Log implicit link information parsing actions

This commit teaches the CMAKE_PARSE_IMPLICIT_LINK_INFO function to log
its actions.  We store the log in CMakeFiles/CMakeOutput.log at the top
of the project build tree.  This will make diagnosis of implicit link
information parsing problems easier.

1 files changed, 21 insertions, 1 deletions

diff --git a/Modules/CMakeParseImplicitLinkInfo.cmake b/Modules/CMakeParseImplicitLinkInfo.cmake
index d0bbc8c097..9cab2de239 100644
--- a/Modules/CMakeParseImplicitLinkInfo.cmake
+++ b/Modules/CMakeParseImplicitLinkInfo.cmake
@@ -16,9 +16,10 @@
 # This is used internally by CMake and should not be included by user
 # code.
 
-function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var)
+function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var log_var)
   set(implicit_libs "")
   set(implicit_dirs_tmp)
+  set(log "")
 
   # Parse implicit linker arguments.
   set(linker "CMAKE_LINKER-NOTFOUND")
@@ -38,38 +39,51 @@ function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var)
       list(GET args 0 cmd)
     endif()
     if("${cmd}" MATCHES "${linker_regex}")
+      set(log "${log}  link line: [${line}]\n")
       string(REGEX REPLACE ";-([LYz]);" ";-\\1" args "${args}")
       foreach(arg IN LISTS args)
         if("${arg}" MATCHES "^-L(.:)?[/\\]")
           # Unix search path.
           string(REGEX REPLACE "^-L" "" dir "${arg}")
           list(APPEND implicit_dirs_tmp ${dir})
+          set(log "${log}    arg [${arg}] ==> dir [${dir}]\n")
         elseif("${arg}" MATCHES "^-l[^:]")
           # Unix library.
           string(REGEX REPLACE "^-l" "" lib "${arg}")
           list(APPEND implicit_libs ${lib})
+          set(log "${log}    arg [${arg}] ==> lib [${lib}]\n")
         elseif("${arg}" MATCHES "^(.:)?[/\\].*\\.a$")
           # Unix library full path.
           list(APPEND implicit_libs ${arg})
+          set(log "${log}    arg [${arg}] ==> lib [${arg}]\n")
         elseif("${arg}" MATCHES "^-Y(P,)?")
           # Sun search path.
           string(REGEX REPLACE "^-Y(P,)?" "" dirs "${arg}")
           string(REPLACE ":" ";" dirs "${dirs}")
           list(APPEND implicit_dirs_tmp ${dirs})
+          set(log "${log}    arg [${arg}] ==> dirs [${dirs}]\n")
         elseif("${arg}" MATCHES "^-l:")
           # HP named library.
           list(APPEND implicit_libs ${arg})
+          set(log "${log}    arg [${arg}] ==> lib [${arg}]\n")
         elseif("${arg}" MATCHES "^-z(all|default|weak)extract")
           # Link editor option.
           list(APPEND implicit_libs ${arg})
+          set(log "${log}    arg [${arg}] ==> opt [${arg}]\n")
+        else()
+          set(log "${log}    arg [${arg}] ==> ignore\n")
         endif()
       endforeach()
       break()
     elseif("${line}" MATCHES "LPATH(=| is:? )")
+      set(log "${log}  LPATH line: [${line}]\n")
       # HP search path.
       string(REGEX REPLACE ".*LPATH(=| is:? *)" "" paths "${line}")
       string(REPLACE ":" ";" paths "${paths}")
       list(APPEND implicit_dirs_tmp ${paths})
+      set(log "${log}    dirs [${paths}]\n")
+    else()
+      set(log "${log}  ignore line: [${line}]\n")
     endif()
   endforeach()
 
@@ -78,10 +92,16 @@ function(CMAKE_PARSE_IMPLICIT_LINK_INFO text lib_var dir_var)
   foreach(d IN LISTS implicit_dirs_tmp)
     get_filename_component(dir "${d}" ABSOLUTE)
     list(APPEND implicit_dirs "${dir}")
+    set(log "${log}  collapse dir [${d}] ==> [${dir}]\n")
   endforeach()
   list(REMOVE_DUPLICATES implicit_dirs)
 
+  # Log results.
+  set(log "${log}  implicit libs: [${implicit_libs}]\n")
+  set(log "${log}  implicit dirs: [${implicit_dirs}]\n")
+
   # Return results.
   set(${lib_var} "${implicit_libs}" PARENT_SCOPE)
   set(${dir_var} "${implicit_dirs}" PARENT_SCOPE)
+  set(${log_var} "${log}" PARENT_SCOPE)
 endfunction()