Introduce CMAKE_STAGING_PREFIX variable.

This variable can be useful in cross-compiling contexts where the
sysroot is read-only or where the sysroot should otherwise remain
pristine.

If the new CMAKE_STAGING_PREFIX variable is set, it is used instead
of CMAKE_INSTALL_PREFIX when generating the installation rules in
cmake_install.cmake.

This way, the CMAKE_INSTALL_PREFIX variable
always refers to the installation prefix on the target device, regardless
of whether host==target.

If any -rpath paths passed to the linker contain the CMAKE_STAGING_PREFIX,
the matching path fragments are replaced with the CMAKE_INSTALL_PREFIX.
Matching paths in the -rpath-link are not transformed.

The cross-prefix usr-move workaround is assumed not to require extension
regarding CMAKE_STAGING_PREFIX. The staging area is a single prefix, so
there is no scope for cross-prefix symlinks. The CMAKE_INSTALL_PREFIX
is still used to determine the workaround path, and that variable
remains the relevant one even if CMAKE_STAGING_PREFIX is used. If the
generated export files are deployed to the target, the workaround
will still be in place, and still be employed if required.

3 files changed, 31 insertions, 1 deletions

diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index 3152c2a..0ef3d2e 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -1902,6 +1902,10 @@ void cmComputeLinkInformation::GetRPath(std::vector<std::string>& runtimeDirs,
   if(use_build_rpath || use_link_rpath)
     {
     std::string rootPath = this->Makefile->GetSafeDefinition("CMAKE_SYSROOT");
+    const char *stagePath
+                  = this->Makefile->GetDefinition("CMAKE_STAGING_PREFIX");
+    const char *installPrefix
+                  = this->Makefile->GetSafeDefinition("CMAKE_INSTALL_PREFIX");
     cmSystemTools::ConvertToUnixSlashes(rootPath);
     std::vector<std::string> const& rdirs = this->GetRuntimeSearchPath();
     for(std::vector<std::string>::const_iterator ri = rdirs.begin();
@@ -1916,6 +1920,14 @@ void cmComputeLinkInformation::GetRPath(std::vector<std::string>& runtimeDirs,
           {
           d = d.substr(rootPath.size());
           }
+        else if (stagePath && *stagePath && d.find(stagePath) == 0)
+          {
+          std::string suffix = d.substr(strlen(stagePath));
+          d = installPrefix;
+          d += "/";
+          d += suffix;
+          cmSystemTools::ConvertToUnixSlashes(d);
+          }
         if(emitted.insert(d).second)
           {
           runtimeDirs.push_back(d);
@@ -1936,6 +1948,14 @@ void cmComputeLinkInformation::GetRPath(std::vector<std::string>& runtimeDirs,
             {
             d = d.substr(rootPath.size());
             }
+          else if (stagePath && *stagePath && d.find(stagePath) == 0)
+            {
+            std::string suffix = d.substr(strlen(stagePath));
+            d = installPrefix;
+            d += "/";
+            d += suffix;
+            cmSystemTools::ConvertToUnixSlashes(d);
+            }
           if(emitted.insert(d).second)
             {
             runtimeDirs.push_back(d);
diff --git a/Source/cmFindCommon.cxx b/Source/cmFindCommon.cxx
index 8c42811..e8c8da3 100644
--- a/Source/cmFindCommon.cxx
+++ b/Source/cmFindCommon.cxx
@@ -165,6 +165,9 @@ void cmFindCommon::RerootPaths(std::vector<std::string>& paths)
     cmSystemTools::ConvertToUnixSlashes(*ri);
     }
 
+  const char* stagePrefix =
+      this->Makefile->GetDefinition("CMAKE_STAGING_PREFIX");
+
   // Copy the original set of unrooted paths.
   std::vector<std::string> unrootedPaths = paths;
   paths.clear();
@@ -179,7 +182,9 @@ void cmFindCommon::RerootPaths(std::vector<std::string>& paths)
       // already inside.  Skip the unrooted path if it is relative to
       // a user home directory or is empty.
       std::string rootedDir;
-      if(cmSystemTools::IsSubDirectory(ui->c_str(), ri->c_str()))
+      if(cmSystemTools::IsSubDirectory(ui->c_str(), ri->c_str())
+          || (stagePrefix
+            && cmSystemTools::IsSubDirectory(ui->c_str(), stagePrefix)))
         {
         rootedDir = *ui;
         }
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index d2784a9..cf5798f 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -370,6 +370,11 @@ void cmLocalGenerator::GenerateInstallRules()
     prefix = "/usr/local";
     }
 #endif
+  if (const char *stagingPrefix
+                  = this->Makefile->GetDefinition("CMAKE_STAGING_PREFIX"))
+    {
+    prefix = stagingPrefix;
+    }
 
   // Compute the set of configurations.
   std::vector<std::string> configurationTypes;