From: Guy Harris <guy@alum.mit.edu>
Date: Fri, 26 Jan 2018 08:49:21 +0000 (-0800)
Subject: Use pcap-config if we have it.
X-Git-Tag: tcpdump-4.99-bp~1352
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/213f7585ebc024fb99c608d96a89b713a8d9e458

Use pcap-config if we have it.

Also, provide support for linking statically with pcap.
---

diff --git a/cmake/Modules/FindPCAP.cmake b/cmake/Modules/FindPCAP.cmake
index dc4f75a7..bc17f7ab 100644
--- a/cmake/Modules/FindPCAP.cmake
+++ b/cmake/Modules/FindPCAP.cmake
@@ -2,11 +2,94 @@
 # Try to find libpcap.
 #
 
-# Try to find the header
-find_path(PCAP_INCLUDE_DIR pcap.h)
+find_program(PCAP_CONFIG pcap-config)
+if(PCAP_CONFIG)
+  # We have pcap-config; use it.
+  # First, get the include directory.
+  execute_process(COMMAND "${PCAP_CONFIG}" "--cflags"
+    RESULT_VARIABLE PCAP_CONFIG_RESULT
+    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+    message(FATAL_ERROR "pcap-config --cflags failed")
+  endif()
+  string(REGEX REPLACE "-I" "" PCAP_INCLUDE_DIR ${PCAP_CONFIG_OUTPUT})
 
-# Try to find the library
-find_library(PCAP_LIBRARY pcap)
+  # Now, get the library directories and libraries.
+  execute_process(COMMAND "${PCAP_CONFIG}" "--libs"
+    RESULT_VARIABLE PCAP_CONFIG_RESULT
+    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+    message(FATAL_ERROR "pcap-config --libs failed")
+  endif()
+  separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
+  set(PCAP_LIBRARY_DIRS)
+  set(PCAP_LIBRARIES)
+  foreach(arg IN LISTS LIBS_LIST)
+    if(arg MATCHES "^-L")
+      # Add this directory to PCAP_LIBRARY_DIRS
+      string(REGEX REPLACE "-L" "" dir ${arg})
+      list(APPEND PCAP_LIBRARY_DIRS ${dir})
+    elseif(arg MATCHES "^-l")
+      string(REGEX REPLACE "-l" "" lib ${arg})
+      list(APPEND PCAP_LIBRARIES ${lib})
+    endif()
+  endforeach()
+
+  # Now, get the library directories and libraries for static linking.
+  execute_process(COMMAND "${PCAP_CONFIG}" "--libs" "--static"
+    RESULT_VARIABLE PCAP_CONFIG_RESULT
+    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+  )
+  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+    message(FATAL_ERROR "pcap-config --libs --static failed")
+  endif()
+  separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
+  set(PCAP_STATIC_LIBRARY_DIRS)
+  set(PCAP_STATIC_LIBRARIES)
+  foreach(arg IN LISTS LIBS_LIST)
+    if(arg MATCHES "^-L")
+      # Add this directory to PCAP_STATIC_LIBRARY_DIRS
+      string(REGEX REPLACE "-L" "" dir ${arg})
+      list(APPEND PCAP_STATIC_LIBRARY_DIRS ${dir})
+    elseif(flag MATCHES "^-l")
+      string(REGEX REPLACE "-l" "" lib ${arg})
+      list(APPEND PCAP_STATIC_LIBRARIES ${lib})
+    endif()
+  endforeach()
+
+  # Try to find the header
+  find_path(PCAP_INCLUDE_DIR pcap.h HINTS ${PCAP_INCLUDE_DIRS})
+
+  # Try to find the library
+  find_library(PCAP_LIBRARY pcap HINTS ${PCAP_LIBRARY_DIRS})
+
+  # Try to find the static library (XXX - what about AIX?)
+  include(CMakePushCheckState)
+  cmake_push_check_state()
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
+  find_library(PCAP_STATIC_LIBRARY pcap HINTS ${PCAP_STATIC_LIBRARY_DIRS})
+  cmake_pop_check_state()
+else(PCAP_CONFIG)
+  # Try to find the header
+  find_path(PCAP_INCLUDE_DIR pcap.h)
+
+  # Try to find the library
+  find_library(PCAP_LIBRARY pcap)
+
+  # Try to find the static library (XXX - what about AIX?)
+  include(CMakePushCheckState)
+  cmake_push_check_state()
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
+  find_library(PCAP_STATIC_LIBRARY pcap)
+  cmake_pop_check_state()
+
+  set(PCAP_INCLUDE_DIRS ${PCAP_INCLUDE_DIR})
+  set(PCAP_LIBRARIES ${PCAP_LIBRARY})
+endif(PCAP_CONFIG)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(PCAP
@@ -18,7 +101,5 @@ find_package_handle_standard_args(PCAP
 mark_as_advanced(
   PCAP_INCLUDE_DIR
   PCAP_LIBRARY
+  PCAP_STATIC_LIBRARY
 )
-
-set(PCAP_INCLUDE_DIRS ${PCAP_INCLUDE_DIR})
-set(PCAP_LIBRARIES ${PCAP_LIBRARY})