[vcpkg | vcpkg_copy_pdbs]: Support copying .pdb when using llvm/clang-mingw

scripts/cmake/vcpkg_copy_pdbs.cmake

@@ -11,37 +11,85 @@ function(vcpkg_copy_pdbs)
             "${CURRENT_PACKAGES_DIR}/debug/bin/*.dll"
         )
     endif()
+    set(debug_packages_prefix "${CURRENT_PACKAGES_DIR}/debug")
 
     set(dlls_without_matching_pdbs "")
 
-    if(VCPKG_LIBRARY_LINKAGE STREQUAL "dynamic" AND VCPKG_TARGET_IS_WINDOWS AND NOT VCPKG_TARGET_IS_MINGW)
+    if(VCPKG_LIBRARY_LINKAGE STREQUAL "dynamic" AND VCPKG_TARGET_IS_WINDOWS)
         file(GLOB_RECURSE dlls ${arg_BUILD_PATHS})
+
+        set(USE_DUMPBIN TRUE)
+        if(NOT VCPKG_HOST_IS_WINDOWS)
+            set(USE_DUMPBIN FALSE)
+        endif()
 
-        set(vslang_backup "$ENV{VSLANG}")
-        set(ENV{VSLANG} 1033)
+        if(USE_DUMPBIN)
+            set(vslang_backup "$ENV{VSLANG}")
+            set(ENV{VSLANG} 1033)
+        endif()
 
         foreach(dll IN LISTS dlls)
-            execute_process(COMMAND dumpbin /PDBPATH "${dll}"
-                            COMMAND findstr PDB
-                OUTPUT_VARIABLE pdb_line
-                ERROR_QUIET
-                RESULT_VARIABLE error_code
-            )
-
-            if(error_code EQUAL "0" AND pdb_line MATCHES "PDB file found at.*'(.*)'")
-                set(pdb_path "${CMAKE_MATCH_1}")
+            set(found_pdb FALSE)
+            if(USE_DUMPBIN)
+                execute_process(COMMAND dumpbin /PDBPATH "${dll}"
+                                COMMAND findstr PDB
+                    OUTPUT_VARIABLE pdb_line
+                    ERROR_QUIET
+                    RESULT_VARIABLE error_code
+                )
+
+                if(error_code EQUAL "0" AND pdb_line MATCHES "PDB file found at.*'(.*)'")
+                    set(pdb_path "${CMAKE_MATCH_1}")
+                    cmake_path(GET dll PARENT_PATH dll_dir)
+                    file(COPY "${pdb_path}" DESTINATION "${dll_dir}")
+                    set(found_pdb TRUE)
+                endif()
+            endif()
+
+            if(NOT found_pdb AND VCPKG_TARGET_IS_MINGW)
+                # Support llvm / clang mingw (with PDB generation) in cross-compilation scenarios by looking for the default case
+                # of a .pdb file matching the dll name in the build directory
+
+                set(dll_build_dir "${CURRENT_BUILDTREES_DIR}/${TARGET_TRIPLET}-rel")
+                cmake_path(IS_PREFIX debug_packages_prefix "${dll}" NORMALIZE is_debug_package)
+                if(is_debug_package)
+                    set(dll_build_dir "${CURRENT_BUILDTREES_DIR}/${TARGET_TRIPLET}-dbg")
+                endif()
+
+                cmake_path(GET dll STEM LAST_ONLY dll_name)
                 cmake_path(GET dll PARENT_PATH dll_dir)
-                file(COPY "${pdb_path}" DESTINATION "${dll_dir}")
-            else()
+                set(pdb_path "${dll_build_dir}/${dll_name}.pdb")
+                if (EXISTS "${pdb_path}")
+                    file(COPY "${pdb_path}" DESTINATION "${dll_dir}")
+                    set(found_pdb TRUE)
+                else()
+                    file(GLOB_RECURSE pdb_path "${dll_build_dir}/${dll_name}.pdb")
+                    list(LENGTH pdb_path pdb_path_count)
+                    if(pdb_path_count EQUAL "1")
+                        file(COPY "${pdb_path}" DESTINATION "${dll_dir}")
+                        set(found_pdb TRUE)
+                    else()
+                        message(WARNING "Unexpectedly found more than one matching PDB for: ${dll}\n${pdb_path}\n")
+                    endif()
+                endif()
+            endif()
+
+            if(NOT found_pdb)
                 list(APPEND dlls_without_matching_pdbs "${dll}")
             endif()
         endforeach()
-
-        set(ENV{VSLANG} "${vslang_backup}")
+
+        if(USE_DUMPBIN)
+            set(ENV{VSLANG} "${vslang_backup}")
+        endif()
 
         if(NOT dlls_without_matching_pdbs STREQUAL "")
             list(JOIN dlls_without_matching_pdbs "\n    " message)
-            message(WARNING "Could not find a matching pdb file for:
+            set(_message_level WARNING)
+            if(VCPKG_TARGET_IS_MINGW)
+                 set(_message_level STATUS) # not all mingw toolchains support generating .pdb
+            endif()
+            message(${_message_level} "Could not find a matching pdb file for:
     ${message}\n")
         endif()
     endif()