spicy/zeekygen: Remove mtime from generated code

Zeekygen implements its own make-style update logic to prevent
re-creation of files that have not changed. To fulfill this, we
currently encode the current time into spicyz generated .cc files.

This degrades ccache efficiency for built-in analyzers and also
for all .evt files compiled during testing. Switch SpicyModuleInfo
to return current time instead. This results in the re-generation
of documentation files unconditionally when running Zeekygen, but
that seems more acceptable IMO.

Generally wonder if Zeekygen should produce output unconditionally
and if we need to clobber prevention, compare with the content of
the existing file.

Closes #3619

scripts/spicy/zeek_rt.hlt

@@ -17,7 +17,7 @@ type ZeekTypeTag = enum {
     Addr, Any, Bool, Count, Double, Enum, Error, File, Func, Int, Interval, List, Opaque, Pattern, Port, Record, String, Subnet, Table, Time, Type, Vector, Void
 } &cxxname="::zeek::spicy::rt::ZeekTypeTag";
 
-declare public void register_spicy_module_begin(string name, string description, time mtime) &cxxname="zeek::spicy::rt::register_spicy_module_begin";
+declare public void register_spicy_module_begin(string name, string description) &cxxname="zeek::spicy::rt::register_spicy_module_begin";
 declare public void register_protocol_analyzer(string name, hilti::Protocol protocol, vector<PortRange> ports, string parser_orig, string parser_resp, string replaces, string linker_scope) &cxxname="zeek::spicy::rt::register_protocol_analyzer" &have_prototype;
 declare public void register_file_analyzer(string name, vector<string> mime_types, string parser, string replaces, string linker_scope) &cxxname="zeek::spicy::rt::register_file_analyzer" &have_prototype;
 declare public void register_packet_analyzer(string name, string parser, string replaces, string linker_scope) &cxxname="zeek::spicy::rt::register_packet_analyzer" &have_prototype;

src/spicy/manager.cc

@@ -47,10 +47,9 @@ static std::pair<std::string, std::string> parseID(const std::string& s) {
 
 Manager::~Manager() {}
 
-void Manager::registerSpicyModuleBegin(const std::string& name, const std::string& description, hilti::rt::Time mtime) {
+void Manager::registerSpicyModuleBegin(const std::string& name, const std::string& description) {
     assert(! _module_info);
-    _module_info =
+    _module_info = std::make_unique<zeekygen::detail::SpicyModuleInfo>(name, description);
-        std::make_unique<zeekygen::detail::SpicyModuleInfo>(name, description, static_cast<time_t>(mtime.seconds()));
 }
 
 void Manager::registerSpicyModuleEnd() {

src/spicy/manager.h

@@ -75,10 +75,8 @@ public:
      * and to index it, inside the Zeekygen documentation.
      * @param description textual description in reST that will be shown for
      * this module inside the Zeekygen documentation
-     * @param mtime timestamp indicating last time of modification of any of
-     * the module's content; used by Zeekygen to trigger rebuilds as necessary
      */
-    void registerSpicyModuleBegin(const std::string& name, const std::string& description, hilti::rt::Time mtime);
+    void registerSpicyModuleBegin(const std::string& name, const std::string& description);
 
     /**
      * Runtime method to register a protocol analyzer with its Zeek-side

src/spicy/runtime-support.cc

@@ -20,9 +20,8 @@
 using namespace zeek;
 using namespace zeek::spicy;
 
-void rt::register_spicy_module_begin(const std::string& name, const std::string& description,
+void rt::register_spicy_module_begin(const std::string& name, const std::string& description) {
-                                     const hilti::rt::Time& mtime) {
+    spicy_mgr->registerSpicyModuleBegin(name, description);
-    spicy_mgr->registerSpicyModuleBegin(name, description, mtime);
 }
 
 void rt::register_spicy_module_end() { spicy_mgr->registerSpicyModuleEnd(); }

src/spicy/runtime-support.h

@@ -94,7 +94,7 @@ public:
  * Begins registration of a Spicy EVT module. All subsequent, other `register_*()`
  * function call will be associated with this module for documentation purposes.
  */
-void register_spicy_module_begin(const std::string& name, const std::string& description, const hilti::rt::Time& mtime);
+void register_spicy_module_begin(const std::string& name, const std::string& description);
 
 /**
  * Registers a Spicy protocol analyzer with its EVT meta information with the

src/spicy/spicyz/glue-compiler.cc

@@ -987,10 +987,10 @@ bool GlueCompiler::compile() {
         return false;
 
     if ( ! _doc_id.empty() ) {
-        auto mtime = hilti::expression::Ctor(hilti::ctor::Time(hilti::rt::time::current_time()));
+        preinit_body.addCall("zeek_rt::register_spicy_module_begin", {
-        preinit_body.addCall("zeek_rt::register_spicy_module_begin",
+                                                                         hilti::builder::string_mut(_doc_id),
-                             {hilti::builder::string_mut(_doc_id), hilti::builder::string_mut(_doc_description),
+                                                                         hilti::builder::string_mut(_doc_description),
-                              mtime});
+                                                                     });
     }
 
     for ( auto& a : _protocol_analyzers ) {

src/zeekygen/SpicyModuleInfo.h

@@ -22,8 +22,8 @@ public:
      * @param name name of the Spicy EVT module.
      * @param description text describing the module further
      */
-    explicit SpicyModuleInfo(const std::string& name, const std::string& description, time_t mtime)
+    explicit SpicyModuleInfo(const std::string& name, const std::string& description)
-        : name(name), description(description), mtime(mtime) {}
+        : name(name), description(description) {}
 
     /** @return textual description of the module */
     const auto& Description() const { return description; }
@@ -45,13 +45,12 @@ public:
     void AddBifItem(const std::string& id, plugin::BifItem::Type type) { bif_items.emplace_back(id, type); }
 
 private:
-    time_t DoGetModificationTime() const override { return mtime; }
+    time_t DoGetModificationTime() const override { return time(nullptr); }
     std::string DoName() const override { return name; }
     std::string DoReStructuredText(bool roles_only) const override { return ""; }
 
     std::string name;
     std::string description;
-    time_t mtime;
 
     std::list<plugin::Component*> components;
     std::list<plugin::BifItem> bif_items;