[PATCH 137/203] Implement the "&&" and "||" operators

[Tom Tromey]

This implements the "&&" and "||" operators.

gdb/ChangeLog
2021-01-01  Tom Tromey  <tom@tromey.com>

	* expop.h (class logical_and_operation)
	(class logical_or_operation): New.
	* eval.c (logical_and_operation::evaluate)
	(logical_or_operation::evaluate): New methods.
	* ax-gdb.c (logical_and_operation::do_generate_ax)
	(logical_or_operation::do_generate_ax): New methods.
---
 gdb/ChangeLog |  9 ++++++++
 gdb/ax-gdb.c  | 56 +++++++++++++++++++++++++++++++++++++++++++++
 gdb/eval.c    | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
 gdb/expop.h   | 48 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 176 insertions(+)

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index bdf4a6dc39a..8ec3dd7cc3d 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2693,6 +2693,62 @@ var_value_operation::do_generate_ax (struct expression *exp,
     }
 }
 
+void
+logical_and_operation::do_generate_ax (struct expression *exp,
+				       struct agent_expr *ax,
+				       struct axs_value *value,
+				       struct type *cast_type)
+{
+  struct axs_value value1, value2;
+  int if1, go1, if2, go2, end;
+
+  /* Generate the obvious sequence of tests and jumps.  */
+  std::get<0> (m_storage)->generate_ax (exp, ax, &value1);
+  gen_usual_unary (ax, &value1);
+  if1 = ax_goto (ax, aop_if_goto);
+  go1 = ax_goto (ax, aop_goto);
+  ax_label (ax, if1, ax->len);
+  std::get<1> (m_storage)->generate_ax (exp, ax, &value2);
+  gen_usual_unary (ax, &value2);
+  if2 = ax_goto (ax, aop_if_goto);
+  go2 = ax_goto (ax, aop_goto);
+  ax_label (ax, if2, ax->len);
+  ax_const_l (ax, 1);
+  end = ax_goto (ax, aop_goto);
+  ax_label (ax, go1, ax->len);
+  ax_label (ax, go2, ax->len);
+  ax_const_l (ax, 0);
+  ax_label (ax, end, ax->len);
+  value->kind = axs_rvalue;
+  value->type = builtin_type (ax->gdbarch)->builtin_int;
+}
+
+void
+logical_or_operation::do_generate_ax (struct expression *exp,
+				      struct agent_expr *ax,
+				      struct axs_value *value,
+				      struct type *cast_type)
+{
+  struct axs_value value1, value2;
+  int if1, if2, end;
+
+  /* Generate the obvious sequence of tests and jumps.  */
+  std::get<0> (m_storage)->generate_ax (exp, ax, &value1);
+  gen_usual_unary (ax, &value1);
+  if1 = ax_goto (ax, aop_if_goto);
+  std::get<1> (m_storage)->generate_ax (exp, ax, &value2);
+  gen_usual_unary (ax, &value2);
+  if2 = ax_goto (ax, aop_if_goto);
+  ax_const_l (ax, 0);
+  end = ax_goto (ax, aop_goto);
+  ax_label (ax, if1, ax->len);
+  ax_label (ax, if2, ax->len);
+  ax_const_l (ax, 1);
+  ax_label (ax, end, ax->len);
+  value->kind = axs_rvalue;
+  value->type = builtin_type (ax->gdbarch)->builtin_int;
+}
+
 }
 
 /* This handles the middle-to-right-side of code generation for binary
diff --git a/gdb/eval.c b/gdb/eval.c
index b1087d1329d..495cd4b26a3 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -2461,6 +2461,69 @@ multi_subscript_operation::evaluate (struct type *expect_type,
 			       gdb::make_array_view (argvec, values.size ()));
 }
 
+value *
+logical_and_operation::evaluate (struct type *expect_type,
+				 struct expression *exp,
+				 enum noside noside)
+{
+  value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
+  if (noside == EVAL_SKIP)
+    return eval_skip_value (exp);
+
+  value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp,
+						   EVAL_AVOID_SIDE_EFFECTS);
+
+  if (binop_user_defined_p (BINOP_LOGICAL_AND, arg1, arg2))
+    {
+      arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+      return value_x_binop (arg1, arg2, BINOP_LOGICAL_AND, OP_NULL, noside);
+    }
+  else
+    {
+      int tem = value_logical_not (arg1);
+      if (!tem)
+	{
+	  arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+	  tem = value_logical_not (arg2);
+	}
+      struct type *type = language_bool_type (exp->language_defn,
+					      exp->gdbarch);
+      return value_from_longest (type, !tem);
+    }
+}
+
+value *
+logical_or_operation::evaluate (struct type *expect_type,
+				struct expression *exp,
+				enum noside noside)
+{
+  value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
+  if (noside == EVAL_SKIP)
+    return eval_skip_value (exp);
+
+  value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp,
+						   EVAL_AVOID_SIDE_EFFECTS);
+
+  if (binop_user_defined_p (BINOP_LOGICAL_OR, arg1, arg2))
+    {
+      arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+      return value_x_binop (arg1, arg2, BINOP_LOGICAL_OR, OP_NULL, noside);
+    }
+  else
+    {
+      int tem = value_logical_not (arg1);
+      if (tem)
+	{
+	  arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+	  tem = value_logical_not (arg2);
+	}
+
+      struct type *type = language_bool_type (exp->language_defn,
+					      exp->gdbarch);
+      return value_from_longest (type, !tem);
+    }
+}
+
 }
 
 struct value *
diff --git a/gdb/expop.h b/gdb/expop.h
index 21c7b9e25da..f858f591baf 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -1979,6 +1979,54 @@ class multi_subscript_operation
   { return MULTI_SUBSCRIPT; }
 };
 
+/* The "&&" operator.  */
+class logical_and_operation
+  : public maybe_constant_operation<operation_up, operation_up>
+{
+public:
+
+  using maybe_constant_operation::maybe_constant_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override;
+
+  enum exp_opcode opcode () const override
+  { return BINOP_LOGICAL_AND; }
+
+protected:
+
+  void do_generate_ax (struct expression *exp,
+		       struct agent_expr *ax,
+		       struct axs_value *value,
+		       struct type *cast_type)
+    override;
+};
+
+/* The "||" operator.  */
+class logical_or_operation
+  : public maybe_constant_operation<operation_up, operation_up>
+{
+public:
+
+  using maybe_constant_operation::maybe_constant_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override;
+
+  enum exp_opcode opcode () const override
+  { return BINOP_LOGICAL_OR; }
+
+protected:
+
+  void do_generate_ax (struct expression *exp,
+		       struct agent_expr *ax,
+		       struct axs_value *value,
+		       struct type *cast_type)
+    override;
+};
+
 } /* namespace expr */
 
 #endif /* EXPOP_H */
-- 
2.26.2