From 8a3359e2ee563951e74926acf7299a5f4081164a Mon Sep 17 00:00:00 2001
From: "Thing-han, Lim" <15379156+potsrevennil@users.noreply.github.com>
Date: Mon, 18 Nov 2024 13:52:31 +0800
Subject: [PATCH] workaround to make -flto work in nix shell

nix gcc comes with lto library, but binutils like ar doesn't seem to
properly configured regarding this.

The easiest workaround to make -flto work is therefore to avoid building
libraries, let gcc take over everything.

`CPPFLAGS += -DMLKEM_USE_NATIVE` in `mk/crypto.mk` is removed btw as
it's duplicated in `mk/schemes.mk`

Signed-off-by: Thing-han, Lim <15379156+potsrevennil@users.noreply.github.com>
---
 mk/bench.mk   |  4 +---
 mk/config.mk  |  3 ---
 mk/crypto.mk  | 11 ++---------
 mk/rules.mk   | 18 ++++++------------
 mk/schemes.mk |  2 +-
 5 files changed, 10 insertions(+), 28 deletions(-)

diff --git a/mk/bench.mk b/mk/bench.mk
index 6293d1eea..a1a115d82 100644
--- a/mk/bench.mk
+++ b/mk/bench.mk
@@ -1,5 +1,3 @@
 # SPDX-License-Identifier: Apache-2.0
-LIBDEPS += $(LIB_DIR)/libhal.a
-LDLIBS += -lhal
 CPPFLAGS += -Itest/hal
-$(LIB_DIR)/libhal.a: $(call OBJS,$(wildcard test/hal/*.c))
+SOURCES += $(wildcard test/hal/*.c)
diff --git a/mk/config.mk b/mk/config.mk
index 193d5fa1a..5a254d12e 100644
--- a/mk/config.mk
+++ b/mk/config.mk
@@ -41,8 +41,6 @@ CFLAGS += \
 	-MMD \
 	$(CPPFLAGS)
 
-LINKDEPS += $(LIBDEPS)
-
 ##################
 # Some Variables #
 ##################
@@ -83,7 +81,6 @@ include mk/auto.mk
 endif
 
 BUILD_DIR := test/build
-LIB_DIR := $(BUILD_DIR)/lib
 
 MAKE_OBJS = $(2:%=$(1)/%.o)
 OBJS = $(call MAKE_OBJS,$(BUILD_DIR),$(1))
diff --git a/mk/crypto.mk b/mk/crypto.mk
index 59ce1f47a..9d096443f 100644
--- a/mk/crypto.mk
+++ b/mk/crypto.mk
@@ -1,14 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
-LDLIBS += -L$(LIB_DIR)
-
-LIBDEPS += $(LIB_DIR)/libfips202.a
-LDLIBS += -lfips202
 CPPFLAGS += -Ifips202 -Ifips202/native
 
-FIPS202_SRCS = $(wildcard fips202/*.c)
+SOURCES += $(wildcard fips202/*.c)
 ifeq ($(OPT),1)
-	FIPS202_SRCS += $(wildcard fips202/native/aarch64/*.S) $(wildcard fips202/native/x86_64/xkcp/*.c)
-	CPPFLAGS += -DMLKEM_USE_NATIVE
+	SOURCES += $(wildcard fips202/native/aarch64/*.S) $(wildcard fips202/native/x86_64/xkcp/*.c)
 endif
-
-$(LIB_DIR)/libfips202.a: $(call OBJS, $(FIPS202_SRCS))
diff --git a/mk/rules.mk b/mk/rules.mk
index 36519837d..dea93fb21 100644
--- a/mk/rules.mk
+++ b/mk/rules.mk
@@ -1,24 +1,18 @@
 # SPDX-License-Identifier: Apache-2.0
-$(BUILD_DIR)/mlkem512/bin/%: $(LINKDEPS) $(CONFIG)
+$(BUILD_DIR)/mlkem512/bin/%: $(CONFIG)
 	$(Q)echo "  LD      $@"
 	$(Q)[ -d $(@D) ] || mkdir -p $(@D)
-	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^) $(LDLIBS)
+	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^)
 
-$(BUILD_DIR)/mlkem768/bin/%: $(LINKDEPS) $(CONFIG)
+$(BUILD_DIR)/mlkem768/bin/%: $(CONFIG)
 	$(Q)echo "  LD      $@"
 	$(Q)[ -d $(@D) ] || mkdir -p $(@D)
-	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^) $(LDLIBS)
+	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^)
 
-$(BUILD_DIR)/mlkem1024/bin/%: $(LINKDEPS) $(CONFIG)
+$(BUILD_DIR)/mlkem1024/bin/%: $(CONFIG)
 	$(Q)echo "  LD      $@"
 	$(Q)[ -d $(@D) ] || mkdir -p $(@D)
-	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^) $(LDLIBS)
-
-$(LIB_DIR)/%.a: $(CONFIG)
-	$(Q)echo "  AR      $@"
-	$(Q)[ -d $(@D) ] || mkdir -p $(@D)
-	$(Q)rm -f $@
-	$(Q)$(AR) rcs $@ $(filter %.o,$^)
+	$(LD) $(CFLAGS) -o $@ $(filter %.o,$^)
 
 $(BUILD_DIR)/%.c.o: %.c $(CONFIG)
 	$(Q)echo "  CC      $@"
diff --git a/mk/schemes.mk b/mk/schemes.mk
index f1dc2be39..6a4e7fec8 100644
--- a/mk/schemes.mk
+++ b/mk/schemes.mk
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
-SOURCES = $(wildcard mlkem/*.c) $(wildcard mlkem/debug/*.c)
+SOURCES += $(wildcard mlkem/*.c) $(wildcard mlkem/debug/*.c)
 ifeq ($(OPT),1)
 	SOURCES += $(wildcard mlkem/native/aarch64/*.[csS]) $(wildcard mlkem/native/x86_64/*.[csS])
 	CPPFLAGS += -DMLKEM_USE_NATIVE