Introduce assign_modify_operation

This adds class assign_modify_operation, which implements
BINOP_ASSIGN_MODIFY.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* expop.h (class assign_modify_operation): New.
	* eval.c (eval_binop_assign_modify): No longer static.
	* ax-gdb.c (assign_modify_operation::do_generate_ax): New method.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6bf3cbf4594297c153f2e0785400d43af099ebdb..c260f04e48c73c988827c5ec9a082daeb5a7d71d 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2021-03-08  Tom Tromey  <tom@tromey.com>
+
+       * expop.h (class assign_modify_operation): New.
+       * eval.c (eval_binop_assign_modify): No longer static.
+       * ax-gdb.c (assign_modify_operation::do_generate_ax): New method.
+
 2021-03-08  Tom Tromey  <tom@tromey.com>
 
        * expop.h (class assign_operation): New.

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index d8b5ed78a407a9755e40292bed85194257e76d08..f81e5b9ad29ad9b1d5b9e7af041e2a779d0d1b73 100644 (file)
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2609,6 +2609,48 @@ assign_operation::do_generate_ax (struct expression *exp,
             "may not assign to it"), name);
 }
 
+void
+assign_modify_operation::do_generate_ax (struct expression *exp,
+                                        struct agent_expr *ax,
+                                        struct axs_value *value,
+                                        struct type *cast_type)
+{
+  operation *subop = std::get<1> (m_storage).get ();
+  if (subop->opcode () != OP_INTERNALVAR)
+    error (_("May only assign to trace state variables"));
+
+  internalvar_operation *ivarop
+    = dynamic_cast<internalvar_operation *> (subop);
+  gdb_assert (ivarop != nullptr);
+
+  const char *name = internalvar_name (ivarop->get_internalvar ());
+  struct trace_state_variable *tsv;
+
+  tsv = find_trace_state_variable (name);
+  if (tsv)
+    {
+      /* The tsv will be the left half of the binary operation.  */
+      ax_tsv (ax, aop_getv, tsv->number);
+      if (ax->tracing)
+       ax_tsv (ax, aop_tracev, tsv->number);
+      /* Trace state variables are always 64-bit integers.  */
+      struct axs_value value1, value2;
+      value1.kind = axs_rvalue;
+      value1.type = builtin_type (ax->gdbarch)->builtin_long_long;
+      /* Now do right half of expression.  */
+      std::get<2> (m_storage)->generate_ax (exp, ax, &value2);
+      gen_expr_binop_rest (exp, std::get<0> (m_storage), ax,
+                          value, &value1, &value2);
+      /* We have a result of the binary op, set the tsv.  */
+      ax_tsv (ax, aop_setv, tsv->number);
+      if (ax->tracing)
+       ax_tsv (ax, aop_tracev, tsv->number);
+    }
+  else
+    error (_("$%s is not a trace state variable, "
+            "may not assign to it"), name);
+}
+
 }
 
 /* This handles the middle-to-right-side of code generation for binary

diff --git a/gdb/eval.c b/gdb/eval.c
index f0bad85e951a76ae62c9cea408e4cb3e661174c8..4a7613565f11648dcaf4b395377eb7b583803886 100644 (file)
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -2074,7 +2074,7 @@ eval_op_type (struct type *expect_type, struct expression *exp,
 
 /* A helper function for BINOP_ASSIGN_MODIFY.  */
 
-static struct value *
+struct value *
 eval_binop_assign_modify (struct type *expect_type, struct expression *exp,
                          enum noside noside, enum exp_opcode op,
                          struct value *arg1, struct value *arg2)

diff --git a/gdb/expop.h b/gdb/expop.h
index 0f223654052e651602e57836814760d7e4e575d7..93af40d9591a39a749c49c963c474dbdc350d7d0 100644 (file)
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -197,6 +197,12 @@ extern struct value *eval_op_memval (struct type *expect_type,
                                     struct expression *exp,
                                     enum noside noside,
                                     struct value *arg1, struct type *type);
+extern struct value *eval_binop_assign_modify (struct type *expect_type,
+                                              struct expression *exp,
+                                              enum noside noside,
+                                              enum exp_opcode op,
+                                              struct value *arg1,
+                                              struct value *arg2);
 
 namespace expr
 {
@@ -1800,6 +1806,36 @@ protected:
     override;
 };
 
+/* Assignment with modification, like "+=".  */
+class assign_modify_operation
+  : public tuple_holding_operation<exp_opcode, operation_up, operation_up>
+{
+public:
+
+  using tuple_holding_operation::tuple_holding_operation;
+
+  value *evaluate (struct type *expect_type,
+                  struct expression *exp,
+                  enum noside noside) override
+  {
+    value *lhs = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+    value *rhs = std::get<2> (m_storage)->evaluate (expect_type, exp, noside);
+    return eval_binop_assign_modify (expect_type, exp, noside,
+                                    std::get<0> (m_storage), lhs, rhs);
+  }
+
+  enum exp_opcode opcode () const override
+  { return BINOP_ASSIGN_MODIFY; }
+
+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 */