[CMake] [PATCH] Optionally skip link dependencies on shared library files

[Leif Walsh]

Cool, thanks. I'll try this!

Sent from my iPhone

On Oct 26, 2012, at 8:43, Brad King <brad.king at kitware.com> wrote:

> Add target property LINK_DEPENDS_NO_SHARED and initialization variable
> CMAKE_LINK_DEPENDS_NO_SHARED to enable this behavior.
> 
> Suggested-by: Leif Walsh <leif.walsh at gmail.com>
> ---
> 
> On 08/03/2012 04:57 PM, Leif Walsh wrote:
>> On 3 Aug, 2012, at 4:44 PM, Andreas Pakulat <apaku at gmx.de> wrote:
>>> Actually no, adding new public API, changing existing API in
>>> compatible ways are things you can do with a shared library which
>>> needs relinking.
>> 
>> Not without changing the header files, which forces
>> recompilation.  As the author of a shared library, your header
>> files are your contract with your clients.
> 
> Great point.  Please try this patch on top of 2.8.10-rc3.
> Then build with -DCMAKE_LINK_DEPENDS_NO_SHARED=1 or add
> 
> set(CMAKE_LINK_DEPENDS_NO_SHARED 1)
> 
> to the top of your project.
> 
> -Brad
> 
> Source/cmComputeLinkInformation.cxx |   10 +++++++++-
> Source/cmComputeLinkInformation.h   |    1 +
> Source/cmDocumentVariables.cxx      |    9 +++++++++
> Source/cmTarget.cxx                 |   17 +++++++++++++++++
> 4 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
> index cd3ef59..d8ffb5e 100644
> --- a/Source/cmComputeLinkInformation.cxx
> +++ b/Source/cmComputeLinkInformation.cxx
> @@ -277,6 +277,10 @@ cmComputeLinkInformation
>   this->UseImportLibrary =
>     this->Makefile->GetDefinition("CMAKE_IMPORT_LIBRARY_SUFFIX")?true:false;
> 
> +  // Check whether we should skip dependencies on shared library files.
> +  this->LinkDependsNoShared =
> +    this->Target->GetPropertyAsBool("LINK_DEPENDS_NO_SHARED");
> +
>   // On platforms without import libraries there may be a special flag
>   // to use when creating a plugin (module) that obtains symbols from
>   // the program that will load it.
> @@ -650,7 +654,11 @@ void cmComputeLinkInformation::AddItem(std::string const& item, cmTarget* tgt)
> 
>       // Pass the full path to the target file.
>       std::string lib = tgt->GetFullPath(config, implib, true);
> -      this->Depends.push_back(lib);
> +      if(!this->LinkDependsNoShared ||
> +         tgt->GetType() != cmTarget::SHARED_LIBRARY)
> +        {
> +        this->Depends.push_back(lib);
> +        }
> 
>       this->AddTargetItem(lib, tgt);
>       this->AddLibraryRuntimeInfo(lib, tgt);
> diff --git a/Source/cmComputeLinkInformation.h b/Source/cmComputeLinkInformation.h
> index f60f8d3..e0078af 100644
> --- a/Source/cmComputeLinkInformation.h
> +++ b/Source/cmComputeLinkInformation.h
> @@ -82,6 +82,7 @@ private:
>   // Configuration information.
>   const char* Config;
>   const char* LinkLanguage;
> +  bool LinkDependsNoShared;
> 
>   // Modes for dealing with dependent shared libraries.
>   enum SharedDepMode
> diff --git a/Source/cmDocumentVariables.cxx b/Source/cmDocumentVariables.cxx
> index 8db0e8f..55d70f8 100644
> --- a/Source/cmDocumentVariables.cxx
> +++ b/Source/cmDocumentVariables.cxx
> @@ -1222,6 +1222,15 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
>      "Variables that Control the Build");
> 
>   cm->DefineProperty
> +    ("CMAKE_LINK_DEPENDS_NO_SHARED", cmProperty::VARIABLE,
> +     "Whether to skip link dependencies on shared library files.",
> +     "This variable initializes the LINK_DEPENDS_NO_SHARED "
> +     "property on targets when they are created.  "
> +     "See that target property for additional information.",
> +     false,
> +     "Variables that Control the Build");
> +
> +  cm->DefineProperty
>     ("CMAKE_AUTOMOC", cmProperty::VARIABLE,
>      "Whether to handle moc automatically for Qt targets.",
>      "This variable is used to initialize the "
> diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
> index 423b350..9cfcb63 100644
> --- a/Source/cmTarget.cxx
> +++ b/Source/cmTarget.cxx
> @@ -651,6 +651,22 @@ void cmTarget::DefineProperties(cmake *cm)
>      "custom Makefile link rules.");
> 
>   cm->DefineProperty
> +    ("LINK_DEPENDS_NO_SHARED", cmProperty::TARGET,
> +     "Do not depend on linked shared library files.",
> +     "Set this property to true to tell CMake generators not to add "
> +     "file-level dependencies on the shared library files linked by "
> +     "this target.  "
> +     "Modification to the shared libraries will not be sufficient to "
> +     "re-link this target.  "
> +     "Logical target-level dependencies will not be affected so the "
> +     "linked shared libraries will still be brought up to date before "
> +     "this target is built."
> +     "\n"
> +     "This property is initialized by the value of the variable "
> +     "CMAKE_LINK_DEPENDS_NO_SHARED if it is set when a target is "
> +     "created.");
> +
> +  cm->DefineProperty
>     ("LINK_INTERFACE_LIBRARIES", cmProperty::TARGET,
>      "List public interface libraries for a shared library or executable.",
>      "By default linking to a shared library target transitively "
> @@ -1314,6 +1330,7 @@ void cmTarget::SetMakefile(cmMakefile* mf)
>   this->SetPropertyDefault("OSX_ARCHITECTURES", 0);
>   this->SetPropertyDefault("AUTOMOC", 0);
>   this->SetPropertyDefault("AUTOMOC_MOC_OPTIONS", 0);
> +  this->SetPropertyDefault("LINK_DEPENDS_NO_SHARED", 0);
>   this->SetPropertyDefault("LINK_INTERFACE_LIBRARIES", 0);
>   this->SetPropertyDefault("WIN32_EXECUTABLE", 0);
>   this->SetPropertyDefault("MACOSX_BUNDLE", 0);
> -- 
> 1.7.10.4
>