[clang] bc7034c - [Concepts] Fix an assertion failure while diagnosing constrained

[Erich Keane via cfe-commits]

Author: Roy Jacobson
Date: 2022-03-15T13:11:32-07:00
New Revision: bc7034c1ecfbe942bc55ed054fca856c5ab90dc8

URL: https://github.com/llvm/llvm-project/commit/bc7034c1ecfbe942bc55ed054fca856c5ab90dc8
DIFF: https://github.com/llvm/llvm-project/commit/bc7034c1ecfbe942bc55ed054fca856c5ab90dc8.diff

LOG: [Concepts] Fix an assertion failure while diagnosing constrained
function candidates

See: https://github.com/llvm/llvm-project/issues/54379

I tried to see if I can reuse ResolveAddressOfOverloadedFunction for
explicit function instantiation and so I managed to hit this ICE.

Bug was the diagnostic required an argument (%0) and specific code path
didn't pass an argument.

Differential Revision: https://reviews.llvm.org/D121646

Added: 
    

Modified: 
    clang/lib/Sema/SemaOverload.cpp
    clang/test/SemaTemplate/concepts.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 767074bdbd15f..fb071eee7c06c 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -10256,10 +10256,19 @@ static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
       return false;
     if (!Satisfaction.IsSatisfied) {
       if (Complain) {
-        if (InOverloadResolution)
+        if (InOverloadResolution) {
+          SmallString<128> TemplateArgString;
+          if (FunctionTemplateDecl *FunTmpl = FD->getPrimaryTemplate()) {
+            TemplateArgString += " ";
+            TemplateArgString += S.getTemplateArgumentBindingsText(
+                FunTmpl->getTemplateParameters(),
+                *FD->getTemplateSpecializationArgs());
+          }
+
           S.Diag(FD->getBeginLoc(),
-                 diag::note_ovl_candidate_unsatisfied_constraints);
-        else
+                 diag::note_ovl_candidate_unsatisfied_constraints)
+              << TemplateArgString;
+        } else
           S.Diag(Loc, diag::err_addrof_function_constraints_not_satisfied)
               << FD;
         S.DiagnoseUnsatisfiedConstraint(Satisfaction);

diff  --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp
index 20af504883566..132761b2d68ae 100644
--- a/clang/test/SemaTemplate/concepts.cpp
+++ b/clang/test/SemaTemplate/concepts.cpp
@@ -208,3 +208,17 @@ namespace PR53911 {
     return (int*)nullptr; // FIXME: should error
   }
 }
+
+namespace PR54379 {
+template <int N>
+struct A {
+  static void f() requires (N == 0) { return; } // expected-note {{candidate template ignored: constraints not satisfied}} expected-note {{evaluated to false}}
+  static void f() requires (N == 1) { return; } // expected-note {{candidate template ignored: constraints not satisfied}} expected-note {{evaluated to false}}
+};
+void (*f1)() = A<2>::f; // expected-error {{address of overloaded function 'f' does not match required type}}
+
+struct B {
+  template <int N2 = 1> static void f() requires (N2 == 0) { return; }  // expected-note {{candidate template ignored: constraints not satisfied [with N2 = 1]}} expected-note {{evaluated to false}}
+};
+void (*f2)() = B::f; // expected-error {{address of overloaded function 'f' does not match required type}}
+}