v.builder: integrate more compile/linker options into parallel_cc.v (#23190)

vlib/v/builder/cbuilder/parallel_cc.v

@@ -8,7 +8,6 @@ import sync.pool
 import v.gen.c
 
 const cc_compiler = os.getenv_opt('CC') or { 'cc' }
-const cc = os.quoted_path(cc_compiler)
 const cc_ldflags = os.getenv_opt('LDFLAGS') or { '' }
 const cc_cflags = os.getenv_opt('CFLAGS') or { '' }
 const cc_cflags_opt = os.getenv_opt('CFLAGS_OPT') or { '' } // '-O3' }
@@ -70,25 +69,38 @@ fn parallel_cc(mut b builder.Builder, result c.GenOutput) {
 		out_files[i].close()
 	}
 
-	// cc := os.quoted_path(cc_compiler)
+	mut cc_path := cc_compiler
+	explicit_cc_flag_passed := b.pref.build_options.any(it.starts_with('-cc '))
+	if explicit_cc_flag_passed {
+		// do not guess, just use the user's preference
+		cc_path = b.pref.ccompiler
+	}
+	cc := os.quoted_path(cc_path)
+	mut compile_args := b.get_compile_args()
+	mut linker_args := b.get_linker_args()
+	if !explicit_cc_flag_passed {
+		compile_args = compile_args.filter(it != '-bt25')
+		linker_args = linker_args.filter(it != '-bt25')
+	}
+	scompile_args := compile_args.join(' ')
+	slinker_args := linker_args.join(' ')
+
 	mut o_postfixes := ['0', 'x']
 	mut cmds := []string{}
 	for i in 0 .. c_files {
 		o_postfixes << (i + 1).str()
 	}
-	str_args := b.str_args.replace('-flto', '') // remove link time optimization, slows down linking 10x
 	for postfix in o_postfixes {
-		cmds << '${cc} ${cc_cflags} ${cc_cflags_opt} ${str_args} -c -w -o ${tmp_dir}/out_${postfix}.o ${tmp_dir}/out_${postfix}.c'
+		cmds << '${cc} ${cc_cflags} ${cc_cflags_opt} ${scompile_args} -w -o ${tmp_dir}/out_${postfix}.o -c ${tmp_dir}/out_${postfix}.c'
 	}
 	sw := time.new_stopwatch()
 	mut pp := pool.new_pool_processor(callback: build_parallel_o_cb)
 	pp.set_max_jobs(util.nr_jobs)
 	pp.work_on_items(cmds)
-	eprintln('> ${sw.elapsed().milliseconds():5} ms, C compilation on ${util.nr_jobs} thread(s), processing ${cmds.len} commands')
+	eprint_time(sw, 'C compilation on ${util.nr_jobs} thread(s), processing ${cmds.len} commands')
-	gc_flag := if b.pref.gc_mode != .no_gc { '-lgc ' } else { '' }
+
 	obj_files := fnames.map(it.replace('.c', '.o')).join(' ')
-	ld_flags := '${gc_flag}${cc_ldflags}'
+	link_cmd := '${cc} ${scompile_args} -o ${os.quoted_path(b.pref.out_name)} ${tmp_dir}/out_0.o ${obj_files} ${tmp_dir}/out_x.o ${slinker_args} ${cc_ldflags}'
-	link_cmd := '${cc} -o ${os.quoted_path(b.pref.out_name)} ${tmp_dir}/out_0.o ${obj_files} ${tmp_dir}/out_x.o -lpthread ${ld_flags}'
 	sw_link := time.new_stopwatch()
 	link_res := os.execute(link_cmd)
 	eprint_result_time(sw_link, 'link_cmd', link_cmd, link_res)

vlib/v/builder/cc.v

@@ -100,7 +100,7 @@ fn (mut v Builder) show_cc(cmd string, response_file string, response_file_conte
 	}
 }
 
-enum CC {
+pub enum CC {
 	tcc
 	gcc
 	icc
@@ -109,8 +109,8 @@ enum CC {
 	unknown
 }
 
-struct CcompilerOptions {
+pub struct CcompilerOptions {
-mut:
+pub mut:
 	guessed_compiler string
 	shared_postfix   string // .so, .dll
 
@@ -235,6 +235,9 @@ fn (mut v Builder) setup_ccompiler_options(ccompiler string) {
 		$if windows {
 			have_flto = false
 		}
+		if v.pref.parallel_cc {
+			have_flto = false
+		}
 		if have_flto {
 			optimization_options << '-flto'
 		}
@@ -252,7 +255,14 @@ fn (mut v Builder) setup_ccompiler_options(ccompiler string) {
 				debug_options << '-no-pie'
 			}
 		}
-		optimization_options = ['-O3', '-flto']
+		optimization_options = ['-O3']
+		mut have_flto := true
+		if v.pref.parallel_cc {
+			have_flto = false
+		}
+		if have_flto {
+			optimization_options << '-flto'
+		}
 	}
 	if ccoptions.cc == .icc {
 		if ccoptions.debug_mode {
@@ -461,6 +471,17 @@ fn (mut v Builder) setup_ccompiler_options(ccompiler string) {
 }
 
 fn (v &Builder) all_args(ccoptions CcompilerOptions) []string {
+	mut all := []string{}
+	all << v.only_compile_args(ccoptions)
+	all << v.only_linker_args(ccoptions)
+	return all
+}
+
+pub fn (v &Builder) get_compile_args() []string {
+	return v.only_compile_args(v.ccoptions)
+}
+
+fn (v &Builder) only_compile_args(ccoptions CcompilerOptions) []string {
 	mut all := []string{}
 	all << ccoptions.env_cflags
 	if v.pref.is_cstrict {
@@ -488,6 +509,15 @@ fn (v &Builder) all_args(ccoptions CcompilerOptions) []string {
 	all << ccoptions.pre_args
 	all << ccoptions.source_args
 	all << ccoptions.post_args
+	return all
+}
+
+pub fn (v &Builder) get_linker_args() []string {
+	return v.only_linker_args(v.ccoptions)
+}
+
+fn (v &Builder) only_linker_args(ccoptions CcompilerOptions) []string {
+	mut all := []string{}
 	// in `build-mode`, we do not need -lxyz flags, since we are
 	// building an (.o) object file, that will be linked later.
 	if v.pref.build_mode != .build_module {
@@ -1014,7 +1044,14 @@ fn (mut c Builder) cc_windows_cross() {
 	mut debug_options := []string{}
 	if c.pref.is_prod {
 		if c.pref.ccompiler != 'msvc' {
-			optimization_options = ['-O3', '-flto']
+			optimization_options = ['-O3']
+			mut have_flto := true
+			if c.pref.parallel_cc {
+				have_flto = false
+			}
+			if have_flto {
+				optimization_options << '-flto'
+			}
 		}
 	}
 	if c.pref.is_debug {