compiler: add "portable" target

This adds a build flag for generating a portable version of the compiler
binary which make it look in its own runtime directory for its assets.

This is useful in particular for the portable release tarballs which
contain the web viewer at the same location instead of a pre-defined one
in the FHS.

GitHub: closes #286

1 files changed, 13 insertions, 1 deletions

diff --git a/compiler/package.yaml b/compiler/package.yaml
index faa2174..b02a40a 100644
--- a/compiler/package.yaml
+++ b/compiler/package.yaml
@@ -5,7 +5,7 @@ github:              "pacien/ldgallery"
 license:             AGPL-3
 author:              "Pacien TRAN-GIRARD, Guillaume FOUET"
 maintainer:          ""
-copyright:           "2019-2020 Pacien TRAN-GIRARD, Guillaume FOUET"
+copyright:           "2019-2021 Pacien TRAN-GIRARD, Guillaume FOUET"
 
 extra-source-files:
 - readme.md
@@ -54,6 +54,15 @@ data-files: ["**/*"]
 library:
   source-dirs: src
 
+flags:
+  portable:
+    description: >
+      Make the output binary portable.
+      It will look in its own runtime location for its assets instead of
+      absolute installation paths.
+    manual: true
+    default: false
+
 executables:
   ldgallery:
     main:                Main.hs
@@ -64,6 +73,9 @@ executables:
     - -with-rtsopts=-N
     dependencies:
     - ldgallery-compiler
+    when:
+    - condition: flag(portable)
+      cpp-options: -DFLAG_PORTABLE
 
 tests:
   ldgallery-compiler-test: