[cmake-developers] [CMake 0016040]: Generated Xcode Projects Have Wrong Paths to Object Library Dependencies

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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https://public.kitware.com/Bug/view.php?id=16040 
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Reported By:                Colin Cornaby
Assigned To:                
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Project:                    CMake
Issue ID:                   16040
Category:                   CMake
Reproducibility:            always
Severity:                   major
Priority:                   high
Status:                     new
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Date Submitted:             2016-03-30 16:57 EDT
Last Modified:              2016-03-30 16:57 EDT
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Summary:                    Generated Xcode Projects Have Wrong Paths to Object
Library Dependencies
Description: 
We have a CMake project that has object libraries, and then a parent build
target that wraps those object libraries into a static library. When I generate
the Xcode output, the parent build target is referencing different paths than
what the .o's were outputted to.

I have a patch that fixes the issue, but I wanted to open a bug first,
especially if I'm duplicating something (apologies, this is my first CMake bug.)

The section of code that seems to be the issue in the Xcode generator is here:
cmGlobalXCodeGenerator::GetObjectsNormalDirectory(
  const std::string &projName,
  const std::string &configName,
  const cmGeneratorTarget *t) const
{
  std::string dir =
    t->GetLocalGenerator()->GetCurrentBinaryDirectory();
  dir += "/";
  dir += projName;
  dir += ".build/";
  dir += configName;
  dir += "/";
  dir += t->GetName();
  dir += ".build/Objects-normal/";

  return dir;
}

There are a few things wrong here:
- The configuration name should be part of this path. Specifically the section
of that path that is "foo.build/release" should be "foo.build/release-iphoneos".
This behavior could be different for Mac targets, but I'm pretty sure it isn't.
One reason I'm not straight submitting the patch yet.
- The .o files get written to the temporary objects directory, not the binary
output directory. I've wrapped this in a new function:
std::string
cmGlobalXCodeGenerator::GetTemporaryFilesDirectory(
                                                  const std::string &projName,
                                                  const std::string &configName,
                                                  const cmGeneratorTarget *t)
const
{
    std::string dir =
    t->GetLocalGenerator()->GetCurrentBinaryDirectory();
    dir += "/";
    dir += projName;
    dir += ".build/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/";
    
    return dir;
}

I've then altered a few functions. GetObjectsNormalDirectory becomes:
//----------------------------------------------------------------------------
std::string
cmGlobalXCodeGenerator::GetObjectsNormalDirectory(
  const std::string &projName,
  const std::string &configName,
  const cmGeneratorTarget *t) const
{
    std::string dir = GetTemporaryFilesDirectory(projName, configName, t);
  dir += t->GetName();
  dir += ".build/Objects-normal/";

  return dir;
}

The build setting creation gets altered a bit a well with:
if(this->XcodeVersion >= 21)
      {
      std::string pncdir = this->GetObjectsNormalDirectory(
                                                           this->CurrentProject,
configName, gtgt);
      std::string tempdir = this->GetTemporaryFilesDirectory(
                                                           this->CurrentProject,
configName, gtgt);
      buildSettings->AddAttribute("CONFIGURATION_BUILD_DIR",
                                  this->CreateString(pncdir.c_str()));
      buildSettings->AddAttribute("CONFIGURATION_TEMP_DIR",
                                      this->CreateString(tempdir.c_str()));
      }
    else
      {
      buildSettings->AddAttribute("OBJROOT",
                                  this->CreateString(pndir.c_str()));
      pndir = this->GetObjectsNormalDirectory(
        this->CurrentProject, configName, gtgt);
      }
    }

Again, mostly submitting this bug because I'm new to Cmake and I don't know if
this is patching on top of behavior that is platform dependent. Please let me
know if there is something I am missing here, or if I'm breaking something else
with these patches!

(I'm attaching a Git patch as well)
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Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2016-03-30 16:57 Colin Cornaby  New Issue                                    
2016-03-30 16:57 Colin Cornaby  File Added: 0001-Fixes-for-.o-generation.patch  
                 
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