kit

commit dddc1f61c90cfd8dce44684c739c6e9242f43a72
parent c6c3fef5166e4061cab5a5959cfc7e10fc069def
Author: Ryan Sepassi <rsepassi@gmail.com>
Date:   Wed,  3 Jun 2026 11:26:48 -0700

cc: drop chatty "ignoring accepted compatibility flag" log

The debug-only log fired for every accepted-but-ignored compatibility
flag (-Wall, -std=, -nostdlib, ...), drowning out real diagnostics. Drop
the cc_log_ignored() helper and its 10 call sites; the flags are still
accepted, now silently. Update the driver test to assert silent
acceptance (clean stderr) instead of the removed message.

Diffstat:
M
driver/cmd/cc.c
 | 
19
-------------------
M
test/driver/run.sh
 | 
16
++++++----------

2 files changed, 6 insertions(+), 29 deletions(-)
diff --git a/driver/cmd/cc.c b/driver/cmd/cc.c
@@ -766,15 +766,6 @@ static int cc_record_mcmodel(CcOptions* o, const char* val) {
   return 1;
 }
 
-static void cc_log_ignored(const char* arg) {
-#ifndef NDEBUG
-  driver_errf(CC_TOOL, "ignoring accepted compatibility flag: %.*s",
-              KIT_SLICE_ARG(kit_slice_cstr(arg)));
-#else
-  (void)arg;
-#endif
-}
-
 static int cc_set_probe(CcOptions* o, int kind, const char* arg) {
   if (o->probe_kind != CC_PROBE_NONE) {
     driver_errf(CC_TOOL, "only one compiler-information probe is supported");
@@ -1201,7 +1192,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
       continue;
     }
     if (driver_streq(a, "-v") || driver_streq(a, "-###")) {
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-E")) {
@@ -1252,7 +1242,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
         driver_streq(a, "-Os") || driver_streq(a, "-Oz") ||
         driver_streq(a, "-Ofast")) {
       o->opt_level = 2;
-      if (!driver_streq(a, "-O")) cc_log_ignored(a);
       continue;
     }
 
@@ -1262,7 +1251,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
     }
     if (driver_strneq(a, "-Werror=", 8)) {
       o->warnings_are_errors = 1;
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-Wall") || driver_streq(a, "-Wextra") ||
@@ -1270,7 +1258,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
         driver_streq(a, "-pedantic-errors") || driver_streq(a, "-w") ||
         driver_strneq(a, "-Wno-", 5) ||
         (driver_strneq(a, "-W", 2) && !driver_strneq(a, "-Wl,", 4))) {
-      cc_log_ignored(a);
       continue;
     }
     if (driver_strneq(a, "-fmax-errors=", 13)) {
@@ -1283,7 +1270,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
       continue;
     }
     if (driver_strneq(a, "-std=", 5) || driver_streq(a, "-ansi")) {
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-ffreestanding")) {
@@ -1329,22 +1315,18 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
     }
     if (driver_streq(a, "-fno-builtin") || driver_streq(a, "-pipe") ||
         driver_streq(a, "-pthread")) {
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-nostdlib")) {
       o->no_stdlib = 1;
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-nodefaultlibs")) {
       o->no_defaultlibs = 1;
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-nostartfiles")) {
       o->no_startfiles = 1;
-      cc_log_ignored(a);
       continue;
     }
     if (driver_streq(a, "-isysroot") || driver_streq(a, "--sysroot")) {
@@ -1419,7 +1401,6 @@ static int cc_parse(int argc, char** argv, CcOptions* o) {
                     KIT_SLICE_ARG(kit_slice_cstr(a)));
         return 1;
       }
-      cc_log_ignored(a);
       continue;
     }
 
diff --git a/test/driver/run.sh b/test/driver/run.sh
@@ -224,18 +224,14 @@ else
     not_ok "cc-print-sysroot" "$work/cc-psysroot.diag"
 fi
 
-# ---- accepted-but-ignored compatibility flags log to stderr ----
+# ---- accepted-but-ignored compatibility flags are silently accepted ----
 if "$KIT" cc -Wall -Wextra -std=c11 -ffreestanding -c "$work/main.c" \
-    -o "$work/ignored.o" > "$work/cc-ignored.out" 2> "$work/cc-ignored.err"; then
-    if grep -q "ignoring accepted compatibility flag: -Wall" "$work/cc-ignored.err" &&
-       grep -q "ignoring accepted compatibility flag: -std=c11" "$work/cc-ignored.err"; then
-        ok "cc-ignored-compat-flags"
-    else
-        cp "$work/cc-ignored.err" "$work/cc-ignored.diag"
-        not_ok "cc-ignored-compat-flags" "$work/cc-ignored.diag"
-    fi
+    -o "$work/ignored.o" > "$work/cc-ignored.out" 2> "$work/cc-ignored.err" &&
+   [ -f "$work/ignored.o" ] && [ ! -s "$work/cc-ignored.err" ]; then
+    ok "cc-ignored-compat-flags"
 else
-    not_ok "cc-ignored-compat-flags" "$work/cc-ignored.err"
+    cp "$work/cc-ignored.err" "$work/cc-ignored.diag"
+    not_ok "cc-ignored-compat-flags" "$work/cc-ignored.diag"
 fi
 
 # ---- --output= long form (cc) ----