Add type check on if-expr

gcc/rust/typecheck/rust-hir-type-check-expr.cc

@@ -475,9 +475,18 @@ TypeCheckExpr::visit (HIR::IfExpr &expr)
 				    expr.get_if_condition ().get_locus ()),
 	      expr.get_locus ());
 
-  TypeCheckExpr::Resolve (expr.get_if_block ());
+  TyTy::BaseType *block_type = TypeCheckExpr::Resolve (expr.get_if_block ());
 
-  infered = TyTy::TupleType::get_unit_type ();
+  TyTy::BaseType *unit_ty = nullptr;
+  ok = context->lookup_builtin ("()", &unit_ty);
+  rust_assert (ok);
+
+  infered
+    = coercion_site (expr.get_mappings ().get_hirid (),
+		     TyTy::TyWithLocation (unit_ty),
+		     TyTy::TyWithLocation (block_type,
+					   expr.get_if_block ().get_locus ()),
+		     expr.get_locus ());
 }
 
 void
@@ -1584,7 +1593,7 @@ TypeCheckExpr::visit (HIR::ClosureExpr &expr)
   TyTy::TyVar result_type
     = expr.has_return_type ()
 	? TyTy::TyVar (
-	  TypeCheckType::Resolve (expr.get_return_type ())->get_ref ())
+	    TypeCheckType::Resolve (expr.get_return_type ())->get_ref ())
 	: TyTy::TyVar::get_implicit_infer_var (expr.get_locus ());
 
   // resolve the block

gcc/testsuite/rust/compile/if-without-else.rs

@@ -0,0 +1,9 @@
+fn foo(pred: bool) -> u8 {
+    if pred { // { dg-error "mismatched types" }
+        1
+    }
+    3
+}
+
+fn main(){
+}

gcc/testsuite/rust/compile/implicit_returns_err3.rs

@@ -1,6 +1,6 @@
 fn test(x: i32) -> i32 { // { dg-error "mismatched types, expected .i32. but got ...." }
     if x > 1 {
-        1
+        return 1;
     }
 }
 

gcc/testsuite/rust/compile/torture/if.rs

@@ -4,6 +4,10 @@ fn foo() -> bool {
 
 fn bar() {}
 
+fn baz(a: i32) {
+    a;
+}
+
 struct Foo1 {
     one: i32
 }
@@ -13,7 +17,7 @@ fn main() {
     if foo() {
         bar();
         let a = Foo1{one: 1};
-        a.one
+        baz (a.one);
     }
 
-}
+}