r217461 - Teach the analyzer that __builtin_assume_aligned returns its first argument.

[Jordan Rose]

Author: jrose
Date: Tue Sep  9 16:42:16 2014
New Revision: 217461

URL: http://llvm.org/viewvc/llvm-project?rev=217461&view=rev
Log:
Teach the analyzer that __builtin_assume_aligned returns its first argument.

Patch by Daniel Fahlgren!

Modified:
    cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
    cfe/trunk/test/Analysis/builtin-functions.cpp

Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp?rev=217461&r1=217460&r2=217461&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp Tue Sep  9 16:42:16 2014
@@ -42,8 +42,10 @@ bool BuiltinFunctionChecker::evalCall(co
     return false;
 
   case Builtin::BI__builtin_expect:
+  case Builtin::BI__builtin_assume_aligned:
   case Builtin::BI__builtin_addressof: {
-    // For __builtin_expect, just return the value of the subexpression.
+    // For __builtin_expect and __builtin_assume_aligned, just return the value
+    // of the subexpression.
     // __builtin_addressof is going from a reference to a pointer, but those
     // are represented the same way in the analyzer.
     assert (CE->arg_begin() != CE->arg_end());

Modified: cfe/trunk/test/Analysis/builtin-functions.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/builtin-functions.cpp?rev=217461&r1=217460&r2=217461&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/builtin-functions.cpp (original)
+++ cfe/trunk/test/Analysis/builtin-functions.cpp Tue Sep  9 16:42:16 2014
@@ -22,3 +22,31 @@ void testSize() {
 
   clang_analyzer_eval(i == 0); // expected-warning{{TRUE}}
 }
+
+void test_assume_aligned_1(char *p) {
+  char *q;
+
+  q = (char*) __builtin_assume_aligned(p, 16);
+  clang_analyzer_eval(p == q); // expected-warning{{TRUE}}
+}
+
+void test_assume_aligned_2(char *p) {
+  char *q;
+
+  q = (char*) __builtin_assume_aligned(p, 16, 8);
+  clang_analyzer_eval(p == q); // expected-warning{{TRUE}}
+}
+
+void test_assume_aligned_3(char *p) {
+  void *q;
+
+  q = __builtin_assume_aligned(p, 16, 8);
+  clang_analyzer_eval(p == q); // expected-warning{{TRUE}}
+}
+
+void test_assume_aligned_4(char *p) {
+  char *q;
+
+  q = (char*) __builtin_assume_aligned(p + 1, 16);
+  clang_analyzer_eval(p == q); // expected-warning{{FALSE}}
+}