(0013076)
Bill Hoffman (manager)
2008-08-19 15:09

Committer: Bill Hoffman <bill.hoffman@kitware.com>
/cvsroot/CMake/CMake/Source/cmGlobalVisualStudio7Generator.cxx,v <-- cmGlobalVisualStudio7Generator.cxx
new revision: 1.101; previous revision: 1.100

BTW, this flag is not supported in VS8 and greater:
cl : Command line warning D9002 : ignoring unknown option '/LTGC'

(0014292)
Luke K (reporter)
2008-12-04 18:32

This MSVC 7.1 issue is not entirely resolved. I am still seeing numerous warnings when dependent static libraries are built prior to linking the final executable:

[ 45%] Building CXX object
Util/CMakeFiles/Util-SL.dir/XMLUtil/XMLWriter.cpp.obj
XMLWriter.cpp
Linking CXX static library ..\build\MT-DLL\Util-SL.lib
XMLWriter.cpp.obj : warning LNK4218: non-native module found; restarting
link with /LTCG
[ 45%] Built target Util-SL

The /LTCG option is added to the executable linker line now (in the "AdditionalOptions" linker section), but I think that the above warning is caused by a missing WholeProgramOptimization="TRUE" element in the static library project files (in the Configuration tag).

I think the best way to resolve this issue is to detect the /GL compiler flag and insert the WholeProgramOptimization="TRUE" element into the Configuration tag. The compiler flag /GL and linker flag /LTCG are almost synonymous flags that mean "perform whole program optimization". This warning is a result of a discrepancy between the /GL flag and the WholeProgramOptimization element. If /GL is passed as a compiler arg, then it is necessarily true that WholeProgramOptimization element should = "TRUE" (otherwise = "FALSE" or omitted).

Thank you for your time and effort. I appreciate the hard work that you have all done to make and keep CMake a high-quality software product.

Sincerely,
Luke Kucalaba

(0014294)
Luke K (reporter)
2008-12-04 18:50

I did some more investigation of this problem, and I think I've nailed it down now. I thought it was the missing WholeProgramOptimization element that was causing the warning, when in fact it is the missing "/LTCG" flag that should be in the Librarian additional command-line options. I realize that for a static library project the linker flags are not included in the generated project file, but this should be an exception case to that rule. As a general rule of thumb, if the /GL compiler flag is passed to a static library project, then the /LTCG flag should be passed to the Librarian AdditionalOptions line.

            <Tool
                Name="VCLibrarianTool"
                AdditionalOptions="/LTCG">

Thanks again,
Luke

(0014314)
Luke K (reporter)
2008-12-09 14:44

Problem solved! I finally found some time today to checkout the CMake source code and get setup for development. I started the build and found the answer I was looking for in cmLocalVisualStudio7Generator::OutputBuildTool() :

    const char* tool = "VCLibrarianTool";
    fout << "\t\t\t<Tool\n"
         << "\t\t\t\tName=\"" << tool << "\"\n";
    if(const char* libflags = target.GetProperty("STATIC_LIBRARY_FLAGS"))
      {
      fout << "\t\t\t\tAdditionalOptions=\"" << libflags << "\"\n";
      }

Here is the solution that worked for me... if you have a similar problem you can use the same concept for your situation:

        If(WIN32 AND MSVC71)
            String(REGEX MATCH "/GL" matchResult "${compilerFlagsDebug}")
            If(matchResult)
                Set_Target_Properties("${targetFilenameDebug}" PROPERTIES
                    STATIC_LIBRARY_FLAGS "/LTCG"
                )
            EndIf()

            String(REGEX MATCH "/GL" matchResult "${compilerFlagsRelease}")
            If(matchResult)
                Set_Target_Properties("${targetFilenameRelease}" PROPERTIES
                    STATIC_LIBRARY_FLAGS "/LTCG"
                )
            EndIf()
        EndIf()

Thanks again for everything. Our build system is now completely free of errors and warnings!

Luke

(0024612)
David Cole (manager)
2011-01-12 06:40

Resolving issue that I accidentally stumbled across... and according to all the notes in the bug, it appears fixed.

Please re-open if there is still an issue here.

(0026329)
David Cole (manager)
2011-05-02 14:45

Closing resolved issues that have not been updated in more than 3 months.

Issue History
Date Modified	Username	Field	Change
2008-04-11 15:49	Luke K	New Issue
2008-08-19 15:09	Bill Hoffman	Status	new => closed
2008-08-19 15:09	Bill Hoffman	Note Added: 0013076
2008-08-19 15:09	Bill Hoffman	Resolution	open => fixed
2008-12-04 18:32	Luke K	Note Added: 0014292
2008-12-04 18:32	Luke K	Status	closed => feedback
2008-12-04 18:32	Luke K	Resolution	fixed => reopened
2008-12-04 18:50	Luke K	Note Added: 0014294
2008-12-09 14:44	Luke K	Note Added: 0014314
2008-12-15 10:35	Bill Hoffman	Status	feedback => assigned
2008-12-15 10:35	Bill Hoffman	Assigned To	=> Bill Hoffman
2011-01-12 06:40	David Cole	Note Added: 0024612
2011-01-12 06:40	David Cole	Status	assigned => resolved
2011-01-12 06:40	David Cole	Resolution	reopened => fixed
2011-05-02 14:45	David Cole	Note Added: 0026329
2011-05-02 14:45	David Cole	Status	resolved => closed

Notes
(0013076) Bill Hoffman (manager) 2008-08-19 15:09	Committer: Bill Hoffman <bill.hoffman@kitware.com> /cvsroot/CMake/CMake/Source/cmGlobalVisualStudio7Generator.cxx,v <-- cmGlobalVisualStudio7Generator.cxx new revision: 1.101; previous revision: 1.100 BTW, this flag is not supported in VS8 and greater: cl : Command line warning D9002 : ignoring unknown option '/LTGC'

(0014292) Luke K (reporter) 2008-12-04 18:32	This MSVC 7.1 issue is not entirely resolved. I am still seeing numerous warnings when dependent static libraries are built prior to linking the final executable: [ 45%] Building CXX object Util/CMakeFiles/Util-SL.dir/XMLUtil/XMLWriter.cpp.obj XMLWriter.cpp Linking CXX static library ..\build\MT-DLL\Util-SL.lib XMLWriter.cpp.obj : warning LNK4218: non-native module found; restarting link with /LTCG [ 45%] Built target Util-SL The /LTCG option is added to the executable linker line now (in the "AdditionalOptions" linker section), but I think that the above warning is caused by a missing WholeProgramOptimization="TRUE" element in the static library project files (in the Configuration tag). I think the best way to resolve this issue is to detect the /GL compiler flag and insert the WholeProgramOptimization="TRUE" element into the Configuration tag. The compiler flag /GL and linker flag /LTCG are almost synonymous flags that mean "perform whole program optimization". This warning is a result of a discrepancy between the /GL flag and the WholeProgramOptimization element. If /GL is passed as a compiler arg, then it is necessarily true that WholeProgramOptimization element should = "TRUE" (otherwise = "FALSE" or omitted). Thank you for your time and effort. I appreciate the hard work that you have all done to make and keep CMake a high-quality software product. Sincerely, Luke Kucalaba

(0014294) Luke K (reporter) 2008-12-04 18:50	I did some more investigation of this problem, and I think I've nailed it down now. I thought it was the missing WholeProgramOptimization element that was causing the warning, when in fact it is the missing "/LTCG" flag that should be in the Librarian additional command-line options. I realize that for a static library project the linker flags are not included in the generated project file, but this should be an exception case to that rule. As a general rule of thumb, if the /GL compiler flag is passed to a static library project, then the /LTCG flag should be passed to the Librarian AdditionalOptions line. <Tool Name="VCLibrarianTool" AdditionalOptions="/LTCG"> Thanks again, Luke

(0014314) Luke K (reporter) 2008-12-09 14:44	Problem solved! I finally found some time today to checkout the CMake source code and get setup for development. I started the build and found the answer I was looking for in cmLocalVisualStudio7Generator::OutputBuildTool() : const char* tool = "VCLibrarianTool"; fout << "\t\t\t<Tool\n" << "\t\t\t\tName=\"" << tool << "\"\n"; if(const char* libflags = target.GetProperty("STATIC_LIBRARY_FLAGS")) { fout << "\t\t\t\tAdditionalOptions=\"" << libflags << "\"\n"; } Here is the solution that worked for me... if you have a similar problem you can use the same concept for your situation: If(WIN32 AND MSVC71) String(REGEX MATCH "/GL" matchResult "${compilerFlagsDebug}") If(matchResult) Set_Target_Properties("${targetFilenameDebug}" PROPERTIES STATIC_LIBRARY_FLAGS "/LTCG" ) EndIf() String(REGEX MATCH "/GL" matchResult "${compilerFlagsRelease}") If(matchResult) Set_Target_Properties("${targetFilenameRelease}" PROPERTIES STATIC_LIBRARY_FLAGS "/LTCG" ) EndIf() EndIf() Thanks again for everything. Our build system is now completely free of errors and warnings! Luke

(0024612) David Cole (manager) 2011-01-12 06:40	Resolving issue that I accidentally stumbled across... and according to all the notes in the bug, it appears fixed. Please re-open if there is still an issue here.

(0026329) David Cole (manager) 2011-05-02 14:45	Closing resolved issues that have not been updated in more than 3 months.

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