Question

I need to modify the below makefile to create a dll (SampleNew.dll) that will run on a 32-bit windows and 64-bit Windows environment. Maybe creating two dlls (one for 64 and one for 32) is the best approach. It needs to use SampleApi.dll (in LIBS declaration below). The below doesn’t create a valid 32 bit dll for Windows. Any ideas on how to modify the below to make it work?

CMODE=

SWIG = swig
CC = $(PREFIX)gcc
LD = $(CC) 

OBJ_DIR = obj
AUTOGEN_DIR = ../src/java
PACKAGE_DIR = $(AUTOGEN_DIR)/com/test/sample

PACKAGE = com.test.sample

INCLUDES = -I$(JAVA_INCLUDE) \
           -I$(SAMPLE_DIR)/include \
           -I$(JDK_HOME)/include

LIB_INCLUDES = -L$(SAMPLE_DIR)/lib

LIBS = /lib/libssl.so.4 \
       /lib/libcrypto.so.4 \
       -lSampleApi \
       -lm

DIRS = $(PACKAGE_DIR) $(DIST_DIR) $(OBJ_DIR) $(AUTOGEN_DIR)

CFLAGS = $(CMODE) -Wall -fpic $(INCLUDES) -O0 -g3
SFLAGS = -java $(INCLUDES) -package $(PACKAGE) -outdir $(PACKAGE_DIR)
LDFLAGS = -shared $(LIB_INCLUDES) $(LIBS)

OBJECTS = $(OBJ_DIR)/test_wrap.o
TARGET = $(LIB_DIR)/SampleNew.dll

all: $(DIRS) $(TARGET)

%_wrap.c: %.i
    $(SWIG) $(SFLAGS) $< 

$(OBJ_DIR)/%.o: %.c
    $(CC) $(CFLAGS) -c $< -o $@

$(TARGET): $(OBJECTS)
    $(LD) $(OBJECTS) $(LDFLAGS) -o $@

$(DIRS):
    mkdir -p $@

clean:
    rm -rf $(TARGET) $(PACKAGE_DIR)/* $(TARGET) $(AUTOGEN_DIR) $(OBJ_DIR)

Exception:

java.lang.UnsatisfiedLinkError c:\test\myDllFile.dll: can't load this .dll (machine code=0x101) on a IA 32-bit platform

update Makefile:

CMODE=

SWIG = swig
PREFIX=/test/mingw/mingw32/bin/i386-mingw32-
CC = $(PREFIX)gcc
LD = $(CC) 

OBJ_DIR = obj
AUTOGEN_DIR = ../src/java
PACKAGE_DIR = $(AUTOGEN_DIR)/com/test/jni

PACKAGE = com.test.jni

INCLUDES = -I$(HEADER_FILES_DIR) # env var that points to a dir with all the .h files

LIB_INCLUDES = -L$(C_API_DIR)/lib # env var that points to a dir with the C libraries (dlls)

LIBS = -lMainApi \ # MainApi.dll
       -lm

DIRS = $(PACKAGE_DIR) $(DIST_DIR) $(OBJ_DIR) $(AUTOGEN_DIR) # DIST_DIR is passed in 

CFLAGS = $(CMODE) -Wall -fpic $(INCLUDES) -O0 -g3
SFLAGS = -java $(INCLUDES) -package $(PACKAGE) -outdir $(PACKAGE_DIR)
LDFLAGS = -shared $(LIB_INCLUDES) $(LIBS) -leay32 -lws2_32 -lrpcrt4

OBJECTS = $(OBJ_DIR)/test_wrap.o
TARGET = $(LIB_DIR)/SampleJni.dll

all: $(DIRS) $(TARGET)

%_wrap.c: %.i
    $(SWIG) $(SFLAGS) $< 

$(OBJ_DIR)/%.o: %.c
    $(CC) $(CFLAGS) -c $< -o $@

$(TARGET): $(OBJECTS)
    $(LD) $(OBJECTS) $(LDFLAGS) -o $@

$(DIRS):
    mkdir -p $@

clean:
    rm -rf $(TARGET) $(PACKAGE_DIR)/* $(TARGET) $(AUTOGEN_DIR) $(OBJ_DIR)

Answer 1

The simplest thing you can do is to build both separately. For example, defining:

CFLAGS = $(CMODE) -Wall -fpic $(INCLUDES) -O0 -g3 -march=$(ARCH)
OBJ_DIR = obj-$(ARCH)
LIB_DIR = lib-$(ARCH)

.PHONY: default
default:
        $(MAKE) ARCH=i686 all
        $(MAKE) ARCH=x86_64 all

Avoid -m32, since it generates 32bit code for x86-64, which may use instructions not available in x86.