Allow link_depends to take strings, Files or generated objects. Closes #1172

Currently only strings can be passed to the link_depends argument of
executable and *library, which solves many cases, but not every one.
This patch allows generated sources and Files to be passed as well.

On the implementation side, it uses a helper method to keep the more
complex logic separated from the __init__ method. This also requires
that Targets set their link_depends paths as Files, and the backend is
responsible for converting to strings when it wants them.

This adds tests for the following cases:
- Using a file in a subdir
- Using a configure_file as an input
- Using a custom_target as an input

It does not support using a generator as an input, since currently that
would require calling the generator twice, once for the -Wl argument,
and once for the link_depends.

Also updates the docs.

5 files changed, 71 insertions, 0 deletions

diff --git a/test cases/linuxlike/3 linker script/bob.map.in b/test cases/linuxlike/3 linker script/bob.map.in
new file mode 100644
index 0000000..f695e4a
--- /dev/null
+++ b/test cases/linuxlike/3 linker script/bob.map.in
@@ -0,0 +1,6 @@
+V1_0_0 {
+  global:
+    "@in@";
+  local:
+    *;
+};
diff --git a/test cases/linuxlike/3 linker script/copy.py b/test cases/linuxlike/3 linker script/copy.py
new file mode 100644
index 0000000..49e7a85
--- /dev/null
+++ b/test cases/linuxlike/3 linker script/copy.py
@@ -0,0 +1,5 @@
+import shutil
+import sys
+
+if __name__ == '__main__':
+    shutil.copy(sys.argv[1], sys.argv[2])
diff --git a/test cases/linuxlike/3 linker script/meson.build b/test cases/linuxlike/3 linker script/meson.build
index 30761c6..63765e7 100644
--- a/test cases/linuxlike/3 linker script/meson.build
+++ b/test cases/linuxlike/3 linker script/meson.build
@@ -1,8 +1,56 @@
 project('linker script', 'c')
 
+# Static map file
 mapfile = 'bob.map'
 vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfile)
 
 l = shared_library('bob', 'bob.c', link_args : vflag, link_depends : mapfile)
 e = executable('prog', 'prog.c', link_with : l)
 test('core', e)
+
+# configure_file
+conf = configuration_data()
+conf.set('in', 'bobMcBob')
+m = configure_file(
+  input : 'bob.map.in',
+  output : 'bob-conf.map',
+  configuration : conf,
+)
+vflag = '-Wl,--version-script,@0@'.format(m)
+
+l = shared_library('bob-conf', 'bob.c', link_args : vflag, link_depends : m)
+e = executable('prog-conf', 'prog.c', link_with : l)
+test('core', e)
+
+# custom_target
+python = find_program('python3')
+m = custom_target(
+  'bob-ct.map',
+  command : [python, '@INPUT0@', '@INPUT1@', 'bob-ct.map'],
+  input : ['copy.py', 'bob.map'],
+  output : 'bob-ct.map',
+  depend_files : 'bob.map',
+)
+vflag = '-Wl,--version-script,@0@'.format(m.full_path())
+
+l = shared_library('bob-ct', ['bob.c', m], link_args : vflag, link_depends : m)
+e = executable('prog-ct', 'prog.c', link_with : l)
+test('core', e)
+
+# File
+mapfile = files('bob.map')
+vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfile[0])
+
+l = shared_library('bob-files', 'bob.c', link_args : vflag, link_depends : mapfile)
+e = executable('prog-files', 'prog.c', link_with : l)
+test('core', e)
+
+subdir('sub')
+
+# With map file in subdir
+mapfile = 'sub/foo.map'
+vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfile)
+
+l = shared_library('bar', 'bob.c', link_args : vflag, link_depends : mapfile)
+e = executable('prog-bar', 'prog.c', link_with : l)
+test('core', e)
diff --git a/test cases/linuxlike/3 linker script/sub/foo.map b/test cases/linuxlike/3 linker script/sub/foo.map
new file mode 100644
index 0000000..e07a780
--- /dev/null
+++ b/test cases/linuxlike/3 linker script/sub/foo.map
@@ -0,0 +1,6 @@
+V1_0_0 {
+  global:
+    "bobMcBob";
+  local:
+    *;
+};
diff --git a/test cases/linuxlike/3 linker script/sub/meson.build b/test cases/linuxlike/3 linker script/sub/meson.build
new file mode 100644
index 0000000..93199f3
--- /dev/null
+++ b/test cases/linuxlike/3 linker script/sub/meson.build
@@ -0,0 +1,6 @@
+mapfile = 'foo.map'
+vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfile)
+
+l = shared_library('foo', '../bob.c', link_args : vflag, link_depends : mapfile)
+e = executable('prog-foo', '../prog.c', link_with : l)
+test('core', e)