[Sema]. Warn when logical expression is a pointer

which evaluates to true. rdar://18716393.
Reviewed by Richard Trieu

llvm-svn: 222009

5 files changed, 88 insertions, 4 deletions

diff --git a/clang/test/Analysis/NSContainers.m b/clang/test/Analysis/NSContainers.m
index 4b349264568..402ce2c90a1 100644
--- a/clang/test/Analysis/NSContainers.m
+++ b/clang/test/Analysis/NSContainers.m
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,osx.cocoa.NonNilReturnValue,osx.cocoa.NilArg,osx.cocoa.Loops,debug.ExprInspection -verify -Wno-objc-root-class %s
+// RUN: %clang_cc1  -Wno-objc-literal-conversion -analyze -analyzer-checker=core,osx.cocoa.NonNilReturnValue,osx.cocoa.NilArg,osx.cocoa.Loops,debug.ExprInspection -verify -Wno-objc-root-class %s
 
 void clang_analyzer_eval(int);
 
diff --git a/clang/test/Analysis/logical-ops.c b/clang/test/Analysis/logical-ops.c
index afaa2f10778..0b63bc9ec83 100644
--- a/clang/test/Analysis/logical-ops.c
+++ b/clang/test/Analysis/logical-ops.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.ExprInspection -verify %s
+// RUN: %clang_cc1 -Wno-pointer-bool-conversion -analyze -analyzer-checker=core,debug.ExprInspection -verify %s
 
 void clang_analyzer_eval(int);
 
diff --git a/clang/test/Analysis/objc-boxing.m b/clang/test/Analysis/objc-boxing.m
index c23192e17e5..73386f463bc 100644
--- a/clang/test/Analysis/objc-boxing.m
+++ b/clang/test/Analysis/objc-boxing.m
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.Malloc,osx.cocoa.NonNilReturnValue,debug.ExprInspection -analyzer-store=region -verify %s
+// RUN: %clang_cc1 -Wno-objc-literal-conversion -analyze -analyzer-checker=core,unix.Malloc,osx.cocoa.NonNilReturnValue,debug.ExprInspection -analyzer-store=region -verify %s
 
 void clang_analyzer_eval(int);
 
diff --git a/clang/test/Sema/exprs.c b/clang/test/Sema/exprs.c
index 2fb17e4880c..17b1aa2851b 100644
--- a/clang/test/Sema/exprs.c
+++ b/clang/test/Sema/exprs.c
@@ -244,6 +244,10 @@ void test22() {
   if ("help")
     (void) 0;
 
-  if (test22)
+  if (test22) // expected-warning {{address of function 'test22' will always evaluate to 'true'}} \
+	      // expected-note {{prefix with the address-of operator to silence this warning}}
+    (void) 0;
+
+  if (&test22)
     (void) 0;
 }
diff --git a/clang/test/Sema/warn-tautological-compare.c b/clang/test/Sema/warn-tautological-compare.c
new file mode 100644
index 00000000000..2856eddc7b0
--- /dev/null
+++ b/clang/test/Sema/warn-tautological-compare.c
@@ -0,0 +1,80 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -verify  %s
+// rdar://18716393
+
+extern int a[] __attribute__((weak));
+int b[] = {8,13,21};
+struct {
+  int x[10];
+} c;
+const char str[] = "text";
+
+void ignore() {
+  if (!a) {}
+}
+void test() {
+  if (!b) {} // expected-warning {{address of array 'b' will always evaluate to 'true'}}
+  if (b == 0) {} // expected-warning {{comparison of array 'b' equal to a null pointer is always false}}
+  if (!c.x) {} // expected-warning {{address of array 'c.x' will always evaluate to 'true'}}
+  if (c.x == 0) {} // expected-warning {{comparison of array 'c.x' equal to a null pointer is always false}}
+  if (!str) {} // expected-warning {{address of array 'str' will always evaluate to 'true'}}
+  if (0 == str) {} // expected-warning {{comparison of array 'str' equal to a null pointer is always false}}
+}
+
+int array[2];
+int test1()
+{
+  if (!array) { // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+    return array[0];
+  } else if (array != 0) { // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
+    return array[1];
+  }
+  if (array == 0) // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
+    return 1;
+  return 0;
+}
+
+#define NULL (void*)0
+
+int test2(int* pointer, char ch, void * pv) {
+   if (!&pointer) {  // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
+     return 0;
+   }
+
+   if (&pointer) {  // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
+     return 0;
+   }
+
+   if (&pointer == NULL) {} // expected-warning {{comparison of address of 'pointer' equal to a null pointer is always false}}
+
+   if (&pointer != NULL) {} // expected-warning {{comparison of address of 'pointer' not equal to a null pointer is always true}}
+
+   return 1;
+}
+
+void test3() {
+   if (array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+   if (array != 0) {} // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
+   if (!array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+   if (array == 0) {} // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
+
+   if (array[0] &&
+       array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+   if (array[0] ||
+       array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+   if (array[0] &&
+       !array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+   if (array[0] ||
+       !array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+   if (array && // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+       array[0]) {}
+   if (!array || // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+       array[0]) {}
+
+   if (array ||  // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+       (!array && array[0])) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ }
+
+