Add Examples for Building and Using Static Libraries #476
Conversation
There was a problem hiding this comment.
This is a great example, but I think the implementation is too complicated.
You can leverage the make lib rule and achieve the same result with a recursive make call.
Below is an example that builds the project in LIB_LOCATION as a static lib and adds it to the project's build. It also builds everything in the project's local folder to address the make clean issues.
# This file can be used to set build configuration
# variables. These variables are defined in a file called
# "Makefile" that is located next to this one.
# For instructions on how to use this system, see
# https://analog-devices-msdk.github.io/msdk/USERGUIDE/#build-system
# **********************************************************
# Move all build products to project's build folder
BUILD_DIR = $(CURDIR)/build
LIB_BUILD_DIR = $(BUILD_DIR)/build_lib
# Point to the location of the library
LIB_LOCATION = ../GPIO
# Add library to the build
LIB_NAME = mylib
MYLIB = $(LIB_BUILD_DIR)/$(LIB_NAME).a
LIBS += $(MYLIB)
# Add rule to build library with a recursive make call
$(MYLIB):
make -C $(LIB_LOCATION) BUILD_DIR=$(LIB_BUILD_DIR) PROJECT=$(LIB_NAME) lib
|
Additionally due to there are two examples, renaming them as below will be better.
|
| printf("SW2 then toggles the red and green LEDs according to the read values.\n"); | ||
|
|
||
| while (1) { | ||
| for (i = 0; i < num_pbs && i < num_leds; i++) { |
There was a problem hiding this comment.
Additionally, simple is better, just blinkig LED0 is fine.
Examples/MAX32650/Library_Use/main.c
Outdated
| printf("switch the red LED on as long as the push button is pressed.\n"); | ||
|
|
||
| while (1) { | ||
| if (gpio_get(&pb_pin[0])) { |
There was a problem hiding this comment.
Thanks for the update, it is better now lets make it more simple.
Because current flow expect user interaction (pressing button) to visualize something (blink led).
Our some boards have multiple buttons that too near each other (especially fthr boards). RST, SW1, SW2...
In that case it will confuse user.
So that demonstrating somethings without any user interaction will be better instead of waiting action by user.
Just blinking led would be better, exactly as Hello_World example.
| SBT=0 | ||
|
|
||
| # Point to the location of the library | ||
| LIB_LOCATION = ../Library_Generate |
There was a problem hiding this comment.
Please add .a and library interface file (.h file) to this project as statically.
There was a problem hiding this comment.
What does static inclusion imply in this case?
| LIB_NAME = Library_Generate | ||
| LIB_BUILD_DIR = $(LIB_LOCATION)/build | ||
| MYLIB = $(LIB_BUILD_DIR)/$(LIB_NAME).a | ||
| LIBS += $(MYLIB) |
There was a problem hiding this comment.
The name of .a file should be myLib.a or testLib.a.
|
Thanks approved. @Jake-Carter could you provide your feedback too, Then this development can be propagated to other MCUs. |
| @@ -0,0 +1,64 @@ | |||
| /** | |||
| * @file gpiolib.h | |||
There was a problem hiding this comment.
gpiolib.h should not be copied into Library_Use.
Add the Library_Generate project to IPATH in the Library_Use project.mk file. The safest way is to reference MAXIM_PATH. Ex:
IPATH += $(MAXIM_PATH)/Examples/$(TARGET_UC)/Library_GenerateLibraries normally provide an Include folder; you wouldn't usually make a copy of the include files to use the library.
There was a problem hiding this comment.
Thanks for the comment but these examples are independent examples.
The purpose of Library_Generate is to demonstrate the step how user create a library.
The purpose of Library_Use is to demonstrate the steps how user use a library that generated by another project.
Making a link to "C:/MaximSDK/Examples/xxx/Library_Generate" not a good idea on my view.
There was a problem hiding this comment.
@ozersa
Ok, even in this case I still think that having myLib.a inside the Library_Use might not be the best practice. Consider the case where a library is external to the project. The user must add:
IPATH += #library include path
PROJ_LDFLAGS += -L#path to library file
LIBS += #library fileHowever the example only demonstrates LIBS += #library file. It's rare that the user will copy the entire library static file and include files directly into the root of their project
There was a problem hiding this comment.
Sounds good, to demonstrate usage of IPATH, PROJ_LDFLAGS too, lets put lib related files under "lib" folder instead of root folder.
@ttmut please create below folders in Library_Use example
- lib
- lib/include
folders and put .a and .h in these folder, apply related changes on the project.mk files.
There was a problem hiding this comment.
I could only make this work with PROJ_LIBS and PROJ_LDFLAGS as shown below. If I am to use LIBS, PROJ_LDFLAGS becomes redundant.
IPATH += lib/include
PROJ_LDFLAGS += -Llib
PROJ_LIBS += myLib
IPATH += lib/include
PROJ_LDFLAGS += -Llib #Unnecessary since lib directory is already included in LIBS
LIBS += lib/libmyLib.a
There was a problem hiding this comment.
You're right, I'm not sure why the core makefiles have both LIBS and PROJ_LIBS. I think the original intention was LIBS would be internal to the SDK. We could streamline this at some point in the future.
PROJ_LIBS is the best choice for this. Looks good!
|
It is ok for me, can be propagated to other MCUs. |
Added an example project that builds and links a static library.
Rename Makefile to libExample.make so that the test build script does not attempt to run make on it.
* Rename StaticLibrary to TestLib * Reorganize the project makefiles * Replace the library api with GPIO functions
Rename TestLib to Library_Generate and StaticLibrary_Example to Library_Use. * Set Library_Generate default target as lib * Eliminate relative include paths * Add missing newlines * Simplify example application * Update documentation
Including the previously generated library to prevent creating a dependency to another project. In the main application, toggle LED every 500ms, do not check the state of the push buttons.
Move myLib.a to lib/ and tell the linker the location of the library using PROJ_LDFLAGS. Rename myLib.a to libmyLib.a so that it can be passed to linker with the -l option. Remove documentation for SBT option in Library_Generate project since it does not output an executable that needs to be signed.
Added Library_Generate and Library_Use examples.
|
After this PR to be merged please add same example on MAX32570 too. |
Jake-Carter
changed the title
This PR adds an example project that shows how to build part of the code as a static library.