make boost::filesystem optional (#81)

__GNUC__ doesn't work as intended on clang, change to another
way to detect the presence of std::filesystem. Also make boost::filesystem
fully optional.

Co-authored-by: Weng Xuetian <[email protected]>

Author: eagleoflqj

Diff for: CMakeLists.txt

@@ -13,6 +13,7 @@ option(ENABLE_COVERAGE "Build the project with gcov support (Need ENABLE_TEST=On
 set(GCOV_TOOL "gcov" CACHE STRING "Path to gcov tool used by coverage.")
 option(ENABLE_DOC "Build doxygen" Off)
 option(ENABLE_DATA "Build data" On)
+option(ENABLE_TOOLS "Build tools" On)
 
 #########################################
 # Dependency
@@ -34,7 +35,19 @@ pkg_check_modules(ZSTD REQUIRED IMPORTED_TARGET "libzstd")
 find_package(Fcitx5Utils REQUIRED)
 include("${FCITX_INSTALL_CMAKECONFIG_DIR}/Fcitx5Utils/Fcitx5CompilerSettings.cmake")
 
-find_package(Boost 1.61 REQUIRED COMPONENTS iostreams filesystem)
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("
+#include <filesystem>
+int main() {
+    return std::filesystem::absolute(\".\").string()[0] == '/';
+}
+" HAS_STD_FILESYSTEM)
+
+find_package(Boost 1.61 REQUIRED COMPONENTS iostreams)
+if (NOT HAS_STD_FILESYSTEM)
+    find_package(Boost REQUIRED COMPONENTS filesystem)
+endif()
+
 set(LIBIME_INSTALL_PKGDATADIR "${CMAKE_INSTALL_FULL_DATADIR}/libime")
 set(LIBIME_INSTALL_LIBDATADIR "${CMAKE_INSTALL_FULL_LIBDIR}/libime")
 
@@ -56,7 +69,10 @@ if(ENABLE_TEST)
 endif()
 
 add_subdirectory(src)
-add_subdirectory(tools)
+
+if (ENABLE_TOOLS)
+  add_subdirectory(tools)
+endif()
 
 if (ENABLE_DATA)
   add_subdirectory(data)

Diff for: tools/CMakeLists.txt

@@ -24,12 +24,19 @@ target_link_libraries(libime_tabledict LibIME::Table)
 install(TARGETS libime_tabledict DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT tools)
 add_executable(LibIME::tabledict ALIAS libime_tabledict)
 
+add_library(filesystem_helper filesystem_helper.cpp)
+if (HAS_STD_FILESYSTEM)
+    target_compile_definitions(filesystem_helper PRIVATE -DHAS_STD_FILESYSTEM)
+else()
+    target_link_libraries(filesystem_helper PUBLIC Boost::filesystem)
+endif()
+
 add_executable(libime_migrate_fcitx4_table libime_migrate_fcitx4_table.cpp)
-target_link_libraries(libime_migrate_fcitx4_table LibIME::Table Boost::iostreams Boost::filesystem)
+target_link_libraries(libime_migrate_fcitx4_table LibIME::Table Boost::iostreams filesystem_helper)
 install(TARGETS libime_migrate_fcitx4_table DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT tools)
 add_executable(LibIME::migrate_fcitx4_table ALIAS libime_migrate_fcitx4_table)
 
 add_executable(libime_migrate_fcitx4_pinyin libime_migrate_fcitx4_pinyin.cpp)
-target_link_libraries(libime_migrate_fcitx4_pinyin LibIME::Pinyin Boost::iostreams Boost::filesystem)
+target_link_libraries(libime_migrate_fcitx4_pinyin LibIME::Pinyin Boost::iostreams filesystem_helper)
 install(TARGETS libime_migrate_fcitx4_pinyin DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT tools)
 add_executable(LibIME::migrate_fcitx4_pinyin ALIAS libime_migrate_fcitx4_pinyin)

Diff for: tools/filesystem_helper.cpp

@@ -0,0 +1,26 @@
+/*
+ * SPDX-FileCopyrightText: 2024~2024 CSSlayer <[email protected]>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include <string>
+#include <string_view>
+
+#ifdef HAS_STD_FILESYSTEM
+#include <filesystem>
+#else
+#include <boost/filesystem.hpp>
+#endif
+
+namespace libime {
+
+std::string absolutePath(const std::string &path) {
+#ifdef HAS_STD_FILESYSTEM
+    return std::filesystem::absolute(path);
+#else
+    return boost::filesystem::absolute(path).string();
+#endif
+}
+
+} // namespace libime

Diff for: tools/filesystem_helper.h

@@ -0,0 +1,19 @@
+/*
+ * SPDX-FileCopyrightText: 2024~2024 CSSlayer <[email protected]>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef _TOOLS_FILESYSTEM_HELPER_H_
+#define _TOOLS_FILESYSTEM_HELPER_H_
+
+#include <string>
+#include <string_view>
+
+namespace libime {
+
+std::string absolutePath(const std::string &path);
+
+}
+
+#endif

Diff for: tools/libime_migrate_fcitx4_pinyin.cpp

@@ -5,6 +5,7 @@
  *
  */
 
+#include "filesystem_helper.h"
 #include "libime/core/historybigram.h"
 #include "libime/core/utils.h"
 #include "libime/core/utils_p.h"
@@ -18,12 +19,6 @@
 #include <string_view>
 #include <unordered_map>
 
-#if __GNUC__ <= 8
-#include <boost/filesystem.hpp>
-#else
-#include <filesystem>
-#endif
-
 static const std::array<std::string, 412> PYFA = {
     "AA", "AB", "AC", "AD", "AE", "AF", "AH", "AI", "AJ", "AU", "AV", "AW",
     "AX", "AY", "AZ", "Aa", "Ac", "Ad", "Ae", "BA", "BB", "BC", "BD", "BE",
@@ -347,11 +342,7 @@ int main(int argc, char *argv[]) {
             if (dictFile[0] == '/') {
                 outputDictFile = dictFile;
             } else {
-#if __GNUC__ <= 8
-                outputDictFile = boost::filesystem::absolute(dictFile).string();
-#else
-                outputDictFile = std::filesystem::absolute(dictFile);
-#endif
+                outputDictFile = absolutePath(dictFile);
             }
         }
         StandardPath::global().safeSave(
@@ -373,12 +364,7 @@ int main(int argc, char *argv[]) {
             if (historyFile[0] == '/') {
                 outputHistoryFile = historyFile;
             } else {
-#if __GNUC__ <= 8
-                outputHistoryFile =
-                    boost::filesystem::absolute(historyFile).string();
-#else
-                outputHistoryFile = std::filesystem::absolute(historyFile);
-#endif
+                outputHistoryFile = absolutePath(historyFile);
             }
         }
         StandardPath::global().safeSave(

Diff for: tools/libime_migrate_fcitx4_table.cpp

@@ -6,6 +6,7 @@
  *
  */
 #include "config.h"
+#include "filesystem_helper.h"
 #include "libime/core/historybigram.h"
 #include "libime/core/utils.h"
 #include "libime/core/utils_p.h"
@@ -17,12 +18,6 @@
 #include <fcntl.h>
 #include <sstream>
 
-#if __GNUC__ <= 8
-#include <boost/filesystem.hpp>
-#else
-#include <filesystem>
-#endif
-
 using namespace libime;
 using namespace fcitx;
 
@@ -82,11 +77,7 @@ struct MigrationCommonOption {
                 return stringutils::joinPath("table", path);
             }
 
-#if __GNUC__ <= 8
-            return boost::filesystem::absolute(path).string();
-#else
-            return std::filesystem::absolute(path);
-#endif
+            return absolutePath(path);
         }
         return path;
     }