From 1bc548b8210366e44ba35b0b11577a8e328c1228 Mon Sep 17 00:00:00 2001
From: Lasse Collin <lasse.collin@tukaani.org>
Date: Sat, 30 Sep 2023 02:14:25 +0300
Subject: [PATCH] CMake: Generate and install liblzma.pc if not using MSVC.

Autotools based build uses -pthread and thus adds it to Libs.private
in liblzma.pc. CMake doesn't use -pthread at all if pthread functions
are available in libc so Libs.private doesn't get -pthread either.
---
 CMakeLists.txt | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ad63d849..0437d7fb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -111,6 +111,7 @@ if((MINGW OR CYGWIN OR MSYS) AND (
     # Use workarounds with GNU windres and llvm-windres >= 17.0.0. The \x20
     # in PACKAGE_NAME_DEFINITION works with gcc and clang too so we don't need
     # to worry how to pass different flags to windres and the C compiler.
+    # Keep the original PACKAGE_NAME intact for generation of liblzma.pc.
     string(APPEND CMAKE_RC_FLAGS " --use-temp-file")
     string(REPLACE " " "\\x20" PACKAGE_NAME_DEFINITION "${PACKAGE_NAME}")
 else()
@@ -152,6 +153,9 @@ tuklib_use_system_extensions(ALL)
 # This is needed by liblzma and xz.
 tuklib_integer(ALL)
 
+# This is used for liblzma.pc generation to add -lrt if needed.
+set(LIBS)
+
 # Check for clock_gettime(). Do this before checking for threading so
 # that we know there if CLOCK_MONOTONIC is available.
 check_symbol_exists(clock_gettime time.h HAVE_CLOCK_GETTIME)
@@ -167,6 +171,7 @@ if(NOT HAVE_CLOCK_GETTIME)
     # CMAKE_REQUIRED_LIBRARIES for further tests too.
     if(HAVE_CLOCK_GETTIME_LIBRT)
         link_libraries(rt)
+        set(LIBS "-lrt") # For liblzma.pc
     else()
         list(REMOVE_AT CMAKE_REQUIRED_LIBRARIES 0)
     endif()
@@ -1004,6 +1009,16 @@ file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/liblzma-config.cmake"
 # Set CMAKE_INSTALL_LIBDIR and friends.
 include(GNUInstallDirs)
 
+# Create liblzma.pc.
+set(prefix "${CMAKE_INSTALL_PREFIX}")
+set(exec_prefix "${CMAKE_INSTALL_PREFIX}")
+set(libdir "${CMAKE_INSTALL_FULL_LIBDIR}")
+set(includedir "${CMAKE_INSTALL_FULL_INCLUDEDIR}")
+set(PTHREAD_CFLAGS "${CMAKE_THREAD_LIBS_INIT}")
+configure_file(src/liblzma/liblzma.pc.in liblzma.pc
+               @ONLY
+               NEWLINE_STYLE LF)
+
 # Install the library binary. The INCLUDES specifies the include path that
 # is exported for other projects to use but it doesn't install any files.
 install(TARGETS liblzma EXPORT liblzmaTargets
@@ -1039,6 +1054,12 @@ install(FILES "${CMAKE_CURRENT_BINARY_DIR}/liblzma-config.cmake"
         DESTINATION "${liblzma_INSTALL_CMAKEDIR}"
         COMPONENT liblzma_Development)
 
+if(NOT MSVC)
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/liblzma.pc"
+            DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig"
+            COMPONENT liblzma_Development)
+endif()
+
 
 #############################################################################
 # libgnu (getopt_long)