[PATCH] D29643: [analyzer] Do not duplicate call graph nodes for function that has definition and forward declaration.

[Ivan Sidorenko via Phabricator via cfe-commits]

IvanSidorenko created this revision.

Fix in call graph construction: don't build call graph node for callee function twice for functions with forward declarations.

Maybe the same fix should be done and for VisitObjCMethodDecl. Unfortunately, I have not enough expertise in ObjC, so I did not touch this code.

Test case:
void do_nothing() {}
void test_single_call();
void test_single_call() {

  do_nothing();

}

Output for the test case WITHOUT patch:
Function: test_single_call calls: **do_nothing do_nothing**
Function: do_nothing calls:

Output for the test case WITH patch:
Function: test_single_call calls: **do_nothing**
Function: do_nothing calls:


https://reviews.llvm.org/D29643

Files:
  include/clang/Analysis/CallGraph.h
  test/Analysis/debug-CallGraph.c


Index: test/Analysis/debug-CallGraph.c
===================================================================
--- test/Analysis/debug-CallGraph.c
+++ test/Analysis/debug-CallGraph.c
@@ -43,8 +43,18 @@
 void eee() {}
 void fff() { eee(); }
 
+// This test case tests that forward declaration for the top-level function
+// does not affect call graph construction.
+void do_nothing() {}
+void test_single_call();
+void test_single_call() {
+  do_nothing();
+}
+
 // CHECK:--- Call graph Dump ---
-// CHECK-NEXT: {{Function: < root > calls: get5 add test_add mmm foo aaa < > bbb ccc ddd eee fff $}}
+// CHECK-NEXT: {{Function: < root > calls: get5 add test_add mmm foo aaa < > bbb ddd ccc eee fff do_nothing test_single_call $}}
+// CHECK-NEXT: {{Function: test_single_call calls: do_nothing $}}
+// CHECK-NEXT: {{Function: do_nothing calls: $}}
 // CHECK-NEXT: {{Function: fff calls: eee $}}
 // CHECK-NEXT: {{Function: eee calls: $}}
 // CHECK-NEXT: {{Function: ddd calls: ccc $}}
Index: include/clang/Analysis/CallGraph.h
===================================================================
--- include/clang/Analysis/CallGraph.h
+++ include/clang/Analysis/CallGraph.h
@@ -98,7 +98,7 @@
   bool VisitFunctionDecl(FunctionDecl *FD) {
     // We skip function template definitions, as their semantics is
     // only determined when they are instantiated.
-    if (includeInGraph(FD)) {
+    if (includeInGraph(FD) && FD->isThisDeclarationADefinition()) {
       // Add all blocks declared inside this function to the graph.
       addNodesForBlocks(FD);
       // If this function has external linkage, anything could call it.


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