[analyzer] Let TK_PreserveContents span across the whole base region.

If an address of a field is passed through a const pointer,
the whole structure's base region should receive the
TK_PreserveContents trait and avoid invalidation.

Additionally, include a few FIXME tests shown up during testing.

Differential Revision: http://reviews.llvm.org/D19057

llvm-svn: 267413

1 files changed, 47 insertions, 0 deletions

diff --git a/clang/test/Analysis/call-invalidation.cpp b/clang/test/Analysis/call-invalidation.cpp
index 7297d1ebec2..80323ffcf18 100644
--- a/clang/test/Analysis/call-invalidation.cpp
+++ b/clang/test/Analysis/call-invalidation.cpp
@@ -118,3 +118,50 @@ void testPureConst() {
 }
 
 
+struct PlainStruct {
+  int x, y;
+  mutable int z;
+};
+
+PlainStruct glob;
+
+void useAnything(void *);
+void useAnythingConst(const void *);
+
+void testInvalidationThroughBaseRegionPointer() {
+  PlainStruct s1;
+  s1.x = 1;
+  s1.z = 1;
+  clang_analyzer_eval(s1.x == 1); // expected-warning{{TRUE}}
+  clang_analyzer_eval(s1.z == 1); // expected-warning{{TRUE}}
+  // Not only passing a structure pointer through const pointer parameter,
+  // but also passing a field pointer through const pointer parameter
+  // should preserve the contents of the structure.
+  useAnythingConst(&(s1.y));
+  clang_analyzer_eval(s1.x == 1); // expected-warning{{TRUE}}
+  // FIXME: Should say "UNKNOWN", because it is not uncommon to
+  // modify a mutable member variable through const pointer.
+  clang_analyzer_eval(s1.z == 1); // expected-warning{{TRUE}}
+  useAnything(&(s1.y));
+  clang_analyzer_eval(s1.x == 1); // expected-warning{{UNKNOWN}}
+}
+
+
+void useFirstConstSecondNonConst(const void *x, void *y);
+void useFirstNonConstSecondConst(void *x, const void *y);
+
+void testMixedConstNonConstCalls() {
+  PlainStruct s2;
+  s2.x = 1;
+  useFirstConstSecondNonConst(&(s2.x), &(s2.y));
+  clang_analyzer_eval(s2.x == 1); // expected-warning{{UNKNOWN}}
+  s2.x = 1;
+  useFirstNonConstSecondConst(&(s2.x), &(s2.y));
+  clang_analyzer_eval(s2.x == 1); // expected-warning{{UNKNOWN}}
+  s2.y = 1;
+  useFirstConstSecondNonConst(&(s2.x), &(s2.y));
+  clang_analyzer_eval(s2.y == 1); // expected-warning{{UNKNOWN}}
+  s2.y = 1;
+  useFirstNonConstSecondConst(&(s2.x), &(s2.y));
+  clang_analyzer_eval(s2.y == 1); // expected-warning{{UNKNOWN}}
+}