[analyzer] Handle C string default values for const char * arguments.

Previously, SValBuilder knew how to evaluate StringLiterals, but couldn't
handle an array-to-pointer decay for constant values. Additionally,
RegionStore was being too strict about loading from an array, refusing to
return a 'char' value from a 'const char' array. Both of these have been
fixed.

llvm-svn: 186520

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/test/Analysis/inline.cpp b/clang/test/Analysis/inline.cpp
index fad77b3bee4..ca126ddf7f3 100644
--- a/clang/test/Analysis/inline.cpp
+++ b/clang/test/Analysis/inline.cpp
@@ -290,6 +290,15 @@ namespace DefaultArgs {
     clang_analyzer_eval(defaultFloatReferenceZero(1) == -1); // expected-warning{{UNKNOWN}}
     clang_analyzer_eval(defaultFloatReferenceZero() == 0); // expected-warning{{UNKNOWN}}
   }
+
+  char defaultString(const char *s = "abc") {
+    return s[1];
+  }
+
+  void testString() {
+    clang_analyzer_eval(defaultString("xyz") == 'y'); // expected-warning{{TRUE}}
+    clang_analyzer_eval(defaultString() == 'b'); // expected-warning{{TRUE}}
+  }
 }
 
 namespace OperatorNew {