[COMMITTED 138/145] gccrs: Improve error messages for operator expressions

[arthur . cohen]

From: Antonio Gomes <antoniospg...@gmail.com>

gcc/rust/ChangeLog:
        * hir/tree/rust-hir-expr.h: Add new get_operator_str method in
        ArithmeticOrLogicalExpr and CompoundAssignmentExpr
        * hir/tree/rust-hir.cc: Likewise
        * typecheck/rust-hir-type-check-expr.cc: Improve error message for
        operator expressions to display the correct operator symbol

gcc/testsuite/ChangeLog:
        * rust/compile/shadow1.rs: Fix test for new error message

Signed-off-by: Antonio Gomes <antoniospg...@gmail.com>
---
 gcc/rust/hir/tree/rust-hir-expr.h             |  4 ++++
 gcc/rust/hir/tree/rust-hir.cc                 | 19 ++++++++++++++++---
 .../typecheck/rust-hir-type-check-expr.cc     |  6 ++++--
 gcc/testsuite/rust/compile/shadow1.rs         |  2 +-
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/gcc/rust/hir/tree/rust-hir-expr.h 
b/gcc/rust/hir/tree/rust-hir-expr.h
index d8cfe68bbc5..ff9fcee1a46 100644
--- a/gcc/rust/hir/tree/rust-hir-expr.h
+++ b/gcc/rust/hir/tree/rust-hir-expr.h
@@ -417,6 +417,8 @@ public:
   std::unique_ptr<Expr> &get_lhs () { return main_or_left_expr; }
   std::unique_ptr<Expr> &get_rhs () { return right_expr; }
 
+  std::string get_operator_str () const;
+
 protected:
   /* Use covariance to implement clone function as returning this object rather
    * than base */
@@ -766,6 +768,8 @@ public:
   void visit_lhs (HIRFullVisitor &vis) { main_or_left_expr->accept_vis (vis); }
   void visit_rhs (HIRFullVisitor &vis) { right_expr->accept_vis (vis); }
 
+  std::string get_operator_str () const;
+
 protected:
   /* Use covariance to implement clone function as returning this object rather
    * than base */
diff --git a/gcc/rust/hir/tree/rust-hir.cc b/gcc/rust/hir/tree/rust-hir.cc
index 8388d580f97..ac0a256fd47 100644
--- a/gcc/rust/hir/tree/rust-hir.cc
+++ b/gcc/rust/hir/tree/rust-hir.cc
@@ -1299,7 +1299,7 @@ AssignmentExpr::as_string () const
 }
 
 std::string
-CompoundAssignmentExpr::as_string () const
+CompoundAssignmentExpr::get_operator_str () const
 {
   std::string operator_str;
   operator_str.reserve (1);
@@ -1344,7 +1344,14 @@ CompoundAssignmentExpr::as_string () const
 
   operator_str += "=";
 
+  return operator_str;
+}
+
+std::string
+CompoundAssignmentExpr::as_string () const
+{
   std::string str ("CompoundAssignmentExpr: ");
+  std::string operator_str = get_operator_str ();
   if (main_or_left_expr == nullptr || right_expr == nullptr)
     {
       str += "error. this is probably a parsing failure.";
@@ -1574,7 +1581,7 @@ ErrorPropagationExpr::as_string () const
 }
 
 std::string
-ArithmeticOrLogicalExpr::as_string () const
+ArithmeticOrLogicalExpr::get_operator_str () const
 {
   std::string operator_str;
   operator_str.reserve (1);
@@ -1617,8 +1624,14 @@ ArithmeticOrLogicalExpr::as_string () const
       break;
     }
 
+  return operator_str;
+}
+
+std::string
+ArithmeticOrLogicalExpr::as_string () const
+{
   std::string str = main_or_left_expr->as_string () + " ";
-  str += operator_str + " ";
+  str += get_operator_str () + " ";
   str += right_expr->as_string ();
 
   return "( " + str + " (" + get_mappings ().as_string () + "))";
diff --git a/gcc/rust/typecheck/rust-hir-type-check-expr.cc 
b/gcc/rust/typecheck/rust-hir-type-check-expr.cc
index 7cbcdedbe4d..6212660e571 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-expr.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-expr.cc
@@ -272,7 +272,8 @@ TypeCheckExpr::visit (HIR::CompoundAssignmentExpr &expr)
   if (!valid)
     {
       rust_error_at (expr.get_locus (),
-                    "cannot apply this operator to types %s and %s",
+                    "cannot apply operator %qs to types %s and %s",
+                    expr.get_operator_str ().c_str (),
                     lhs->as_string ().c_str (), rhs->as_string ().c_str ());
       return;
     }
@@ -303,7 +304,8 @@ TypeCheckExpr::visit (HIR::ArithmeticOrLogicalExpr &expr)
   if (!valid)
     {
       rust_error_at (expr.get_locus (),
-                    "cannot apply this operator to types %s and %s",
+                    "cannot apply operator %qs to types %s and %s",
+                    expr.get_operator_str ().c_str (),
                     lhs->as_string ().c_str (), rhs->as_string ().c_str ());
       return;
     }
diff --git a/gcc/testsuite/rust/compile/shadow1.rs 
b/gcc/testsuite/rust/compile/shadow1.rs
index cef972adf33..43d2764a98d 100644
--- a/gcc/testsuite/rust/compile/shadow1.rs
+++ b/gcc/testsuite/rust/compile/shadow1.rs
@@ -2,5 +2,5 @@ fn main() {
     let mut x = 5;
     let mut x;
     x = true;
-    x = x + 2; // { dg-error "cannot apply this operator to types bool and 
<integer>"  }
+    x = x + 2; // { dg-error "cannot apply operator .+. to types bool and 
<integer>"  }
 }
-- 
2.45.2