Index: lib/StaticAnalyzer/Checkers/CStringChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -97,14 +97,17 @@
   void evalStrcpy(CheckerContext &C, const CallExpr *CE) const;
   void evalStrncpy(CheckerContext &C, const CallExpr *CE) const;
   void evalStpcpy(CheckerContext &C, const CallExpr *CE) const;
+  void evalStrlcpy(CheckerContext &C, const CallExpr *CE) const;
   void evalStrcpyCommon(CheckerContext &C,
                         const CallExpr *CE,
                         bool returnEnd,
                         bool isBounded,
-                        bool isAppending) const;
+                        bool isAppending,
+                        bool canOverlap = false) const;
 
   void evalStrcat(CheckerContext &C, const CallExpr *CE) const;
   void evalStrncat(CheckerContext &C, const CallExpr *CE) const;
+  void evalStrlcat(CheckerContext &C, const CallExpr *CE) const;
 
   void evalStrcmp(CheckerContext &C, const CallExpr *CE) const;
   void evalStrncmp(CheckerContext &C, const CallExpr *CE) const;
@@ -1397,6 +1400,18 @@
                    /* isAppending = */ false);
 }
 
+void CStringChecker::evalStrlcpy(CheckerContext &C, const CallExpr *CE) const {
+  if (CE->getNumArgs() < 3)
+    return;
+
+  // char *strlcpy(char *dst, const char *src, size_t n);
+  evalStrcpyCommon(C, CE,
+                   /* returnEnd = */ true,
+                   /* isBounded = */ true,
+                   /* isAppending = */ false,
+                   /* canOverlap = */ true);
+}
+
 void CStringChecker::evalStrcat(CheckerContext &C, const CallExpr *CE) const {
   if (CE->getNumArgs() < 2)
     return;
@@ -1419,9 +1434,21 @@
                    /* isAppending = */ true);
 }
 
+void CStringChecker::evalStrlcat(CheckerContext &C, const CallExpr *CE) const {
+  if (CE->getNumArgs() < 3)
+    return;
+
+  //char *strlcat(char *s1, const char *s2, size_t n);
+  evalStrcpyCommon(C, CE,
+                   /* returnEnd = */ false,
+                   /* isBounded = */ true,
+                   /* isAppending = */ true,
+                   /* canOverlap = */ true);
+}
+
 void CStringChecker::evalStrcpyCommon(CheckerContext &C, const CallExpr *CE,
                                       bool returnEnd, bool isBounded,
-                                      bool isAppending) const {
+                                      bool isAppending, bool canOverlap) const {
   CurrentFunctionDescription = "string copy function";
   ProgramStateRef state = C.getState();
   const LocationContext *LCtx = C.getLocationContext();
@@ -1459,6 +1486,12 @@
   SVal maxLastElementIndex = UnknownVal();
   const char *boundWarning = nullptr;
 
+  if (canOverlap)
+    state = CheckOverlap(C, state, CE->getArg(2), Dst, srcExpr);
+
+  if (!state)
+    return;
+
   // If the function is strncpy, strncat, etc... it is bounded.
   if (isBounded) {
     // Get the max number of characters to copy.
@@ -2095,10 +2128,14 @@
     evalFunction =  &CStringChecker::evalStrncpy;
   else if (C.isCLibraryFunction(FDecl, "stpcpy"))
     evalFunction =  &CStringChecker::evalStpcpy;
+  else if (C.isCLibraryFunction(FDecl, "strlcpy"))
+    evalFunction =  &CStringChecker::evalStrlcpy;
   else if (C.isCLibraryFunction(FDecl, "strcat"))
     evalFunction =  &CStringChecker::evalStrcat;
   else if (C.isCLibraryFunction(FDecl, "strncat"))
     evalFunction =  &CStringChecker::evalStrncat;
+  else if (C.isCLibraryFunction(FDecl, "strlcat"))
+    evalFunction =  &CStringChecker::evalStrlcat;
   else if (C.isCLibraryFunction(FDecl, "strlen"))
     evalFunction =  &CStringChecker::evalstrLength;
   else if (C.isCLibraryFunction(FDecl, "strnlen"))
Index: test/Analysis/bsd-string.c
===================================================================
--- /dev/null
+++ test/Analysis/bsd-string.c
@@ -0,0 +1,32 @@
+// 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 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}}
+}