[scons] Simplify Scons tooling, misc. fixes and improvements

.gitignore

@@ -31,6 +31,7 @@ CMakeLists.txt
 
 # ignore generated code in the example folder
 examples/**/modm
+examples/**/artifacts
 examples/**/compile_commands.json
 examples/**/SConstruct
 examples/**/Makefile

.gitmodules

@@ -4,9 +4,6 @@
 [submodule "ext/modm-devices"]
 	path = ext/modm-devices
 	url = https://github.com/modm-io/modm-devices.git
-[submodule "ext/dlr/scons-build-tools"]
-	path = ext/dlr/scons-build-tools
-	url = https://github.com/modm-io/scons-build-tools.git
 [submodule "ext/ros/ros-lib"]
 	path = ext/ros/ros-lib
 	url = https://github.com/modm-io/ros-lib

examples/README.md

@@ -10,7 +10,10 @@ Make sure you've [installed all tools required for building modm](https://modm.i
 
 ## TL;DR
 
+To compile any example:
+
 ```
+cd modm/examples/generic/blinky  # cd into the example
 lbuild build    # generate modm library (call only once)
 scons program   # compile and upload to your development board
 ```
@@ -19,7 +22,7 @@ To debug with GDB in TUI mode:
 
 ```
 scons program profile=debug # compile and upload debug profile
-scons gdb profile=debug     # launch OpenOCD and GDB for debugging
+scons debug profile=debug   # launch OpenOCD and GDB for debugging
 ```
 
 To generate your target specific Doxygen documentation:

src/modm/platform/core/cortex/module.lb

@@ -166,6 +166,14 @@ def prepare(module, options):
             maximum=2 ** 16,
             default="3*1024"))
 
+    if "f" in options[":target"].get_driver("core")["type"]:
+        module.add_option(
+            EnumerationOption(
+                name="float-abi",
+                description="Floating point ABI",
+                enumeration=["soft", "softfp", "hard"],
+                default="hard"))
+
     memories = listify(options[":target"].get_driver("core")["memory"])
 
     # Cortex-M0 does not have remappable vector table, so it will remain in Flash
@@ -258,6 +266,7 @@ def build(env):
         "with_fault_storage": env.has_module(":platform:fault"),
         "with_memory_traits": env.has_module(":architecture:memory"),
         "with_assert": env.has_module(":architecture:assert"),
+        "with_fpu": env.get("float-abi", "soft") != "soft",
     })
     env.outbasepath = "modm/src/modm/platform/core"
 
@@ -345,7 +354,7 @@ def build(env):
             "7f": "-mfpu=fpv5-sp-d16",
             "7fd": "-mfpu=fpv5-d16",
         }[fpu]
-        env.collect(":build:archflags", "-mfloat-abi=hard", fpu_spec)
+        env.collect(":build:archflags", "-mfloat-abi={}".format(env["float-abi"]), fpu_spec)
         single_precision = ("-sp-" in fpu_spec)
     if single_precision:
         env.collect(":build:ccflags", "-fsingle-precision-constant",

src/modm/platform/core/cortex/module.md

@@ -309,7 +309,7 @@ This module adds these architecture specific [compiler options][options]:
 
 - `-mcpu=cortex-m{type}`: the target to compile for.
 - `-mthumb`: only Thumb2 instruction set is supported.
-- `-mfloat-abi=hard`: if FPU available use the fastest ABI available.
+- `-mfloat-abi={soft, softfp, hard}`: the FPU ABI: `hard` is fastest.
 - `-mfpu=fpv{4, 5}-{sp}-d16`: single or double precision FPU.
 - `-fsingle-precision-constant`: if SP-FPU, treat all FP constants as SP.
 - `-Wdouble-promotion`: if SP-FPU, warn if FPs are promoted to doubles.

src/modm/platform/core/cortex/startup.c.in

@@ -97,7 +97,7 @@ void __modm_startup(void)
 	SCB_EnableICache();
 %% endif
 
-%% if "f" in core
+%% if with_fpu
 	// Enable FPU in privileged and user mode
 	SCB->CPACR |= ((3UL << 10*2) | (3UL << 11*2));
 %% endif

tools/build_script_generator/cmake/cmake_scripts/configure-gcc.cmake.in

@@ -1,5 +1,5 @@
 # Copyright (c) 2018, Sergiy Yevtushenko
-# Copyright (c) 2018-2019, Niklas Hauser
+# Copyright (c) 2018-2019, 2021, Niklas Hauser
 #
 # This file is part of the modm project.
 #
@@ -13,7 +13,9 @@ endif()
 
 set(CMAKE_SYSTEM_NAME Generic)
 set(CMAKE_SYSTEM_PROCESSOR arm)
+%% if platform == "hosted"
 find_package(PkgConfig)
+%% endif
 
 if(NOT TOOL_EXECUTABLE_PREFIX)
 %% if core.startswith("cortex-m")
@@ -44,11 +46,11 @@ set(CMAKE_C_COMPILER "${TOOL_EXECUTABLE_PREFIX}gcc${TOOL_EXECUTABLE_SUFFIX}" CAC
 set(CMAKE_CXX_COMPILER "${TOOL_EXECUTABLE_PREFIX}g++${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++")
 set(CMAKE_ASM_COMPILER "${CMAKE_C_COMPILER}"     CACHE INTERNAL "asm")
 
-set(CMAKE_AR           "${TOOL_EXECUTABLE_PREFIX}ar"      CACHE INTERNAL "ar")
-set(CMAKE_RANLIB       "${TOOL_EXECUTABLE_PREFIX}ranlib"  CACHE INTERNAL "ranlib")
 if(TOOL_EXECUTABLE_SUFFIX STREQUAL "")
     set(CMAKE_AS       "${TOOL_EXECUTABLE_PREFIX}as"      CACHE INTERNAL "as")
     set(CMAKE_NM       "${TOOL_EXECUTABLE_PREFIX}nm"      CACHE INTERNAL "nm")
+    set(CMAKE_AR       "${TOOL_EXECUTABLE_PREFIX}ar"      CACHE INTERNAL "ar")
+    set(CMAKE_RANLIB   "${TOOL_EXECUTABLE_PREFIX}ranlib"  CACHE INTERNAL "ranlib")
 else()
     set(CMAKE_AS       "${CMAKE_CXX_COMPILER}"            CACHE INTERNAL "as")
     set(CMAKE_NM       "${TOOL_EXECUTABLE_PREFIX}gcc-nm${TOOL_EXECUTABLE_SUFFIX}"     CACHE INTERNAL "nm")
@@ -71,6 +73,12 @@ set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 
+# Used to make stdlibc++ paths in ELF relative to compiler
+find_program(MODM_GCC_PATH NAMES ${CMAKE_C_COMPILER})
+get_filename_component(MODM_GCC_PATH ${MODM_GCC_PATH} REALPATH)
+get_filename_component(MODM_GCC_PATH ${MODM_GCC_PATH} DIRECTORY)
+get_filename_component(MODM_GCC_PATH ${MODM_GCC_PATH} DIRECTORY)
+
 if(APPLE)
 %% if platform == "hosted"
     # Using homebrew include and lib paths on macOS

tools/build_script_generator/cmake/module.lb

@@ -46,6 +46,7 @@ def build(env):
         subs = {
             "target_base": "${CMAKE_PROJECT_NAME}",
             "project_source_dir": "${CMAKE_CURRENT_SOURCE_DIR}",
+            "gccpath": "${MODM_GCC_PATH}",
         }
         if "{" in flag:
             return flag.format(**subs)

tools/build_script_generator/cmake/resources/Makefile.in

@@ -1,5 +1,5 @@
 # Copyright (c) 2018, Sergiy Yevtushenko
-# Copyright (c) 2018-2019, Niklas Hauser
+# Copyright (c) 2018-2019, 2021, Niklas Hauser
 #
 # This file is part of the modm project.
 #
@@ -59,6 +59,7 @@ program-bmp: build
 ui?=tui
 debug: build
 	@python3 modm/modm_tools/gdb.py -x modm/gdbinit -x modm/openocd_gdbinit \
+			-ex "dir $(dir $(realpath $(dir $(realpath $(shell which arm-none-eabi-gcc)))))" \
 			$(ELF_FILE) -ui=$(ui) \
 			openocd -f modm/openocd.cfg
 

tools/build_script_generator/common.py

@@ -218,6 +218,8 @@ def common_compiler_flags(compiler, target):
         "-funsigned-char",
         "-fwrapv",
         # "-fmerge-all-constants",
+        "-ffile-prefix-map={project_source_dir}=.",
+        "-ffile-prefix-map={gccpath}=.",
 
         "-g3",
         "-gdwarf-3",

tools/build_script_generator/module.lb

@@ -99,9 +99,14 @@ def prepare(module, options):
     module.add_collector(
         PathCollector(name="path.library",
                       description="Search path for static libraries"))
+    def validate_library(library):
+        if library.startswith("lib") or library.endswith(".a"):
+            raise ValueError("Libraries must only contain `name` not `libname.a`!")
+        return library
     module.add_collector(
         StringCollector(name="library",
-                        description="Libraries to link against"))
+                        description="Libraries to link against",
+                        validate=validate_library))
     module.add_collector(
         StringCollector(name="pkg-config",
                         description="Packages to configure against"))

tools/build_script_generator/scons/module.lb

@@ -25,6 +25,9 @@ def prepare(module, options):
     module.add_option(
         PathOption(name="cache_dir", default="", empty_ok=True, absolute=True,
                    description=descr_cache_dir))
+    module.add_option(
+        PathOption(name="path.artifact", default="artifacts", absolute=True,
+                   description=descr_path_artifact))
     module.add_option(
         PathOption(name="image.source", default="", empty_ok=True, absolute=True,
                    description=descr_image_source))
@@ -64,8 +67,9 @@ def build(env):
 
     def flag_format(flag):
         subs = {
-            "target_base": "\"${TARGET.base}\"",
-            "project_source_dir": "abspath(\"..\")",
+            "target_base": '"${TARGET.base}"',
+            "project_source_dir": 'env["BASEPATH"]',
+            "gccpath": 'env["GCC_PATH"]'
         }
         flag = '"{}"'.format(flag)
         vals = ["{}={}".format(t, r) for t, r in subs.items() if "{{{}}}".format(t) in flag]
@@ -80,15 +84,16 @@ def build(env):
     # SCons tools and toolpaths
     toolpaths = {
         "scons/site_tools",
-        "ext/dlr/scons/site_tools"
     }
     tools = {
         "build_target",
+        "comstr",
         "find_files",
+        "gcc_retarget",
         "qtcreator",
-        "settings_buildpath",
         "template",
-        "utils_buildformat",
+        "utils",
+        "utils_buildpath",
     }
     if env.has_module(":communication:xpcc:generator"):
         tools.add("xpcc_generator")
@@ -101,30 +106,16 @@ def build(env):
 
     device = env.query("::device")
     if device["core"].startswith("cortex-m"):
-        tools.update({"compiler_arm_none_eabi_gcc", "size", "log_itm", "artifact",
-                      "openocd", "openocd_remote", "bmp", "crashdebug", "dfu"})
+        tools.update({"size", "log_itm", "artifact", "openocd",
+                     "openocd_remote", "bmp", "crashdebug", "dfu"})
         if device["platform"] in ["sam"]:
             tools.update({"bossac"})
     elif device["core"].startswith("avr"):
-        tools.update({"compiler_avr_gcc", "size", "avrdude"})
-    else: # hosted
-        tools.update({"compiler_hosted_gcc"})
+        tools.update({"size", "avrdude"})
 
     env.collect("path.tools", *toolpaths)
     env.collect("tools", *tools)
 
-    # Add common DLR SCons build tools
-    tools.update({
-        "settings_gcc_default_internal",
-        "utils_common",
-        "utils_gcc_version",
-    })
-    env.outbasepath = "modm/ext/dlr/scons/site_tools"
-    for tool in tools:
-        path = repopath("ext/dlr/scons-build-tools/site_tools/{}.py".format(tool))
-        if exists(path):
-            env.copy(path, "{}.py".format(tool))
-
     # Copy only these modm SCons build tools
     env.outbasepath = "modm/scons/"
     for tool in tools:
@@ -137,10 +128,16 @@ def build(env):
         env.copy("site_tools/info.c.in")
 
     # Generate the env.BuildTarget tool
+    linkerscript = env.get(":platform:cortex-m:linkerscript.override")
+    linkerscript = env.relative_outpath(linkerscript) if linkerscript \
+                   else "$BASEPATH/modm/link/linkerscript.ld"
     env.substitutions = env.query("::device")
-    env.substitutions["upload_with_artifact"] = env.has_module(":crashcatcher")
-    env.substitutions["with_compilation_db"] = env.has_module(":build:compilation_db")
-    env.substitutions["program_extension"] = ".exe" if env[":target"].identifier.family == "windows" else ".elf"
+    env.substitutions.update({
+        "upload_with_artifact": env.has_module(":crashcatcher"),
+        "with_compilation_db": env.has_module(":build:compilation_db"),
+        "program_extension": ".exe" if env[":target"].identifier.family == "windows" else ".elf",
+        "linkerscript": linkerscript,
+    })
     env.outbasepath = "modm/scons/site_tools"
     env.template("resources/build_target.py.in", "build_target.py")
 
@@ -167,6 +164,7 @@ def post_build(env):
     subs.update({
         "build_path": env.relative_outpath(env[":build:build.path"]),
         "cache_dir": env.relative_outpath(cache_dir) if len(cache_dir) else "",
+        "artifact_path": env.relative_outpath(env["path.artifact"]),
         "generated_paths": repositories,
         "is_unittest": is_unittest,
 
@@ -252,6 +250,13 @@ If value is `$cache`, the cache is placed into the top-level `build/` folder.
 You can disable CacheDir by setting an empty string.
 """
 
+descr_path_artifact = """# Path to Artifact Store
+
+The artifact folder contains ELF files named by their GNU build id hash. This
+allows identification of firmware on the device via serial output and is useful
+for archiving or post-mortem debugging.
+"""
+
 descr_image_source = """# Path to directory containing .pbm files"""
 
 descr_unittest_source = """# Path to directory containing unittests