From 5db899a53593f39edd69de86ace4a6485bf70570 Mon Sep 17 00:00:00 2001
From: Harmen Stoppels <me@harmenstoppels.nl>
Date: Fri, 15 May 2026 16:43:54 +0200
Subject: [PATCH] add -Werror unit tests

Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>
---
 test/run.sh | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/test/run.sh b/test/run.sh
index a59b0a9..5f8eae9 100644
--- a/test/run.sh
+++ b/test/run.sh
@@ -1056,6 +1056,77 @@ hello.c')
     expect_contains frandom_seed_user_passthrough "$_out" '-frandom-seed=custom'
 }
 
+# ---------------------------------------------------------------------------
+# -Werror handling
+# ---------------------------------------------------------------------------
+
+# _werror_set_mode MODE -> exports KEEP/REPLACE for one of three modes:
+#   all      keep every -Werror* flag
+#   specific keep -Werror-* and -Werror=*, rewrite bare -Werror to -Wno-error
+#   none     rewrite all -Werror* to -Wno-error*
+_werror_set_mode() {
+    case "$1" in
+        all)
+            SPACK_COMPILER_FLAGS_KEEP='-Werror*'
+            SPACK_COMPILER_FLAGS_REPLACE=''
+            ;;
+        specific)
+            SPACK_COMPILER_FLAGS_KEEP='-Werror-*|-Werror=*'
+            SPACK_COMPILER_FLAGS_REPLACE='-Werror-|-Wno-error= -Werror|-Wno-error'
+            ;;
+        none)
+            SPACK_COMPILER_FLAGS_KEEP=''
+            SPACK_COMPILER_FLAGS_REPLACE='-Werror-|-Wno-error= -Werror|-Wno-error'
+            ;;
+    esac
+    export SPACK_COMPILER_FLAGS_KEEP SPACK_COMPILER_FLAGS_REPLACE
+}
+
+test_werror_handling() {
+    wrapper_environment
+
+    # Family 1: -Werror / -Werror=specific
+    _in1='-Werror
+-Werror=specific'
+
+    _werror_set_mode all
+    _out=$(dump_args cc "$_in1")
+    expect_contains werror_all1 "$_out" '-Werror'
+
+    _werror_set_mode specific
+    _out=$(dump_args cc "$_in1")
+    expect_contains     werror_spec1 "$_out" '-Wno-error'
+    expect_not_contains werror_spec1 "$_out" '-Werror'
+
+    _werror_set_mode none
+    _out=$(dump_args cc "$_in1")
+    expect_contains     werror_none1 "$_out" '-Wno-error'
+    expect_contains     werror_none1 "$_out" '-Wno-error=specific'
+    expect_not_contains werror_none1 "$_out" '-Werror'
+    expect_not_contains werror_none1 "$_out" '-Werror=specific'
+
+    # Family 2: -Werror-implicit-function-declaration (non-standard dash form)
+    _in2='-Werror
+-Werror-implicit-function-declaration'
+
+    _werror_set_mode all
+    _out=$(dump_args cc "$_in2")
+    expect_contains werror_all2 "$_out" '-Werror'
+
+    _werror_set_mode specific
+    _out=$(dump_args cc "$_in2")
+    expect_contains     werror_spec2 "$_out" '-Wno-error'
+    expect_contains     werror_spec2 "$_out" '-Werror-implicit-function-declaration'
+    expect_not_contains werror_spec2 "$_out" '-Werror'
+
+    _werror_set_mode none
+    _out=$(dump_args cc "$_in2")
+    expect_contains     werror_none2 "$_out" '-Wno-error'
+    expect_contains     werror_none2 "$_out" '-Wno-error=implicit-function-declaration'
+    expect_not_contains werror_none2 "$_out" '-Werror'
+    expect_not_contains werror_none2 "$_out" '-Werror-implicit-function-declaration'
+}
+
 # ---------------------------------------------------------------------------
 # Runner
 # ---------------------------------------------------------------------------
@@ -1076,6 +1147,7 @@ test_linker_strips_loopopt
 test_spack_managed_dirs_are_prioritized
 test_frandom_seed_not_added_without_env
 test_frandom_seed_filters_args
+test_werror_handling
 '
 
 if [ $# -gt 0 ]; then