From b62e28dba5cccb39699a241ba38bc787d330f558 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 20 Dec 2019 22:06:11 +0200
Subject: [PATCH] compiler: fix interface generation for unused interfaces

---
 vlib/compiler/cgen.v | 23 ++++++++++++++++-------
 vlib/compiler/fn.v   | 27 ++++++++++++++-------------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/vlib/compiler/cgen.v b/vlib/compiler/cgen.v
index a9cbf6edfa..593e829a62 100644
--- a/vlib/compiler/cgen.v
+++ b/vlib/compiler/cgen.v
@@ -462,25 +462,34 @@ fn (v &V) interface_table() string {
 		if t.cat != .interface_ {
 			continue
 		}
+		interface_name := t.name
 		mut methods := ''
 		sb.writeln('// NR methods = $t.gen_types.len')
 		for i, gen_type in t.gen_types {
-			methods += '{'
+			gen_concrete_type_name := gen_type.replace('*', '')
+			methods += '{\n'
 			for j, method in t.methods {
 				// Cat_speak
-				methods += '${gen_type}_${method.name}'
+				methods += ' (void*)    ${gen_concrete_type_name}_${method.name}'
 				if j < t.methods.len - 1 {
-					methods += ', '
+					methods += ', \n'
 				}
 			}
-			methods += '}, '
-			// Speaker_Cat_index = 0
-			sb.writeln('int _${t.name}_${gen_type}_index = $i;')
+			methods += '\n},\n\n'
+			// Speaker_Cat_index = 0      
+			concrete_type_name := gen_type.replace('*', '_ptr')			
+			sb.writeln('int _${interface_name}_${concrete_type_name}_index = $i;')
 		}
+		
 		if t.gen_types.len > 0 {
 			// methods = '{TCCSKIP(0)}'
 			// }
-			sb.writeln('void* (* ${t.name}_name_table[][$t.methods.len]) = ' + '{ $methods }; ')
+			sb.writeln('void* (* ${interface_name}_name_table[][$t.methods.len]) = ' + '{ \n $methods \n }; ')
+		}else{
+			// The line below is needed so that C compilation succeeds,
+			// even if no interface methods are called.
+			// See https://github.com/zenith391/vgtk3/issues/7
+			sb.writeln('void* (* ${interface_name}_name_table[][1]) = ' + '{ {NULL} }; ')
 		}
 		continue
 	}
diff --git a/vlib/compiler/fn.v b/vlib/compiler/fn.v
index dbefd82587..9bcd9dd26a 100644
--- a/vlib/compiler/fn.v
+++ b/vlib/compiler/fn.v
@@ -1019,18 +1019,18 @@ fn (p mut Parser) fn_call_args(f mut Fn) {
 			// if f.args[0].typ.ends_with('*') {
 			// p.gen('&/*119*/')
 			// }
-			/*
-			pos := p.cgen.cur_line.index('/* ? */')
-			if pos > -1 {
-				expr := p.cgen.cur_line[pos..]
-				// TODO hack
-				// If current expression is a func call, generate the array hack
-				if expr.contains('(') {
-					p.cgen.set_placeholder(pos, '(${arg.typ[..arg.typ.len-1]}[]){')
-					p.gen('}[0] ')
-				}
-			}
-			*/
+
+			//pos := p.cgen.cur_line.index('/* ? */')
+			//if pos > -1 {
+			//	expr := p.cgen.cur_line[pos..]
+			//	// TODO hack
+			//	// If current expression is a func call, generate the array hack
+			//	if expr.contains('(') {
+			//		p.cgen.set_placeholder(pos, '(${arg.typ[..arg.typ.len-1]}[]){')
+			//		p.gen('}[0] ')
+			//	}
+			//}
+			
 
 			continue
 		}
@@ -1082,8 +1082,9 @@ fn (p mut Parser) fn_call_args(f mut Fn) {
 			if t.cat == .interface_ {
 				// perform((Speaker) { ._object = &dog,
 				// _interface_idx = _Speaker_Dog_index })
+				concrete_type_name := typ.replace('*', '_ptr')
 				p.cgen.set_placeholder(ph, '($arg.typ) { ._object = &')
-				p.gen(', ._interface_idx = _${arg.typ}_${typ}_index} /* i. arg*/')
+				p.gen(', ._interface_idx = _${arg.typ}_${concrete_type_name}_index} /* i. arg*/')
 				p.table.add_gen_type(arg.typ, typ)
 			}
 		}