meson: modify gperf test to remove sh dependency

modifies the gperf test to instead rely on a file input
rather than piping in using sh, as sh is often not reliable
on Windows due to paths.

Also changes the if else ladder into a foreach loop.

Signed-off-by: Christopher Degawa <ccom@randomderp.com>

meson-cc-tests/gperf.txt

@@ -0,0 +1 @@
+foo,bar

meson.build

@@ -315,39 +315,33 @@ if fc_configdir.startswith(fc_baseconfigdir + '/')
   fonts_conf.set('CONFIGDIR', fc_configdir.split(fc_baseconfigdir + '/')[1])
 endif
 
-# It will automatically fallback to subproject if not found on system
-gperf = find_program('gperf')
+gperf = find_program('gperf', required: false)
+gperf_len_type = ''
 
-sh = find_program('sh', required : false)
-
-if not sh.found() # host_machine.system() == 'windows' or not sh.found()
-  # TODO: This is not always correct
-  if cc.get_id() == 'msvc'
-    gperf_len_type = 'size_t'
-  else
-    gperf_len_type = 'unsigned'
-  endif
-else
+if gperf.found()
   gperf_test_format = '''
   #include <string.h>
   const char * in_word_set(const char *, @0@);
   @1@
   '''
-  gperf_snippet_format = 'echo foo,bar | @0@ -L ANSI-C'
-  gperf_snippet = run_command(sh, '-c', gperf_snippet_format.format(gperf.full_path()),
-    check: true)
-  gperf_test = gperf_test_format.format('size_t', gperf_snippet.stdout())
+  gperf_snippet = run_command(gperf, '-L', 'ANSI-C', files('meson-cc-tests/gperf.txt'),
+    check: true).stdout()
 
-  if cc.compiles(gperf_test)
-    gperf_len_type = 'size_t'
-  else
-    gperf_test = gperf_test_format.format('unsigned', gperf_snippet.stdout())
-    if cc.compiles(gperf_test)
-      gperf_len_type = 'unsigned'
-    else
-      error('unable to determine gperf len type')
+  foreach type : ['size_t', 'unsigned']
+    if cc.compiles(gperf_test_format.format(type, gperf_snippet))
+      gperf_len_type = type
+      break
     endif
+  endforeach
+
+  if gperf_len_type == ''
+    error('unable to determine gperf len type')
   endif
+else
+  # Fallback to subproject
+  gperf = find_program('gperf')
+  # assume if we are compiling from the wrap, the size is just size_t
+  gperf_len_type = 'size_t'
 endif
 
 message('gperf len type is @0@'.format(gperf_len_type))