[cfe-commits] r109986 - in /cfe/trunk: include/clang/AST/Expr.h lib/AST/Expr.cpp lib/Sema/SemaDecl.cpp test/SemaCXX/warn-global-constructors.cpp
John McCall
rjmccall at apple.com
Sun Aug 1 14:51:45 PDT 2010
Author: rjmccall
Date: Sun Aug 1 16:51:45 2010
New Revision: 109986
URL: http://llvm.org/viewvc/llvm-project?rev=109986&view=rev
Log:
Kill off RequiresGlobalConstructor in favor of isConstantInitializer.
Note some obvious false positives in the test case.
Modified:
cfe/trunk/include/clang/AST/Expr.h
cfe/trunk/lib/AST/Expr.cpp
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/test/SemaCXX/warn-global-constructors.cpp
Modified: cfe/trunk/include/clang/AST/Expr.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Expr.h?rev=109986&r1=109985&r2=109986&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Expr.h (original)
+++ cfe/trunk/include/clang/AST/Expr.h Sun Aug 1 16:51:45 2010
@@ -309,7 +309,7 @@
}
/// isConstantInitializer - Returns true if this expression is a constant
/// initializer, which can be emitted at compile-time.
- bool isConstantInitializer(ASTContext &Ctx) const;
+ bool isConstantInitializer(ASTContext &Ctx) const;
/// EvalResult is a struct with detailed info about an evaluated expression.
struct EvalResult {
Modified: cfe/trunk/lib/AST/Expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Expr.cpp?rev=109986&r1=109985&r2=109986&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Expr.cpp (original)
+++ cfe/trunk/lib/AST/Expr.cpp Sun Aug 1 16:51:45 2010
@@ -1358,6 +1358,20 @@
case ObjCStringLiteralClass:
case ObjCEncodeExprClass:
return true;
+ case CXXTemporaryObjectExprClass:
+ case CXXConstructExprClass: {
+ const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
+ if (!CE->getConstructor()->isTrivial()) return false;
+ for (CXXConstructExpr::const_arg_iterator
+ I = CE->arg_begin(), E = CE->arg_end(); I != E; ++I)
+ if (!(*I)->isConstantInitializer(Ctx))
+ return false;
+ return true;
+ }
+ case CXXBindReferenceExprClass: {
+ const CXXBindReferenceExpr *RE = cast<CXXBindReferenceExpr>(this);
+ return RE->getSubExpr()->isConstantInitializer(Ctx);
+ }
case CompoundLiteralExprClass: {
// This handles gcc's extension that allows global initializers like
// "struct x {int x;} x = (struct x) {};".
@@ -1397,6 +1411,7 @@
return true;
break;
}
+ case CXXStaticCastExprClass:
case ImplicitCastExprClass:
case CStyleCastExprClass:
// Handle casts with a destination that's a struct or union; this
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=109986&r1=109985&r2=109986&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Sun Aug 1 16:51:45 2010
@@ -3866,57 +3866,6 @@
AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false);
}
-/// Make a reasonable guess at whether the given initializer will
-/// require a global constructor.
-static bool RequiresGlobalConstructor(Sema &S, Expr *Init) {
- // FIXME: reproducing the logic of CGExprConstant is kindof dumb.
- // Maybe this should be integrated into the constant-evaluator?
- // We'd need array and struct value types.
- //
- // It's probably okay to still warn in the theoretical cases where
- // IR gen can eliminate a global constructor based on
- // initialization order (not that it actually does that
- // optimization at the moment).
- if (Init->isEvaluatable(S.Context)) return false;
-
- Init = Init->IgnoreParenNoopCasts(S.Context);
-
- // Look through reference-bindings.
- if (CXXBindReferenceExpr *BE = dyn_cast<CXXBindReferenceExpr>(Init))
- return RequiresGlobalConstructor(S, BE);
-
- // A constructor call needs a global constructor if:
- if (CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(Init)) {
- // - the constructor is non-trivial
- if (!CE->getConstructor()->isTrivial()) return true;
-
- // - any of the argument expressions needs a global constructor
- for (CXXConstructExpr::arg_iterator
- I = CE->arg_begin(), E = CE->arg_end(); I != E; ++I)
- if (RequiresGlobalConstructor(S, *I))
- return true;
-
- // We don't have to worry about building temporaries with
- // non-trivial destructors because we should never have walked
- // through the CXXExprWithTemporaries.
-
- // So it should be emitted as a constant expression.
- return false;
- }
-
- /// An initializer list requires a global constructor if any of the
- /// components do.
- if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
- for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I)
- if (RequiresGlobalConstructor(S, ILE->getInit(I)))
- return true;
- return false;
- }
-
- // Assume everything else does.
- return true;
-}
-
/// AddInitializerToDecl - Adds the initializer Init to the
/// declaration dcl. If DirectInit is true, this is C++ direct
/// initialization rather than copy initialization.
@@ -4118,7 +4067,7 @@
if (getLangOptions().CPlusPlus) {
if (!VDecl->isInvalidDecl() &&
!VDecl->getDeclContext()->isDependentContext() &&
- VDecl->hasGlobalStorage() && RequiresGlobalConstructor(*this, Init))
+ VDecl->hasGlobalStorage() && !Init->isConstantInitializer(Context))
Diag(VDecl->getLocation(), diag::warn_global_constructor);
// Make sure we mark the destructor as used if necessary.
@@ -4332,7 +4281,7 @@
if (getLangOptions().CPlusPlus && !Var->isInvalidDecl() &&
Var->hasGlobalStorage() &&
!Var->getDeclContext()->isDependentContext() &&
- RequiresGlobalConstructor(*this, Var->getInit()))
+ !Var->getInit()->isConstantInitializer(Context))
Diag(Var->getLocation(), diag::warn_global_constructor);
}
}
Modified: cfe/trunk/test/SemaCXX/warn-global-constructors.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-global-constructors.cpp?rev=109986&r1=109985&r2=109986&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-global-constructors.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-global-constructors.cpp Sun Aug 1 16:51:45 2010
@@ -29,6 +29,11 @@
A a; // expected-warning {{global constructor}}
A b[10]; // expected-warning {{global constructor}}
A c[10][10]; // expected-warning {{global constructor}}
+
+ // FIXME: false positives!
+ A &d = a; // expected-warning {{global constructor}}
+ A &e = b[5]; // expected-warning {{global constructor}}
+ A &f = c[5][7]; // expected-warning {{global constructor}}
}
namespace test3 {
@@ -36,4 +41,15 @@
A a; // expected-warning {{global destructor}}
A b[10]; // expected-warning {{global destructor}}
A c[10][10]; // expected-warning {{global destructor}}
+
+ // FIXME: false positives!
+ A &d = a; // expected-warning {{global constructor}}
+ A &e = b[5]; // expected-warning {{global constructor}}
+ A &f = c[5][7]; // expected-warning {{global constructor}}
+}
+
+namespace test4 {
+ char a[] = "hello";
+ char b[5] = "hello";
+ char c[][5] = { "hello" };
}
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