add trackexpression test

track subexpression instead of the whole cast

Author: Endre Fülöp

clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp

@@ -100,7 +100,7 @@ void EnumCastOutOfRangeChecker::reportWarning(CheckerContext &C,
 
     auto BR = std::make_unique<PathSensitiveBugReport>(*EnumValueCastOutOfRange,
                                                        Msg, N);
-    bugreporter::trackExpressionValue(N, CE, *BR);
+    bugreporter::trackExpressionValue(N, CE->getSubExpr(), *BR);
     BR->addNote("enum declared here",
                 PathDiagnosticLocation::create(E, C.getSourceManager()),
                 {E->getSourceRange()});

clang/test/Analysis/enum-cast-out-of-range.c

@@ -1,8 +1,9 @@
 // RUN: %clang_analyze_cc1 \
 // RUN:   -analyzer-checker=core,alpha.cplusplus.EnumCastOutOfRange \
+// RUN:   -analyzer-output text \
 // RUN:   -verify %s
 
-// expected-note@+1 6 {{enum declared here}}
+// expected-note@+1 + {{enum declared here}}
 enum En_t {
   En_0 = -4,
   En_1,
@@ -13,16 +14,22 @@ enum En_t {
 
 void unscopedUnspecifiedCStyle(void) {
   enum En_t Below = (enum En_t)(-5);    // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
   enum En_t NegVal1 = (enum En_t)(-4);  // OK.
   enum En_t NegVal2 = (enum En_t)(-3);  // OK.
   enum En_t InRange1 = (enum En_t)(-2); // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
   enum En_t InRange2 = (enum En_t)(-1); // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
   enum En_t InRange3 = (enum En_t)(0);  // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
   enum En_t PosVal1 = (enum En_t)(1);   // OK.
   enum En_t PosVal2 = (enum En_t)(2);   // OK.
   enum En_t InRange4 = (enum En_t)(3);  // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
   enum En_t PosVal3 = (enum En_t)(4);   // OK.
   enum En_t Above = (enum En_t)(5);     // expected-warning {{not in the valid range of values for 'En_t'}}
+                                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
 }
 
 enum En_t unused;
@@ -33,3 +40,17 @@ void unusedExpr(void) {
   // generate a warning having nothing to do with this checker.
   unused; // expected-warning {{expression result unused}}
 }
+
+// Test expression tracking
+void set(int* p, int v) {
+  *p = v; // expected-note {{The value -1 is assigned to 'i'}}
+}
+
+
+void testTrackExpression(int i) {
+  set(&i, -1); // expected-note {{Passing the value -1 via 2nd parameter 'v'}}
+               // expected-note@-1 {{Calling 'set'}}
+               // expected-note@-2 {{Returning from 'set'}}
+  (void)(enum En_t)(i); // expected-warning {{not in the valid range of values for 'En_t'}}
+                        // expected-note@-1 {{not in the valid range of values for 'En_t'}}
+}