Changeset 32248 for gs2-extensions/xpdf-tools/trunk/src/packages/gs-CMakeLists.txt

Timestamp:

2018-07-06T21:31:53+12:00 (6 years ago)

Author:

ak19

Message:

1. Overhaul to the GS-README for the xpdf-tools extension. 2. Moved a lot of verbose comments that explain reasonings behind doing things from gs-CMakeLists.txt and somewhat from XPDFTOOLS.sh

File:

• gs2-extensions/xpdf-tools/trunk/src/packages/gs-CMakeLists.txt (modified) (4 diffs)

gs2-extensions/xpdf-tools/trunk/src/packages/gs-CMakeLists.txt

@@ -10 +10 @@
 
 #========================================================================
-# This is a customised version of Xpdf Tools' CMake file.
-# Customised for Greenstone.
+# This is a customised version of Xpdf Tools' CMake file for Greenstone
+# where we want to build static xpdf-tools executables.
+# Refer to the GS-README.txt file for the Greenstone "xpdf-tools"
+# gs2-extension and read section D for the GS specific customisations
+# in this file and the reasoning behind them, most of which have to do
+# with attempting to successfully build xpdf-tools statically.
 #========================================================================
 
@@ -21 +25 @@
 
 
-# For Mac OSX, when -static is passed in for linking, we end up with the error "ld: library not found for -lcrt0.o"
-# See https://stackoverflow.com/questions/3801011/ld-library-not-found-for-lcrt0-o-on-osx-10-6-with-gcc-clang-static-flag
-# On Mac OSX, compile it with -Bstatic, as per https://stackoverflow.com/questions/844819/how-to-static-link-on-os-x
-# XPDFTOOLS.sh will have set the GSDLFLAG_STATIC to either "-static" (for linux) or "-Bstatic" for darwin
+# When compiling statically, XPDFTOOLS.sh will have set the custom
+# GSDLFLAG_STATIC flag to either "-static" for linux or "-Bstatic" for darwin
 
 if(GSDLFLAG_STATIC)
@@ -131 +133 @@
 endif ()
 
-# We want to build static xpdf-tools binaries. See
-# https://stackoverflow.com/questions/24648357/compiling-a-static-executable-with-cmake
-# Want to make the min number of changes for building statically, so using the way
-# below. Beware, must *append* "-static" to existing CMAKE_EXE_LINKER_FLAGS=LD_FLAGS
-##SET(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
-##SET(BUILD_SHARED_LIBS OFF)
-##SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
-
-# The original, unmodified CMakeLists.txt was not set up sufficiently
-# for static compilation of xpdf-tools. As a result, compile would first fail
-# with errors about undefined refs to mutex / lpthread.
-# When building xpdf-tools statically, need to add the following 2 lines as well
-# as append "Threads::Threads" to the end of each "target_link_libraries(<list>)"
-# See https://stackoverflow.com/questions/1620918/cmake-and-libpthread
-# found googling cmake and "-lpthread" (pthread) after ERRORS to do with this, like:
-#   undefined reference to `pthread_mutex_unlock'
-##set(THREADS_PREFER_PTHREAD_FLAG ON)
-##find_package(Threads REQUIRED)
-
 #--- pdftops
 
@@ -222 +205 @@
                           ${LCMS_LIBRARY} ${PNG_LIBRARIES})
   endif ()
-# Doing the regular target_link_libraries() in static mode results in building with 
-# "-Wl,-Bstatic -lfreetype -lpng15 -lz -Wl,-Bdynamic -lpthread" at end of link line
-# and produces broken binaries for pdftohtml/pdftoppm/pdftops/pdftopng.
-# Note that PNG_LIBRARIES includes zlib/lz: "-lpng -lz", and along with freetype,
-# these are linked statically. However, Threads/lpthread is included as a dynamically
-# linked library instead of including a .a (regardless of whether it's appended
-# as -lpthread or Threads::Threads in else above), contributing to the pdfhtml binary
-# produced being a partially static, partially dynamic one,
-# so a dynamic executable overall.
-# The order of dynamic .so files listed by ldd in the broken binary differs from
-# a manually linked working version of pdftohtml, and seems to be the only difference
-# between the two in ldd output. Not using "-Wl,-Bstatic" and using -static (-Bstatic on Mac)
-# in its place creates a partially static dynamic executable that isn't broken, whereas
-# additionally removing "-Wl,-Bdynamic -lpthread" and replacing it with -lpthread
-# moreover produces a working pdftohtml that is a fully static linked executable.
-# The inclusion of the math lib and c lib (lm and lc) in the final link command
-# are to completely bypass the remaining .so dependencies that were present in
-# the executable and produce the fully static executable.
-# Not sure what colormanager (lcms) and typelibrary, or how they're written in -l
-# form as they were not present when the original unmodified static linking command
-# was run, so they've not been included in the replacement static linking command. 
   install(TARGETS pdftohtml RUNTIME DESTINATION bin)
   install(FILES ${PROJECT_SOURCE_DIR}/doc/pdftohtml.1 DESTINATION man/man1)