Merge branch 'supported-chains-env-var' of github.com:poanetwork/blockscout into supported-chains-env-var

CHANGELOG.md

@@ -21,6 +21,9 @@
 - [#1869](https://github.com/poanetwork/blockscout/pull/1869) - Fix output and gas extraction in JS tracer for Geth
 - [#1868](https://github.com/poanetwork/blockscout/pull/1868) - fix: logs list endpoint performance
 - [#1822](https://github.com/poanetwork/blockscout/pull/1822) - Fix style breaks in decompiled contract code view
+- [#1885](https://github.com/poanetwork/blockscout/pull/1885) - highlight reserved words in decompiled code
+- [#1896](https://github.com/poanetwork/blockscout/pull/1896) - re-query tokens in top nav automplete
+- [#1881](https://github.com/poanetwork/blockscout/pull/1881) - fix: store solc versions locally for performance
 
 ### Chore
 
@@ -204,4 +207,3 @@
  - [https://github.com/poanetwork/blockscout/pull/1532](https://github.com/poanetwork/blockscout/pull/1532) - Upgrade elixir to 1.8.1
  - [https://github.com/poanetwork/blockscout/pull/1553](https://github.com/poanetwork/blockscout/pull/1553) - Dockerfile: remove 1.7.1 version pin FROM bitwalker/alpine-elixir-phoenix
  - [https://github.com/poanetwork/blockscout/pull/1465](https://github.com/poanetwork/blockscout/pull/1465) - Resolve lodash security alert
-

README.md

@@ -139,7 +139,7 @@ The [development stack page](https://github.com/poanetwork/blockscout/wiki/Devel
       ```
       * If using Chrome, Enable `chrome://flags/#allow-insecure-localhost`.
 
-  9. Start Phoenix Server.
+  9. Run the Phoenix Server from the root directory of your application.
   `mix phx.server`
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.

apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex

@@ -112,9 +112,8 @@
                   "data-test": "search_input"
                   ],
                   [ url: "#{chain_path(@conn, :token_autocomplete)}?q=",
-                  prepop: true,
-                  minChars: 3,
-                  maxItems: 8,
+                  limit: 0,
+                  minChars: 2,
                   value: "contract_address_hash",
                   label: "contract_address_hash",
                   descrSearch: true,

apps/block_scout_web/lib/block_scout_web/views/address_decompiled_contract_view.ex

@@ -2,51 +2,231 @@ defmodule BlockScoutWeb.AddressDecompiledContractView do
   use BlockScoutWeb, :view
 
   @colors %{
-    "\e[95m" => "136, 0, 0",
+    "\e[95m" => "",
     # red
-    "\e[91m" => "236, 89, 58",
+    "\e[91m" => "",
     # gray
-    "\e[38;5;8m" => "111, 110, 111",
+    "\e[38;5;8m" => "<span style=\"color:rgb(111, 110, 111)\">",
     # green
-    "\e[32m" => "57, 115, 0",
+    "\e[32m" => "",
     # yellowgreen
-    "\e[93m" => "57, 115, 0",
+    "\e[93m" => "",
     # yellow
-    "\e[92m" => "119, 232, 81",
+    "\e[92m" => "",
     # red
-    "\e[94m" => "136, 0, 0"
+    "\e[94m" => ""
   }
 
+  @comment_start "#"
+
+  @reserved_words_types [
+    "var",
+    "bool",
+    "string",
+    "int",
+    "uint",
+    "int8",
+    "uint8",
+    "int16",
+    "uint16",
+    "int24",
+    "uint24",
+    "int32",
+    "uint32",
+    "int40",
+    "uint40",
+    "int48",
+    "uint48",
+    "int56",
+    "uint56",
+    "int64",
+    "uint64",
+    "int72",
+    "uint72",
+    "int80",
+    "uint80",
+    "int88",
+    "uint88",
+    "int96",
+    "uint96",
+    "int104",
+    "uint104",
+    "int112",
+    "uint112",
+    "int120",
+    "uint120",
+    "int128",
+    "uint128",
+    "int136",
+    "uint136",
+    "int144",
+    "uint144",
+    "int152",
+    "uint152",
+    "int160",
+    "uint160",
+    "int168",
+    "uint168",
+    "int176",
+    "uint176",
+    "int184",
+    "uint184",
+    "int192",
+    "uint192",
+    "int200",
+    "uint200",
+    "int208",
+    "uint208",
+    "int216",
+    "uint216",
+    "int224",
+    "uint224",
+    "int232",
+    "uint232",
+    "int240",
+    "uint240",
+    "int248",
+    "uint248",
+    "int256",
+    "uint256",
+    "byte",
+    "bytes",
+    "bytes1",
+    "bytes2",
+    "bytes3",
+    "bytes4",
+    "bytes5",
+    "bytes6",
+    "bytes7",
+    "bytes8",
+    "bytes9",
+    "bytes10",
+    "bytes11",
+    "bytes12",
+    "bytes13",
+    "bytes14",
+    "bytes15",
+    "bytes16",
+    "bytes17",
+    "bytes18",
+    "bytes19",
+    "bytes20",
+    "bytes21",
+    "bytes22",
+    "bytes23",
+    "bytes24",
+    "bytes25",
+    "bytes26",
+    "bytes27",
+    "bytes28",
+    "bytes29",
+    "bytes30",
+    "bytes31",
+    "bytes32",
+    "true",
+    "false",
+    "enum",
+    "struct",
+    "mapping",
+    "address"
+  ]
+
+  @reserved_words_keywords [
+    "def",
+    "require",
+    "revert",
+    "return",
+    "assembly",
+    "memory",
+    "mem"
+  ]
+
+  @modifiers [
+    "payable",
+    "public",
+    "view",
+    "pure",
+    "returns",
+    "internal"
+  ]
+
+  @reserved_words @reserved_words_keywords ++ @reserved_words_types
+
+  @reserved_words_regexp ([@comment_start | @reserved_words] ++ @modifiers)
+                         |> Enum.reduce("", fn el, acc -> acc <> "|" <> el end)
+                         |> Regex.compile!()
+
   def highlight_decompiled_code(code) do
     {_, result} =
       @colors
       |> Enum.reduce(code, fn {symbol, rgb}, acc ->
-        String.replace(acc, symbol, "<span style=\"color:rgb(#{rgb})\">")
+        String.replace(acc, symbol, rgb)
       end)
       |> String.replace("\e[1m", "<span style=\"font-weight:bold\">")
       |> String.replace("»", "&raquo;")
       |> String.replace("\e[0m", "</span>")
       |> String.split(~r/\<span style=.*?\)"\>|\<\/span\>/, include_captures: true, trim: true)
-      |> Enum.reduce({"", []}, fn part, {style, acc} ->
-        new_style =
-          cond do
-            String.contains?(part, "<span style") -> part
-            part == "</span>" -> ""
-            true -> style
-          end
-
-        new_part = new_part(part, new_style)
-
-        {new_style, [new_part | acc]}
-      end)
+      |> add_styles_to_every_line()
 
     result
     |> Enum.reduce("", fn part, acc ->
       part <> acc
     end)
+    |> add_styles_to_reserved_words()
     |> add_line_numbers()
   end
 
+  defp add_styles_to_every_line(lines) do
+    lines
+    |> Enum.reduce({"", []}, fn part, {style, acc} ->
+      new_style =
+        cond do
+          String.contains?(part, "<span style") -> part
+          part == "</span>" -> ""
+          true -> style
+        end
+
+      new_part = new_part(part, new_style)
+
+      {new_style, [new_part | acc]}
+    end)
+  end
+
+  defp add_styles_to_reserved_words(code) do
+    code
+    |> String.split("\n")
+    |> Enum.map(fn line ->
+      add_styles_to_line(line)
+    end)
+    |> Enum.reduce("", fn el, acc ->
+      acc <> el <> "\n"
+    end)
+  end
+
+  defp add_styles_to_line(line) do
+    parts =
+      line
+      |> String.split(@reserved_words_regexp,
+        include_captures: true
+      )
+
+    comment_position = Enum.find_index(parts, fn part -> part == "#" end)
+
+    parts
+    |> Enum.with_index()
+    |> Enum.map(fn {el, index} ->
+      cond do
+        !(is_nil(comment_position) || comment_position > index) -> el
+        el in @reserved_words -> "<span class=\"hljs-keyword\">" <> el <> "</span>"
+        el in @modifiers -> "<span class=\"hljs-title\">" <> el <> "</span>"
+        true -> el
+      end
+    end)
+    |> Enum.reduce("", fn el, acc ->
+      acc <> el
+    end)
+  end
+
   def sort_contracts_by_version(decompiled_contracts) do
     decompiled_contracts
     |> Enum.sort_by(& &1.decompiler_version)
@@ -76,18 +256,12 @@ defmodule BlockScoutWeb.AddressDecompiledContractView do
         part
 
       true ->
-        result =
-          part
-          |> String.split("\n")
-          |> Enum.reduce("", fn p, a ->
-            a <> new_style <> p <> "</span>\n"
-          end)
-
-        if String.ends_with?(part, "\n") do
-          result
-        else
-          String.slice(result, 0..-2)
-        end
+        part
+        |> String.split("\n")
+        |> Enum.reduce("", fn p, a ->
+          a <> new_style <> p <> "</span>\n"
+        end)
+        |> String.slice(0..-2)
     end
   end
 end

apps/block_scout_web/priv/gettext/default.pot

@@ -714,7 +714,7 @@ msgstr ""
 
 #, elixir-format
 #: lib/block_scout_web/templates/layout/_topnav.html.eex:111
-#: lib/block_scout_web/templates/layout/_topnav.html.eex:129
+#: lib/block_scout_web/templates/layout/_topnav.html.eex:128
 msgid "Search"
 msgstr ""
 

apps/block_scout_web/priv/gettext/en/LC_MESSAGES/default.po

@@ -714,7 +714,7 @@ msgstr ""
 
 #, elixir-format
 #: lib/block_scout_web/templates/layout/_topnav.html.eex:111
-#: lib/block_scout_web/templates/layout/_topnav.html.eex:129
+#: lib/block_scout_web/templates/layout/_topnav.html.eex:128
 msgid "Search"
 msgstr ""
 

apps/block_scout_web/test/block_scout_web/views/address_decompiled_contract_view_test.exs

@@ -56,7 +56,7 @@ defmodule BlockScoutWeb.AddressDecompiledContractViewTest do
       result = AddressDecompiledContractView.highlight_decompiled_code(code)
 
       assert result ==
-               "<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  eveem.org 6 Feb 2019</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Decompiled source of </span>0x00Bd9e214FAb74d6fC21bf1aF34261765f57e875<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Let's make the world open source</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  # </span></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  I failed with these:</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  </span><span style=\"color:rgb(111, 110, 111)\">#  - </span><span style=\"color:rgb(236, 89, 58)\">unknowne77c646d(?)</span><span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  </span><span style=\"color:rgb(111, 110, 111)\">#  - </span><span style=\"color:rgb(236, 89, 58)\">transferFromWithData(address _from, address _to, uint256 _value, bytes _data)</span><span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  All the rest is below.</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#  Storage definitions and getters</span></code>\n<code></code>\n<code>  <span style=\"color:rgb(57, 115, 0)\">def</span> storage:</code>\n<code>    <span style=\"color:rgb(57, 115, 0)\">allowance</span> is uint256 => uint256 <span style=\"color:rgb(111, 110, 111)\"># mask(256, 0) at storage #2</span></code>\n<code>    <span style=\"color:rgb(57, 115, 0)\">stor4</span> is uint256 => uint8 <span style=\"color:rgb(111, 110, 111)\"># mask(8, 0) at storage #4</span></code>\n<code></code>\n<code>  <span style=\"color:rgb(136, 0, 0)\">def </span>allowance(address <span style=\"color:rgb(57, 115, 0)\">_owner</span>, address <span style=\"color:rgb(57, 115, 0)\">_spender</span>) <span style=\"color:rgb(136, 0, 0)\">payable</span>: 64</code>\n<code>    return <span style=\"color:rgb(57, 115, 0)\">allowance</span><span style=\"color:rgb(57, 115, 0)\">[</span>sha3(((320 - 1)<span style=\"font-weight:bold\"> and </span>(320 - 1)<span style=\"font-weight:bold\"> and </span><span style=\"color:rgb(57, 115, 0)\">_owner</span>), 1), ((320 - 1)<span style=\"font-weight:bold\"> and </span><span style=\"color:rgb(57, 115, 0)\">_spender</span><span style=\"font-weight:bold\"> and </span>(320 - 1))<span style=\"color:rgb(57, 115, 0)\">]</span></code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Regular functions - see Tutorial for understanding quirks of the code</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\"># folder failed in this function - may be terribly long, sorry</span></code>\n<code>  <span style=\"color:rgb(136, 0, 0)\">def </span>unknownc47d033b(?) <span style=\"color:rgb(136, 0, 0)\">payable</span>: not cd[4]:</code>\n<code>            revert</code>\n<code>        else:</code>\n<code>            <span style=\"color:rgb(136, 0, 0)\">mem[</span>0<span style=\"color:rgb(136, 0, 0)\">]</span>cd[4]</code>\n<code>            <span style=\"color:rgb(136, 0, 0)\">mem[</span>32<span style=\"color:rgb(136, 0, 0)\">]</span> = 4</code>\n<code>            <span style=\"color:rgb(136, 0, 0)\">mem[</span>96<span style=\"color:rgb(136, 0, 0)\">]</span> = bool(<span style=\"color:rgb(57, 115, 0)\">stor4</span><span style=\"color:rgb(57, 115, 0)\">[</span>((320 - 1)<span style=\"font-weight:bold\"> and </span>(320 - 1)<span style=\"font-weight:bold\"> and </span>cd[4])<span style=\"color:rgb(57, 115, 0)\">]</span>)</code>\n<code>            return bool(<span style=\"color:rgb(57, 115, 0)\">stor4</span><span style=\"color:rgb(57, 115, 0)\">[</span>((320 - 1)<span style=\"font-weight:bold\"> and </span>(320 - 1)<span style=\"font-weight:bold\"> and </span>cd[4])<span style=\"color:rgb(57, 115, 0)\">]</span>)</code>\n<code></code>\n<code>  <span style=\"color:rgb(136, 0, 0)\">def </span>_fallback() <span style=\"color:rgb(136, 0, 0)\">payable</span>: <span style=\"color:rgb(111, 110, 111)\"># default function</span></code>\n<code>    revert</code>\n<code></code>\n"
+               "<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  eveem.org 6 Feb 2019</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Decompiled source of </span>0x00Bd9e214FAb74d6fC21bf1aF34261765f57e875<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Let's make the world open source</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  # </span></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  I failed with these:</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  </span><span style=\"color:rgb(111, 110, 111)\">#  - </span>unknowne77c646d(?)<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  </span><span style=\"color:rgb(111, 110, 111)\">#  - </span>transferFromWithData(address _from, address _to, uint256 _value, bytes _data)<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  All the rest is below.</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#  Storage definitions and getters</span></code>\n<code></code>\n<code>  <span class=\"hljs-keyword\">def</span> storage:</code>\n<code>    allowance is <span class=\"hljs-keyword\">uint</span>256 => <span class=\"hljs-keyword\">uint</span>256 <span style=\"color:rgb(111, 110, 111)\"># mask(256, 0) at storage #2</span></code>\n<code>    stor4 is <span class=\"hljs-keyword\">uint</span>256 => <span class=\"hljs-keyword\">uint</span>8 <span style=\"color:rgb(111, 110, 111)\"># mask(8, 0) at storage #4</span></code>\n<code></code>\n<code>  <span class=\"hljs-keyword\">def</span> allowance(<span class=\"hljs-keyword\">address</span> _owner, <span class=\"hljs-keyword\">address</span> _spender) <span class=\"hljs-title\">payable</span>: 64</code>\n<code>    <span class=\"hljs-keyword\">return</span> allowance[_owner_spender(320 - 1))]</code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Regular functions - see Tutorial for understanding quirks of the code</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code></code>\n<code></code>\n<code>  <span style=\"color:rgb(111, 110, 111)\"># folder failed in this function - may be terribly long, sorry</span></code>\n<code>  <span class=\"hljs-keyword\">def</span> unknownc47d033b(?) <span class=\"hljs-title\">payable</span>: not cd[4]:</code>\n<code>            <span class=\"hljs-keyword\">revert</span></code>\n<code>        else:</code>\n<code>            <span class=\"hljs-keyword\">mem</span>[0]cd[4]</code>\n<code>            <span class=\"hljs-keyword\">mem</span>[32] = 4</code>\n<code>            <span class=\"hljs-keyword\">mem</span>[96] = <span class=\"hljs-keyword\">bool</span>(stor4[cd[4])])</code>\n<code>            <span class=\"hljs-keyword\">return</span> <span class=\"hljs-keyword\">bool</span>(stor4[cd[4])])</code>\n<code></code>\n<code>  <span class=\"hljs-keyword\">def</span> _fallback() <span class=\"hljs-title\">payable</span>: <span style=\"color:rgb(111, 110, 111)\"># default function</span></code>\n<code>    <span class=\"hljs-keyword\">revert</span></code>\n<code></code>\n<code></code>\n"
     end
 
     test "adds style span to every line" do
@@ -70,7 +70,7 @@ defmodule BlockScoutWeb.AddressDecompiledContractViewTest do
       """
 
       assert AddressDecompiledContractView.highlight_decompiled_code(code) ==
-               "<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  eveem.org 6 Feb 2019</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Decompiled source of </span>0x00Bd9e214FAb74d6fC21bf1aF34261765f57e875<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Let's make the world open source</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  # </span></code>\n<code></code>\n"
+               "<code>  <span style=\"color:rgb(111, 110, 111)\">#</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  eveem.org 6 Feb 2019</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Decompiled source of </span>0x00Bd9e214FAb74d6fC21bf1aF34261765f57e875<span style=\"color:rgb(111, 110, 111)\"></span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  #  Let's make the world open source</span></code>\n<code><span style=\"color:rgb(111, 110, 111)\">  # </span></code>\n<code></code>\n<code></code>\n"
     end
   end
 

apps/explorer/.gitignore

@@ -1 +1,2 @@
 priv/.recovery
+priv/solc_compilers/

apps/explorer/lib/explorer/application.ex

@@ -26,6 +26,7 @@ defmodule Explorer.Application do
       Supervisor.Spec.worker(SpandexDatadog.ApiServer, [datadog_opts()]),
       Supervisor.child_spec({Task.Supervisor, name: Explorer.MarketTaskSupervisor}, id: Explorer.MarketTaskSupervisor),
       Supervisor.child_spec({Task.Supervisor, name: Explorer.TaskSupervisor}, id: Explorer.TaskSupervisor),
+      Explorer.SmartContract.SolcDownloader,
       {Registry, keys: :duplicate, name: Registry.ChainEvents, id: Registry.ChainEvents},
       {Admin.Recovery, [[], [name: Admin.Recovery]]},
       {TransactionCountCache, [[], []]}

apps/explorer/lib/explorer/smart_contract/solc_downloader.ex

@@ -0,0 +1,92 @@
+defmodule Explorer.SmartContract.SolcDownloader do
+  @moduledoc """
+  Checks to see if the requested solc compiler version exists, and if not it
+  downloads and stores the file.
+  """
+  use GenServer
+
+  alias Explorer.SmartContract.Solidity.CompilerVersion
+
+  @latest_compiler_refetch_time :timer.minutes(30)
+
+  def ensure_exists(version) do
+    path = file_path(version)
+
+    if File.exists?(path) do
+      path
+    else
+      {:ok, compiler_versions} = CompilerVersion.fetch_versions()
+
+      if version in compiler_versions do
+        GenServer.call(__MODULE__, {:ensure_exists, version}, 60_000)
+      else
+        false
+      end
+    end
+  end
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  # sobelow_skip ["Traversal"]
+  @impl true
+  def init([]) do
+    File.mkdir(compiler_dir())
+
+    {:ok, []}
+  end
+
+  # sobelow_skip ["Traversal"]
+  @impl true
+  def handle_call({:ensure_exists, version}, _from, state) do
+    path = file_path(version)
+
+    if fetch?(version, path) do
+      temp_path = file_path("#{version}-tmp")
+
+      contents = download(version)
+
+      file = File.open!(temp_path, [:write, :exclusive])
+
+      IO.binwrite(file, contents)
+
+      File.rename(temp_path, path)
+    end
+
+    {:reply, path, state}
+  end
+
+  defp fetch?("latest", path) do
+    case File.stat(path) do
+      {:error, :enoent} ->
+        true
+
+      {:ok, %{mtime: mtime}} ->
+        last_modified = NaiveDateTime.from_erl!(mtime)
+        diff = Timex.diff(NaiveDateTime.utc_now(), last_modified, :milliseconds)
+
+        diff > @latest_compiler_refetch_time
+    end
+  end
+
+  defp fetch?(_, path) do
+    not File.exists?(path)
+  end
+
+  defp file_path(version) do
+    Path.join(compiler_dir(), "#{version}.js")
+  end
+
+  defp compiler_dir do
+    Application.app_dir(:explorer, "priv/solc_compilers/")
+  end
+
+  defp download(version) do
+    download_path = "https://ethereum.github.io/solc-bin/bin/soljson-#{version}.js"
+
+    download_path
+    |> HTTPoison.get!([], timeout: 60_000)
+    |> Map.get(:body)
+  end
+end

apps/explorer/lib/explorer/smart_contract/solidity/code_compiler.ex

@@ -3,6 +3,8 @@ defmodule Explorer.SmartContract.Solidity.CodeCompiler do
   Module responsible to compile the Solidity code of a given Smart Contract.
   """
 
+  alias Explorer.SmartContract.SolcDownloader
+
   @new_contract_name "New.sol"
   @allowed_evm_versions ["homestead", "tangerineWhistle", "spuriousDragon", "byzantium", "constantinople", "petersburg"]
 
@@ -79,31 +81,36 @@ defmodule Explorer.SmartContract.Solidity.CodeCompiler do
         "byzantium"
       end
 
-    {response, _status} =
-      System.cmd(
-        "node",
-        [
-          Application.app_dir(:explorer, "priv/compile_solc.js"),
-          code,
-          compiler_version,
-          optimize_value(optimize),
-          optimization_runs,
-          @new_contract_name,
-          external_libs_string,
-          checked_evm_version
-        ]
-      )
-
-    with {:ok, contracts} <- Jason.decode(response),
-         %{"abi" => abi, "evm" => %{"deployedBytecode" => %{"object" => bytecode}}} <-
-           get_contract_info(contracts, name) do
-      {:ok, %{"abi" => abi, "bytecode" => bytecode, "name" => name}}
-    else
-      {:error, %Jason.DecodeError{}} ->
-        {:error, :compilation}
-
-      error ->
-        parse_error(error)
+    path = SolcDownloader.ensure_exists(compiler_version)
+
+    if path do
+      {response, _status} =
+        System.cmd(
+          "node",
+          [
+            Application.app_dir(:explorer, "priv/compile_solc.js"),
+            code,
+            compiler_version,
+            optimize_value(optimize),
+            optimization_runs,
+            @new_contract_name,
+            external_libs_string,
+            checked_evm_version,
+            path
+          ]
+        )
+
+      with {:ok, contracts} <- Jason.decode(response),
+           %{"abi" => abi, "evm" => %{"deployedBytecode" => %{"object" => bytecode}}} <-
+             get_contract_info(contracts, name) do
+        {:ok, %{"abi" => abi, "bytecode" => bytecode, "name" => name}}
+      else
+        {:error, %Jason.DecodeError{}} ->
+          {:error, :compilation}
+
+        error ->
+          parse_error(error)
+      end
     end
   end
 

apps/explorer/priv/compile_solc.js

@@ -1,7 +1,5 @@
 #!/usr/bin/env node
 
-const solc = require('solc');
-
 var sourceCode = process.argv[2];
 var version = process.argv[3];
 var optimize = process.argv[4];
@@ -9,38 +7,38 @@ var optimizationRuns = parseInt(process.argv[5], 10);
 var newContractName = process.argv[6];
 var externalLibraries = JSON.parse(process.argv[7])
 var evmVersion = process.argv[8];
+var compilerVersionPath = process.argv[9];
+
+var solc = require('solc')
+var compilerSnapshot = require(compilerVersionPath);
+var solc = solc.setupMethods(compilerSnapshot);
 
-var compiled_code = solc.loadRemoteVersion(version, function (err, solcSnapshot) {
-  if (err) {
-    console.log(JSON.stringify(err.message));
-  } else {
-    const input = {
-      language: 'Solidity',
-      sources: {
-        [newContractName]: {
-          content: sourceCode
-        }
-      },
-      settings: {
-        evmVersion: evmVersion,
-        optimizer: {
-          enabled: optimize == '1',
-          runs: optimizationRuns
-        },
-        libraries: {
-          [newContractName]: externalLibraries
-        },
-        outputSelection: {
-          '*': {
-            '*': ['*']
-          }
-        }
+const input = {
+  language: 'Solidity',
+  sources: {
+    [newContractName]: {
+      content: sourceCode
+    }
+  },
+  settings: {
+    evmVersion: evmVersion,
+    optimizer: {
+      enabled: optimize == '1',
+      runs: optimizationRuns
+    },
+    libraries: {
+      [newContractName]: externalLibraries
+    },
+    outputSelection: {
+      '*': {
+        '*': ['*']
       }
     }
-
-    const output = JSON.parse(solcSnapshot.compile(JSON.stringify(input)))
-    /** Older solc-bin versions don't use filename as contract key */
-    const response = output.contracts[newContractName] || output.contracts['']
-    console.log(JSON.stringify(response));
   }
-});
+}
+
+
+const output = JSON.parse(solc.compile(JSON.stringify(input)))
+/** Older solc-bin versions don't use filename as contract key */
+const response = output.contracts[newContractName] || output.contracts['']
+console.log(JSON.stringify(response));