Makefile: Adding 2nd directory for .h and .cpp files - makefile

Question

I am adapting my Makefile to look into 4 directories, rather than 2 (it had one for source files and one for header files, but I've added a new folder for common source and include). I have something like follows:
CC = g++
FLAGS = -g -c
BUILDDIR = build
INCLUDEDIR = -Icode/inc -I../common/code/inc -I/usr/include/libxml2
SOURCEDIR = code/src ../common/code/src
SOURCES = $(wildcard $(SOURCEDIR)/*.cpp)
OBJECTS = $(patsubst $(SOURCEDIR)/%.cpp,$(BUILDDIR)/%.o,$(SOURCES))
EXECUTABLE = Exec
all: $(BUILDDIR)/$(EXECUTABLE)
$(BUILDDIR)/$(EXECUTABLE): $(OBJECTS)
$(CC) $^ -o $# -lpthread -lxml2
$(OBJECTS): $(BUILDDIR)/%.o : $(SOURCEDIR)/%.cpp
$(CC) $(FLAGS) $< $(INCLUDEDIR) -o $# -Wno-write-strings
I tried to add one entry to INCLUDEDIR as follows:
-I../common/code/inc
And added ../common/code/src to SOURCEDIR:
SOURCEDIR = code/src ../common/code/src
This is not currently working and I am wondering how to fix it please. I am getting the error:
Makefile:27: target `code/src' doesn't match the target pattern
but I cannot find how to fix it so far. Any help would be appreciated.
EDIT: After following MadScientist response below, I am getting the following output:
g++ -c -o code/src/Client.o code/src/Client.cpp
code/src/Client.cpp:1:20: fatal error: Client.h: No such file or directory
compilation terminated.
make: *** [code/src/Client.o] Error 1
Updated Makefile:
SOURCEDIR = code/src ../common/code/src
SOURCES = $(wildcard $(addsuffix /*.cpp,$(SOURCEDIR)))
OBJECTS = $(SOURCES:%.cpp=%.o)
$(BUILDDIR)/$(EXECUTABLE): $(OBJECTS)
$(CC) $^ -o $# -lpthread -lxml2
$(BUILDDIR)/%.o : ../common/code/src/%.cpp
$(CC) $(FLAGS) $< $(INCLUDEDIR) -o $# -Wno-write-strings
$(BUILDDIR)/%.o : code/src/%.cpp
$(CC) $(FLAGS) $< $(INCLUDEDIR) -o $# -Wno-write-strings
PS:
I was able to fix it using the following:
SOURCEDIR = code/src ../common/code/src
SOURCES = $(wildcard $(addsuffix /*.cpp,$(SOURCEDIR)))
TEMP_OBJ = $(SOURCES:%.cpp=%.o)
NOT_DIR = $(notdir $(TEMP_OBJ))
OBJECTS = $(addprefix $(BUILDDIR)/, $(NOT_DIR))

Answer 1

Sure, because now your static pattern rule expands to:
$(OBJECTS): build/%.o : code/src ../common/code/src/%.cpp
which is illegal syntax. If you avoid using static pattern rules, and instead use pattern rules, then it will just work. Replace your single static pattern rule with two pattern rules:
$(BUILDDIR)/%.o : code/src/%.cpp
$(CC) $(FLAGS) $< $(INCLUDEDIR) -o $# -Wno-write-strings
$(BUILDDIR)/%.o : ../common/code/src/%.cpp
$(CC) $(FLAGS) $< $(INCLUDEDIR) -o $# -Wno-write-strings
EDIT: you also need to change other uses of SOURCEDIR:
SOURCES = $(wildcard $(addsuffix /*.cpp,$(SOURCEDIR))
OBJECTS = $(patsubst %.cpp,$(BUILDDIR)/%.o,$(notdir $(SOURCES)))