More CMake flag fixes (#60)

amends #59 

- cmake defaults to empty variables. if repo is some place else, git
simply errors out and the resulting description var will also be empty
(like it is currently happening in actions .yml)
- toolchain .cmake is 'sourced' multiple times when running cmake for
the first time. Instead of using list var, just use the built-in global flag
setter (which also takes care of flag unique-ness, as well as caching)
- -std=... flags were missing
- files with platform-specific things are suffixed with *-esp8266.cmake

.github/workflows/run.yml

@@ -49,7 +49,7 @@ jobs:
           ESP8266_ARDUINO_CORE_DIR: ${{ github.workspace }}/esp8266
         run: |
           cmake \
-             --toolchain=${{ github.workspace }}/repo/cmake/toolchain.cmake \
+             --toolchain=${{ github.workspace }}/repo/cmake/toolchain-esp8266.cmake \
             -DCMAKE_PROGRAM_PATH=${ESP8266_ARDUINO_CORE_DIR}/tools/xtensa-lx106-elf/bin \
             -DESP8266_ARDUINO_CORE_DIR=${ESP8266_ARDUINO_CORE_DIR} \
             -S repo \

CMakeLists.txt

@@ -1,29 +1,28 @@
 cmake_minimum_required(VERSION 3.11)
 project(lwip-glue-builder
-    VERSION 20220704
+    VERSION 20220711
     DESCRIPTION "lwip-glue-builder"
     LANGUAGES C
 )
 
-list(APPEND compile_options
-    "-nostdlib"
-    "-ffunction-sections"
-    "-fdata-sections"
-    "-falign-functions=4")
+set(CMAKE_C_STANDARD 99)
+set(CMAKE_CXX_STANDARD 11)
 
-list(APPEND compile_options
-    "-Wall"
-    "-Wextra"
-    "-Wpointer-arith"
-    "-Werror=return-type")
+add_compile_options(
+    -nostdlib
+    -ffunction-sections
+    -fdata-sections
+    -falign-functions=4)
 
-list(APPEND compile_options
-    "-Os"
-    "-g")
+add_compile_options(
+    -Wall
+    -Wextra
+    -Wpointer-arith
+    -Werror=return-type)
 
-add_compile_options("${compile_options}")
-
-message(STATUS "default options: " "${compile_options}")
+add_compile_options(
+    -Os
+    -g)
 
 set(UPSTREAM_VERSION "STABLE-2_1_3_RELEASE")
 set(LWIP_TAG ${UPSTREAM_VERSION})

README-CMake.md

@@ -9,8 +9,8 @@
 To build & install everything into the specific ESP8266 Core directory:
 ```
 $ cmake \
-    --toolchain=cmake/toolchain.cmake \
-    -DCMAKE_PROGRAM_PATH=<path to the toolchain bin directory> \
+    --toolchain=cmake/toolchain-esp8266.cmake \
+    -DCMAKE_PROGRAM_PATH=<path to the gcc toolchain bin directory> \
     -DESP8266_ARDUINO_CORE_DIR=<path to the arduino core directory> \
     -B build
 $ cmake --build build

cmake/common.cmake

@@ -2,7 +2,7 @@
 
 execute_process(
     COMMAND git describe --tag
-    WORKING_DIRECTORY "${GLUE_DIR}"
+    WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
     OUTPUT_VARIABLE GLUE_REPO_DESC_STR
     OUTPUT_STRIP_TRAILING_WHITESPACE
 )

cmake/toolchain.cmake → cmake/toolchain-esp8266.cmake

@@ -1,16 +1,16 @@
 include(Compiler/GNU)
 
-set(CMAKE_USER_MAKE_RULES_OVERRIDE "${CMAKE_CURRENT_LIST_DIR}/esp8266-platform.cmake")
+set(CMAKE_USER_MAKE_RULES_OVERRIDE "${CMAKE_CURRENT_LIST_DIR}/platform-esp8266.cmake")
 set(CMAKE_SYSTEM_NAME "Generic")
 
 set(triple xtensa-lx106-elf)
 
 set(CMAKE_C_COMPILER ${triple}-gcc)
 set(CMAKE_CXX_COMPILER ${triple}-g++)
 
-list(APPEND compile_options
-    "-mlongcalls"
-    "-mtext-section-literals")
+add_compile_options(
+    -mlongcalls
+    -mtext-section-literals)
 
 set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")