RocksDB: Avoids modifying source code inside the build script

cargo publish does not like it.

rocksdb-sys/api/build_version.cc

@@ -0,0 +1,36 @@
+// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+
+#include <memory>
+
+#include "rocksdb/version.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+const std::unordered_map<std::string, std::string>& GetRocksBuildProperties() {
+  static std::unique_ptr<std::unordered_map<std::string, std::string>> props;
+  return *props;
+}
+
+std::string GetRocksVersionAsString(bool with_patch) {
+  std::string version = ToString(ROCKSDB_MAJOR) + "." + ToString(ROCKSDB_MINOR);
+  if (with_patch) {
+    return version + "." + ToString(ROCKSDB_PATCH);
+  } else {
+    return version;
+  }
+}
+  
+std::string GetRocksBuildInfoAsString(const std::string& program, bool verbose) {
+  std::string info = program + " (RocksDB) " + GetRocksVersionAsString(true);
+  if (verbose) {
+    for (const auto& it : GetRocksBuildProperties()) {
+      info.append("\n    ");
+      info.append(it.first);
+      info.append(": ");
+      info.append(it.second);
+    }
+  }
+  return info;
+}
+} // namespace ROCKSDB_NAMESPACE
+

rocksdb-sys/build.rs

@@ -1,13 +1,10 @@
 // Code from https://github.com/rust-rocksdb/rust-rocksdb/blob/eb2d302682418b361a80ad8f4dcf335ade60dcf5/librocksdb-sys/build.rs
 // License: https://github.com/rust-rocksdb/rust-rocksdb/blob/master/LICENSE
 
-use std::env;
+use std::env::var;
-use std::fs::File;
+use std::path::PathBuf;
-use std::io::Write;
-use std::path::{Path, PathBuf};
 
 fn link(name: &str, bundled: bool) {
-    use std::env::var;
     let target = var("TARGET").unwrap();
     let target: Vec<_> = target.split('-').collect();
     if target.get(2) == Some(&"windows") {
@@ -29,12 +26,12 @@ fn bindgen_rocksdb() {
         .allowlist_var("rocksdb_.*")
         .generate()
         .expect("unable to generate rocksdb bindings")
-        .write_to_file(PathBuf::from(env::var("OUT_DIR").unwrap()).join("bindings.rs"))
+        .write_to_file(PathBuf::from(var("OUT_DIR").unwrap()).join("bindings.rs"))
         .expect("unable to write rocksdb bindings");
 }
 
 fn build_rocksdb() {
-    let target = env::var("TARGET").unwrap();
+    let target = var("TARGET").unwrap();
 
     let mut config = cc::Build::new();
     config
@@ -42,6 +39,7 @@ fn build_rocksdb() {
         .include("rocksdb/include/")
         .include("rocksdb/")
         .file("api/c.cc")
+        .file("api/build_version.cc")
         .define("NDEBUG", Some("1"))
         .define("LZ4", Some("1"))
         .include("lz4/lib/");
@@ -62,7 +60,7 @@ fn build_rocksdb() {
         // This is needed to enable hardware CRC32C. Technically, SSE 4.2 is
         // only available since Intel Nehalem (about 2010) and AMD Bulldozer
         // (about 2011).
-        let target_feature = env::var("CARGO_CFG_TARGET_FEATURE").unwrap();
+        let target_feature = var("CARGO_CFG_TARGET_FEATURE").unwrap();
         let target_features: Vec<_> = target_feature.split(',').collect();
         if target_features.contains(&"sse2") {
             config.flag_if_supported("-msse2");
@@ -148,29 +146,13 @@ fn build_rocksdb() {
         config.flag("-std=c++11");
     }
 
-    // version file
-    let build_version_cc_path = Path::new("rocksdb/util/build_version.cc");
-    if !build_version_cc_path.exists() {
-        let build_version_cc = include_str!("rocksdb/util/build_version.cc.in")
-            .replace("@GIT_SHA@", "")
-            .replace("@GIT_TAG@", "")
-            .replace("@GIT_MOD@", "0")
-            .replace("@GIT_DATE@", "")
-            .replace("@BUILD_DATE@", "");
-        File::create(build_version_cc_path)
-            .unwrap()
-            .write_all(build_version_cc.as_bytes())
-            .unwrap();
-    }
-
     for file in lib_sources {
-        if file == "db/c.cc" {
+        if file == "db/c.cc" || file == "util/build_version.cc" {
             continue;
         }
         let file = "rocksdb/".to_string() + file;
         config.file(&file);
     }
-    config.cpp(true);
     config.compile("rocksdb");
 }
 
@@ -181,7 +163,7 @@ fn build_lz4() {
         .file("lz4/lib/lz4frame.c")
         .file("lz4/lib/lz4hc.c")
         .file("lz4/lib/xxhash.c");
-    if env::var("TARGET").unwrap() == "i686-pc-windows-gnu" {
+    if var("TARGET").unwrap() == "i686-pc-windows-gnu" {
         config.flag("-fno-tree-vectorize");
     }
     config.compile("lz4");