[SEH] Defer checking filter expression types until instantiaton

[rnk]

Summary

While here, wordsmith the error a bit. Now clang says:

error: filter expression has non-integral type 'Foo'

Fixes PR43779

[amccarth]

LGTM.

clang/include/clang/Basic/DiagnosticSemaKinds.td

def err_unknown_any_addrof_call : Error<
   "address-of operator cannot be applied to a call to a function with "
   "unknown return type">;
 def err_unknown_any_var_function_type : Error<
   "variable %0 with unknown type cannot be given a function type">;
 def err_unknown_any_function : Error<
   "function %0 with unknown type must be given a function type">;
 
 def err_filter_expression_integral : Error<
-  "filter expression type should be an integral value not %0">;
+  "filter expression has non-integral type %0">;
 
 def err_non_asm_stmt_in_naked_function : Error<
   "non-ASM statement in naked function is not supported">;
 def err_asm_naked_this_ref : Error<
   "'this' pointer references not allowed in naked functions">;
 def err_asm_naked_parm_ref : Error<
   "parameter references not allowed in naked functions">;
 

clang/lib/Sema/SemaStmt.cpp

StmtResult Sema::ActOnSEHTryBlock(bool IsCXXTry, SourceLocation TryLoc,
 
   // Reject __try on unsupported targets.
   if (!Context.getTargetInfo().isSEHTrySupported())
     Diag(TryLoc, diag::err_seh_try_unsupported);
 
   return SEHTryStmt::Create(Context, IsCXXTry, TryLoc, TryBlock, Handler);
 }
 
-StmtResult
-Sema::ActOnSEHExceptBlock(SourceLocation Loc,
-                          Expr *FilterExpr,
+StmtResult Sema::ActOnSEHExceptBlock(SourceLocation Loc, Expr *FilterExpr,
                                      Stmt *Block) {
   assert(FilterExpr && Block);
-
-  if(!FilterExpr->getType()->isIntegerType()) {
-    return StmtError(Diag(FilterExpr->getExprLoc(),
-                     diag::err_filter_expression_integral)
-                     << FilterExpr->getType());
+  QualType FTy = FilterExpr->getType();
+  if (!FTy->isIntegerType() && !FTy->isDependentType()) {
+    return StmtError(
+        Diag(FilterExpr->getExprLoc(), diag::err_filter_expression_integral)
+        << FTy);
   }
-
-  return SEHExceptStmt::Create(Context,Loc,FilterExpr,Block);
+  return SEHExceptStmt::Create(Context, Loc, FilterExpr, Block);
 }
 
 void Sema::ActOnStartSEHFinallyBlock() {
   CurrentSEHFinally.push_back(CurScope);
 }
 
 void Sema::ActOnAbortSEHFinallyBlock() {
   CurrentSEHFinally.pop_back();

clang/test/Sema/__try.c

void TEST() {
 
   }
 }
 
 void TEST() {
   __try {
 
   }
-  __except ( NotFilterExpression() ) { // expected-error{{filter expression type should be an integral value not 'const char *'}}
+  __except ( NotFilterExpression() ) { // expected-error{{filter expression has non-integral type 'const char *'}}
 
   }
 }
 
 void TEST() {
   int function_scope = 0;
   __try {
     int try_scope = 0;

clang/test/SemaCXX/exceptions-seh.cpp

 };
 
 void (^use_cxx_in_global_block)() = ^{
   try {
     might_crash();
   } catch(int) {
   }
 };
+
+template <class T> void dependent_filter() {
+  __try {
+    might_crash();
+  } __except (T()) { // expected-error {{filter expression has non-integral type 'NotInteger'}}
+  }
+}
+
+struct NotInteger { int x; };
+
+void instantiate_dependent_filter() {
+  dependent_filter<int>();
+  dependent_filter<NotInteger>(); // expected-note {{requested here}}
+}