[analyzer] const init: handle non-explicit cases more accurately

Summary: If the access is out of bounds, return UndefinedVal. If it is missing an explicit init, return the implicit zero value it must have.

Reviewers: NoQ, xazax.hun, george.karpenkov

Reviewed By: NoQ

Subscribers: szepet, rnkovacs, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D46823

llvm-svn: 333417

1 files changed, 23 insertions, 2 deletions

diff --git a/clang/test/Analysis/initialization.c b/clang/test/Analysis/initialization.c
index a6fe9be2b70..c1d6361f124 100644
--- a/clang/test/Analysis/initialization.c
+++ b/clang/test/Analysis/initialization.c
@@ -1,7 +1,28 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
-// expected-no-diagnostics
+// RUN: %clang_cc1 -triple i386-apple-darwin10 -analyze -analyzer-checker=core.builtin,debug.ExprInspection -verify %s
+
+void clang_analyzer_eval(int);
 
 void initbug() {
   const union { float a; } u = {};
   (void)u.a; // no-crash
 }
+
+int const parr[2] = {1};
+void constarr() {
+  int i = 2;
+  clang_analyzer_eval(parr[i]); // expected-warning{{UNDEFINED}}
+  i = 1;
+  clang_analyzer_eval(parr[i] == 0); // expected-warning{{TRUE}}
+  i = -1;
+  clang_analyzer_eval(parr[i]); // expected-warning{{UNDEFINED}}
+}
+
+struct SM {
+  int a;
+  int b;
+};
+const struct SM sm = {.a = 1};
+void multinit() {
+  clang_analyzer_eval(sm.a == 1); // expected-warning{{TRUE}}
+  clang_analyzer_eval(sm.b == 0); // expected-warning{{TRUE}}
+}