r316900 - [analyzer] Use the signature of the primary template for issue hash calculation

[Gabor Horvath via cfe-commits]

Author: xazax
Date: Mon Oct 30 05:16:07 2017
New Revision: 316900

URL: http://llvm.org/viewvc/llvm-project?rev=316900&view=rev
Log:
[analyzer] Use the signature of the primary template for issue hash calculation

Now when a template is instantiated more times and there is a bug found in the
instantiations the issue hash will be different for each instantiation even if
every other property of the bug (path, message, location) is the same.

This patch aims to resolve this issue. Note that explicit specializations still
generate different hashes but that is intended.

Differential Revision: https://reviews.llvm.org/D38728

Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/IssueHash.cpp
    cfe/trunk/test/Analysis/bug_hash_test.cpp
    cfe/trunk/test/Analysis/edges-new.mm

Modified: cfe/trunk/lib/StaticAnalyzer/Core/IssueHash.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/IssueHash.cpp?rev=316900&r1=316899&r2=316900&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/IssueHash.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/IssueHash.cpp Mon Oct 30 05:16:07 2017
@@ -33,6 +33,13 @@ static std::string GetSignature(const Fu
     return "";
   std::string Signature;
 
+  // When a flow sensitive bug happens in templated code we should not generate
+  // distinct hash value for every instantiation. Use the signature from the
+  // primary template.
+  if (const FunctionDecl *InstantiatedFrom =
+          Target->getTemplateInstantiationPattern())
+    Target = InstantiatedFrom;
+
   if (!isa<CXXConstructorDecl>(Target) && !isa<CXXDestructorDecl>(Target) &&
       !isa<CXXConversionDecl>(Target))
     Signature.append(Target->getReturnType().getAsString()).append(" ");

Modified: cfe/trunk/test/Analysis/bug_hash_test.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/bug_hash_test.cpp?rev=316900&r1=316899&r2=316900&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/bug_hash_test.cpp (original)
+++ cfe/trunk/test/Analysis/bug_hash_test.cpp Mon Oct 30 05:16:07 2017
@@ -71,15 +71,13 @@ void testLambda() {
 
 template <typename T>
 void f(T) {
-  clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void f(double)$27$clang_analyzer_hashDump(5);$Category}}
-                               // expected-warning at -1{{debug.ExprInspection$void f(int)$27$clang_analyzer_hashDump(5);$Category}}
+  clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void f(T)$27$clang_analyzer_hashDump(5);$Category}}
 }
 
 template <typename T>
 struct TX {
   void f(T) {
-    clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void TX<double>::f(double)$29$clang_analyzer_hashDump(5);$Category}}
-                                 // expected-warning at -1{{debug.ExprInspection$void TX<int>::f(int)$29$clang_analyzer_hashDump(5);$Category}}
+    clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void TX::f(T)$29$clang_analyzer_hashDump(5);$Category}}
   }
 };
 
@@ -99,11 +97,17 @@ template <typename T>
 struct TTX {
   template<typename S>
   void f(T, S) {
-    clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void TTX<int>::f(int, int)$29$clang_analyzer_hashDump(5);$Category}}
+    clang_analyzer_hashDump(5); // expected-warning {{debug.ExprInspection$void TTX::f(T, S)$29$clang_analyzer_hashDump(5);$Category}}
   }
 };
 
 void g() {
+  // TX<int> and TX<double> is instantiated from the same code with the same
+  // source locations. The same error happining in both of the instantiations
+  // should share the common hash. This means we should not include the
+  // template argument for these types in the function signature.
+  // Note that, we still want the hash to be different for explicit
+  // specializations.
   TX<int> x;
   TX<double> y;
   TX<long> xl;

Modified: cfe/trunk/test/Analysis/edges-new.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/edges-new.mm?rev=316900&r1=316899&r2=316900&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/edges-new.mm (original)
+++ cfe/trunk/test/Analysis/edges-new.mm Mon Oct 30 05:16:07 2017
@@ -20288,7 +20288,7 @@ namespace rdar14960554 {
 // CHECK-NEXT:    <key>type</key><string>Bad deallocator</string>
 // CHECK-NEXT:    <key>check_name</key><string>unix.MismatchedDeallocator</string>
 // CHECK-NEXT:    <!-- This hash is experimental and going to change! -->
-// CHECK-NEXT:    <key>issue_hash_content_of_line_in_context</key><string>d9dbbf68db41ab74e2158f4b131abe34</string>
+// CHECK-NEXT:    <key>issue_hash_content_of_line_in_context</key><string>046c88d1c91ff46d6506dff5ff880756</string>
 // CHECK-NEXT:   <key>issue_hash_function_offset</key><string>0</string>
 // CHECK-NEXT:   <key>location</key>
 // CHECK-NEXT:   <dict>