[clang][Interp] Visit Logical-not operand as bool

[tbaeder]

Summary

The invBool op here expects a bool operand, but in C, the operand might be of a different type (usually int).

[aaron.ballman]

LGTM with a testing request.

clang/test/AST/Interp/c.c

12–13

These tests should also work in C++.

clang/lib/AST/Interp/ByteCodeExprGen.cpp

if (T == PT_Float) {
       return this->emitStoreFloat(E);
     }
     this->emitLoad(*T, E);
     this->emitConst(1, E);
     this->emitSub(*T, E);
     return this->emitStore(*T, E);
   }
   case UO_LNot: // !x
-    if (!this->visit(SubExpr))
+    if (DiscardResult)
+      return this->discard(SubExpr);
+
+    if (!this->visitBool(SubExpr))
       return false;
-    // The Inv doesn't change anything, so skip it if we don't need the result.
-    return DiscardResult ? this->emitPop(*T, E) : this->emitInvBool(E);
+
+    if (!this->emitInvBool(E))
+      return false;
+
+    if (PrimType ET = classifyPrim(E->getType()); ET != PT_Bool)
+      return this->emitCast(PT_Bool, ET, E);
+    return true;
   case UO_Minus: // -x
     if (!this->visit(SubExpr))
       return false;
     return DiscardResult ? this->emitPop(*T, E) : this->emitNeg(*T, E);
   case UO_Plus:  // +x
     if (!this->visit(SubExpr)) // noop
       return false;
     return DiscardResult ? this->emitPop(*T, E) : true;

clang/test/AST/Interp/c.c

 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify %s
 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -pedantic -verify=pedantic-expected %s
 // RUN: %clang_cc1 -verify=ref %s
 // RUN: %clang_cc1 -pedantic -verify=pedantic-ref %s
 
 _Static_assert(1, "");
 _Static_assert(0 != 1, "");
 _Static_assert(1.0 == 1.0, ""); // pedantic-ref-warning {{not an integer constant expression}} \
                                 // pedantic-expected-warning {{not an integer constant expression}}
 _Static_assert(1 && 1.0, "");
 _Static_assert( (5 > 4) + (3 > 2) == 2, "");
+_Static_assert(!!1.0, "");
+_Static_assert(!!1, "");
 
 /// FIXME: Should also be rejected in the new interpreter
 int a = (1 == 1 ? 5 : 3);
 _Static_assert(a == 5, ""); // ref-error {{not an integral constant expression}} \
                             // pedantic-ref-error {{not an integral constant expression}} \
                             // pedantic-expected-warning {{not an integer constant expression}}
 
 const int b = 3;