From 7b8ee2d186087d42520e99eedf49b50d75067d09 Mon Sep 17 00:00:00 2001
From: Eric Ratliff <eric@nxlearn.net>
Date: Sun, 15 Feb 2026 08:42:32 -0600
Subject: [PATCH] Supporting configuration settings for include and warnings

---
 .arduino-build.conf |  11 ++++
 arduino-build.sh    | 129 ++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 135 insertions(+), 5 deletions(-)
 create mode 100644 .arduino-build.conf

diff --git a/.arduino-build.conf b/.arduino-build.conf
new file mode 100644
index 0000000..ead2928
--- /dev/null
+++ b/.arduino-build.conf
@@ -0,0 +1,11 @@
+# .arduino-build.conf -- Project-level build configuration
+#
+# Discovered by arduino-build.sh when it walks up from the sketch directory.
+# All paths are relative to this file's location (the project root).
+
+# Include paths -- each becomes a -I flag to the compiler
+INCLUDE_DIRS="lib/hal lib/app"
+EXTRA_BUILD_FLAGS="-Werror"
+
+# Additional compiler flags (uncomment as needed)
+# EXTRA_BUILD_FLAGS="-DDEBUG=1"
\ No newline at end of file
diff --git a/arduino-build.sh b/arduino-build.sh
index 4cebd1e..2198a0c 100755
--- a/arduino-build.sh
+++ b/arduino-build.sh
@@ -14,7 +14,7 @@ FQBN="${ARDUINO_FQBN:-arduino:avr:uno}"
 BAUD="${ARDUINO_BAUD:-115200}"
 BUILD_DIR="${ARDUINO_BUILD_DIR:-/tmp/arduino-build}"
 ARDUINO_CLI="${ARDUINO_CLI_BIN:-arduino-cli}"
-VERSION="1.1.0"
+VERSION="1.2.0"
 
 # -- Color output (disabled if stdout is not a terminal) ---------------------
 if [[ -t 1 ]]; then
@@ -58,6 +58,7 @@ $(_help_section_commands)
 $(_help_section_build_options)
 $(_help_section_config_options)
 $(_help_section_env_vars)
+$(_help_section_project_config)
 $(_help_section_examples)
 $(_help_section_cheatsheet)
 $(_help_section_sketch_layout)
@@ -193,6 +194,42 @@ ${BLD}ENVIRONMENT VARIABLES${RST}
 EOF
 }
 
+_help_section_project_config() {
+    cat <<EOF
+
+${BLD}PROJECT CONFIGURATION (.arduino-build.conf)${RST}
+    Per-project build settings. Place this file at the project root (the
+    directory containing .git or the top-level directory above your sketch).
+
+    The script walks up from the sketch directory to find it, similar to
+    how git finds .git/.
+
+    ${BLD}Supported variables:${RST}
+
+    INCLUDE_DIRS="lib/hal lib/app"
+        Space-separated list of directories to add to the compiler include
+        path. Paths are relative to the .arduino-build.conf file location.
+        Each directory becomes a -I flag.
+
+    EXTRA_BUILD_FLAGS="-DDEBUG=1 -DVERSION=2"
+        Additional compiler flags appended after include dirs. Use for
+        preprocessor defines, optimization overrides, etc.
+
+    ${BLD}Example .arduino-build.conf:${RST}
+
+        # Project-level build configuration
+        INCLUDE_DIRS="lib/hal lib/app lib/drivers"
+        EXTRA_BUILD_FLAGS="-DBOARD_REV=3"
+
+    ${BLD}How it works:${RST}
+        The flags are passed via arduino-cli's --build-property mechanism:
+            --build-property "build.extra_flags=-Ilib/hal -Ilib/app ..."
+
+        This is per-project, not global. Different projects can have
+        different include paths and flags. The script itself stays generic.
+EOF
+}
+
 _help_section_examples() {
     cat <<EOF
 
@@ -664,6 +701,83 @@ auto_detect_port() {
     echo "${candidates[0]}"
 }
 
+# ============================================================================
+# PROJECT CONFIG DISCOVERY
+# ============================================================================
+# Walk up from a directory to find .arduino-build.conf at the project root.
+# Echoes the project root path.  Returns 1 if not found.
+find_project_root() {
+    local dir="$1"
+    local max_depth=10
+    local depth=0
+
+    while [[ $depth -lt $max_depth ]] && [[ "$dir" != "/" ]]; do
+        if [[ -f "$dir/.arduino-build.conf" ]]; then
+            echo "$dir"
+            return 0
+        fi
+        dir="$(dirname "$dir")"
+        depth=$((depth + 1))
+    done
+    return 1
+}
+
+# Load project config and build extra compiler flags.
+# Sets PROJECT_ROOT and EXTRA_COMPILE_FLAGS as side effects.
+PROJECT_ROOT=""
+EXTRA_COMPILE_FLAGS=""
+
+load_project_config() {
+    local sketch_dir="$1"
+    local conf_file=""
+
+    PROJECT_ROOT="$(find_project_root "$sketch_dir")" || {
+        info "No .arduino-build.conf found (using default settings)."
+        return 0
+    }
+
+    conf_file="$PROJECT_ROOT/.arduino-build.conf"
+    info "Project config: ${DIM}${conf_file}${RST}"
+
+    # Parse the conf file (only accept known variables, ignore everything else)
+    local include_dirs="" extra_flags=""
+
+    while IFS='=' read -r key value; do
+        # Strip leading/trailing whitespace
+        key="$(echo "$key" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')"
+        value="$(echo "$value" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//;s/^"//;s/"$//')"
+
+        # Skip blank lines and comments
+        [[ -z "$key" || "$key" == \#* ]] && continue
+
+        case "$key" in
+            INCLUDE_DIRS)      include_dirs="$value" ;;
+            EXTRA_BUILD_FLAGS) extra_flags="$value" ;;
+        esac
+    done < "$conf_file"
+
+    # Build -I flags from INCLUDE_DIRS (paths relative to project root)
+    local flags=""
+    for dir in $include_dirs; do
+        local abs_dir="$PROJECT_ROOT/$dir"
+        if [[ -d "$abs_dir" ]]; then
+            flags="$flags -I$abs_dir"
+            info "  Include: ${DIM}$dir${RST}"
+        else
+            warn "  Include dir not found: $dir (skipped)"
+        fi
+    done
+
+    # Append any extra flags
+    if [[ -n "$extra_flags" ]]; then
+        flags="$flags $extra_flags"
+        info "  Extra flags: ${DIM}$extra_flags${RST}"
+    fi
+
+    # Trim leading space
+    EXTRA_COMPILE_FLAGS="$(echo "$flags" | sed 's/^[[:space:]]*//')"
+}
+
 # ============================================================================
 # PERSISTENT SERIAL MONITOR (--watch)
 # ============================================================================
@@ -885,9 +999,6 @@ if [[ $DO_CLEAN -eq 1 ]] && [[ -d "$SKETCH_BUILD_DIR" ]]; then
     ok "Cache cleared."
 fi
 
-# ============================================================================
-# COMPILE
-# ============================================================================
 # ============================================================================
 # COMPILE (skipped with --upload-only)
 # ============================================================================
@@ -916,16 +1027,24 @@ if [[ $UPLOAD_ONLY -eq 1 ]]; then
         echo ""
     fi
 else
+    # Load per-project configuration (include paths, extra flags)
+    load_project_config "$SKETCH_DIR"
+
     info "Compiling..."
     mkdir -p "$SKETCH_BUILD_DIR"
 
     COMPILE_ARGS=(
         --fqbn "$FQBN"
         --build-path "$SKETCH_BUILD_DIR"
-        --warnings all
+        --warnings more
     )
     [[ $DO_VERBOSE -eq 1 ]] && COMPILE_ARGS+=(--verbose)
 
+    # Inject per-project build flags (include paths, defines, etc.)
+    if [[ -n "$EXTRA_COMPILE_FLAGS" ]]; then
+        COMPILE_ARGS+=(--build-property "build.extra_flags=$EXTRA_COMPILE_FLAGS")
+    fi
+
     if ! $ARDUINO_CLI compile "${COMPILE_ARGS[@]}" "$SKETCH_DIR"; then
         die "Compilation failed."
     fi