[dev-tool] add fast-compile-fe.sh for incremental FE compilation

Add `tools/fast-compile-fe.sh`, a developer utility that incrementally
compiles only changed Java source files and patches them directly into
`doris-fe.jar`, avoiding a full Maven rebuild during development.

Key features:
- Auto-detects stale `.java` files by comparing mtime with `.class` files
- Supports explicit file arguments (by path or filename search under src/)
- Caches the classpath derived from `target/lib` to skip repeated mvn calls
- Updates both `target/doris-fe.jar` and `output/fe/lib/doris-fe.jar`
- Handles inner classes and anonymous classes (e.g. `Foo$Bar.class`)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: englefly

tools/fast-compile-fe.sh

@@ -0,0 +1,243 @@
+#!/usr/bin/env bash
+# fast-compile-fe.sh — 增量编译 FE 并更新 doris-fe.jar
+#
+# 用法:
+#   ./fast-compile-fe.sh              # 自动检测改动文件并编译
+#   ./fast-compile-fe.sh Foo.java Bar.java  # 指定编译某些文件
+#
+# 依赖: javac, jar（JDK 8+），mvn（首次获取 classpath 时需要）
+
+set -euo pipefail
+
+DORIS_HOME="$(cd "$(dirname "$0")/.." && pwd)"
+FE_CORE="$DORIS_HOME/fe/fe-core"
+SRC_ROOT="$FE_CORE/src/main/java"
+TARGET_CLASSES="$FE_CORE/target/classes"
+TARGET_LIB="$FE_CORE/target/lib"
+OUTPUT_JAR="$DORIS_HOME/output/fe/lib/doris-fe.jar"
+TARGET_JAR="$FE_CORE/target/doris-fe.jar"
+CP_CACHE="$FE_CORE/target/fast-compile-cp.txt"
+
+# 生成的源码目录（protobuf/thrift/annotation processor 生成的 java 文件）
+GEN_SOURCES=(
+    "$FE_CORE/target/generated-sources/doris"
+    "$FE_CORE/target/generated-sources/org"
+    "$FE_CORE/target/generated-sources/java"
+    "$FE_CORE/target/generated-sources/annotations"
+    "$FE_CORE/target/generated-sources/antlr4"
+)
+
+# ─── 颜色输出 ────────────────────────────────────────────────────────────────
+RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; NC='\033[0m'
+info()  { echo -e "${GREEN}[INFO]${NC}  $*"; }
+warn()  { echo -e "${YELLOW}[WARN]${NC}  $*"; }
+error() { echo -e "${RED}[ERROR]${NC} $*" >&2; }
+
+# ─── 检查环境 ─────────────────────────────────────────────────────────────────
+check_env() {
+    if [[ ! -d "$TARGET_CLASSES" ]]; then
+        error "target/classes 不存在，请先完整编译一次: cd $DORIS_HOME && mvn package -pl fe/fe-core -DskipTests -T4"
+        exit 1
+    fi
+    if [[ ! -f "$OUTPUT_JAR" && ! -f "$TARGET_JAR" ]]; then
+        error "doris-fe.jar 不存在，请先完整编译一次"
+        exit 1
+    fi
+}
+
+# ─── 获取 classpath（带缓存）─────────────────────────────────────────────────
+get_classpath() {
+    # 如果 pom.xml 比缓存新，则重新生成 classpath
+    if [[ ! -f "$CP_CACHE" || ! -s "$CP_CACHE" || "$FE_CORE/pom.xml" -nt "$CP_CACHE" ]]; then
+        info "生成 classpath 缓存..."
+        # 直接使用 target/lib（本次完整构建产生的依赖，比 .m2 仓库更可靠）
+        find "$TARGET_LIB" -name "*.jar" | tr '\n' ':' | sed 's/:$//' > "$CP_CACHE"
+        info "classpath 缓存已保存到 $CP_CACHE"
+    fi
+
+    # classpath = 依赖 jars + target/classes（项目内部依赖）
+    echo "$(cat "$CP_CACHE"):$TARGET_CLASSES"
+}
+
+# ─── 找出需要编译的 java 文件 ────────────────────────────────────────────────
+find_stale_java_files() {
+    local stale_files=()
+
+    while IFS= read -r java_file; do
+        # java_file: /path/to/src/main/java/org/apache/doris/Foo.java
+        # 转换为 class 文件路径
+        local rel_path="${java_file#$SRC_ROOT/}"       # org/apache/doris/Foo.java
+        local class_path="$TARGET_CLASSES/${rel_path%.java}.class"
+
+        if [[ ! -f "$class_path" ]]; then
+            # class 文件不存在，肯定需要编译
+            stale_files+=("$java_file")
+        elif [[ "$java_file" -nt "$class_path" ]]; then
+            # java 文件比主 class 文件新
+            stale_files+=("$java_file")
+        fi
+    done < <(find "$SRC_ROOT" -name "*.java")
+
+    printf '%s\n' "${stale_files[@]}"
+}
+
+# ─── 编译 java 文件 ───────────────────────────────────────────────────────────
+compile_files() {
+    local classpath="$1"
+    shift
+    local java_files=("$@")
+
+    # 构建源码路径（包含生成的源码目录）
+    local source_path="$SRC_ROOT"
+    for gen_src in "${GEN_SOURCES[@]}"; do
+        [[ -d "$gen_src" ]] && source_path="$source_path:$gen_src"
+    done
+
+    info "编译 ${#java_files[@]} 个文件..."
+    for f in "${java_files[@]}"; do
+        echo "  → ${f#$DORIS_HOME/}"
+    done
+
+    # javac 编译
+    javac \
+        -source 8 -target 8 \
+        -encoding UTF-8 \
+        -cp "$classpath" \
+        -sourcepath "$source_path" \
+        -d "$TARGET_CLASSES" \
+        "${java_files[@]}" 2>&1
+
+    info "编译完成"
+}
+
+# ─── 收集需要更新到 jar 的 class 文件 ────────────────────────────────────────
+collect_updated_classes() {
+    local java_files=("$@")
+    local class_files=()
+
+    for java_file in "${java_files[@]}"; do
+        local rel_path="${java_file#$SRC_ROOT/}"
+        local class_prefix="$TARGET_CLASSES/${rel_path%.java}"
+        local dir
+        dir="$(dirname "$class_prefix")"
+        local base
+        base="$(basename "$class_prefix")"
+
+        # 主 class 文件
+        [[ -f "$class_prefix.class" ]] && class_files+=("$class_prefix.class")
+
+        # 内部类和匿名类：Foo$Bar.class, Foo$1.class 等
+        while IFS= read -r inner; do
+            class_files+=("$inner")
+        done < <(find "$dir" -maxdepth 1 -name "${base}\$*.class" 2>/dev/null)
+    done
+
+    printf '%s\n' "${class_files[@]}"
+}
+
+# ─── 更新 jar ─────────────────────────────────────────────────────────────────
+update_jar() {
+    local class_files=("$@")
+
+    info "更新 jar（共 ${#class_files[@]} 个 class 文件）..."
+
+    # 将 class 文件路径转为相对于 TARGET_CLASSES 的路径，供 jar 命令使用
+    local tmpfile
+    tmpfile="$(mktemp)"
+    trap "rm -f $tmpfile" EXIT
+
+    for cf in "${class_files[@]}"; do
+        echo "${cf#$TARGET_CLASSES/}" >> "$tmpfile"
+    done
+
+    # 在 TARGET_CLASSES 目录下执行 jar uf，使 jar 内路径正确
+    pushd "$TARGET_CLASSES" > /dev/null
+
+    # 更新 target/doris-fe.jar
+    if [[ -f "$TARGET_JAR" ]]; then
+        xargs jar uf "$TARGET_JAR" < "$tmpfile"
+        info "已更新 $TARGET_JAR"
+    fi
+
+    # 更新 output/fe/lib/doris-fe.jar
+    if [[ -f "$OUTPUT_JAR" ]]; then
+        xargs jar uf "$OUTPUT_JAR" < "$tmpfile"
+        info "已更新 $OUTPUT_JAR"
+    fi
+
+    popd > /dev/null
+}
+
+# ─── 主流程 ───────────────────────────────────────────────────────────────────
+main() {
+    check_env
+
+    local java_files=()
+
+    if [[ $# -gt 0 ]]; then
+        # 用户直接指定文件
+        for arg in "$@"; do
+            # 支持相对路径和绝对路径
+            local abs_path
+            if [[ "$arg" = /* ]]; then
+                abs_path="$arg"
+            else
+                abs_path="$(pwd)/$arg"
+            fi
+            if [[ ! -f "$abs_path" ]]; then
+                # 尝试在 SRC_ROOT 下搜索
+                local found
+                found="$(find "$SRC_ROOT" -name "$(basename "$arg")" | head -1)"
+                if [[ -z "$found" ]]; then
+                    error "文件不存在: $arg"
+                    exit 1
+                fi
+                abs_path="$found"
+            fi
+            java_files+=("$abs_path")
+        done
+        info "手动指定 ${#java_files[@]} 个文件"
+    else
+        # 自动检测改动
+        info "扫描改动的 Java 文件..."
+        while IFS= read -r f; do
+            [[ -n "$f" ]] && java_files+=("$f")
+        done < <(find_stale_java_files)
+
+        if [[ ${#java_files[@]} -eq 0 ]]; then
+            info "没有发现需要编译的文件，已是最新状态"
+            exit 0
+        fi
+        info "发现 ${#java_files[@]} 个文件需要重新编译"
+    fi
+
+    local start_time
+    start_time=$(date +%s)
+
+    # 获取 classpath
+    local classpath
+    classpath="$(get_classpath)"
+
+    # 编译
+    compile_files "$classpath" "${java_files[@]}"
+
+    # 收集 class 文件（含内部类）π
+    local class_files=()
+    while IFS= read -r cf; do
+        [[ -n "$cf" ]] && class_files+=("$cf")
+    done < <(collect_updated_classes "${java_files[@]}")
+
+    if [[ ${#class_files[@]} -eq 0 ]]; then
+        warn "未找到编译产物，跳过 jar 更新"
+        exit 0
+    fi
+
+    # 更新 jar
+    update_jar "${class_files[@]}"
+
+    local end_time
+    end_time=$(date +%s)
+    info "完成！耗时 $((end_time - start_time)) 秒"
+}
+
+main "$@"