cmake: add pthread dependency

Fixes: PCRE2Project#103

Author: carenas

CMakeLists.txt

@@ -103,8 +103,8 @@
 PROJECT(PCRE2 C)
 
 # Increased minimum to 2.8.5 to support GNUInstallDirs.
-# Increased minimum to 3.0.0 because older than 2.8.12 is deprecated.
-CMAKE_MINIMUM_REQUIRED(VERSION 3.0.0)
+# Increased minimum to 3.1 to support imported targets.
+CMAKE_MINIMUM_REQUIRED(VERSION 3.1)
 
 # Set policy CMP0026 to avoid warnings for the use of LOCATION in
 # GET_TARGET_PROPERTY. This should no longer be required.
@@ -382,7 +382,13 @@ IF(PCRE2_SUPPORT_UNICODE)
 ENDIF(PCRE2_SUPPORT_UNICODE)
 
 IF(PCRE2_SUPPORT_JIT)
-        SET(SUPPORT_JIT 1)
+	SET(SUPPORT_JIT 1)
+	IF(UNIX)
+		FIND_PACKAGE(Threads REQUIRED)
+		IF(CMAKE_USE_PTHREADS_INIT)
+			SET(REQUIRE_PTHREAD 1)
+		ENDIF(CMAKE_USE_PTHREADS_INIT)
+	ENDIF(UNIX)
 ENDIF(PCRE2_SUPPORT_JIT)
 
 IF(PCRE2_SUPPORT_JIT_SEALLOC)
@@ -697,6 +703,9 @@ IF(PCRE2_BUILD_PCRE2_8)
       VERSION ${LIBPCRE2_8_VERSION}
       SOVERSION ${LIBPCRE2_8_SOVERSION})
     TARGET_COMPILE_DEFINITIONS(pcre2-8-static PUBLIC PCRE2_STATIC)
+    IF(REQUIRE_PTHREAD)
+        TARGET_LINK_LIBRARIES(pcre2-8-static Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-8-static)
     ADD_LIBRARY(pcre2-posix-static STATIC ${PCRE2POSIX_HEADERS} ${PCRE2POSIX_SOURCES})
     SET_TARGET_PROPERTIES(pcre2-posix-static PROPERTIES
@@ -730,6 +739,9 @@ IF(PCRE2_BUILD_PCRE2_8)
       VERSION ${LIBPCRE2_8_VERSION}
       SOVERSION ${LIBPCRE2_8_SOVERSION}
       OUTPUT_NAME pcre2-8)
+    IF(REQUIRE_PTHREAD)
+        TARGET_LINK_LIBRARIES(pcre2-8-shared Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-8-shared)
     ADD_LIBRARY(pcre2-posix-shared SHARED ${PCRE2POSIX_HEADERS} ${PCRE2POSIX_SOURCES})
     SET_TARGET_PROPERTIES(pcre2-posix-shared PROPERTIES
@@ -773,6 +785,9 @@ IF(PCRE2_BUILD_PCRE2_16)
       VERSION ${LIBPCRE2_16_VERSION}
       SOVERSION ${LIBPCRE2_16_SOVERSION})
     TARGET_COMPILE_DEFINITIONS(pcre2-16-static PUBLIC PCRE2_STATIC)
+    IF(REQUIRE_PTHREAD)
+      TARGET_LINK_LIBRARIES(pcre2-16-static Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-16-static)
 
     IF(MSVC)
@@ -794,6 +809,9 @@ IF(PCRE2_BUILD_PCRE2_16)
       VERSION ${LIBPCRE2_16_VERSION}
       SOVERSION ${LIBPCRE2_16_SOVERSION}
       OUTPUT_NAME pcre2-16)
+    IF(REQUIRE_PTHREAD)
+      TARGET_LINK_LIBRARIES(pcre2-16-shared Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-16-shared)
 
     IF(MINGW)
@@ -825,6 +843,9 @@ IF(PCRE2_BUILD_PCRE2_32)
       VERSION ${LIBPCRE2_32_VERSION}
       SOVERSION ${LIBPCRE2_32_SOVERSION})
     TARGET_COMPILE_DEFINITIONS(pcre2-32-static PUBLIC PCRE2_STATIC)
+    IF(REQUIRE_PTHREAD)
+      TARGET_LINK_LIBRARIES(pcre2-32-static Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-32-static)
 
     IF(MSVC)
@@ -846,6 +867,9 @@ IF(PCRE2_BUILD_PCRE2_32)
       VERSION ${LIBPCRE2_32_VERSION}
       SOVERSION ${LIBPCRE2_32_SOVERSION}
       OUTPUT_NAME pcre2-32)
+    IF(REQUIRE_PTHREAD)
+      TARGET_LINK_LIBRARIES(pcre2-32-shared Threads::Threads)
+    ENDIF(REQUIRE_PTHREAD)
     SET(targets ${targets} pcre2-32-shared)
 
     IF(MINGW)