meson: Ensure things build with Windows

We must link to ws2_32.lib for all Windows builds, and we need to use
workarounds for alloca() and snprintf() since Visual Studio uses
_alloca() for alloca() and provides snprintf() only on Visual Studio
2015 or later, meaning that we need to use _snprintf() here.

Also fix the parts where we run the Python scripts to generate items,
since those scripts already have shebang lines for Meson to pick up.

meson.build

@@ -12,6 +12,7 @@ libidn2_dep = notfound
 libicu_dep = notfound
 libidn_dep = notfound
 libunistring = notfound
+networking_deps = notfound
 
 # FIXME: Cleanup this when Meson gets 'feature-combo':
 # https://github.com/mesonbuild/meson/issues/4566
@@ -73,6 +74,10 @@ if libidn2_dep.found() or libidn_dep.found()
   libunistring = cc.find_library('unistring')
 endif
 
+if host_machine.system() == 'windows'
+  networking_deps = cc.find_library('ws2_32')
+endif
+
 if enable_runtime == 'auto'
   enable_runtime = 'no'
 endif
@@ -114,6 +119,17 @@ endif
 python = import('python').find_installation()
 pkgconfig = import('pkgconfig')
 
+if cc.get_id() == 'msvc'
+  if not cc.has_header_symbol('stdio.h', 'snprintf')
+    if cc.has_header_symbol('stdio.h', '_snprintf')
+      add_project_arguments('-Dsnprintf=_snprintf', language: 'c')
+    endif
+  endif
+  if cc.has_header_symbol('malloc.h', '_alloca')
+    add_project_arguments('-Dalloca=_alloca', language: 'c')
+  endif
+endif
+
 subdir('include')
 subdir('src')
 subdir('tools')

src/meson.build

@@ -3,7 +3,7 @@ psl_make_dafsa = find_program('psl-make-dafsa')
 suffixes_dafsa_h = custom_target('suffixes_dafsa.h',
   input : psl_file,
   output : 'suffixes_dafsa.h',
-  command : [python, psl_make_dafsa, '--output-format=cxx+', '@INPUT@', '@OUTPUT@'])
+  command : [psl_make_dafsa, '--output-format=cxx+', '@INPUT@', '@OUTPUT@'])
 
 sources = [
   'lookup_string_in_fixed_set.c',
@@ -19,7 +19,7 @@ cargs = [
 libpsl = library('psl', sources, suffixes_dafsa_h,
   include_directories : [configinc, includedir],
   c_args : cargs,
-  dependencies : [libidn2_dep, libidn_dep, libicu_dep, libunistring],
+  dependencies : [libidn2_dep, libidn_dep, libicu_dep, libunistring, networking_deps],
 )
 
 pkgconfig.generate(libpsl,

tests/meson.build

@@ -1,12 +1,12 @@
 psl_dafsa = custom_target('psl.dafsa',
   input : psl_file,
   output : 'psl.dafsa',
-  command : [python, psl_make_dafsa, '--output-format=binary', '@INPUT@', '@OUTPUT@'])
+  command : [psl_make_dafsa, '--output-format=binary', '@INPUT@', '@OUTPUT@'])
 
 psl_ascii_dafsa = custom_target('psl_ascii.dafsa',
   input : psl_file,
   output : 'psl_ascii.dafsa',
-  command : [python, psl_make_dafsa, '--output-format=binary', '--encoding=ascii', '@INPUT@', '@OUTPUT@'])
+  command : [psl_make_dafsa, '--output-format=binary', '--encoding=ascii', '@INPUT@', '@OUTPUT@'])
 
 tests_cargs = [
   '-DHAVE_CONFIG_H',