build: introduce declarative non-recursive build graph

2 files changed, 35 insertions, 66 deletions

diff --git a/lib/Build.mk b/lib/Build.mk
new file mode 100644
index 0000000..77d380c
--- /dev/null
+++ b/lib/Build.mk
@@ -0,0 +1,35 @@
+targets += lib/runtime lib/string lib/libfdt lib/core
+
+target.lib/runtime.kind := source-set
+target.lib/runtime.sources := \
+    lib/cxx_abi.cc lib/rbtree.cc lib/kobject.cc lib/kprintf.cc lib/klog.cc \
+    lib/random.cc lib/printf.c
+
+target.lib/string.kind := static-library
+target.lib/string.sources := $(sort $(wildcard lib/string/*.c))
+
+# Architecture assembly replaces the matching generic C implementation.
+string-arch.riscv :=
+string-arch.x86_64 := x86_64
+string-arch.aarch64 := aarch64
+string-arch.i386 := i386
+string-arch.arm := arm
+string-arch := $(string-arch.$(ARCH))
+ifneq ($(string-arch),)
+string-asm := $(sort $(wildcard lib/string/$(string-arch)/*.S) \
+                           $(wildcard lib/string/$(string-arch)/*.s))
+string-asm-names := $(sort $(basename $(notdir $(string-asm))))
+target.lib/string.sources := $(filter-out \
+    $(foreach name,$(string-asm-names),lib/string/$(name).c), \
+    $(target.lib/string.sources)) $(string-asm)
+endif
+
+target.lib/libfdt.kind := static-library
+target.lib/libfdt.sources := \
+    lib/fdt.c lib/fdt_ro.c lib/fdt_wip.c lib/fdt_rw.c lib/fdt_sw.c \
+    lib/fdt_strerror.c lib/fdt_empty_tree.c lib/fdt_addresses.c
+target.lib/libfdt.private-includes := scripts/dtc/libfdt
+target.lib/libfdt.cflags := -Wno-parentheses -Wno-sign-compare
+
+target.lib/core.kind := header-library
+target.lib/core.deps := lib/runtime lib/string lib/libfdt
diff --git a/lib/module.mk b/lib/module.mk
deleted file mode 100644
index 0b178f8..0000000
--- a/lib/module.mk
+++ /dev/null
@@ -1,66 +0,0 @@
-# lib/module.mk
-SRCS_CC += lib/cxx_abi.cc
-SRCS_CC += lib/rbtree.cc
-SRCS_CC += lib/kobject.cc
-SRCS_CC += lib/kprintf.cc
-SRCS_CC += lib/klog.cc
-SRCS_CC += lib/random.cc
-SRCS_C  += lib/printf.c
-
-# ============================================================
-# musl string library (cross-platform with arch asm overrides)
-# ============================================================
-
-# Map LumeOS ARCH to musl string arch directory
-# riscv has no musl asm optimizations → pure C fallback
-MUSL_STRING_ARCH_riscv  :=
-MUSL_STRING_ARCH_x86_64 := x86_64
-MUSL_STRING_ARCH_i386   := i386
-MUSL_STRING_ARCH_aarch64:= aarch64
-MUSL_STRING_ARCH_arm    := arm
-
-MUSL_STRING_ARCH := $(MUSL_STRING_ARCH_$(ARCH))
-
-# Collect arch-specific asm sources (if any for this arch)
-MUSL_ASM_SRCS :=
-ifneq ($(MUSL_STRING_ARCH),)
-    MUSL_ASM_SRCS += $(wildcard lib/string/$(MUSL_STRING_ARCH)/*.S) \
-                     $(wildcard lib/string/$(MUSL_STRING_ARCH)/*.s)
-endif
-
-# Derive which C files are overridden by asm (strip path+ext to get base name)
-MUSL_ASM_BASENAMES := $(sort $(basename $(notdir $(MUSL_ASM_SRCS))))
-
-# All C sources, then filter out those with asm replacements
-MUSL_ALL_C := $(wildcard lib/string/*.c)
-MUSL_EXCLUDED_C := $(foreach name,$(MUSL_ASM_BASENAMES),lib/string/$(name).c)
-MUSL_C_SRCS := $(filter-out $(MUSL_EXCLUDED_C),$(MUSL_ALL_C))
-
-SRCS_C += $(MUSL_C_SRCS)
-SRCS_S += $(filter %.S,$(MUSL_ASM_SRCS))
-SRCS_s += $(filter %.s,$(MUSL_ASM_SRCS))
-
-# ============================================================
-# libfdt — kernel adapter shims around scripts/dtc/libfdt/.
-#
-# Each shim is two lines:
-#     #include <linux/libfdt_env.h>
-#     #include "../scripts/dtc/libfdt/fdt*.c"
-# matching Linux lib/fdt*.c verbatim.  The compile recipe needs:
-#   - <linux/libfdt_env.h>  reachable via the default -Iinclude path
-#   - -I scripts/dtc/libfdt  so the upstream source's #include <libfdt.h>
-#     and friends resolve to scripts/dtc/libfdt/libfdt.h
-# Overriding CFLAGS_LIBC (which the %.o: %.c rule uses) avoids dragging
-# in libc-shim headers — libfdt is freestanding-compatible and uses
-# only the string functions forward-declared in <linux/libfdt_env.h>.
-# ============================================================
-LIBFDT_FILES := fdt.c fdt_ro.c fdt_wip.c fdt_rw.c fdt_sw.c \
-                fdt_strerror.c fdt_empty_tree.c fdt_addresses.c
-SRCS_C += $(addprefix lib/,$(LIBFDT_FILES))
-
-# Per-target CFLAGS override: plain CFLAGS plus the upstream include dir.
-# Use `=` (recursive) not `:=` because $(CFLAGS) is defined in the top
-# Makefile AFTER this file is included — `:=` would expand it now (empty)
-# and lose -Iinclude, breaking <linux/libfdt_env.h>.
-$(addprefix $(BUILD)/lib/,$(LIBFDT_FILES:.c=.o)): CFLAGS_LIBC = \
-    $(CFLAGS) -I scripts/dtc/libfdt