit c236b7327f989c1e7fe6b08a188bfef86727513d
author Jordan Rose <jordan_rose@apple.com> Thu Mar 07 01:23:25 2013 +0000
committer Jordan Rose <jordan_rose@apple.com> Thu Mar 07 01:23:25 2013 +0000
tree 719d2044a91b2612bd4f760f6b53b3f638dedaed
parent 962fbc46664f2486d6805549130fa6b310de6d60

[analyzer] Check for returning null references in ReturnUndefChecker.

Officially in the C++ standard, a null reference cannot exist. However,
it's still very easy to create one:

int &getNullRef() {
  int *p = 0;
  return *p;
}

We already check that binds to reference regions don't create null references.
This patch checks that we don't create null references by returning, either.

<rdar://problem/13364378>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176601 91177308-0d34-0410-b5e6-96231b3b80d8

test/Analysis/inlining/path-notes.cpp

diff --git a/test/Analysis/inlining/path-notes.cpp b/test/Analysis/inlining/path-notes.cpp
index 86b2864..6c63e14 100644
--- a/test/Analysis/inlining/path-notes.cpp
+++ b/test/Analysis/inlining/path-notes.cpp
@@ -184,6 +184,15 @@
   }
 }
 
+
+int &returnNullReference() {
+  int *x = 0;
+  // expected-note@-1 {{'x' initialized to a null pointer value}}
+  return *x; // expected-warning{{Returning null reference}}
+  // expected-note@-1 {{Returning null reference}}
+}
+
+
 // CHECK:  <key>diagnostics</key>
 // CHECK-NEXT:  <array>
 // CHECK-NEXT:   <dict>
@@ -3214,4 +3223,113 @@
 // 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>189</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>189</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>189</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>&apos;x&apos; initialized to a null pointer value</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>&apos;x&apos; initialized to a null pointer 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>189</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>189</integer>
+// CHECK-NEXT:            <key>col</key><integer>5</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>191</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>191</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>191</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>191</integer>
+// CHECK-NEXT:          <key>col</key><integer>10</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>191</integer>
+// CHECK-NEXT:          <key>col</key><integer>11</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>Returning null reference</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>Returning null reference</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:    </array>
+// CHECK-NEXT:    <key>description</key><string>Returning null reference</string>
+// CHECK-NEXT:    <key>category</key><string>Logic error</string>
+// CHECK-NEXT:    <key>type</key><string>Returning null reference</string>
+// CHECK-NEXT:   <key>issue_context_kind</key><string>function</string>
+// CHECK-NEXT:   <key>issue_context</key><string>returnNullReference</string>
+// CHECK-NEXT:   <key>issue_hash</key><string>3</string>
+// CHECK-NEXT:   <key>location</key>
+// CHECK-NEXT:   <dict>
+// CHECK-NEXT:    <key>line</key><integer>191</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:  </array>