find_program: add a kwarg to specify custom version argument

When trying to get the version of a program, meson was previously
hardcoded to run the binary with `--version`. This does work with the
vast majority of programs, but there are a few outliers (e.g. ffmpeg)
which have an unusual argument for printing out the version. Support
these programs by introducing a version_argument kwarg in find_program
which allows users to override `--version` with whatever the custom
argument for printing the version may be for the program.

2 files changed, 11 insertions, 0 deletions

diff --git a/test cases/common/26 find program/meson.build b/test cases/common/26 find program/meson.build
index 3c4d15c..a20f6b4 100644
--- a/test cases/common/26 find program/meson.build
+++ b/test cases/common/26 find program/meson.build
@@ -32,6 +32,9 @@ assert(prog.version() == '1.0', 'Program version should be detectable')
 prog = find_program('print-version-with-prefix.py', version : '>=1.0')
 assert(prog.found(), 'Program version should match')
 
+prog = find_program('print-version-custom-argument.py', version : '>=1.0', version_argument : '-version')
+assert(prog.found(), 'Program version should match')
+
 prog = find_program('test_subdir.py', required : false)
 assert(not prog.found(), 'Program should not be found')
 
diff --git a/test cases/common/26 find program/print-version-custom-argument.py b/test cases/common/26 find program/print-version-custom-argument.py
new file mode 100644
index 0000000..7d9ad58
--- /dev/null
+++ b/test cases/common/26 find program/print-version-custom-argument.py
@@ -0,0 +1,8 @@
+#!/usr/bin/env python3
+
+import sys
+
+if len(sys.argv) != 2 or sys.argv[1] != '-version':
+    exit(1)
+
+print('1.0')