Go patch committed: Reject duplicate bool keys in a map literal

[Ian Lance Taylor via Gcc-patches]

This patch to the Go frontend rejects duplicate bool keys in a map
literal.  This is hardly a common case, but we may as well get it
right.  This is for https://go.dev/issue/35945 and
htps://go.dev/issue/28104.  Bootstrapped and ran Go testsuite on
x86_64-pc-linux-gnu.  Committed to mainline.

Ian

374b3c936d62c8b6e7c607fdf6e84a83748e85c7
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index ef20a0aafd6..4559551ab7b 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-70ca85f08edf63f46c87d540fa99c45e2903edc2
+fbadca004b1e09db177c8e071706841038d1dd64
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/expressions.cc b/gcc/go/gofrontend/expressions.cc
index 1b3b3bf135e..dce48e03bf4 100644
--- a/gcc/go/gofrontend/expressions.cc
+++ b/gcc/go/gofrontend/expressions.cc
@@ -17266,6 +17266,8 @@ Composite_literal_expression::lower_map(Gogo* gogo, 
Named_object* function,
   Location location = this->location();
   Unordered_map(unsigned int, std::vector<Expression*>) st;
   Unordered_map(unsigned int, std::vector<Expression*>) nt;
+  bool saw_false = false;
+  bool saw_true = false;
   if (this->vals_ != NULL)
     {
       if (!this->has_keys_)
@@ -17300,6 +17302,7 @@ Composite_literal_expression::lower_map(Gogo* gogo, 
Named_object* function,
            continue;
          std::string sval;
          Numeric_constant nval;
+         bool bval;
          if ((*p)->string_constant_value(&sval)) // Check string keys.
            {
              unsigned int h = Gogo::hash_string(sval, 0);
@@ -17373,6 +17376,19 @@ Composite_literal_expression::lower_map(Gogo* gogo, 
Named_object* function,
                  mit->second.push_back(*p);
                }
            }
+         else if ((*p)->boolean_constant_value(&bval))
+           {
+             if ((bval && saw_true) || (!bval && saw_false))
+               {
+                 go_error_at((*p)->location(),
+                             "duplicate key in map literal");
+                 return Expression::make_error(location);
+               }
+             if (bval)
+               saw_true = true;
+             else
+               saw_false = true;
+           }
        }
     }