stdio stdlib: add empty getenv/system/tmpnam/tmpfile for Lua

CMakeLists.txt

@@ -145,6 +145,8 @@ set(SOURCES
   src/stdio/snprintf.c
   src/stdio/sprintf.c
   src/stdio/streams.c
+  src/stdio/tmpfile.c
+  src/stdio/tmpnam.c
   src/stdio/ungetc.c
   src/stdio/vasprintf.c
   src/stdio/vdprintf.c
@@ -162,6 +164,7 @@ set(SOURCES
   src/stdlib/calloc.c
   src/stdlib/div.c
   src/stdlib/exit.c
+  src/stdlib/getenv.c
   src/stdlib/labs.c
   src/stdlib/ldiv.c
   src/stdlib/llabs.c
@@ -177,6 +180,7 @@ set(SOURCES
   src/stdlib/strtoll.c
   src/stdlib/strtoul.c
   src/stdlib/strtoull.c
+  src/stdlib/system.c
   # string
   src/string/memchr.c
   src/string/memcmp.c

src/stdio/tmpfile.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+FILE *tmpfile(void)
+{
+    return NULL;
+}

src/stdio/tmpnam.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+char *tmpnam(char *s)
+{
+    (void)s;
+    return NULL;
+}

src/stdlib/getenv.c

@@ -0,0 +1,7 @@
+#include <stdlib.h>
+
+char *getenv(char const *name)
+{
+    (void)name;
+    return NULL;
+}

src/stdlib/system.c

@@ -0,0 +1,11 @@
+#include <stdlib.h>
+
+int system(char const *command)
+{
+    /* No command: determine whether there is a shell */
+    if(!command)
+        return 0;
+
+    /* Command: pretend it fails and return 1 */
+    return 1;
+}