[Mesa-dev] [PATCH v3 27/48] meson: Add support for using win_flex and win_bison on windows

[Dylan Baker]

---
 meson.build | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index 39b542730a9..b7d277b7bc0 100644
--- a/meson.build
+++ b/meson.build
@@ -1329,8 +1329,31 @@ endif
 
 # pthread stubs. Lets not and say we didn't
 
-prog_bison = find_program('bison', required : with_any_opengl)
-prog_flex = find_program('flex', required : with_any_opengl)
+if host_machine.system() == 'windows'
+  # Prefer the winflexbison versions, they're much easier to install and have
+  # better windows support.
+
+  prog_flex = find_program('win_flex', required : false)
+  if prog_flex.found()
+    # windows compatibility (uses <io.h> instead of <unistd.h> and _isatty,
+    # _fileno functions)
+    prog_flex = [prog_flex, '--wincompat']
+  else
+    prog_flex = [find_program('lex', 'flex', required : with_any_opengl)]
+  endif
+  # Force flex to use const keyword in prototypes, as relies on __cplusplus or
+  # __STDC__ macro to determine whether it's safe to use const keyword, but
+  # MSVC never defines __STDC__ unless we disable all MSVC extensions.
+  prog_flex += '-DYY_USE_CONST='
+
+  prog_bison = find_program('win_bison', required : false)
+  if not prog_bison.found()
+    prog_bison = find_program('yacc', 'bison', required : with_any_opengl)
+  endif
+else
+  prog_bison = find_program('bison', required : with_any_opengl)
+  prog_flex = find_program('flex', required : with_any_opengl)
+endif
 
 dep_selinux = null_dep
 if get_option('selinux')
-- 
2.18.0