root-project · pcanal · Aug 20, 2026
@@ -0,0 +1,13 @@
+# Check the way the dynamic (shared library) search path is assembled from
+# ROOT_LIBRARY_PATH, the system loader path and the .rootrc resource.
+#
+# This used to be implemented by the shell script `test_dynpath_setup.sh`; it
+# is now driven by the CMake script `dynamicPathSetup.cmake` so that the test
+# also runs on Windows.
+
+ROOTTEST_ADD_TEST(DynPathSetup
+                  COMMAND ${CMAKE_COMMAND}
+                          -DROOT_EXE=${ROOT_root_CMD}
+                          -DWORKDIR=${CMAKE_CURRENT_BINARY_DIR}/rootlibpath_test
+                          -P ${CMAKE_CURRENT_SOURCE_DIR}/dynamicPathSetup.cmake
+                  ENVIRONMENT ROOTENV_NO_HOME=1)
@@ -0,0 +1,219 @@
+# CMake re-implementation of the former `test_dynpath_setup.sh` shell script.
+#
+# It verifies the way `TSystem::GetDynamicPath()` is assembled out of
+#   * the `ROOT_LIBRARY_PATH` environment variable,
+#   * the platform specific loader search path
+#     (`LD_LIBRARY_PATH` / `DYLD_LIBRARY_PATH` / `PATH`),
+#   * the `<Unix|WinNT>.*.Root.DynamicPath` resource of the local `.rootrc`,
+#   * and the ROOT library (resp. binary) directory.
+#
+# Being a plain CMake script (executed via `cmake -P`) it runs on all the
+# platforms supported by ROOT, including Windows.
+#
+# Required arguments (passed with -D):
+#   ROOT_EXE : full path to the `root` executable
+#   WORKDIR  : scratch directory used to run the checks
+
+cmake_minimum_required(VERSION 3.20 FATAL_ERROR)
+
+foreach(var ROOT_EXE WORKDIR)
+  if(NOT DEFINED ${var})
+    message(FATAL_ERROR "${var} must be defined (cmake -D${var}=...)")
+  endif()
+endforeach()
+
+#---Platform dependent settings-------------------------------------------------
+# `sep`    : separator used in path lists
+# `rc_key` : name of the .rootrc resource holding the dynamic path
+# `ld_var` : environment variable used by the system loader
+if(WIN32)
+  set(sep ";")
+  set(rc_key "WinNT.*.Root.DynamicPath")
+  set(ld_var "PATH")
+elseif(APPLE)
+  set(sep ":")
+  set(rc_key "Unix.*.Root.DynamicPath")
+  set(ld_var "DYLD_LIBRARY_PATH")
+else()
+  set(sep ":")
+  set(rc_key "Unix.*.Root.DynamicPath")
+  set(ld_var "LD_LIBRARY_PATH")
+endif()
+
+#---Helpers---------------------------------------------------------------------
+
+# Run `root` on the given C++ expression and return the last line of its output.
+# The statement is wrapped into a block so that `root` exits with 0 rather than
+# with the (truncated) value of the last expression.
+function(root_eval expr outvar)
+  set(stmt "{ std::cout << ${expr} << std::endl; }")
+  execute_process(COMMAND "${ROOT_EXE}" -b -q -l -e "${stmt}"
+                  WORKING_DIRECTORY "${WORKDIR}"
+                  OUTPUT_VARIABLE out
+                  ERROR_VARIABLE err
+                  RESULT_VARIABLE rc)
+  if(NOT rc EQUAL 0)
+    message(FATAL_ERROR "'${ROOT_EXE} -b -q -l -e ${stmt}' failed with ${rc}\n${out}\n${err}")
+  endif()
+  string(REPLACE "\r" "" out "${out}")
+  string(STRIP "${out}" out)
+  # Keep only the last line (the value printed by `expr`), like `tail -1`.
+  string(REGEX MATCH "[^\n]*$" out "${out}")
+  set(${outvar} "${out}" PARENT_SCOPE)
+endfunction()
+
+# Write the local .rootrc with the requested dynamic path; an empty value
+# results in the resource being commented out.
+function(set_rootrc value)
+  if("${value}" STREQUAL "")
+    file(WRITE "${WORKDIR}/.rootrc" "# ${rc_key}:\n")
+  else()
+    file(WRITE "${WORKDIR}/.rootrc" "${rc_key}: ${value}\n")
+  endif()
+endfunction()
+
+# Query the dynamic path as seen by ROOT.
+macro(get_dynpath)
+  root_eval("gSystem->GetDynamicPath()" cur_dynpath)
+endmacro()
+
+# The dynamic path must start with `expected`.
+function(check_begin expected)
+  string(FIND "${cur_dynpath}${sep}" "${expected}${sep}" pos)
+  if(NOT pos EQUAL 0)
+    message(FATAL_ERROR "dynamic path: ${cur_dynpath}\n"
+                        "dynamic path should start with: ${expected}")
+  endif()
+endfunction()
+
+# The dynamic path must contain `expected` as a whole sequence of entries.
+function(check_mid expected)
+  string(FIND "${sep}${cur_dynpath}${sep}" "${sep}${expected}${sep}" pos)
+  if(pos EQUAL -1)
+    message(FATAL_ERROR "dynamic path: ${cur_dynpath}\n"
+                        "dynamic path should contain: ${expected}")
+  endif()
+endfunction()
+
+function(check_begin_and_mid begin mid)
+  check_begin("${begin}")
+  check_mid("${mid}")
+endfunction()
+
+# Assemble the "environment part" of the dynamic path the same way
+# TUnixSystem/TWinNTSystem do, i.e. ROOT_LIBRARY_PATH, followed by the loader
+# search path, followed by the `.rootrc` entries.
+function(root_env_part rdynpath outvar)
+  if(WIN32)
+    set(ld "$ENV{PATH}")
+  elseif(APPLE)
+    # On macOS ROOT concatenates all three of these.
+    set(ld "$ENV{DYLD_LIBRARY_PATH}${sep}$ENV{LD_LIBRARY_PATH}${sep}$ENV{DYLD_FALLBACK_LIBRARY_PATH}")
+  else()
+    set(ld "$ENV{LD_LIBRARY_PATH}")
+  endif()
+  set(${outvar} "$ENV{ROOT_LIBRARY_PATH}${sep}${ld}${sep}${rdynpath}" PARENT_SCOPE)
+endfunction()
+
+# ROOT guarantees that the library directory is part of the dynamic path. It is
+# appended right after the `.rootrc` entries, but *only* if it does not already
+# occur in the environment derived part -- see the
+# `if (!dynpath_envpart.Contains(TROOT::GetLibDir()))` guard in TUnixSystem.cxx
+# (a plain substring test, hence the plain string(FIND) below).
+#
+# Both situations occur in practice: when the test is run through ctest the
+# driver puts $ROOTSYS/lib into (DY)LD_LIBRARY_PATH, so the library directory is
+# already present and nothing gets appended.
+function(check_rootrc_then_libdir rdynpath)
+  root_env_part("${rdynpath}" envpart)
+  string(FIND "${envpart}" "${libdir}" pos)
+  if(pos EQUAL -1)
+    # Not seen yet: it must be appended right behind the .rootrc entries.
+    check_mid("${rdynpath}${sep}${libdir}")
+  else()
+    # Already provided by the environment: both must still be present.
+    check_mid("${rdynpath}")
+    check_mid("${libdir}")
+  endif()
+endfunction()
+
+#---Set up the scratch area-----------------------------------------------------
+file(REMOVE_RECURSE "${WORKDIR}")
+file(MAKE_DIRECTORY "${WORKDIR}")
+file(MAKE_DIRECTORY "${WORKDIR}/rootlibpath")
+file(MAKE_DIRECTORY "${WORKDIR}/rootrcpath")
+file(MAKE_DIRECTORY "${WORKDIR}/ldpath")
+
+set(rootlibpath "${WORKDIR}/rootlibpath")
+set(rootrcpath  "${WORKDIR}/rootrcpath")
+set(ldpath      "${WORKDIR}/ldpath")
+
+# Start from a well defined state.
+unset(ENV{ROOT_LIBRARY_PATH})
+set_rootrc("")
+
+root_eval("TROOT::GetLibDir()" libdir)
+if(WIN32)
+  # On Windows the built-in default is `.;<bindir>` while on Unix it is
+  # `.:<libdir>` (see TWinNTSystem.cxx / TUnixSystem.cxx).
+  root_eval("TROOT::GetBinDir()" defaultdir)
+else()
+  set(defaultdir "${libdir}")
+endif()
+
+message(STATUS "ROOT library directory: ${libdir}")
+message(STATUS "default dynamic path  : .${sep}${defaultdir}")
+
+#---Checks without an explicit loader search path-------------------------------
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("${rootrcpath}")
+get_dynpath()
+check_begin("${rootlibpath}")
+check_rootrc_then_libdir("${rootrcpath}")
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("${libdir}${sep}${rootrcpath}")
+get_dynpath()
+check_begin_and_mid("${rootlibpath}" "${libdir}${sep}${rootrcpath}")
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("")
+get_dynpath()
+check_begin_and_mid("${rootlibpath}" ".${sep}${defaultdir}")
+
+unset(ENV{ROOT_LIBRARY_PATH})
+set_rootrc("")
+get_dynpath()
+check_mid(".${sep}${defaultdir}")
+
+#---Checks with the loader search path (LD_LIBRARY_PATH & Co.)------------------
+
+if(DEFINED ENV{${ld_var}} AND NOT "$ENV{${ld_var}}" STREQUAL "")
+  set(ENV{${ld_var}} "${ldpath}${sep}$ENV{${ld_var}}")
+else()
+  set(ENV{${ld_var}} "${ldpath}")
+endif()
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("${rootrcpath}")
+get_dynpath()
+check_begin("${rootlibpath}${sep}${ldpath}")
+check_rootrc_then_libdir("${rootrcpath}")
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("${libdir}${sep}${rootrcpath}")
+get_dynpath()
+check_begin_and_mid("${rootlibpath}${sep}${ldpath}" "${libdir}${sep}${rootrcpath}")
+
+set(ENV{ROOT_LIBRARY_PATH} "${rootlibpath}")
+set_rootrc("")
+get_dynpath()
+check_begin_and_mid("${rootlibpath}${sep}${ldpath}" ".${sep}${defaultdir}")
+
+unset(ENV{ROOT_LIBRARY_PATH})
+set_rootrc("")
+get_dynpath()
+check_begin_and_mid("${ldpath}" ".${sep}${defaultdir}")
+
+message(STATUS "dynamic path setup: all checks passed")