platform: use build.opt instead of build_opt.h

See:
arduino/arduino-cli#1338

When the above issue will be fix. This change should be reviewed.

This is backward compatible.

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

platform.txt

@@ -105,7 +105,7 @@ build.flags.ldspecs=--specs=nano.specs
 build.flash_offset=0
 
 # Pre and post build hooks
-build.opt.name=build_opt.h
+build.opt.name=build.opt
 build.opt.path={build.path}/sketch/{build.opt.name}
 
 extras.path={build.system.path}/extras

system/extras/prebuild.sh

@@ -8,10 +8,15 @@ if [ ! -f "$BUILD_PATH/sketch" ]; then
   mkdir -p "$BUILD_PATH/sketch"
 fi
 
-# Create empty build.opt.h if not exists in the original sketch dir
+# Create empty build.opt if build_opt.h does not exists in the original sketch dir
 if [ ! -f "$BUILD_SOURCE_PATH/build_opt.h" ]; then
-  touch "$BUILD_PATH/sketch/build_opt.h"
+  touch "$BUILD_PATH/sketch/build.opt"
+else
+  # Else copy the build_opt.h as build.opt
+  # Workaround to the header file preprocessing done by arduino-cli
+  # See https://github.com/arduino/arduino-cli/issues/1338
+  cp "$BUILD_SOURCE_PATH/build_opt.h" "$BUILD_PATH/sketch/build.opt"
 fi
 
 # Force include of SrcWrapper library
-echo "#include <SrcWrapper.h>" >"$BUILD_PATH/sketch/SrcWrapper.cpp"
+echo "#include <SrcWrapper.h>" > "$BUILD_PATH/sketch/SrcWrapper.cpp"