[clang] detect integer overflow through temporary values

[lnihlen]

Summary

Fixes #63629.

[cjdb]

Fixes GH63629.

Would you mind changing this to Fixes #63629 please? That'll get it connected in GitHub.

The patch looks good, would you mind adding some release notes before I give LGTM please?

[shafik]

Nice catch, I missed that in my last fix: https://reviews.llvm.org/D137897

[shafik]

LGTM after adding release note.

[lnihlen]

Add release note.

[lnihlen]

Added release note, fixed commit log. PTAL, thanks!

[aeubanks]

clang/lib/Sema/SemaChecking.cpp

15215

nit: clang:: isn't necessary

[lnihlen]

remove extrneous clang::

clang/docs/ReleaseNotes.rst

 - Fix C++17 mode assert when parsing malformed code and the compiler is
   attempting to see if it could be type template for class template argument
   deduction. This fixes
   (`Issue 57495 <https://github.com/llvm/llvm-project/issues/57495>`_)
 - Fix missing destructor calls and therefore memory leaks in generated code
   when an immediate invocation appears as a part of an expression that produces
   temporaries.
   (`#60709 <https://github.com/llvm/llvm-project/issues/60709>`_).
+- Fixed a missed integer overflow warning with temporary values.
+  (`#63629 <https://github.com/llvm/llvm-project/issues/63629>`_)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Bug Fixes to Attribute Support
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed a bug where attribute annotations on type specifiers (enums, classes,
   structs, unions, and scoped enums) were not properly ignored, resulting in

clang/lib/Sema/SemaChecking.cpp

do {
     else if (isa<ObjCBoxedExpr>(OriginalE))
       E->EvaluateForOverflow(Context);
     else if (auto Call = dyn_cast<CallExpr>(E))
       Exprs.append(Call->arg_begin(), Call->arg_end());
     else if (auto Message = dyn_cast<ObjCMessageExpr>(E))
       Exprs.append(Message->arg_begin(), Message->arg_end());
     else if (auto Construct = dyn_cast<CXXConstructExpr>(E))
       Exprs.append(Construct->arg_begin(), Construct->arg_end());
+    else if (auto Temporary = dyn_cast<CXXBindTemporaryExpr>(E))
+      Exprs.push_back(Temporary->getSubExpr());
     else if (auto Array = dyn_cast<ArraySubscriptExpr>(E))
       Exprs.push_back(Array->getIdx());
     else if (auto Compound = dyn_cast<CompoundLiteralExpr>(E))
       Exprs.push_back(Compound->getInitializer());
     else if (auto New = dyn_cast<CXXNewExpr>(E)) {
       if (New->isArray())
         if (auto ArraySize = New->getArraySize())
           Exprs.push_back(*ArraySize);

clang/test/SemaCXX/integer-overflow.cpp

namespace EvaluationCrashes {
   }
 }
 
 namespace GH31643 {
 void f() {
   int a = -(1<<31); // expected-warning {{overflow in expression; result is -2147483648 with type 'int'}}
 }
 }
+
+#if __cplusplus >= 201103L
+namespace GH63629 {
+typedef long long int64_t;
+
+template<typename T>
+class u_ptr {
+  T *ptr;
+public:
+  u_ptr(const u_ptr&) = delete;
+  u_ptr &operator=(const u_ptr&) = delete;
+  u_ptr(u_ptr &&other) : ptr(other.ptr) { other.ptr = 0; }
+  u_ptr(T *ptr) : ptr(ptr) { }
+  ~u_ptr() { delete ptr; }
+};
+
+u_ptr<bool> Wrap(int64_t x) {
+    return nullptr;
+}
+
+int64_t Pass(int64_t x) { return x; }
+
+int m() {
+    int64_t x = Pass(30 * 24 * 60 * 59 * 1000);  // expected-warning {{overflow in expression; result is -1746167296 with type 'int'}}
+    auto r = Wrap(Pass(30 * 24 * 60 * 59 * 1000));  // expected-warning {{overflow in expression; result is -1746167296 with type 'int'}}
+    return 0;
+}
+}
+#endif