12 files changed, 112 insertions, 11 deletions
diff --git a/Modules/FindCUDAToolkit.cmake b/Modules/FindCUDAToolkit.cmake
index 469a7ad..ac72c17 100644
--- a/Modules/FindCUDAToolkit.cmake
+++ b/Modules/FindCUDAToolkit.cmake
@@ -1100,7 +1100,10 @@ if(CUDAToolkit_FOUND)
     if(CUDA_${lib_name}_LIBRARY MATCHES "/stubs/" AND NOT WIN32)
       # Use a SHARED library with IMPORTED_IMPLIB, but not IMPORTED_LOCATION,
       # to indicate that the stub is for linkers but not dynamic loaders.
-      # It will not contribute any RPATH entry.
+      # It will not contribute any RPATH entry.  When encountered as
+      # a private transitive dependency of another shared library,
+      # it will be passed explicitly to linkers so they can find it
+      # even when the runtime library file does not exist on disk.
       set(CUDA_IMPORT_PROPERTY IMPORTED_IMPLIB)
       set(CUDA_IMPORT_TYPE     SHARED)
     endif()
diff --git a/Source/cmComputeLinkInformation.cxx b/Source/cmComputeLinkInformation.cxx
index e7bef68..40eb902 100644
--- a/Source/cmComputeLinkInformation.cxx
+++ b/Source/cmComputeLinkInformation.cxx
@@ -1331,7 +1331,17 @@ void cmComputeLinkInformation::AddSharedDepItem(LinkEntry const& entry)
   }
 
   // If in linking mode, just link to the shared library.
-  if (this->SharedDependencyMode == SharedDepModeLink) {
+  if (this->SharedDependencyMode == SharedDepModeLink ||
+      // For an imported shared library without a known runtime artifact,
+      // such as a CUDA stub, a library file named with the real soname
+      // may not be available at all, so '-rpath-link' cannot help linkers
+      // find it to satisfy '--no-allow-shlib-undefined' recursively.
+      // Pass this dependency to the linker explicitly just in case.
+      // If the linker also uses '--as-needed' behavior, this will not
+      // add an unnecessary direct dependency.
+      (tgt && tgt->IsImported() &&
+       !tgt->HasKnownRuntimeArtifactLocation(this->Config) &&
+       this->Target->LinkerEnforcesNoAllowShLibUndefined(this->Config))) {
     this->AddItem(entry);
     return;
   }
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 289bb24..11253db 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -5596,6 +5596,20 @@ std::string cmGeneratorTarget::GetLinkerTool(const std::string& lang,
   return linkerTool;
 }
 
+bool cmGeneratorTarget::LinkerEnforcesNoAllowShLibUndefined(
+  std::string const& config) const
+{
+  // FIXME(#25486): Account for the LINKER_TYPE target property.
+  // Also factor out the hard-coded list below into a platform
+  // information table based on the linker id.
+  std::string ll = this->GetLinkerLanguage(config);
+  std::string linkerIdVar = cmStrCat("CMAKE_", ll, "_COMPILER_LINKER_ID");
+  cmValue linkerId = this->Makefile->GetDefinition(linkerIdVar);
+  // The GNU bfd-based linker may enforce '--no-allow-shlib-undefined'
+  // recursively by default.  The Solaris linker has similar behavior.
+  return linkerId && (*linkerId == "GNU" || *linkerId == "Solaris");
+}
+
 std::string cmGeneratorTarget::GetPDBOutputName(
   const std::string& config) const
 {
diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index cfb08fa..fb56a0d 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -805,6 +805,9 @@ public:
   std::string GetLinkerTool(const std::string& lang,
                             const std::string& config) const;
 
+  /** Is the linker known to enforce '--no-allow-shlib-undefined'? */
+  bool LinkerEnforcesNoAllowShLibUndefined(std::string const& config) const;
+
   /** Does this target have a GNU implib to convert to MS format?  */
   bool HasImplibGNUtoMS(std::string const& config) const;
 
diff --git a/Tests/RunCMake/CMakeLists.txt b/Tests/RunCMake/CMakeLists.txt
index 324a4da..a4e4800 100644
--- a/Tests/RunCMake/CMakeLists.txt
+++ b/Tests/RunCMake/CMakeLists.txt
@@ -434,8 +434,11 @@ endif()
 add_RunCMake_test(ObjectLibrary)
 add_RunCMake_test(ParseImplicitIncludeInfo)
 add_RunCMake_test(ParseImplicitLinkInfo)
-if(UNIX AND CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG AND CMAKE_EXECUTABLE_FORMAT STREQUAL "ELF")
-  add_RunCMake_test(RuntimePath)
+if(UNIX AND CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG)
+  add_RunCMake_test(RuntimePath
+    -DCMAKE_SYSTEM_NAME=${CMAKE_SYSTEM_NAME}
+    -DCMAKE_EXECUTABLE_FORMAT=${CMAKE_EXECUTABLE_FORMAT}
+    )
 endif()
 add_RunCMake_test(ScriptMode)
 add_RunCMake_test(Swift -DCMAKE_SYSTEM_NAME=${CMAKE_SYSTEM_NAME}
diff --git a/Tests/RunCMake/RuntimePath/RunCMakeTest.cmake b/Tests/RunCMake/RuntimePath/RunCMakeTest.cmake
index ad446e9..180a0fe 100644
--- a/Tests/RunCMake/RuntimePath/RunCMakeTest.cmake
+++ b/Tests/RunCMake/RuntimePath/RunCMakeTest.cmake
@@ -21,12 +21,39 @@ if(RunCMake_GENERATOR_IS_MULTI_CONFIG)
   set(cfg_dir /Debug)
 endif()
 
-run_RuntimePath(SymlinkImplicit)
-run_cmake_command(SymlinkImplicitCheck
-  ${CMAKE_COMMAND} -Ddir=${RunCMake_BINARY_DIR}/SymlinkImplicit-build -Dcfg_dir=${cfg_dir} -P ${RunCMake_SOURCE_DIR}/SymlinkImplicitCheck.cmake)
+if(CMAKE_EXECUTABLE_FORMAT STREQUAL "ELF")
+  run_RuntimePath(SymlinkImplicit)
+  run_cmake_command(SymlinkImplicitCheck
+    ${CMAKE_COMMAND} -Ddir=${RunCMake_BINARY_DIR}/SymlinkImplicit-build -Dcfg_dir=${cfg_dir} -P ${RunCMake_SOURCE_DIR}/SymlinkImplicitCheck.cmake)
 
-run_RuntimePath(Relative)
+  run_RuntimePath(Relative)
 
-run_RuntimePath(Genex)
-run_cmake_command(GenexCheck
-  ${CMAKE_COMMAND} -Ddir=${RunCMake_BINARY_DIR}/Genex-build -P ${RunCMake_SOURCE_DIR}/GenexCheck.cmake)
+  run_RuntimePath(Genex)
+  run_cmake_command(GenexCheck
+    ${CMAKE_COMMAND} -Ddir=${RunCMake_BINARY_DIR}/Genex-build -P ${RunCMake_SOURCE_DIR}/GenexCheck.cmake)
+endif()
+
+block()
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/Stub-build)
+  if(RunCMake_GENERATOR_IS_MULTI_CONFIG)
+    set(bin_dir "${RunCMake_TEST_BINARY_DIR}/Debug")
+    set(lib_dir "${RunCMake_TEST_BINARY_DIR}/lib/Debug")
+  else()
+    set(bin_dir "${RunCMake_TEST_BINARY_DIR}")
+    set(lib_dir "${RunCMake_TEST_BINARY_DIR}/lib")
+  endif()
+  run_cmake(Stub)
+  set(RunCMake_TEST_NO_CLEAN 1)
+  run_cmake_command(Stub-build ${CMAKE_COMMAND} --build . --config Debug)
+  if(CMAKE_SYSTEM_NAME MATCHES "^(Linux|SunOS)$|BSD")
+    set(ldpath LD_LIBRARY_PATH)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "^(Darwin)$")
+    set(ldpath DYLD_LIBRARY_PATH)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "^(AIX)$")
+    set(ldpath LIBPATH)
+  endif()
+  if(ldpath)
+    run_cmake_command(Stub-fail ${CMAKE_COMMAND} -E env LANG=C ${bin_dir}/StubExe)
+    run_cmake_command(Stub-pass ${CMAKE_COMMAND} -E env --modify ${ldpath}=path_list_prepend:${lib_dir} ${bin_dir}/StubExe)
+  endif()
+endblock()
diff --git a/Tests/RunCMake/RuntimePath/Stub-fail-result.txt b/Tests/RunCMake/RuntimePath/Stub-fail-result.txt
new file mode 100644
index 0000000..d197c91
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/Stub-fail-result.txt
@@ -0,0 +1 @@
+[^0]
diff --git a/Tests/RunCMake/RuntimePath/Stub-fail-stderr.txt b/Tests/RunCMake/RuntimePath/Stub-fail-stderr.txt
new file mode 100644
index 0000000..9c17414
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/Stub-fail-stderr.txt
@@ -0,0 +1 @@
+(error while loading shared libraries: libStub\.so\.1|Library not loaded: '?@rpath/libStub\.1\.dylib'?|(Cannot|Could not) load module libStub\.so|fatal: libStub\.so\.1: open failed|Shared object "libStub\.so\.1" not found)
diff --git a/Tests/RunCMake/RuntimePath/Stub.c b/Tests/RunCMake/RuntimePath/Stub.c
new file mode 100644
index 0000000..2ff333a
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/Stub.c
@@ -0,0 +1,4 @@
+int Stub(void)
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/RuntimePath/Stub.cmake b/Tests/RunCMake/RuntimePath/Stub.cmake
new file mode 100644
index 0000000..18e99c1
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/Stub.cmake
@@ -0,0 +1,25 @@
+enable_language(C)
+
+add_library(Stub SHARED Stub.c)
+set_target_properties(Stub PROPERTIES
+  SOVERSION 1
+  LIBRARY_OUTPUT_DIRECTORY lib
+  )
+
+set(StubDir ${CMAKE_CURRENT_BINARY_DIR}/lib/stubs)
+set(Stub "${StubDir}/${CMAKE_SHARED_LIBRARY_PREFIX}Stub${CMAKE_SHARED_LIBRARY_SUFFIX}")
+add_custom_target(StubCopy
+  COMMAND ${CMAKE_COMMAND} -E make_directory "${StubDir}"
+  COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_SONAME_FILE:Stub>" "${Stub}"
+  BYPRODUCTS ${Stub}
+  )
+add_dependencies(StubCopy Stub)
+add_library(Imp::Stub SHARED IMPORTED)
+set_property(TARGET Imp::Stub PROPERTY IMPORTED_IMPLIB "${Stub}")
+add_dependencies(Imp::Stub StubCopy)
+
+add_library(StubUse SHARED StubUse.c)
+target_link_libraries(StubUse PRIVATE Imp::Stub)
+
+add_executable(StubExe StubExe.c)
+target_link_libraries(StubExe PRIVATE StubUse)
diff --git a/Tests/RunCMake/RuntimePath/StubExe.c b/Tests/RunCMake/RuntimePath/StubExe.c
new file mode 100644
index 0000000..14b3fe4
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/StubExe.c
@@ -0,0 +1,5 @@
+extern int StubUse(void);
+int main(void)
+{
+  return StubUse();
+}
diff --git a/Tests/RunCMake/RuntimePath/StubUse.c b/Tests/RunCMake/RuntimePath/StubUse.c
new file mode 100644
index 0000000..ffdaf6d
--- /dev/null
+++ b/Tests/RunCMake/RuntimePath/StubUse.c
@@ -0,0 +1,5 @@
+extern int Stub(void);
+int StubUse(void)
+{
+  return Stub();
+}