[analyzer] do not crash on libcxx03 call_once implementation

Addresses https://bugs.llvm.org/show_bug.cgi?id=35075, rdar://35230961

Differential Revision: https://reviews.llvm.org/D39518

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@317293 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/BodyFarm.cpp b/lib/Analysis/BodyFarm.cpp
index 58a129c411fc3b012b743f95d3e6deb5d87caf49..3e62ae5fe63372dbdb1502c8a930eb696e4b47f7 100644 (file)
--- a/lib/Analysis/BodyFarm.cpp
+++ b/lib/Analysis/BodyFarm.cpp
@@ -325,6 +325,16 @@ static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
 
   const ParmVarDecl *Flag = D->getParamDecl(0);
   const ParmVarDecl *Callback = D->getParamDecl(1);
+
+  if (!Callback->getType()->isReferenceType()) {
+    llvm::dbgs() << "libcxx03 std::call_once implementation, skipping.\n";
+    return nullptr;
+  }
+  if (!Flag->getType()->isReferenceType()) {
+    llvm::dbgs() << "unknown std::call_once implementation, skipping.\n";
+    return nullptr;
+  }
+
   QualType CallbackType = Callback->getType().getNonReferenceType();
 
   // Nullable pointer, non-null iff function is a CXXRecordDecl.
@@ -346,15 +356,13 @@ static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
   // Otherwise, try libstdc++ implementation, with a field
   // `_M_once`
   if (!FlagFieldDecl) {
-    DEBUG(llvm::dbgs() << "No field __state_ found on std::once_flag struct, "
-                       << "assuming libstdc++ implementation\n");
     FlagFieldDecl = M.findMemberField(FlagRecordDecl, "_M_once");
   }
 
   if (!FlagFieldDecl) {
-    DEBUG(llvm::dbgs() << "No field _M_once found on std::once flag struct: "
-                       << "unknown std::call_once implementation, "
-                       << "ignoring the call");
+    DEBUG(llvm::dbgs() << "No field _M_once or __state_ found on "
+                       << "std::once_flag struct: unknown std::call_once "
+                       << "implementation, ignoring the call.");
     return nullptr;
   }
 
@@ -388,9 +396,9 @@ static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
 
   // First two arguments are used for the flag and for the callback.
   if (D->getNumParams() != CallbackFunctionType->getNumParams() + 2) {
-    DEBUG(llvm::dbgs() << "Number of params of the callback does not match "
-                       << "the number of params passed to std::call_once, "
-                       << "ignoring the call");
+    DEBUG(llvm::dbgs() << "Types of params of the callback do not match "
+                       << "params passed to std::call_once, "
+                       << "ignoring the call\n");
     return nullptr;
   }
 

diff --git a/test/Analysis/call_once.cpp b/test/Analysis/call_once.cpp
index 5013cd423e3d5d8f58c28564eeae279293c7aa5a..db9e5cc7ca164835e2f2cdc83a8f54e7ac660dd0 100644 (file)
--- a/test/Analysis/call_once.cpp
+++ b/test/Analysis/call_once.cpp
@@ -1,6 +1,11 @@
 // RUN: %clang_analyze_cc1 -std=c++11 -fblocks -analyzer-checker=core,debug.ExprInspection -verify %s
 // RUN: %clang_analyze_cc1 -std=c++11 -fblocks -analyzer-checker=core,debug.ExprInspection -DEMULATE_LIBSTDCPP -verify %s
 
+// We do NOT model libcxx03 implementation, but the analyzer should still
+// not crash.
+// RUN: %clang_analyze_cc1 -std=c++11 -fblocks -analyzer-checker=core,debug.ExprInspection -DEMULATE_LIBCXX03 -verify %s
+// RUN: %clang_analyze_cc1 -std=c++11 -fblocks -analyzer-checker=core,debug.ExprInspection -DEMULATE_LIBCXX03 -DEMULATE_LIBSTDCPP -verify %s
+
 void clang_analyzer_eval(bool);
 
 // Faking std::std::call_once implementation.
@@ -16,8 +21,13 @@ typedef struct once_flag_s {
 } once_flag;
 #endif
 
+#ifndef EMULATE_LIBCXX03
 template <class Callable, class... Args>
 void call_once(once_flag &o, Callable&& func, Args&&... args) {};
+#else
+template <class Callable, class... Args> // libcxx03 call_once
+void call_once(once_flag &o, Callable func, Args&&... args) {};
+#endif
 
 } // namespace std
 
@@ -28,7 +38,9 @@ void test_called_warning() {
 
   std::call_once(g_initialize, [&] {
     int *x = nullptr;
+#ifndef EMULATE_LIBCXX03
     int y = *x; // expected-warning{{Dereference of null pointer (loaded from variable 'x')}}
+#endif
     z = 200;
   });
 }
@@ -45,8 +57,10 @@ void test_called_on_path_inside_no_warning() {
     x = &z;
   });
 
+#ifndef EMULATE_LIBCXX03
   *x = 100; // no-warning
   clang_analyzer_eval(z == 100); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_called_on_path_no_warning() {
@@ -59,7 +73,11 @@ void test_called_on_path_no_warning() {
     x = &y;
   });
 
+#ifndef EMULATE_LIBCXX03
   *x = 100; // no-warning
+#else
+  *x = 100; // expected-warning{{Dereference of null pointer (loaded from variable 'x')}}
+#endif
 }
 
 void test_called_on_path_warning() {
@@ -72,7 +90,9 @@ void test_called_on_path_warning() {
     x = nullptr;
   });
 
+#ifndef EMULATE_LIBCXX03
   *x = 100; // expected-warning{{Dereference of null pointer (loaded from variable 'x')}}
+#endif
 }
 
 void test_called_once_warning() {
@@ -89,7 +109,9 @@ void test_called_once_warning() {
     x = &y;
   });
 
+#ifndef EMULATE_LIBCXX03
   *x = 100; // expected-warning{{Dereference of null pointer (loaded from variable 'x')}}
+#endif
 }
 
 void test_called_once_no_warning() {
@@ -106,7 +128,9 @@ void test_called_once_no_warning() {
     x = nullptr;
   });
 
+#ifndef EMULATE_LIBCXX03
   *x = 100; // no-warning
+#endif
 }
 
 static int global = 0;
@@ -117,7 +141,9 @@ void funcPointer() {
 void test_func_pointers() {
   static std::once_flag flag;
   std::call_once(flag, &funcPointer);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(global == 1); // expected-warning{{TRUE}}
+#endif
 }
 
 template <class _Fp>
@@ -157,7 +183,9 @@ void test_param_passing_lambda() {
   },
                  x);
 
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(y == 120); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_param_passing_lambda_false() {
@@ -169,7 +197,9 @@ void test_param_passing_lambda_false() {
   },
                  x);
 
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(x == 120); // expected-warning{{FALSE}}
+#endif
 }
 
 void test_param_passing_stored_lambda() {
@@ -182,7 +212,9 @@ void test_param_passing_stored_lambda() {
   };
 
   std::call_once(flag, lambda, x);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(y == 120); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_multiparam_passing_lambda() {
@@ -194,8 +226,10 @@ void test_multiparam_passing_lambda() {
   },
                  1, 2, 3);
 
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(x == 120); // expected-warning{{FALSE}}
   clang_analyzer_eval(x == 6); // expected-warning{{TRUE}}
+#endif
 }
 
 static int global2 = 0;
@@ -206,7 +240,9 @@ void test_param_passing_lambda_global() {
     global2 = a + b + c;
   },
                  1, 2, 3);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(global2 == 6); // expected-warning{{TRUE}}
+#endif
 }
 
 static int global3 = 0;
@@ -220,7 +256,9 @@ void test_param_passing_funcptr() {
 
   std::call_once(flag, &funcptr, 1, 2, 3);
 
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(global3 == 6); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_blocks() {
@@ -229,7 +267,9 @@ void test_blocks() {
   std::call_once(flag, ^{
     global3 = 120;
   });
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(global3 == 120); // expected-warning{{TRUE}}
+#endif
 }
 
 int call_once() {
@@ -238,7 +278,9 @@ int call_once() {
 
 void test_non_std_call_once() {
   int x = call_once();
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(x == 5); // expected-warning{{TRUE}}
+#endif
 }
 
 namespace std {
@@ -247,28 +289,36 @@ void call_once(d, e);
 }
 void g();
 void test_no_segfault_on_different_impl() {
+#ifndef EMULATE_LIBCXX03
   std::call_once(g, false); // no-warning
+#endif
 }
 
 void test_lambda_refcapture() {
   static std::once_flag flag;
   int a = 6;
   std::call_once(flag, [&](int &a) { a = 42; }, a);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(a == 42); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_lambda_refcapture2() {
   static std::once_flag flag;
   int a = 6;
   std::call_once(flag, [=](int &a) { a = 42; }, a);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(a == 42); // expected-warning{{TRUE}}
+#endif
 }
 
 void test_lambda_fail_refcapture() {
   static std::once_flag flag;
   int a = 6;
   std::call_once(flag, [=](int a) { a = 42; }, a);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(a == 42); // expected-warning{{FALSE}}
+#endif
 }
 
 void mutator(int &param) {
@@ -278,7 +328,9 @@ void test_reftypes_funcptr() {
   static std::once_flag flag;
   int a = 6;
   std::call_once(flag, &mutator, a);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(a == 42); // expected-warning{{TRUE}}
+#endif
 }
 
 void fail_mutator(int param) {
@@ -288,7 +340,9 @@ void test_mutator_noref() {
   static std::once_flag flag;
   int a = 6;
   std::call_once(flag, &fail_mutator, a);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(a == 42); // expected-warning{{FALSE}}
+#endif
 }
 
 // Function is implicitly treated as a function pointer
@@ -301,5 +355,7 @@ void test_implicit_funcptr() {
   static std::once_flag flagn;
 
   std::call_once(flagn, callbackn, x);
+#ifndef EMULATE_LIBCXX03
   clang_analyzer_eval(x == 42); // expected-warning{{TRUE}}
+#endif
 }