From 26bee8ad36030c89b1300d5095f56fa635b53b95 Mon Sep 17 00:00:00 2001
From: YAMAMOTO Takashi <yamamoto@midokura.com>
Date: Mon, 7 Apr 2025 16:06:01 +0900
Subject: [PATCH 1/3] drop a few unsupported CFLAGS for clang

---
 Makefile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 51e9f98e..1fd856f9 100644
--- a/Makefile
+++ b/Makefile
@@ -59,12 +59,15 @@ BENCH_PERF  := $(BENCH_RUNNER:%=%.perf)
 BENCH_TRACE := $(BENCH_RUNNER:%=%.trace)
 BENCH_CSV   := $(BENCH_RUNNER:%=%.csv)
 
-CFLAGS += -fcallgraph-info=su
 CFLAGS += -g3
 CFLAGS += -I.
 CFLAGS += -std=c99 -Wall -Wextra -pedantic
 CFLAGS += -Wmissing-prototypes
+ifeq ($(shell $(CC) --version | grep clang),)
 CFLAGS += -ftrack-macro-expansion=0
+CFLAGS += -fcallgraph-info=su
+endif
+
 ifdef DEBUG
 CFLAGS += -O0
 else

From bff4dfd1b1f6f2ee53bd4aae6de5d3b66c172251 Mon Sep 17 00:00:00 2001
From: Christopher Haster <geky@geky.net>
Date: Wed, 7 May 2025 22:46:31 -0500
Subject: [PATCH 2/3] Added NO_GCC to allow users to explicitly disable
 GCC-specific flags

This is the same as the implicit Clang => NO_GCC behavior introduced by
yamt, but with an explicit variable that can be assigned by users using
other, non-gcc, compilers:

  $ NO_GCC=1 make

Note, stack measurements are currently GCC specific:

  $ NO_GCC=1 make stack
  ... snip ...
  FileNotFoundError: [Errno 2] No such file or directory: 'lfs.ci'
  make: *** [Makefile:494: lfs.stack.csv] Error 1
---
 Makefile | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 1fd856f9..588e095d 100644
--- a/Makefile
+++ b/Makefile
@@ -18,6 +18,12 @@ VALGRIND ?= valgrind
 GDB		 ?= gdb
 PERF	 ?= perf
 
+# guess clang or gcc (clang sometimes masquerades as gcc because of
+# course it does)
+ifneq ($(shell $(CC) --version | grep clang),)
+NO_GCC = 1
+endif
+
 SRC  ?= $(filter-out $(wildcard *.t.* *.b.*),$(wildcard *.c))
 OBJ  := $(SRC:%.c=$(BUILDDIR)/%.o)
 DEP  := $(SRC:%.c=$(BUILDDIR)/%.d)
@@ -63,9 +69,9 @@ CFLAGS += -g3
 CFLAGS += -I.
 CFLAGS += -std=c99 -Wall -Wextra -pedantic
 CFLAGS += -Wmissing-prototypes
-ifeq ($(shell $(CC) --version | grep clang),)
-CFLAGS += -ftrack-macro-expansion=0
+ifndef NO_GCC
 CFLAGS += -fcallgraph-info=su
+CFLAGS += -ftrack-macro-expansion=0
 endif
 
 ifdef DEBUG

From 0115cf6b74cc27e288678aeb7f8c977be0792be0 Mon Sep 17 00:00:00 2001
From: Christopher Haster <geky@geky.net>
Date: Wed, 7 May 2025 23:45:29 -0500
Subject: [PATCH 3/3] gha: Dropped explicit CFLAGS from clang testing in CI

Thanks to yamt, GCC-specific flags should now be disabled if compiling
with clang. Dropping the explicit flags also doubles as a test that the
NO_GCC inference works.
---
 .github/workflows/test.yml | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f3100bee..f18c23d4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -454,8 +454,7 @@ jobs:
           TESTFLAGS="$TESTFLAGS --valgrind --context=1024 -Gdefault -Pnone" \
             make test
 
-  # test that compilation is warning free under clang
-  # run with Clang, mostly to check for Clang-specific warnings
+  # compile/run with Clang, mostly to check for Clang-specific warnings
   test-clang:
     runs-on: ubuntu-latest
     steps:
@@ -469,12 +468,8 @@ jobs:
           python3 --version
       - name: test-clang
         run: |
-          # override CFLAGS since Clang does not support -fcallgraph-info
-          # and -ftrack-macro-expansions
-          make \
-            CC=clang \
-            CFLAGS="$CFLAGS -MMD -g3 -I. -std=c99 -Wall -Wextra -pedantic" \
-            test
+          CC=clang \
+            make test
 
   # run benchmarks
   #