Add NULL fd test for vfscanf and vfprintf

Author: alejandro-alvarez-sonarsource

clang/test/Analysis/Inputs/system-header-simulator-for-valist.h

@@ -23,6 +23,8 @@ int vprintf (const char *restrict format, va_list arg);
 
 int vsprintf (char *restrict s, const char *restrict format, va_list arg);
 
+int vfprintf(FILE *stream, const char *format, va_list ap);
+
 int vfscanf(FILE *stream, const char *format, va_list ap);
 
 int some_library_function(int n, va_list arg);

clang/test/Analysis/stream.c

@@ -1,6 +1,7 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.Stream,debug.ExprInspection -verify %s
 
 #include "Inputs/system-header-simulator.h"
+#include "Inputs/system-header-simulator-for-valist.h"
 
 void clang_analyzer_eval(int);
 
@@ -141,6 +142,18 @@ void f_dopen(int fd) {
   fclose(F);
 }
 
+void f_vfprintf(int fd, va_list args) {
+  FILE *F = fdopen(fd, "r");
+  vfprintf(F, "%d", args); // expected-warning {{Stream pointer might be NULL}}
+  fclose(F);
+}
+
+void f_vfscanf(int fd, va_list args) {
+  FILE *F = fdopen(fd, "r");
+  vfscanf(F, "%u", args); // expected-warning {{Stream pointer might be NULL}}
+  fclose(F);
+}
+
 void f_seek(void) {
   FILE *p = fopen("foo", "r");
   if (!p)