From 5d0a8b1abc3f8a6d8d23772251b4ef2758d2def6 Mon Sep 17 00:00:00 2001 From: Bill Somerville Date: Wed, 29 Jul 2015 17:36:38 +0100 Subject: GetPrerequisites: Optionally filter "objdump" output for speed As dumpbin.exe is no longer reliable for gcc libraries on MinGW because it crashes on many common libraries like libgcc_s and libgfortran it is now necessary too resort to using objdump for DLL dependency walking. Using objdump has a secondary problem in that it generates a lot of output for large libraries and causes fixup_bundle() to take many minutes to process what took fractions of a second with "dumpbin.exe /dependents". Add a 'grep' pre-filter in the execute_process() command pipeline to reduce this output to a minimum for a several orders of magnitude speed up. If grep is not available just use the full output. As there does not seem to be a reliable way of detecting MinGW, callers of fixup_bundle() may have to set the variable gp_tool to "objdump" if dumpbin.exe is installed on the build machine to stop it using the broken MS dumpbin.exe for library dependency walking. --- Modules/GetPrerequisites.cmake | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Modules/GetPrerequisites.cmake b/Modules/GetPrerequisites.cmake index a359d2c..e4018b6 100644 --- a/Modules/GetPrerequisites.cmake +++ b/Modules/GetPrerequisites.cmake @@ -700,6 +700,8 @@ function(get_prerequisites target prerequisites_var exclude_system recurse exepa return() endif() + set(gp_cmd_maybe_filter) # optional command to pre-filter gp_tool results + if(gp_tool STREQUAL "ldd") set(gp_cmd_args "") set(gp_regex "^[\t ]*[^\t ]+ => ([^\t\(]+) .*${eol_char}$") @@ -724,6 +726,11 @@ function(get_prerequisites target prerequisites_var exclude_system recurse exepa set(gp_regex_error "") set(gp_regex_fallback "") set(gp_regex_cmp_count 1) + # objdump generaates copious output so we create a grep filter to pre-filter results + find_program(gp_grep_cmd grep) + if(gp_grep_cmd) + set(gp_cmd_maybe_filter COMMAND ${gp_grep_cmd} "^[[:blank:]]*DLL Name: ") + endif() else() message(STATUS "warning: gp_tool='${gp_tool}' is an unknown tool...") message(STATUS "CMake function get_prerequisites needs more code to handle '${gp_tool}'") @@ -780,6 +787,7 @@ function(get_prerequisites target prerequisites_var exclude_system recurse exepa # execute_process( COMMAND ${gp_cmd} ${gp_cmd_args} ${target} + ${gp_cmd_maybe_filter} RESULT_VARIABLE gp_rv OUTPUT_VARIABLE gp_cmd_ov ERROR_VARIABLE gp_ev -- cgit v0.12