From ae898e77c56343091d2dfd31136ccb96f9c16dc0 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Mon, 3 May 2021 18:22:10 +0300
Subject: [PATCH] v.markused: handle interface implementation methods, and vweb
 programs

---
 vlib/v/ast/table.v         |  2 ++
 vlib/v/checker/checker.v   |  8 ++++++--
 vlib/v/markused/markused.v | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index a4e59df410..3d7101c2eb 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -24,6 +24,7 @@ pub mut:
 	is_fmt           bool
 	used_fns         map[string]bool // filled in by the checker, when pref.skip_unused = true;
 	used_consts      map[string]bool // filled in by the checker, when pref.skip_unused = true;
+	used_vweb_types  []Type // vweb context types, filled in by checker, when pref.skip_unused = true;
 	panic_handler    FnPanicHandler = default_table_panic_handler
 	panic_userdata   voidptr        = voidptr(0) // can be used to pass arbitrary data to panic_handler;
 	panic_npanics    int
@@ -44,6 +45,7 @@ pub fn (t &Table) free() {
 		t.cmod_prefix.free()
 		t.used_fns.free()
 		t.used_consts.free()
+		t.used_vweb_types.free()
 	}
 }
 
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 078eb78480..3b569657f5 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -79,7 +79,6 @@ mut:
 	timers                           &util.Timers = util.new_timers(false)
 	comptime_fields_type             map[string]ast.Type
 	fn_scope                         &ast.Scope = voidptr(0)
-	used_fns                         map[string]bool // used_fns['println'] == true
 	main_fn_decl_node                ast.FnDecl
 	match_exhaustive_cutoff_limit    int = 10
 	// TODO: these are here temporarily and used for deprecations; remove soon
@@ -6746,7 +6745,11 @@ fn (mut c Checker) post_process_generic_fns() {
 			node.cur_concrete_types = concrete_types
 			c.fn_decl(mut node)
 			if node.name in ['vweb.run_app', 'vweb.run'] {
-				c.vweb_gen_types << concrete_types
+				for ct in concrete_types {
+					if ct !in c.vweb_gen_types {
+						c.vweb_gen_types << ct
+					}
+				}
 			}
 		}
 		node.cur_concrete_types = []
@@ -6961,6 +6964,7 @@ fn (mut c Checker) verify_all_vweb_routes() {
 	if c.vweb_gen_types.len == 0 {
 		return
 	}
+	c.table.used_vweb_types = c.vweb_gen_types
 	typ_vweb_result := c.table.find_type_idx('vweb.Result')
 	old_file := c.file
 	for vgt in c.vweb_gen_types {
diff --git a/vlib/v/markused/markused.v b/vlib/v/markused/markused.v
index cbe92e4abe..cbc79c7393 100644
--- a/vlib/v/markused/markused.v
+++ b/vlib/v/markused/markused.v
@@ -158,6 +158,8 @@ pub fn mark_used(mut table ast.Table, pref &pref.Preferences, ast_files []ast.Fi
 			continue
 		}
 	}
+
+	// handle assertions and testing framework callbacks:
 	if pref.is_debug {
 		all_fn_root_names << 'panic_debug'
 	}
@@ -174,6 +176,40 @@ pub fn mark_used(mut table ast.Table, pref &pref.Preferences, ast_files []ast.Fi
 		}
 	}
 
+	// handle interface implementation methods:
+	for isym in table.type_symbols {
+		if isym.kind != .interface_ {
+			continue
+		}
+		interface_info := isym.info as ast.Interface
+		if interface_info.methods.len == 0 {
+			continue
+		}
+		for itype in interface_info.types {
+			for method in interface_info.methods {
+				interface_implementation_method_name := '${itype}.$method.name'
+				all_fn_root_names << interface_implementation_method_name
+			}
+		}
+	}
+
+	// handle vweb magic router methods:
+	typ_vweb_result := table.find_type_idx('vweb.Result')
+	if typ_vweb_result != 0 {
+		for vgt in table.used_vweb_types {
+			sym_app := table.get_type_symbol(vgt)
+			for m in sym_app.methods {
+				if m.return_type == typ_vweb_result {
+					pvgt := vgt.set_nr_muls(1)
+					eprintln('vgt: $vgt | pvgt: $pvgt | sym_app.name: $sym_app.name | m.name: $m.name')
+					all_fn_root_names << '${pvgt}.$m.name'
+				}
+			}
+		}
+	}
+
+	//
+
 	mut walker := Walker{
 		table: table
 		files: ast_files