ci: fix -usecache for programs using thirdparty C libs

cmd/tools/vtest-all.v

@@ -5,10 +5,10 @@ import term
 import time
 
 const (
-	vexe = os.getenv('VEXE')
-	vroot = os.dir(vexe)
+	vexe        = os.getenv('VEXE')
+	vroot       = os.dir(vexe)
 	args_string = os.args[1..].join(' ')
-	vargs = args_string.all_before('test-all')
+	vargs       = args_string.all_before('test-all')
 )
 
 fn main() {
@@ -49,6 +49,14 @@ mut:
 
 fn get_all_commands() []Command {
 	mut res := []Command{}
+	res << Command{
+		line: '$vexe examples/hello_world.v'
+		okmsg: 'V can compile hello world.'
+	}
+	res << Command{
+		line: '$vexe -o vtmp cmd/v'
+		okmsg: 'V can compile itself.'
+	}
 	res << Command{
 		line: '$vexe $vargs -progress test-cleancode'
 		okmsg: 'All important .v files are invariant when processed with `v fmt`'
@@ -78,6 +86,13 @@ fn get_all_commands() []Command {
 		line: '$vexe install nedpals.args'
 		okmsg: '`v install` works.'
 	}
+	// NB: test that a program that depends on thirdparty libraries with its
+	// own #flags (tetris depends on gg, which uses sokol) can be compiled
+	// with -usecache:
+	res << Command{
+		line: '$vexe -usecache examples/tetris/tetris.v'
+		okmsg: '`v -usecache` works.'
+	}
 	$if macos {
 		res << Command{
 			line: '$vexe -o v.c cmd/v && cc -Werror v.c && rm -rf v.c'

vlib/v/builder/cc.v

@@ -174,6 +174,7 @@ mut:
 	//
 	args         []string // ordinary C options like `-O2`
 	wargs        []string // for `-Wxyz` *exclusively*
+	pre_args     []string // options that should go before .o_args
 	o_args       []string // for `-o target`
 	source_args  []string // for `x.tmp.c`
 	post_args    []string // options that should go after .o_args
@@ -321,8 +322,8 @@ fn (mut v Builder) setup_ccompiler_options(ccompiler string) {
 	cflags := v.get_os_cflags()
 	ccoptions.o_args << cflags.c_options_only_object_files()
 	defines, others, libs := cflags.defines_others_libs()
-	ccoptions.args << defines
-	ccoptions.args << others
+	ccoptions.pre_args << defines
+	ccoptions.pre_args << others
 	ccoptions.linker_flags << libs
 	// TODO: why is this duplicated from above?
 	if v.pref.use_cache && v.pref.build_mode != .build_module {
@@ -382,6 +383,7 @@ fn (ccoptions CcompilerOptions) all_args() []string {
 	all << ccoptions.env_cflags
 	all << ccoptions.args
 	all << ccoptions.o_args
+	all << ccoptions.pre_args
 	all << ccoptions.source_args
 	all << ccoptions.post_args
 	all << ccoptions.linker_flags
@@ -537,7 +539,7 @@ fn (mut v Builder) cc() {
 		//
 		mut libs := []string{} // builtin.o os.o http.o etc
 		if v.pref.build_mode == .build_module {
-			v.ccoptions.args << '-c'
+			v.ccoptions.pre_args << '-c'
 		} else if v.pref.use_cache {
 			mut built_modules := []string{}
 			builtin_obj_path := v.rebuild_cached_module(vexe, 'vlib/builtin')