[analyzer] Fix modeling of strnlen to be more conservative. Move tests we can't properly model (yet?) to string-fail.c.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132955 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/string-fail.c b/test/Analysis/string-fail.c
new file mode 100644
index 0000000..bdd4664
--- /dev/null
+++ b/test/Analysis/string-fail.c
@@ -0,0 +1,113 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,cplusplus.experimental.CString,deadcode.experimental.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,cplusplus.experimental.CString,deadcode.experimental.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// XFAIL: *
+
+// This file is for tests that may eventually go into string.c, or may be
+// deleted outright. At one point these tests passed, but only because we
+// weren't correctly modelling the behavior of the relevant string functions.
+// The tests aren't incorrect, but require the analyzer to be smarter about
+// conjured values than it currently is.
+
+//===----------------------------------------------------------------------===
+// Declarations
+//===----------------------------------------------------------------------===
+
+// Some functions are so similar to each other that they follow the same code
+// path, such as memcpy and __memcpy_chk, or memcmp and bcmp. If VARIANT is
+// defined, make sure to use the variants instead to make sure they are still
+// checked by the analyzer.
+
+// Some functions are implemented as builtins. These should be #defined as
+// BUILTIN(f), which will prepend "__builtin_" if USE_BUILTINS is defined.
+
+// Functions that have variants and are also available as builtins should be
+// declared carefully! See memcpy() for an example.
+
+#ifdef USE_BUILTINS
+# define BUILTIN(f) __builtin_ ## f
+#else /* USE_BUILTINS */
+# define BUILTIN(f) f
+#endif /* USE_BUILTINS */
+
+#define NULL 0
+typedef typeof(sizeof(int)) size_t;
+
+
+//===----------------------------------------------------------------------===
+// strnlen()
+//===----------------------------------------------------------------------===
+
+#define strnlen BUILTIN(strnlen)
+size_t strnlen(const char *s, size_t maxlen);
+
+void strnlen_liveness(const char *x) {
+ if (strnlen(x, 10) < 5)
+ return;
+ if (strnlen(x, 10) < 5)
+ (void)*(char*)0; // no-warning
+}
+
+void strnlen_subregion() {
+ struct two_stringsn { char a[2], b[2]; };
+ extern void use_two_stringsn(struct two_stringsn *);
+
+ struct two_stringsn z;
+ use_two_stringsn(&z);
+
+ size_t a = strnlen(z.a, 10);
+ z.b[0] = 5;
+ size_t b = strnlen(z.a, 10);
+ if (a == 0 && b != 0)
+ (void)*(char*)0; // expected-warning{{never executed}}
+
+ use_two_stringsn(&z);
+
+ size_t c = strnlen(z.a, 10);
+ if (a == 0 && c != 0)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+extern void use_stringn(char *);
+void strnlen_argument(char *x) {
+ size_t a = strnlen(x, 10);
+ size_t b = strnlen(x, 10);
+ if (a == 0 && b != 0)
+ (void)*(char*)0; // expected-warning{{never executed}}
+
+ use_stringn(x);
+
+ size_t c = strnlen(x, 10);
+ if (a == 0 && c != 0)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+extern char global_strn[];
+void strnlen_global() {
+ size_t a = strnlen(global_strn, 10);
+ size_t b = strnlen(global_strn, 10);
+ if (a == 0 && b != 0)
+ (void)*(char*)0; // expected-warning{{never executed}}
+
+ // Call a function with unknown effects, which should invalidate globals.
+ use_stringn(0);
+
+ size_t c = strnlen(global_strn, 10);
+ if (a == 0 && c != 0)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+void strnlen_indirect(char *x) {
+ size_t a = strnlen(x, 10);
+ char *p = x;
+ char **p2 = &p;
+ size_t b = strnlen(x, 10);
+ if (a == 0 && b != 0)
+ (void)*(char*)0; // expected-warning{{never executed}}
+
+ extern void use_stringn_ptr(char*const*);
+ use_stringn_ptr(p2);
+
+ size_t c = strnlen(x, 10);
+ if (a == 0 && c != 0)
+ (void)*(char*)0; // expected-warning{{null}}
+}
diff --git a/test/Analysis/string.c b/test/Analysis/string.c
index e6baf51..ac1026c 100644
--- a/test/Analysis/string.c
+++ b/test/Analysis/string.c
@@ -199,76 +199,59 @@
return strnlen((char*)&&label, 3); // expected-warning{{Argument to byte string function is the address of the label 'label', which is not a null-terminated string}}
}
-void strnlen_subregion() {
- struct two_stringsn { char a[2], b[2]; };
- extern void use_two_stringsn(struct two_stringsn *);
-
- struct two_stringsn z;
- use_two_stringsn(&z);
-
- size_t a = strnlen(z.a, 10);
- z.b[0] = 5;
- size_t b = strnlen(z.a, 10);
- if (a == 0 && b != 0)
- (void)*(char*)0; // expected-warning{{never executed}}
-
- use_two_stringsn(&z);
-
- size_t c = strnlen(z.a, 10);
- if (a == 0 && c != 0)
- (void)*(char*)0; // expected-warning{{null}}
-}
-
-extern void use_stringn(char *);
-void strnlen_argument(char *x) {
- size_t a = strnlen(x, 10);
- size_t b = strnlen(x, 10);
- if (a == 0 && b != 0)
- (void)*(char*)0; // expected-warning{{never executed}}
-
- use_stringn(x);
-
- size_t c = strnlen(x, 10);
- if (a == 0 && c != 0)
- (void)*(char*)0; // expected-warning{{null}}
-}
-
-extern char global_strn[];
-void strnlen_global() {
- size_t a = strnlen(global_strn, 10);
- size_t b = strnlen(global_strn, 10);
- if (a == 0 && b != 0)
- (void)*(char*)0; // expected-warning{{never executed}}
-
- // Call a function with unknown effects, which should invalidate globals.
- use_stringn(0);
-
- size_t c = strnlen(global_str, 10);
- if (a == 0 && c != 0)
- (void)*(char*)0; // expected-warning{{null}}
-}
-
-void strnlen_indirect(char *x) {
- size_t a = strnlen(x, 10);
- char *p = x;
- char **p2 = &p;
- size_t b = strnlen(x, 10);
- if (a == 0 && b != 0)
- (void)*(char*)0; // expected-warning{{never executed}}
-
- extern void use_stringn_ptr(char*const*);
- use_stringn_ptr(p2);
-
- size_t c = strnlen(x, 10);
- if (a == 0 && c != 0)
- (void)*(char*)0; // expected-warning{{null}}
-}
-
-void strnlen_liveness(const char *x) {
- if (strnlen(x, 10) < 5)
- return;
- if (strnlen(x, 10) < 5)
+void strnlen_zero() {
+ if (strnlen("abc", 0) != 0)
(void)*(char*)0; // no-warning
+ if (strnlen(NULL, 0) != 0) // no-warning
+ (void)*(char*)0; // no-warning
+}
+
+size_t strnlen_compound_literal() {
+ // This used to crash because we don't model the string lengths of
+ // compound literals.
+ return strnlen((char[]) { 'a', 'b', 0 }, 1);
+}
+
+size_t strnlen_unknown_limit(float f) {
+ // This used to crash because we don't model the integer values of floats.
+ return strnlen("abc", (int)f);
+}
+
+void strnlen_is_not_strlen(char *x) {
+ if (strnlen(x, 10) != strlen(x))
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+void strnlen_at_limit(char *x) {
+ size_t len = strnlen(x, 10);
+ if (len > 10)
+ (void)*(char*)0; // expected-warning{{never executed}}
+ if (len == 10)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+void strnlen_less_than_limit(char *x) {
+ size_t len = strnlen(x, 10);
+ if (len > 10)
+ (void)*(char*)0; // expected-warning{{never executed}}
+ if (len < 10)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+void strnlen_at_actual(size_t limit) {
+ size_t len = strnlen("abc", limit);
+ if (len > 3)
+ (void)*(char*)0; // expected-warning{{never executed}}
+ if (len == 3)
+ (void)*(char*)0; // expected-warning{{null}}
+}
+
+void strnlen_less_than_actual(size_t limit) {
+ size_t len = strnlen("abc", limit);
+ if (len > 3)
+ (void)*(char*)0; // expected-warning{{never executed}}
+ if (len < 3)
+ (void)*(char*)0; // expected-warning{{null}}
}
//===----------------------------------------------------------------------===