new test: package depends on empty library

Author: perazz

example_packages/shared_lib_empty/fpm.toml

@@ -0,0 +1,5 @@
+name = "shared_lib_empty"
+library.type="shared"
+[dependencies]
+shared_lib = { path = "../shared_lib" }
+shared_app_only = { path = "../shared_app_only" }

example_packages/static_app_only/fpm.toml

@@ -1,5 +1,5 @@
 # App only, use shared lib from other folder
-name = "shared_app_only"
+name = "static_app_only"
 library.type="static"
 install.library=true
 [dependencies]

src/fpm_model.f90

@@ -174,6 +174,9 @@ module fpm_model
 
     contains
 
+        !> Check if a package will create a library
+        procedure :: has_library => package_has_library
+    
         !> Serialization interface
         procedure :: serializable_is_same => package_is_same
         procedure :: dump_to_toml   => package_dump_to_toml
@@ -1153,6 +1156,7 @@ function get_package_libraries_link(model, package_name, prefix, exclude_self, d
     integer :: id,ndep,i
     logical :: no_root
     integer, allocatable :: sorted_package_IDs(:)
+    logical, allocatable :: empty_package(:)
     type(string_t), allocatable :: package_deps(:)
 
     ! Get dependency ID of this target 
@@ -1184,6 +1188,14 @@ function get_package_libraries_link(model, package_name, prefix, exclude_self, d
         ndep = size(sorted_package_IDs)
     endif
 
+    ! Exclusion of package IDs marked "empty" (i.e. they contain no sources)
+    empty_package = .not.model%packages%has_library()
+    
+    if (any(empty_package)) then 
+        sorted_package_IDs = pack(sorted_package_IDs, .not.empty_package(sorted_package_IDs))
+        ndep = size(sorted_package_IDs)
+    end if
+    
     package_deps = [(string_t(model%deps%dep(sorted_package_IDs(i))%name),i=1,ndep)]
 
     r = model%compiler%enumerate_libraries(prefix, package_deps)
@@ -1193,4 +1205,17 @@ function get_package_libraries_link(model, package_name, prefix, exclude_self, d
 
 end function get_package_libraries_link
 
+!> Check whether a package has an object library
+elemental logical function package_has_library(self) result(has_library)
+    class(package_t), intent(in) :: self
+    
+    if (allocated(self%sources)) then 
+        has_library = any(self%sources%unit_scope==FPM_SCOPE_LIB)
+    else
+        has_library = .false.
+    end if
+    
+end function package_has_library
+
+
 end module fpm_model

src/fpm_targets.f90

@@ -270,7 +270,7 @@ subroutine targets_from_sources(targets,model,prune,library,error)
     should_prune = prune
     if (present(library)) should_prune = should_prune .and. library%monolithic()
 
-    if (should_prune) call prune_build_targets(targets,root_package=model%package_name)
+    call prune_build_targets(targets,model%package_name,should_prune)
 
     call resolve_target_linking(targets,model,library,error)
     if (allocated(error)) return
@@ -321,9 +321,7 @@ subroutine build_target_list(targets,model,library)
 
     if (n_source < 1) return
 
-    with_lib = any([((model%packages(j)%sources(i)%unit_scope == FPM_SCOPE_LIB, &
-                      i=1,size(model%packages(j)%sources)), &
-                      j=1,size(model%packages))])
+    with_lib = any(model%packages%has_library())
 
     if (with_lib .and. present(library)) then 
         shared_lib = library%shared()
@@ -737,13 +735,16 @@ end function find_module_dependency
 
 
 !> Perform tree-shaking to remove unused module targets
-subroutine prune_build_targets(targets, root_package)
+subroutine prune_build_targets(targets, root_package, prune_unused_objects)
 
     !> Build target list to prune
     type(build_target_ptr), intent(inout), allocatable :: targets(:)
 
     !> Name of root package
     character(*), intent(in) :: root_package
+    
+    !> Whether unused objects should be pruned
+    logical, intent(in) :: prune_unused_objects
 
     integer :: i, j, nexec
     type(string_t), allocatable :: modules_used(:)
@@ -805,8 +806,8 @@ subroutine prune_build_targets(targets, root_package)
             if (allocated(target%source)) then
                 if (target%source%unit_type == FPM_UNIT_MODULE) then
 
-                    exclude_target(i) = .true.
-                    target%skip = .true.
+                    exclude_target(i) = prune_unused_objects
+                    target%skip = prune_unused_objects
 
                     do j=1,size(target%source%modules_provided)
 
@@ -822,8 +823,8 @@ subroutine prune_build_targets(targets, root_package)
                 elseif (target%source%unit_type == FPM_UNIT_SUBMODULE) then
                     ! Remove submodules if their parents are not used
 
-                    exclude_target(i) = .true.
-                    target%skip = .true.
+                    exclude_target(i) = prune_unused_objects
+                    target%skip = prune_unused_objects
                     do j=1,size(target%source%parent_modules)
 
                         if (target%source%parent_modules(j)%s .in. modules_used) then
@@ -858,27 +859,32 @@ subroutine prune_build_targets(targets, root_package)
 
     targets = pack(targets,.not.exclude_target)
 
-    ! Remove unused targets from archive dependency list
-    if (targets(1)%ptr%target_type == FPM_TARGET_ARCHIVE) then
-        associate(archive=>targets(1)%ptr)
+    ! Remove unused targets from library dependency list
+    do j=1,size(targets)
+        associate(archive=>targets(j)%ptr)
+            
+            if (any(archive%target_type==[FPM_TARGET_ARCHIVE,FPM_TARGET_OBJECT])) then 
 
-            allocate(exclude_from_archive(size(archive%dependencies)))
-            exclude_from_archive(:) = .false.
+                allocate(exclude_from_archive(size(archive%dependencies)),source=.false.)
 
-            do i=1,size(archive%dependencies)
+                do i=1,size(archive%dependencies)
 
-                if (archive%dependencies(i)%ptr%skip) then
+                    if (archive%dependencies(i)%ptr%skip) then
 
-                    exclude_from_archive(i) = .true.
+                        exclude_from_archive(i) = .true.
 
-                end if
+                    end if
 
-            end do
+                end do
 
-            archive%dependencies = pack(archive%dependencies,.not.exclude_from_archive)
+                archive%dependencies = pack(archive%dependencies,.not.exclude_from_archive)
+                
+                deallocate(exclude_from_archive)
+            
+            endif
 
         end associate
-    end if
+    end do
 
     contains
 
@@ -1106,8 +1112,8 @@ subroutine resolve_target_linking(targets, model, library, error)
                         has_self_lib = .false.
                         find_self: do j=1,size(targets)
                             associate(target_loop=>targets(j)%ptr)
-                                if (target_loop%target_type==FPM_TARGET_SHARED .and. &
-                                    target_loop%package_name==target%package_name) then 
+                                if (any(target_loop%target_type==[FPM_TARGET_SHARED,FPM_TARGET_ARCHIVE]) &
+                                    .and. target_loop%package_name==target%package_name) then 
                                     has_self_lib = .true.
                                     exit find_self
                                 end if