From cc9828b4814f4d2bc7094d83d4b5388f636343e5 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Thu, 16 Apr 2020 16:30:19 +0300
Subject: [PATCH] checker: fix building of shared .so libs

---
 cmd/v/v.v                |  4 +++-
 vlib/v/checker/checker.v | 20 ++++++++++++--------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/cmd/v/v.v b/cmd/v/v.v
index 2455904fea..695e502204 100644
--- a/cmd/v/v.v
+++ b/cmd/v/v.v
@@ -126,7 +126,9 @@ fn parse_args(args []string) (&pref.Preferences, string) {
 		match arg {
 			'-v' {	res.is_verbose = true	}
 			'-cg' {	res.is_debug = true	}
-			'-live' {	res.is_solive = true	}
+			'-live' { res.is_live = true }
+			'-solive' {	res.is_solive = true res.is_so = true }
+			'-shared' { res.is_so = true }
 			'-autofree' {	res.autofree = true	}
 			'-compress' {	res.compress = true	}
 			'-freestanding' {	res.is_bare = true	}
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index fecb8ebc28..1366b4b7b1 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -60,25 +60,29 @@ pub fn (c mut Checker) check2(ast_file ast.File) []scanner.Error {
 }
 
 pub fn (c mut Checker) check_files(ast_files []ast.File) {
+	mut all_mods := map[string]int
 	for file in ast_files {
 		c.check(file)
+		all_mods[ file.mod.name ] = all_mods[ file.mod.name ] + 1
 	}
 	// Make sure fn main is defined in non lib builds
 	if c.pref.build_mode == .build_module || c.pref.is_test {
 		return
 	}
-	if ast_files.len > 1 && ast_files[0].mod.name == 'builtin' {
-		// TODO hack to fix vv tests
+	if c.pref.is_so {
+		// shared libs do not need to have a main
 		return
 	}
-	for i, f in c.table.fns {
-		if f.name == 'main' {
-			return
+	// check that a main program has a `fn main(){}` function:
+	if all_mods['main'] > 0 {
+		for i, f in c.table.fns {
+			if f.name == 'main' {
+				return
+			}
 		}
+		c.error('function `main` is undeclared in the main module', token.Position{})
+		exit(1)
 	}
-	eprintln('function `main` is undeclared in the main module')
-	// eprintln(ast_files[0].mod.name)
-	exit(1)
 }
 
 pub fn (c mut Checker) struct_decl(decl ast.StructDecl) {