[NFC][analyzer] OOB test consolidation II: constraint checking (#126748)

This commit heavily refactors `out-of-bounds-constraint-check.c`:
1. The complex combinations of several `clang_analyzer_eval` calls were
replaced by `clang_analyzer_value`, which can directly query the range
of a symbol.
2. Testcases were renamed to a (hopefully) more consistent scheme.
3. The use of `size_t` as an argument type was replaced by `unsigned
long long`, which is usually a no-op, but seems to be a better choice if
I look for `64u` in the output of `clang_analyzer_value`.
4. The single "dynamic extent" case was generalized into a full set of
tests that use `malloc`.
5. Half of the testcases (the ones that don't use `malloc`) were changed
to use an `int[5]` array instead of a string literal. After this change
the tests in this file cover every functionality that was tested by the
testcases `test_assume_after_access{,2}` in the file `out-of-bounds.c`
so I was able to delete those two testcases (and therefore consolidate
the validation of these constraints within a single test file).

This is the second commit in a series that reorganizes the tests of
`security.ArrayBound` to system that's easier to understand and
maintain. (Note that this file wasn't significantly modified by the
recent commit 6e17ed9b04e5523cc910bf171c3122dcc64b86db which renamed
`alpha.security.ArrayBoundV2` to `security.ArrayBound`; but I still felt
that this cleanup may be useful.)

clang/test/Analysis/out-of-bounds-constraint-check.c

@@ -1,112 +1,163 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.Malloc,security.ArrayBound,debug.ExprInspection \
 // RUN:   -analyzer-config eagerly-assume=false -verify %s
 
-void clang_analyzer_eval(int);
-void clang_analyzer_printState(void);
+// When the checker security.ArrayBound encounters an array subscript operation
+// that _may be_ in bounds, it assumes that indexing _is_ in bound. This test
+// file validates these assumptions.
 
-typedef typeof(sizeof(int)) size_t;
-const char a[] = "abcd"; // extent: 5 bytes
+void clang_analyzer_value(int);
 
-void symbolic_size_t_and_int0(size_t len) {
-  (void)a[len + 1]; // no-warning
-  // We infered that the 'len' must be in a specific range to make the previous indexing valid.
-  // len: [0,3]
-  clang_analyzer_eval(len <= 3); // expected-warning {{TRUE}}
-  clang_analyzer_eval(len <= 2); // expected-warning {{UNKNOWN}}
+// Simple case: memory area with a static extent.
+
+extern int FiveInts[5];
+
+void int_plus_one(int len) {
+  (void)FiveInts[len + 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [-1, 3] }}}
 }
 
-void symbolic_size_t_and_int1(size_t len) {
-  (void)a[len]; // no-warning
-  // len: [0,4]
-  clang_analyzer_eval(len <= 4); // expected-warning {{TRUE}}
-  clang_analyzer_eval(len <= 3); // expected-warning {{UNKNOWN}}
+void int_neutral(int len) {
+  (void)FiveInts[len]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
 }
 
-void symbolic_size_t_and_int2(size_t len) {
-  (void)a[len - 1]; // no-warning
-  // len: [1,5]
-  clang_analyzer_eval(1 <= len && len <= 5); // expected-warning {{TRUE}}
-  clang_analyzer_eval(2 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 4);             // expected-warning {{UNKNOWN}}
+void int_minus_one(int len) {
+  (void)FiveInts[len - 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
 }
 
-void symbolic_uint_and_int0(unsigned len) {
-  (void)a[len + 1]; // no-warning
-  // len: [0,3]
-  clang_analyzer_eval(0 <= len && len <= 3); // expected-warning {{TRUE}}
-  clang_analyzer_eval(1 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 2);             // expected-warning {{UNKNOWN}}
+void unsigned_plus_one(unsigned len) {
+  (void)FiveInts[len + 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 3] }}}
 }
 
-void symbolic_uint_and_int1(unsigned len) {
-  (void)a[len]; // no-warning
-  // len: [0,4]
-  clang_analyzer_eval(0 <= len && len <= 4); // expected-warning {{TRUE}}
-  clang_analyzer_eval(1 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 3);             // expected-warning {{UNKNOWN}}
-}
-void symbolic_uint_and_int2(unsigned len) {
-  (void)a[len - 1]; // no-warning
-  // len: [1,5]
-  clang_analyzer_eval(1 <= len && len <= 5); // expected-warning {{TRUE}}
-  clang_analyzer_eval(2 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 4);             // expected-warning {{UNKNOWN}}
+void unsigned_neutral(unsigned len) {
+  (void)FiveInts[len]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
 }
 
-void symbolic_int_and_int0(int len) {
-  (void)a[len + 1]; // no-warning
-  // len: [-1,3]
-  clang_analyzer_eval(-1 <= len && len <= 3); // expected-warning {{TRUE}}
-  clang_analyzer_eval(0 <= len);              // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 2);              // expected-warning {{UNKNOWN}}
-}
-void symbolic_int_and_int1(int len) {
-  (void)a[len]; // no-warning
-  // len: [0,4]
-  clang_analyzer_eval(0 <= len && len <= 4); // expected-warning {{TRUE}}
-  clang_analyzer_eval(1 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 3);             // expected-warning {{UNKNOWN}}
-}
-void symbolic_int_and_int2(int len) {
-  (void)a[len - 1]; // no-warning
-  // len: [1,5]
-  clang_analyzer_eval(1 <= len && len <= 5); // expected-warning {{TRUE}}
-  clang_analyzer_eval(2 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 4);             // expected-warning {{UNKNOWN}}
+void unsigned_minus_one(unsigned len) {
+  (void)FiveInts[len - 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
 }
 
-void symbolic_longlong_and_int0(long long len) {
-  (void)a[len + 1]; // no-warning
-  // len: [-1,3]
-  clang_analyzer_eval(-1 <= len && len <= 3); // expected-warning {{TRUE}}
-  clang_analyzer_eval(0 <= len);              // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 2);              // expected-warning {{UNKNOWN}}
+void ll_plus_one(long long len) {
+  (void)FiveInts[len + 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [-1, 3] }}}
 }
 
+void ll_neutral(long long len) {
+  (void)FiveInts[len]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+}
+
+void ll_minus_one(long long len) {
+  (void)FiveInts[len - 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+}
+
+void ull_plus_one(unsigned long long len) {
+  (void)FiveInts[len + 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 3] }}}
+}
+
+void ull_neutral(unsigned long long len) {
+  (void)FiveInts[len]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+}
+
+void ull_minus_one(unsigned long long len) {
+  (void)FiveInts[len - 1]; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+}
+
+// Also try the same with a dynamically allocated memory block, because in the
+// past there were issues with the type/signedness of dynamic extent symbols.
+
+typedef __typeof(sizeof(int)) size_t;
 void *malloc(size_t);
 void free(void *);
-void symbolic_longlong_and_int0_dynamic_extent(long long len) {
-  char *b = malloc(5);
-  (void)b[len + 1]; // no-warning
-  // len: [-1,3]
-  clang_analyzer_eval(-1 <= len && len <= 3); // expected-warning {{TRUE}}
-  clang_analyzer_eval(0 <= len);              // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 2);              // expected-warning {{UNKNOWN}}
-  free(b);
+
+void dyn_int_plus_one(int len) {
+  char *p = malloc(5);
+  p[len + 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [-1, 3] }}}
+  free(p);
 }
 
-void symbolic_longlong_and_int1(long long len) {
-  (void)a[len]; // no-warning
-  // len: [0,4]
-  clang_analyzer_eval(0 <= len && len <= 4); // expected-warning {{TRUE}}
-  clang_analyzer_eval(1 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 3);             // expected-warning {{UNKNOWN}}
+void dyn_int_neutral(int len) {
+  char *p = malloc(5);
+  p[len] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+  free(p);
 }
 
-void symbolic_longlong_and_int2(long long len) {
-  (void)a[len - 1]; // no-warning
-  // len: [1,5]
-  clang_analyzer_eval(1 <= len && len <= 5); // expected-warning {{TRUE}}
-  clang_analyzer_eval(2 <= len);             // expected-warning {{UNKNOWN}}
-  clang_analyzer_eval(len <= 4);             // expected-warning {{UNKNOWN}}
+void dyn_int_minus_one(int len) {
+  char *p = malloc(5);
+  p[len - 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+  free(p);
+}
+
+void dyn_unsigned_plus_one(unsigned len) {
+  char *p = malloc(5);
+  p[len + 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 3] }}}
+  free(p);
+}
+
+void dyn_unsigned_neutral(unsigned len) {
+  char *p = malloc(5);
+  p[len] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+  free(p);
+}
+
+void dyn_unsigned_minus_one(unsigned len) {
+  char *p = malloc(5);
+  p[len - 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+  free(p);
+}
+
+void dyn_ll_plus_one(long long len) {
+  char *p = malloc(5);
+  p[len + 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [-1, 3] }}}
+  free(p);
+}
+
+void dyn_ll_neutral(long long len) {
+  char *p = malloc(5);
+  p[len] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+  free(p);
+}
+
+void dyn_ll_minus_one(long long len) {
+  char *p = malloc(5);
+  p[len - 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+  free(p);
+}
+
+void dyn_ull_plus_one(unsigned long long len) {
+  char *p = malloc(5);
+  p[len + 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 3] }}}
+  free(p);
+}
+
+void dyn_ull_neutral(unsigned long long len) {
+  char *p = malloc(5);
+  p[len] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [0, 4] }}}
+  free(p);
+}
+
+void dyn_ull_minus_one(unsigned long long len) {
+  char *p = malloc(5);
+  p[len - 1] = 1; // no-warning
+  clang_analyzer_value(len); // expected-warning {{{ [1, 5] }}}
+  free(p);
 }

clang/test/Analysis/out-of-bounds.c

@@ -1,6 +1,4 @@
-// RUN: %clang_analyze_cc1 -Wno-array-bounds -analyzer-checker=core,security.ArrayBound,debug.ExprInspection -verify %s
-
-void clang_analyzer_eval(int);
+// RUN: %clang_analyze_cc1 -Wno-array-bounds -analyzer-checker=core,security.ArrayBound -verify %s
 
 // Tests doing an out-of-bounds access after the end of an array using:
 // - constant integer index
@@ -142,12 +140,6 @@ void test4(int x) {
     buf[x] = 1; // expected-warning{{Out of bound access to memory}}
 }
 
-void test_assume_after_access(unsigned long x) {
-  int buf[100];
-  buf[x] = 1;
-  clang_analyzer_eval(x <= 99); // expected-warning{{TRUE}}
-}
-
 // Don't warn when indexing below the start of a symbolic region's whose
 // base extent we don't know.
 int *get_symbolic(void);
@@ -180,12 +172,6 @@ void test_extern_void(void) {
   p[1] = 42; // no-warning
 }
 
-void test_assume_after_access2(unsigned long x) {
-  char buf[100];
-  buf[x] = 1;
-  clang_analyzer_eval(x <= 99); // expected-warning{{TRUE}}
-}
-
 struct incomplete;
 char test_comparison_with_extent_symbol(struct incomplete *p) {
   // Previously this was reported as a (false positive) overflow error because