[analyzer] Re-apply r331096 "CStringChecker: Add support for BSD strlcpy()...".

Fixed after revert in r331401.

Patch by David Carlier!

Differential Revision: https://reviews.llvm.org/D45177

llvm-svn: 332303
diff --git a/clang/test/Analysis/bsd-string.c b/clang/test/Analysis/bsd-string.c
new file mode 100644
index 0000000..4c57c86
--- /dev/null
+++ b/clang/test/Analysis/bsd-string.c
@@ -0,0 +1,40 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.cstring,alpha.unix.cstring,debug.ExprInspection -analyzer-store=region -verify %s
+
+#define NULL ((void *)0)
+
+typedef __typeof(sizeof(int)) size_t;
+size_t strlcpy(char *dst, const char *src, size_t n);
+size_t strlcat(char *dst, const char *src, size_t n);
+void clang_analyzer_eval(int);
+
+void f1() {
+  char overlap[] = "123456789";
+  strlcpy(overlap, overlap + 1, 3); // expected-warning{{Arguments must not be overlapping buffers}}
+}
+
+void f2() {
+  char buf[5];
+  strlcpy(buf, "abcd", sizeof(buf)); // expected-no-warning
+  strlcat(buf, "efgh", sizeof(buf)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
+}
+
+void f3() {
+  char dst[2];
+  const char *src = "abdef";
+  strlcpy(dst, src, 5); // expected-warning{{Size argument is greater than the length of the destination buffer}}
+}
+
+void f4() {
+  strlcpy(NULL, "abcdef", 6); // expected-warning{{Null pointer argument in call to string copy function}}
+}
+
+void f5() {
+  strlcat(NULL, "abcdef", 6); // expected-warning{{Null pointer argument in call to string copy function}}
+}
+
+void f6() {
+  char buf[8];
+  strlcpy(buf, "abc", 3);
+  size_t len = strlcat(buf, "defg", 4);
+  clang_analyzer_eval(len == 7); // expected-warning{{TRUE}}
+}