Hi Richard, Would you mind if I merged this into the 3.9 branch? :)
Thanks, George On Thu, Aug 11, 2016 at 9:12 PM, George Burgess IV via cfe-commits < cfe-commits@lists.llvm.org> wrote: > Author: gbiv > Date: Thu Aug 11 23:12:31 2016 > New Revision: 278471 > > URL: http://llvm.org/viewvc/llvm-project?rev=278471&view=rev > Log: > [Sema] Fix a crash on variadic enable_if functions. > > Currently, when trying to evaluate an enable_if condition, we try to > evaluate all arguments a user passes to a function. Given that we can't > use variadic arguments from said condition anyway, not converting them > is a reasonable thing to do. So, this patch makes us ignore any varargs > when attempting to check an enable_if condition. > > We'd crash because, in order to convert an argument, we need its > ParmVarDecl. Variadic arguments don't have ParmVarDecls. > > Modified: > cfe/trunk/lib/Sema/SemaOverload.cpp > cfe/trunk/test/Sema/enable_if.c > cfe/trunk/test/SemaCXX/enable_if.cpp > > Modified: cfe/trunk/lib/Sema/SemaOverload.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/ > SemaOverload.cpp?rev=278471&r1=278470&r2=278471&view=diff > ============================================================ > ================== > --- cfe/trunk/lib/Sema/SemaOverload.cpp (original) > +++ cfe/trunk/lib/Sema/SemaOverload.cpp Thu Aug 11 23:12:31 2016 > @@ -5974,8 +5974,12 @@ EnableIfAttr *Sema::CheckEnableIf(Functi > SmallVector<Expr *, 16> ConvertedArgs; > bool InitializationFailed = false; > > + // Ignore any variadic parameters. Converting them is pointless, since > the > + // user can't refer to them in the enable_if condition. > + unsigned ArgSizeNoVarargs = std::min(Function->param_size(), > Args.size()); > + > // Convert the arguments. > - for (unsigned I = 0, E = Args.size(); I != E; ++I) { > + for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) { > ExprResult R; > if (I == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) && > !cast<CXXMethodDecl>(Function)->isStatic() && > > Modified: cfe/trunk/test/Sema/enable_if.c > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/ > enable_if.c?rev=278471&r1=278470&r2=278471&view=diff > ============================================================ > ================== > --- cfe/trunk/test/Sema/enable_if.c (original) > +++ cfe/trunk/test/Sema/enable_if.c Thu Aug 11 23:12:31 2016 > @@ -149,4 +149,25 @@ void PR27122_ext() { > regular_enable_if(1, 2); // expected-error{{too many arguments}} > regular_enable_if(); // expected-error{{too few arguments}} > } > + > +// We had a bug where we'd crash upon trying to evaluate varargs. > +void variadic_enable_if(int a, ...) __attribute__((enable_if(a, ""))); // > expected-note 6 {{disabled}} > +void variadic_test() { > + variadic_enable_if(1); > + variadic_enable_if(1, 2); > + variadic_enable_if(1, "c", 3); > + > + variadic_enable_if(0); // expected-error{{no matching}} > + variadic_enable_if(0, 2); // expected-error{{no matching}} > + variadic_enable_if(0, "c", 3); // expected-error{{no matching}} > + > + int m; > + variadic_enable_if(1); > + variadic_enable_if(1, m); > + variadic_enable_if(1, m, "c"); > + > + variadic_enable_if(0); // expected-error{{no matching}} > + variadic_enable_if(0, m); // expected-error{{no matching}} > + variadic_enable_if(0, m, 3); // expected-error{{no matching}} > +} > #endif > > Modified: cfe/trunk/test/SemaCXX/enable_if.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/ > SemaCXX/enable_if.cpp?rev=278471&r1=278470&r2=278471&view=diff > ============================================================ > ================== > --- cfe/trunk/test/SemaCXX/enable_if.cpp (original) > +++ cfe/trunk/test/SemaCXX/enable_if.cpp Thu Aug 11 23:12:31 2016 > @@ -417,3 +417,26 @@ template <int N> constexpr int callTempl > constexpr int B = callTemplated<0>(); // expected-error{{initialized by a > constant expression}} expected-error@-2{{no matching function for call to > 'templated'}} expected-note{{in instantiation of function template}} > expected-note@-9{{candidate disabled}} > static_assert(callTemplated<1>() == 1, ""); > } > + > +namespace variadic { > +void foo(int a, int b = 0, ...) __attribute__((enable_if(a && b, ""))); > // expected-note 6{{disabled}} > + > +void testFoo() { > + foo(1, 1); > + foo(1, 1, 2); > + foo(1, 1, 2, 3); > + > + foo(1, 0); // expected-error{{no matching}} > + foo(1, 0, 2); // expected-error{{no matching}} > + foo(1, 0, 2, 3); // expected-error{{no matching}} > + > + int m; > + foo(1, 1); > + foo(1, 1, m); > + foo(1, 1, m, 3); > + > + foo(1, 0); // expected-error{{no matching}} > + foo(1, 0, m); // expected-error{{no matching}} > + foo(1, 0, m, 3); // expected-error{{no matching}} > +} > +} > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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