From ebc55063c0136d545cecdc1c2f3ed385076c236a Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 27 May 2026 21:59:36 +0300
Subject: [PATCH] builder: cc fixes

---
 vlib/v/builder/cc.v                           |  6 +++++
 vlib/v/builder/cc_test.v                      | 26 +++++++++++++++++++
 .../v/tests/shared_library_system_link_test.v |  6 ++---
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/vlib/v/builder/cc.v b/vlib/v/builder/cc.v
index cc6a2f0bb..c4c990f1b 100644
--- a/vlib/v/builder/cc.v
+++ b/vlib/v/builder/cc.v
@@ -793,6 +793,12 @@ fn (mut v Builder) setup_ccompiler_options(ccompiler string) {
 			// This avoids cross-DSO symbol interposition between multiple V binaries
 			// in one process (for example, host executable + loaded V plugin).
 			ccoptions.linker_flags << '-Wl,-Bsymbolic'
+			if ccoptions.cc != .tcc {
+				// Do not leak symbols from the statically linked libgc archive into
+				// the shared library ABI. Only functions explicitly tagged with
+				// @[export] should be visible.
+				ccoptions.linker_flags << '-Wl,--exclude-libs,ALL'
+			}
 		}
 	}
 	if v.pref.is_bare && v.pref.os != .wasm32 {
diff --git a/vlib/v/builder/cc_test.v b/vlib/v/builder/cc_test.v
index 464b0ccfd..fe3ee5fed 100644
--- a/vlib/v/builder/cc_test.v
+++ b/vlib/v/builder/cc_test.v
@@ -481,6 +481,32 @@ fn test_shared_tcc_compile_args_skip_bt25_after_late_compiler_resolution() {
 	assert !builder.get_compile_args().contains('-bt25')
 }
 
+fn test_linux_shared_boehm_linker_args_hide_static_gc_archive_symbols() {
+	linker_args := builder_linker_args_with_cc([
+		'-os',
+		'linux',
+		'-shared',
+		'-gc',
+		'boehm',
+		hello_world_example(),
+	], .gcc)
+	assert linker_args.contains('-Wl,-Bsymbolic')
+	assert linker_args.contains('-Wl,--exclude-libs,ALL')
+}
+
+fn test_linux_shared_boehm_tcc_linker_args_skip_gnu_exclude_libs() {
+	linker_args := builder_linker_args_with_cc([
+		'-os',
+		'linux',
+		'-shared',
+		'-gc',
+		'boehm',
+		hello_world_example(),
+	], .tcc)
+	assert linker_args.contains('-Wl,-Bsymbolic')
+	assert !linker_args.contains('-Wl,--exclude-libs,ALL')
+}
+
 fn test_should_use_rsp_for_linux_by_default() {
 	builder := new_test_builder([hello_world_example()])
 	assert builder.should_use_rsp(['-o', builder.out_name_c])
diff --git a/vlib/v/tests/shared_library_system_link_test.v b/vlib/v/tests/shared_library_system_link_test.v
index 03795b2fb..0a1b87bf3 100644
--- a/vlib/v/tests/shared_library_system_link_test.v
+++ b/vlib/v/tests/shared_library_system_link_test.v
@@ -55,9 +55,9 @@ fn test_shared_library_only_exports_tagged_symbols() {
 	if uos !in ['linux', 'macos'] {
 		return
 	}
-	// tcc on macOS does not honor `-fvisibility=hidden`, so the symbol-set check
-	// would be noisy there; rely on Linux + a `-cc clang` path on macOS.
-	cc_flag := if uos == 'macos' { '-cc clang' } else { '' }
+	// tcc does not honor `-fvisibility=hidden`, so the symbol-set check would be
+	// noisy there; use a system compiler for Linux and clang on macOS.
+	cc_flag := if uos == 'macos' { '-cc clang' } else { '-cc cc' }
 	workdir := os.join_path(os.vtmp_dir(), 'v_shared_visibility_${rand.ulid()}')
 	os.mkdir_all(workdir) or { panic(err) }
 	defer {
-- 
2.39.5