llvm/clang/test/Analysis/debug-exprinspection-istainted.c
Balazs Benics 859bcf4e3b [analyzer][taint] Add isTainted debug expression inspection check
Summary:
This patch introduces the `clang_analyzer_isTainted` expression inspection
check for checking taint.

Using this we could query the analyzer whether the expression used as the
argument is tainted or not. This would be useful in tests, where we don't want
to issue warning for all tainted expressions in a given file
(like the `debug.TaintTest` would do) but only for certain expressions.

Example usage:

```lang=c++
int read_integer() {
  int n;
  clang_analyzer_isTainted(n);     // expected-warning{{NO}}
  scanf("%d", &n);
  clang_analyzer_isTainted(n);     // expected-warning{{YES}}
  clang_analyzer_isTainted(n + 2); // expected-warning{{YES}}
  clang_analyzer_isTainted(n > 0); // expected-warning{{YES}}
  int next_tainted_value = n; // no-warning
  return n;
}
```

Reviewers: NoQ, Szelethus, baloghadamsoftware, xazax.hun, boga95

Reviewed By: Szelethus

Subscribers: martong, rnkovacs, whisperity, xazax.hun,
baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy,
Charusso, cfe-commits, boga95, dkrupp, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74131
2020-03-03 14:40:23 +01:00

28 lines
996 B
C

// RUN: %clang_analyze_cc1 -verify %s \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=debug.ExprInspection \
// RUN: -analyzer-checker=alpha.security.taint
int scanf(const char *restrict format, ...);
void clang_analyzer_isTainted(char);
void clang_analyzer_isTainted_any_suffix(char);
void clang_analyzer_isTainted_many_arguments(char, int, int);
void foo() {
char buf[32] = "";
clang_analyzer_isTainted(buf[0]); // expected-warning {{NO}}
clang_analyzer_isTainted_any_suffix(buf[0]); // expected-warning {{NO}}
scanf("%s", buf);
clang_analyzer_isTainted(buf[0]); // expected-warning {{YES}}
clang_analyzer_isTainted_any_suffix(buf[0]); // expected-warning {{YES}}
int tainted_value = buf[0]; // no-warning
}
void exactly_one_argument_required() {
char buf[32] = "";
scanf("%s", buf);
clang_analyzer_isTainted_many_arguments(buf[0], 42, 42);
// expected-warning@-1 {{clang_analyzer_isTainted() requires exactly one argument}}
}