Nested struct list segfault

lib/unifex/app.ex

@@ -0,0 +1,11 @@
+defmodule Unifex.App do
+  @moduledoc false
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [Unifex.Counter]
+    opts = [strategy: :one_for_one, name: __MODULE__]
+    Supervisor.start_link(children, opts)
+  end
+end

lib/unifex/code_generator/base_types/list.ex

@@ -32,10 +32,12 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
 
   @impl true
   def generate_destruction(name, ctx) do
+    counter_value = Unifex.Counter.get_and_increment()
+
     ~g"""
     if(#{name} != NULL) {
-      for(unsigned int i = 0; i < #{name}_length; i++) {
-        #{BaseType.generate_destruction(ctx.subtype, :"#{name}[i]", ctx.generator, ctx)}
+      for(unsigned int i_#{counter_value} = 0; i_#{counter_value} < #{name}_length; i_#{counter_value}++) {
+        #{BaseType.generate_destruction(ctx.subtype, :"#{name}[i_#{counter_value}]", ctx.generator, ctx)}
       }
       unifex_free(#{name});
     }
@@ -49,13 +51,15 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
 
     @impl true
     def generate_arg_serialize(name, ctx) do
+      counter_value = Unifex.Counter.get_and_increment()
+
       ~g"""
       ({
         ERL_NIF_TERM list = enif_make_list(env, 0);
-        for(int i = #{name}_length-1; i >= 0; i--) {
+        for(int i_#{counter_value} = #{name}_length-1; i_#{counter_value} >= 0; i_#{counter_value}--) {
           list = enif_make_list_cell(
             env,
-            #{BaseType.generate_arg_serialize(ctx.subtype, :"#{name}[i]", ctx.generator, ctx)},
+            #{BaseType.generate_arg_serialize(ctx.subtype, :"#{name}[i_#{counter_value}]", ctx.generator, ctx)},
             list
           );
         }
@@ -66,6 +70,7 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
 
     @impl true
     def generate_arg_parse(arg, var_name, ctx) do
+      counter_value = Unifex.Counter.get_and_increment()
       elem_name = :"#{Unifex.CodeGenerator.Utils.sanitize_var_name("#{var_name}")}_i"
 
       len_var_name = "#{var_name}_length"
@@ -83,12 +88,12 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
         }
 
         ERL_NIF_TERM list = #{arg};
-        for(unsigned int i = 0; i < #{len_var_name}; i++) {
+        for(unsigned int i_#{counter_value} = 0; i_#{counter_value} < #{len_var_name}; i_#{counter_value}++) {
           ERL_NIF_TERM elem;
           enif_get_list_cell(env, list, &elem, &list);
-          #{native_type} #{elem_name} = #{var_name}[i];
+          #{native_type} #{elem_name} = #{var_name}[i_#{counter_value}];
           #{BaseType.generate_arg_parse(subtype, elem_name, ~g<elem>, postproc_fun, generator, ctx)}
-          #{var_name}[i] = #{elem_name};
+          #{var_name}[i_#{counter_value}] = #{elem_name};
         }
       }
       get_list_length_result;
@@ -104,11 +109,13 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
 
     @impl true
     def generate_arg_serialize(name, ctx) do
+      counter_value = Unifex.Counter.get_and_increment()
+
       ~g"""
       ({
         ei_x_encode_list_header(out_buff, #{name}_length);
-        for(unsigned int i = 0; i < #{name}_length; i++) {
-          #{BaseType.generate_arg_serialize(ctx.subtype, :"#{name}[i]", ctx.generator, ctx)}
+        for(unsigned int i_#{counter_value} = 0; i_#{counter_value} < #{name}_length; i_#{counter_value}++) {
+          #{BaseType.generate_arg_serialize(ctx.subtype, :"#{name}[i_#{counter_value}]", ctx.generator, ctx)}
         }
         ei_x_encode_empty_list(out_buff);
       });
@@ -117,7 +124,9 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
 
     @impl true
     def generate_arg_parse(arg, var_name, ctx) do
-      elem_name = :"#{var_name}[i]"
+      counter_value = Unifex.Counter.get_and_increment()
+
+      elem_name = :"#{var_name}[i_#{counter_value}]"
       len_var_name = "#{var_name}_length"
       native_type = BaseType.generate_native_type(ctx.subtype, ctx.generator, ctx)
       %{subtype: subtype, postproc_fun: postproc_fun, generator: generator} = ctx
@@ -131,34 +140,34 @@ defmodule Unifex.CodeGenerator.BaseTypes.List do
         #{len_var_name} = (unsigned int) size;
 
         int index = 0;
-        UnifexCNodeInBuff unifex_buff;
-        UnifexCNodeInBuff *unifex_buff_ptr = &unifex_buff;
+        UnifexCNodeInBuff unifex_buff_#{counter_value};
+        UnifexCNodeInBuff *unifex_buff_ptr_#{counter_value} = &unifex_buff_#{counter_value};
         if(type == ERL_STRING_EXT) {
           ei_x_buff buff = unifex_cnode_string_to_list(#{arg}, #{len_var_name});
-          unifex_buff.buff = buff.buff;
-          unifex_buff.index = &index;
+          unifex_buff_#{counter_value}.buff = buff.buff;
+          unifex_buff_#{counter_value}.index = &index;
         } else {
-          unifex_buff.buff = #{arg}->buff;
-          unifex_buff.index = #{arg}->index;
+          unifex_buff_#{counter_value}.buff = #{arg}->buff;
+          unifex_buff_#{counter_value}.index = #{arg}->index;
         }
-        int header_res = ei_decode_list_header(unifex_buff_ptr->buff, unifex_buff_ptr->index, &size);
+        int header_res = ei_decode_list_header(unifex_buff_ptr_#{counter_value}->buff, unifex_buff_ptr_#{counter_value}->index, &size);
         #{len_var_name} = (unsigned int) size;
         #{var_name} = (#{native_type} *)malloc(sizeof(#{native_type}) * #{len_var_name});
 
-        for(unsigned int i = 0; i < #{len_var_name}; i++) {
+        for(unsigned int i_#{counter_value} = 0; i_#{counter_value} < #{len_var_name}; i_#{counter_value}++) {
           #{BaseType.generate_initialization(subtype, elem_name, generator, ctx)}
         }
 
-        for(unsigned int i = 0; i < #{len_var_name}; i++) {
+        for(unsigned int i_#{counter_value} = 0; i_#{counter_value} < #{len_var_name}; i_#{counter_value}++) {
           #{BaseType.generate_arg_parse(subtype,
       elem_name,
-      "unifex_buff_ptr",
+      "unifex_buff_ptr_#{counter_value}",
       postproc_fun,
       generator,
       ctx)}
         }
         if(#{len_var_name}) {
-          header_res = ei_decode_list_header(unifex_buff_ptr->buff, unifex_buff_ptr->index, &size);
+          header_res = ei_decode_list_header(unifex_buff_ptr_#{counter_value}->buff, unifex_buff_ptr_#{counter_value}->index, &size);
         }
         header_res;
       })

lib/unifex/counter.ex

@@ -0,0 +1,14 @@
+defmodule Unifex.Counter do
+  @moduledoc false
+  use Agent
+
+  @spec start_link(any) :: Agent.on_start()
+  def start_link(_opts) do
+    Agent.start_link(fn -> 0 end, name: __MODULE__)
+  end
+
+  @spec get_and_increment() :: integer()
+  def get_and_increment do
+    Agent.get_and_update(__MODULE__, fn state -> {state, state + 1} end)
+  end
+end

mix.exs

@@ -28,7 +28,8 @@ defmodule Unifex.MixProject do
 
   def application do
     [
-      extra_applications: []
+      extra_applications: [],
+      mod: {Unifex.App, []}
     ]
   end