Pugixml fetch only

.github/workflows/cppcmake.yml

@@ -39,17 +39,17 @@ jobs:
       matrix:
         config:
         # x86_64 Linux builds
-        - {name: "ubuntu-22.04-x64", os: "ubuntu-22.04", arch: "x86_64", cmake_extra: "-DLSL_BUNDLED_PUGIXML=OFF" }
-        - {name: "ubuntu-24.04-x64", os: "ubuntu-24.04", arch: "x86_64", cmake_extra: "-DLSL_BUNDLED_PUGIXML=OFF" }
+        - {name: "ubuntu-22.04-x64", os: "ubuntu-22.04", arch: "x86_64" }
+        - {name: "ubuntu-24.04-x64", os: "ubuntu-24.04", arch: "x86_64" }
 
         # ARM Linux builds - cross-compiled with QEMU testing (Jetson, Raspberry Pi compatible)
         # SHLIBDEPS must be disabled for cross-compiled packages as the host system
         # does not have the target architecture libraries installed
-        - {name: "ubuntu-22.04-arm64", os: "ubuntu-22.04", arch: "aarch64", cross_compile: true, cmake_extra: "-DLSL_BUNDLED_PUGIXML=ON -DLSL_DISABLE_PACKAGE_SHLIBDEPS=ON" }
-        - {name: "ubuntu-22.04-armhf", os: "ubuntu-22.04", arch: "armv7", cross_compile: true, cmake_extra: "-DLSL_BUNDLED_PUGIXML=ON -DLSL_DISABLE_PACKAGE_SHLIBDEPS=ON" }
+        - {name: "ubuntu-22.04-arm64", os: "ubuntu-22.04", arch: "aarch64", cross_compile: true, cmake_extra: "-DLSL_DISABLE_PACKAGE_SHLIBDEPS=ON" }
+        - {name: "ubuntu-22.04-armhf", os: "ubuntu-22.04", arch: "armv7", cross_compile: true, cmake_extra: "-DLSL_DISABLE_PACKAGE_SHLIBDEPS=ON" }
 
         # Native ARM build
-        # - {name: "ubuntu-24.04-arm64-native", os: "ubuntu-24.04-arm", arch: "aarch64", cmake_extra: "-DLSL_BUNDLED_PUGIXML=OFF" }
+        # - {name: "ubuntu-24.04-arm64-native", os: "ubuntu-24.04-arm", arch: "aarch64" }
 
         # Windows builds
         - {name: "windows-x64", os: "windows-latest", arch: "x86_64", cmake_extra: "-T v142,host=x86"}
@@ -114,13 +114,6 @@ jobs:
         ccache --max-size=500M
         ccache --set-config=compression=true
 
-    - name: Install dependencies
-      if: runner.os == 'Linux'
-      run: |
-        if [[ "${{ matrix.config.cross_compile }}" != "true" ]]; then
-          sudo apt-get install -y --no-install-recommends libpugixml-dev
-        fi
-
     - name: Configure CMake
       run: |
         # Set up ccache as compiler wrapper (skip for cross-compilation)

cmake/Dependencies.cmake

@@ -3,17 +3,37 @@ find_package(Threads REQUIRED)
 # Git version information
 include(cmake/GitVersion.cmake)
 
-# PugiXML dependency
-if(LSL_BUNDLED_PUGIXML)
-    message(STATUS "Using bundled pugixml")
-    # We will later add the pugixml source files to the lslobj target
-else()
-    message(STATUS "Using system pugixml")
-    find_package(pugixml REQUIRED)
-    if(NOT TARGET pugixml::pugixml)
-        add_library(pugixml::pugixml ALIAS pugixml)
-    endif()
+# PugiXML dependency via FetchContent
+# Always use static pugixml to avoid symbol visibility issues
+# Note: We use features of pugixml >= 1.15. Once that is available
+#  on target platforms' package managers, then we can allow using
+#  system pugixml.
+include(FetchContent)
+set(PUGIXML_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+set(PUGIXML_NO_EXCEPTIONS OFF CACHE BOOL "" FORCE)
+set(PUGIXML_INSTALL OFF CACHE BOOL "" FORCE)
+# Force static library even if parent project sets BUILD_SHARED_LIBS
+set(PUGIXML_BUILD_SHARED_AND_STATIC_LIBS OFF CACHE BOOL "" FORCE)
+set(_lsl_saved_build_shared_libs ${BUILD_SHARED_LIBS})
+set(BUILD_SHARED_LIBS OFF)
+FetchContent_Declare(
+    pugixml
+    GIT_REPOSITORY https://github.com/zeux/pugixml.git
+    GIT_TAG v1.15
+    GIT_SHALLOW TRUE
+    EXCLUDE_FROM_ALL
+)
+FetchContent_MakeAvailable(pugixml)
+set(BUILD_SHARED_LIBS ${_lsl_saved_build_shared_libs})
+unset(_lsl_saved_build_shared_libs)
+if(TARGET pugixml AND NOT TARGET pugixml::pugixml)
+    add_library(pugixml::pugixml ALIAS pugixml)
 endif()
+# Hide pugixml symbols - apply hidden visibility to the pugixml target
+set_target_properties(pugixml PROPERTIES
+    CXX_VISIBILITY_PRESET hidden
+    VISIBILITY_INLINES_HIDDEN ON
+)
 
 # Create lslboost target
 add_library(lslboost INTERFACE)

cmake/Installation.cmake

@@ -41,10 +41,9 @@ write_basic_package_version_file(
 )
 
 # Define installation targets
+# Note: We only export the final 'lsl' library, not intermediate targets like lslobj.
+# Consumers should link to LSL::lsl, not internal object libraries.
 set(LSLTargets lsl)
-if(LSL_BUILD_STATIC)
-    list(APPEND LSLTargets lslobj lslboost)
-endif()
 
 # Install the targets and store configuration information.
 install(TARGETS ${LSLTargets}

cmake/ProjectOptions.cmake

@@ -8,7 +8,6 @@ option(LSL_FRAMEWORK "Build LSL as an Apple Framework (Mac only)" ON)
 option(LSL_LEGACY_CPP_ABI "Build legacy C++ ABI into lsl-static" OFF)
 option(LSL_OPTIMIZATIONS "Enable some more compiler optimizations" ON)
 option(LSL_BUNDLED_BOOST "Use the bundled Boost by default" ON)
-option(LSL_BUNDLED_PUGIXML "Use the bundled pugixml by default" ON)
 cmake_dependent_option(LSL_TOOLS "Build some experimental tools for in-depth tests" OFF "CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR" OFF)
 cmake_dependent_option(LSL_UNITTESTS "Build LSL library unit tests" OFF "CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR" OFF)
 cmake_dependent_option(LSL_INSTALL "Generate install targets" ON "CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR" OFF)

cmake/TargetLib.cmake

@@ -28,7 +28,9 @@ endif()
 # Link dependencies. The only dependency is lslobj, which contains the bulk of the library code and linkages.
 # Note: We link PRIVATE because lslobj exposes extra symbols that are not part of the public API
 #  but are used by the internal tests.
-target_link_libraries(lsl PRIVATE lslobj)
+# Note: We use BUILD_INTERFACE to avoid requiring lslobj in the export set - the object library's
+#  objects are linked directly into lsl, so consumers don't need lslobj.
+target_link_libraries(lsl PRIVATE $<BUILD_INTERFACE:lslobj>)
 
 # Set the include directories for the lsl target.
 # Note: We had to link lslobj as a PRIVATE dependency, therefore we must manually expose the include directories

cmake/TargetObjLib.cmake

@@ -79,14 +79,11 @@ if(NOT LSL_OPTIMIZATIONS)
     target_compile_definitions(lslobj PUBLIC ASIO_SEPARATE_COMPILATION)
 endif()
 
-# - pugixml
-# Note: We use `PUBLIC` because 'internal tests' import individual source files and link lslobj.
-if(LSL_BUNDLED_PUGIXML)
-    target_sources(lslobj PRIVATE thirdparty/pugixml/pugixml.cpp)
-    target_include_directories(lslobj
-        PUBLIC
-            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/pugixml>
-    )
-else()
-    target_link_libraries(lslobj PUBLIC pugixml::pugixml)
+# - pugixml (fetched via FetchContent, linked statically and privately)
+# Use BUILD_INTERFACE to avoid requiring pugixml in the export set - the static
+# library objects are linked into lsl directly, so consumers don't need pugixml.
+target_link_libraries(lslobj PRIVATE $<BUILD_INTERFACE:pugixml::pugixml>)
+# Hide pugixml symbols from the shared library on Linux
+if(UNIX AND NOT APPLE)
+    target_link_options(lslobj PRIVATE "LINKER:--exclude-libs,libpugixml.a")
 endif()

src/stream_info_impl.cpp

@@ -47,7 +47,7 @@ template <typename T> void append_text_node(xml_node &node, const char *name, co
 }
 
 template <> void append_text_node(xml_node &node, const char *name, const std::string &value) {
-	node.append_child(name).append_child(node_pcdata).set_value(value.c_str());
+	node.append_child(name).append_child(node_pcdata).set_value(value);
 }
 
 void stream_info_impl::write_xml(xml_document &doc) {
@@ -264,17 +264,17 @@ uint32_t lsl::stream_info_impl::calc_transport_buf_samples(
 
 void stream_info_impl::version(int v) {
 	version_ = v;
-	doc_.child("info").child("version").first_child().set_value(to_string(version_ / 100.).c_str());
+	doc_.child("info").child("version").first_child().set_value(to_string(version_ / 100.));
 }
 
 void stream_info_impl::created_at(double v) {
 	created_at_ = v;
-	doc_.child("info").child("created_at").first_child().set_value(to_string(created_at_).c_str());
+	doc_.child("info").child("created_at").first_child().set_value(to_string(created_at_));
 }
 
 void stream_info_impl::uid(const std::string &v) {
 	uid_ = v;
-	doc_.child("info").child("uid").first_child().set_value(uid_.c_str());
+	doc_.child("info").child("uid").first_child().set_value(uid_);
 }
 
 const std::string& stream_info_impl::reset_uid()
@@ -285,17 +285,17 @@ const std::string& stream_info_impl::reset_uid()
 
 void stream_info_impl::session_id(const std::string &v) {
 	session_id_ = v;
-	doc_.child("info").child("session_id").first_child().set_value(session_id_.c_str());
+	doc_.child("info").child("session_id").first_child().set_value(session_id_);
 }
 
 void stream_info_impl::hostname(const std::string &v) {
 	hostname_ = v;
-	doc_.child("info").child("hostname").first_child().set_value(hostname_.c_str());
+	doc_.child("info").child("hostname").first_child().set_value(hostname_);
 }
 
 void stream_info_impl::v4address(const std::string &v) {
 	v4address_ = v;
-	doc_.child("info").child("v4address").first_child().set_value(v4address_.c_str());
+	doc_.child("info").child("v4address").first_child().set_value(v4address_);
 }
 
 void stream_info_impl::v4data_port(uint16_t v) {
@@ -310,7 +310,7 @@ void stream_info_impl::v4service_port(uint16_t v) {
 
 void stream_info_impl::v6address(const std::string &v) {
 	v6address_ = v;
-	doc_.child("info").child("v6address").first_child().set_value(v6address_.c_str());
+	doc_.child("info").child("v6address").first_child().set_value(v6address_);
 }
 
 void stream_info_impl::v6data_port(uint16_t v) {

testing/CMakeLists.txt

@@ -76,6 +76,8 @@ endif()
 message(STATUS ${LSL_TEST_INTERNAL_SRCS})
 add_executable(lsl_test_internal ${LSL_TEST_INTERNAL_SRCS})
 target_link_libraries(lsl_test_internal PRIVATE lslobj lslboost common catch_main)
+# Internal tests need pugixml headers (lslobj links pugixml privately)
+target_include_directories(lsl_test_internal PRIVATE ${pugixml_SOURCE_DIR}/src)
 # Pretend that lsl_test_internal is part of a shared lib so that it can use the __export symbols lslobj. REQ by MinGW.
 target_compile_definitions(lsl_test_internal PRIVATE LIBLSL_EXPORTS)