Merge #19386: rpc: Assert that RPCArg names are equal to CRPCCommand ones (server)

fa7592bfa8691eb0289b21da3571709a18391b0f rpc: Update server to use new RPCHelpMan (MarcoFalke)
aaaaad562790cd4dce1568ae193f5393aacacedf rpc: Add option to hide RPCArg (MarcoFalke)
fa9708f94c01cb8bf2971bdf404af38c38fa341b rpc: Assert that passed arg names are equal to hardcoded ones (MarcoFalke)
faaeb2b0b347b40ce456a951eec5e820587e5b02 rpc: Add CRPCCommand constructor which takes RPCHelpMan (MarcoFalke)
fa8ec00061567e56333bb69c5623919d45a9a92d rpc: Check that left section is not multiline (MarcoFalke)

Pull request description:

  This is split out from #18531 to just touch the RPC methods in server. Description from the main pr:

  ### Motivation

  RPCArg names in the rpc help are currently only used for documentation. However, in the future they could be used to teach the server the named arguments. Named arguments are currently registered by the `CRPCCommand`s and duplicate the RPCArg names from the documentation. This redundancy is fragile, and has lead to errors in the past (despite having linters to catch those kind of errors). See section "bugs found" for a list of bugs that have been found as a result of the changes here.

  ### Changes

  The changes here add an assert in the `CRPCCommand` constructor that the RPCArg names are identical to the ones in the `CRPCCommand`.

  ### Future work

  > Here or follow up, makes sense to also assert type of returned UniValue?

  Sure, but let's not get ahead of ourselves. I am going to submit any further works as follow-ups, including:

  * Removing the CRPCCommand arguments, now that they are asserted to be equal and thus redundant
  * Removing all python regex linters on the args, now that RPCMan can be used to generate any output, including the cli.cpp table
  * Auto-formatting and sanity checking the RPCExamples with RPCMan
  * Checking passed-in json in self-check. Removing redundant checks
  * Checking returned json against documentation to avoid regressions or false documentation
  * Compile the RPC documentation at compile-time to ensure it doesn't change at runtime and is completely static

  ### Bugs found

  * The assert identified issue #18607
  * The changes itself fixed bug #19250

ACKs for top commit:
  laanwj:
    ACK fa7592bfa8691eb0289b21da3571709a18391b0f
  ryanofsky:
    Code review ACK fa7592bfa8691eb0289b21da3571709a18391b0f. Looks great! Just some hidden arg and Check() and comment cleanups since last review

Tree-SHA512: e64b6a212f4a3aeedeee47557559bde104d5fd40cdc1746b27eb2f3d4c8885d5e6e4dd287595ea11cdbc6a939654fe103cae765fd505875444d851f0abb11308

1 files changed, 25 insertions, 19 deletions

diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index ca73c699c9..9f4c7bee9c 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -385,9 +385,7 @@ struct Sections {
             PushSection({indent + "]" + (outer_type != OuterType::NONE ? "," : ""), ""});
             break;
         }
-
-            // no default case, so the compiler can warn about missing cases
-        }
+        } // no default case, so the compiler can warn about missing cases
     }
 
     /**
@@ -398,6 +396,9 @@ struct Sections {
         std::string ret;
         const size_t pad = m_max_pad + 4;
         for (const auto& s : m_sections) {
+            // The left part of a section is assumed to be a single line, usually it is the name of the JSON struct or a
+            // brace like {, }, [, or ]
+            CHECK_NONFATAL(s.m_left.find('\n') == std::string::npos);
             if (s.m_right.empty()) {
                 ret += s.m_left;
                 ret += "\n";
@@ -432,7 +433,11 @@ struct Sections {
 };
 
 RPCHelpMan::RPCHelpMan(std::string name, std::string description, std::vector<RPCArg> args, RPCResults results, RPCExamples examples)
+    : RPCHelpMan{std::move(name), std::move(description), std::move(args), std::move(results), std::move(examples), nullptr} {}
+
+RPCHelpMan::RPCHelpMan(std::string name, std::string description, std::vector<RPCArg> args, RPCResults results, RPCExamples examples, RPCMethodImpl fun)
     : m_name{std::move(name)},
+      m_fun{std::move(fun)},
       m_description{std::move(description)},
       m_args{std::move(args)},
       m_results{std::move(results)},
@@ -481,6 +486,16 @@ bool RPCHelpMan::IsValidNumArgs(size_t num_args) const
     }
     return num_required_args <= num_args && num_args <= m_args.size();
 }
+
+std::vector<std::string> RPCHelpMan::GetArgNames() const
+{
+    std::vector<std::string> ret;
+    for (const auto& arg : m_args) {
+        ret.emplace_back(arg.m_names);
+    }
+    return ret;
+}
+
 std::string RPCHelpMan::ToString() const
 {
     std::string ret;
@@ -489,6 +504,7 @@ std::string RPCHelpMan::ToString() const
     ret += m_name;
     bool was_optional{false};
     for (const auto& arg : m_args) {
+        if (arg.m_hidden) continue;
         const bool optional = arg.IsOptional();
         ret += " ";
         if (optional) {
@@ -510,6 +526,7 @@ std::string RPCHelpMan::ToString() const
     Sections sections;
     for (size_t i{0}; i < m_args.size(); ++i) {
         const auto& arg = m_args.at(i);
+        if (arg.m_hidden) continue;
 
         if (i == 0) ret += "\nArguments:\n";
 
@@ -589,9 +606,7 @@ std::string RPCArg::ToDescriptionString() const
             ret += "json array";
             break;
         }
-
-            // no default case, so the compiler can warn about missing cases
-        }
+        } // no default case, so the compiler can warn about missing cases
     }
     if (m_fallback.which() == 1) {
         ret += ", optional, default=" + boost::get<std::string>(m_fallback);
@@ -609,9 +624,7 @@ std::string RPCArg::ToDescriptionString() const
             ret += ", required";
             break;
         }
-
-            // no default case, so the compiler can warn about missing cases
-        }
+        } // no default case, so the compiler can warn about missing cases
     }
     ret += ")";
     ret += m_description.empty() ? "" : " " + m_description;
@@ -706,10 +719,7 @@ void RPCResult::ToSections(Sections& sections, const OuterType outer_type, const
         sections.PushSection({indent + "}" + maybe_separator, ""});
         return;
     }
-
-        // no default case, so the compiler can warn about missing cases
-    }
-
+    } // no default case, so the compiler can warn about missing cases
     CHECK_NONFATAL(false);
 }
 
@@ -746,9 +756,7 @@ std::string RPCArg::ToStringObj(const bool oneline) const
     case Type::OBJ_USER_KEYS:
         // Currently unused, so avoid writing dead code
         CHECK_NONFATAL(false);
-
-        // no default case, so the compiler can warn about missing cases
-    }
+    } // no default case, so the compiler can warn about missing cases
     CHECK_NONFATAL(false);
 }
 
@@ -783,9 +791,7 @@ std::string RPCArg::ToString(const bool oneline) const
         }
         return "[" + res + "...]";
     }
-
-        // no default case, so the compiler can warn about missing cases
-    }
+    } // no default case, so the compiler can warn about missing cases
     CHECK_NONFATAL(false);
 }