Add time-trace scope for removeDead

Author: necto

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -74,6 +74,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/GraphWriter.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstdint>
@@ -1031,6 +1032,7 @@ void ExprEngine::removeDead(ExplodedNode *Pred, ExplodedNodeSet &Out,
                             const LocationContext *LC,
                             const Stmt *DiagnosticStmt,
                             ProgramPoint::Kind K) {
+  llvm::TimeTraceScope TimeScope("ExprEngine::removeDead");
   assert((K == ProgramPoint::PreStmtPurgeDeadSymbolsKind ||
           ReferenceStmt == nullptr || isa<ReturnStmt>(ReferenceStmt))
           && "PostStmt is not generally supported by the SymbolReaper yet");

clang/test/Analysis/ftime-trace-removeDead.cpp

@@ -0,0 +1,17 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core %s -ftime-trace=%t.raw.json -ftime-trace-granularity=0 -verify
+// RUN: %python -c 'import json, sys; print(json.dumps(json.load(sys.stdin), indent=4))' < %t.raw.json > %t.formatted.json
+// RUN: FileCheck --input-file=%t.formatted.json --check-prefix=CHECK %s
+
+// The trace file is rather large, but it should contain at least one scope for removeDead:
+//
+// CHECK:          "name": "ExprEngine::removeDead"
+
+bool coin();
+int f() {
+    int x = 0;
+    int y = 0;
+    while (coin()) {
+        x = 1;
+    }
+    return x / y; // expected-warning{{Division by zero}}
+}