Add Linux and MinGW build support

.gitignore

@@ -0,0 +1,46 @@
+# New Makefile build directories
+/obj/
+/lib/
+
+# Compiler and linker output
+*.o
+*.obj
+*.d
+*.a
+*.so
+*.so.*
+*.dll
+*.dll.a
+*.lib
+*.exe
+*.out
+*.pdb
+
+# Files produced by the legacy makefile
+/ccsds_tab.c
+/ccsds_tal.c
+/gen_ccsds
+/gen_ccsds_tal
+/peaktest
+/sumsq_test
+/dtest
+/vtest27
+/vtest29
+/vtest615
+/rstest
+/core
+/core.*
+/autom4te.cache/
+
+# Editor and operating-system files
+*~
+*.swp
+*.swo
+*.tmp
+*.bak
+.DS_Store
+Thumbs.db
+
+# IDE settings
+/.idea/
+/.vscode/

GNUmakefile

@@ -0,0 +1,2 @@
+# GNU Make prefers this file over the legacy autotools-generated "makefile".
+include Makefile

Makefile

@@ -0,0 +1,160 @@
+# Build libfec on Linux and on/for 64-bit Windows with MinGW-w64.
+#
+#   make                 build for the host platform
+#   make linux           build Linux libraries
+#   make windows         build Windows libraries (cross-build on Linux)
+#   make static          build only the static library
+#   make shared          build only the shared library
+#   make clean           remove obj/ and lib/
+
+ifeq ($(OS),Windows_NT)
+  HOST_OS := windows
+else
+  HOST_OS := linux
+endif
+
+BUILD ?= $(HOST_OS)
+
+OBJROOT := obj
+OUTROOT := lib
+OBJDIR  := $(OBJROOT)/$(BUILD)
+OUTDIR  := $(OUTROOT)/$(BUILD)
+GENDIR  := $(OBJDIR)/generated
+TOOLDIR := $(OBJROOT)/tools/$(HOST_OS)
+
+# Command-line assignments (for example CC=clang) still take precedence.
+ifeq ($(BUILD),windows)
+  ifeq ($(HOST_OS),windows)
+    CROSS_PREFIX ?=
+  else
+    CROSS_PREFIX ?= x86_64-w64-mingw32-
+  endif
+  ifeq ($(origin CC),default)
+    CC := $(CROSS_PREFIX)gcc
+  endif
+  ifeq ($(origin AR),default)
+    AR := $(CROSS_PREFIX)ar
+  endif
+  ifeq ($(origin RANLIB),undefined)
+    RANLIB := $(CROSS_PREFIX)ranlib
+  endif
+  SHARED_LIB := $(OUTDIR)/libfec.dll
+  IMPORT_LIB := $(OUTDIR)/libfec.dll.a
+  SHARED_FLAGS := -shared -Wl,--out-implib,$(IMPORT_LIB)
+  PIC_CFLAGS :=
+else ifeq ($(BUILD),linux)
+  ifeq ($(origin CC),default)
+    CC := gcc
+  endif
+  ifeq ($(origin AR),default)
+    AR := ar
+  endif
+  ifeq ($(origin RANLIB),undefined)
+    RANLIB := ranlib
+  endif
+  SHARED_LIB := $(OUTDIR)/libfec.so
+  IMPORT_LIB :=
+  SHARED_FLAGS := -shared -Wl,-soname,libfec.so
+  PIC_CFLAGS := -fPIC
+else
+  $(error Unsupported BUILD='$(BUILD)'; use BUILD=linux or BUILD=windows)
+endif
+
+ifeq ($(origin HOSTCC),undefined)
+  HOSTCC := gcc
+endif
+
+CPPFLAGS ?=
+CFLAGS ?= -O2 -Wall -Wno-implicit-int -Wno-implicit-function-declaration -Wno-int-conversion
+LDFLAGS ?=
+LDLIBS ?= -lm
+HOSTCFLAGS ?= -O2
+
+STATIC_LIB := $(OUTDIR)/libfec.a
+
+SOURCES := \
+	cpu_mode_generic.c fec.c sim.c \
+	viterbi27.c viterbi27_port.c \
+	viterbi29.c viterbi29_port.c \
+	viterbi615.c viterbi615_port.c \
+	encode_rs_char.c encode_rs_int.c encode_rs_8.c \
+	decode_rs_char.c decode_rs_int.c decode_rs_8.c \
+	init_rs_char.c init_rs_int.c \
+	encode_rs_ccsds.c decode_rs_ccsds.c \
+	dotprod.c dotprod_port.c \
+	peakval.c peakval_port.c \
+	sumsq.c sumsq_port.c
+
+GENERATED_SOURCES := $(GENDIR)/ccsds_tab.c $(GENDIR)/ccsds_tal.c
+OBJECTS := $(addprefix $(OBJDIR)/,$(SOURCES:.c=.o)) \
+	$(OBJDIR)/ccsds_tab.o $(OBJDIR)/ccsds_tal.o
+DEPS := $(OBJECTS:.o=.d)
+
+GEN_CCSDS := $(TOOLDIR)/gen_ccsds$(if $(filter windows,$(HOST_OS)),.exe)
+GEN_TAL   := $(TOOLDIR)/gen_ccsds_tal$(if $(filter windows,$(HOST_OS)),.exe)
+HOST_GEN_OBJECTS := $(TOOLDIR)/gen_ccsds.o $(TOOLDIR)/init_rs_char.o
+
+.DEFAULT_GOAL := all
+.PHONY: all build linux windows static shared check-tools clean
+
+all: build
+build: check-tools static shared
+static: $(STATIC_LIB)
+shared: $(SHARED_LIB)
+
+# Explicit platform aliases are recursive so their toolchains and paths are
+# resolved with the requested BUILD value from the start.
+linux:
+	$(MAKE) BUILD=linux build
+
+windows:
+	$(MAKE) BUILD=windows build
+
+check-tools:
+	@command -v $(CC) >/dev/null 2>&1 || { \
+		echo "Error: compiler '$(CC)' was not found."; \
+		echo "On Linux install MinGW-w64; on Windows run this from an MSYS2 MinGW 64-bit shell."; \
+		exit 1; \
+	}
+
+$(STATIC_LIB): $(OBJECTS) | $(OUTDIR)
+	$(AR) rcs $@ $^
+	$(RANLIB) $@
+
+$(SHARED_LIB): $(OBJECTS) | $(OUTDIR)
+	$(CC) $(SHARED_FLAGS) $(LDFLAGS) -o $@ $^ $(LDLIBS)
+
+$(OBJDIR)/%.o: %.c | $(OBJDIR)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(PIC_CFLAGS) -MMD -MP -I. -c -o $@ $<
+
+$(OBJDIR)/ccsds_tab.o: $(GENDIR)/ccsds_tab.c | $(OBJDIR)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(PIC_CFLAGS) -MMD -MP -I. -c -o $@ $<
+
+$(OBJDIR)/ccsds_tal.o: $(GENDIR)/ccsds_tal.c | $(OBJDIR)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(PIC_CFLAGS) -MMD -MP -I. -c -o $@ $<
+
+$(GENDIR)/ccsds_tab.c: $(GEN_CCSDS) | $(GENDIR)
+	$(GEN_CCSDS) > $@
+
+$(GENDIR)/ccsds_tal.c: $(GEN_TAL) | $(GENDIR)
+	$(GEN_TAL) > $@
+
+$(GEN_CCSDS): $(HOST_GEN_OBJECTS) | $(TOOLDIR)
+	$(HOSTCC) -o $@ $^
+
+$(GEN_TAL): gen_ccsds_tal.c | $(TOOLDIR)
+	$(HOSTCC) $(HOSTCFLAGS) -I. -o $@ $<
+
+$(TOOLDIR)/gen_ccsds.o: gen_ccsds.c char.h rs-common.h fec.h | $(TOOLDIR)
+	$(HOSTCC) $(HOSTCFLAGS) -I. -c -o $@ $<
+
+$(TOOLDIR)/init_rs_char.o: init_rs_char.c char.h rs-common.h init_rs.h fec.h | $(TOOLDIR)
+	$(HOSTCC) $(HOSTCFLAGS) -I. -c -o $@ $<
+
+$(OBJDIR) $(OUTDIR) $(GENDIR) $(TOOLDIR):
+	mkdir -p $@
+
+clean:
+	-rm -rf $(OBJROOT) $(OUTROOT)
+
+-include $(DEPS)

README

@@ -85,6 +85,28 @@ http://people.qualcomm.com/karn
 This software may be used under the terms of the GNU Lesser General
 Public License (LGPL); see the file lesser.txt for details.
 
+BUILDING
+
+The GNU Make build keeps intermediate files under obj/ and libraries under
+lib/. Platform-specific subdirectories allow Linux and Windows builds to
+coexist.
+
+On Linux:
+
+    make linux
+
+To cross-compile for 64-bit Windows on Linux (requires MinGW-w64):
+
+    make windows
+
+To build natively on Windows, open an MSYS2 MinGW 64-bit shell and run:
+
+    make
+
+The resulting files are in lib/linux/ or lib/windows/. Use `make static` or
+`make shared` to build only one library type, and `make clean` to remove all
+generated files.
+
 Revision history:
 Version 1.0 released 29 May 2001