Can add extra #includes to sizeof checks.

environment.py

@@ -133,8 +133,10 @@ class CCompiler():
             pass
         return p.returncode == 0
 
-    def sizeof(self, element):
+    def sizeof(self, element, prefix):
         templ = '''#include<stdio.h>
+%s
+
 int main(int argc, char **argv) {
     printf("%%ld\\n", (long)(sizeof(%s)));
     return 0;
@@ -144,7 +146,8 @@ int main(int argc, char **argv) {
         exename = srcname + '.exe' # Is guaranteed to be executable on every platform.
         os.close(fd)
         ofile = open(srcname, 'w')
-        code = templ % element
+        code = templ % (prefix, element)
+        print(code)
         ofile.write(code)
         ofile.close()
         commands = self.get_exelist()

interpreter.py

@@ -546,10 +546,13 @@ class CompilerHolder(InterpreterObject):
     def sizeof_method(self, args, kwargs):
         if len(args) != 1:
             raise InterpreterException('Sizeof takes exactly one argument.')
-        string = args[0]
-        if not isinstance(string, str):
+        element = args[0]
+        if not isinstance(element, str):
             raise InterpreterException('Argument to sizeof must be a string.')
-        return self.compiler.sizeof(string)
+        prefix = kwargs.get('prefix', '')
+        if not isinstance(prefix, str):
+            raise InterpreterException('Prefix argument of sizeof must be a string.')
+        return self.compiler.sizeof(element, prefix)
 
     def compiles_method(self, args, kwargs):
         if len(args) != 1:

test cases/common/35 sizeof/config.h.in

@@ -1 +1,2 @@
 #define INTSIZE @INTSIZE@
+#define WCHARSIZE @WCHARSIZE@

test cases/common/35 sizeof/meson.build

@@ -2,9 +2,11 @@ project('sizeof', 'c')
 
 cc = meson.get_compiler('c')
 intsize = cc.sizeof('int')
+wcharsize = cc.sizeof('wchar_t', prefix : '#include<wchar.h>')
 
 cd = configuration_data()
 cd.set('INTSIZE', intsize)
+cd.set('WCHARSIZE', wcharsize)
 configure_file(input : 'config.h.in', output : 'config.h', configuration : cd)
 
 e = executable('prog', 'prog.c', include_dirs : include_directories('.'))

test cases/common/35 sizeof/prog.c

@@ -1,10 +1,15 @@
 #include"config.h"
 #include<stdio.h>
+#include<wchar.h>
 
 int main(int argc, char **argv) {
     if(INTSIZE != sizeof(int)) {
         fprintf(stderr, "Mismatch: detected int size %d, actual size %d.\n", INTSIZE, (int)sizeof(int));
         return 1;
     }
+    if(WCHARSIZE != sizeof(wchar_t)) {
+        fprintf(stderr, "Mismatch: detected wchar size %d, actual size %d.\n", WCHARSIZE, (int)sizeof(wchar_t));
+        return 1;
+    }
     return 0;
 }