r257467 - [analyzer] Fix RangeConstraintManager's pinning of single value ranges.

[Pierre Gousseau via cfe-commits]

Author: pgousseau
Date: Tue Jan 12 04:40:45 2016
New Revision: 257467

URL: http://llvm.org/viewvc/llvm-project?rev=257467&view=rev
Log:
[analyzer] Fix RangeConstraintManager's pinning of single value ranges.

This fix a bug in RangeSet::pin causing single value ranges to be considered non conventionally ordered.

Differential Revision: http://reviews.llvm.org/D12901

Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
    cfe/trunk/test/Analysis/range_casts.c

Modified: cfe/trunk/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp?rev=257467&r1=257466&r2=257467&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp Tue Jan 12 04:40:45 2016
@@ -171,7 +171,7 @@ private:
       case APSIntType::RTR_Below:
         // The entire range is outside the symbol's set of possible values.
         // If this is a conventionally-ordered range, the state is infeasible.
-        if (Lower < Upper)
+        if (Lower <= Upper)
           return false;
 
         // However, if the range wraps around, it spans all possible values.
@@ -222,7 +222,7 @@ private:
       case APSIntType::RTR_Above:
         // The entire range is outside the symbol's set of possible values.
         // If this is a conventionally-ordered range, the state is infeasible.
-        if (Lower < Upper)
+        if (Lower <= Upper)
           return false;
 
         // However, if the range wraps around, it spans all possible values.

Modified: cfe/trunk/test/Analysis/range_casts.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/range_casts.c?rev=257467&r1=257466&r2=257467&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/range_casts.c (original)
+++ cfe/trunk/test/Analysis/range_casts.c Tue Jan 12 04:40:45 2016
@@ -73,6 +73,16 @@ void f7(long foo)
     clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
 }
 
+void f8(long foo)
+{
+  unsigned index = -1;
+  if (index < foo) index = foo;
+  if (index + 1L == 0L)
+    clang_analyzer_warnIfReached(); // no-warning
+  else
+    clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
+}
+
 void f9(long foo)
 {
   unsigned index = -1;
@@ -93,6 +103,16 @@ void f10(long foo)
     clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
 }
 
+void f11(long foo)
+{
+  unsigned index = -1;
+  if (index < foo) index = foo;
+  if (index + 1UL == 0L)
+    clang_analyzer_warnIfReached(); // no-warning
+  else
+    clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
+}
+
 void f12(long foo)
 {
   unsigned index = -1;
@@ -102,6 +122,16 @@ void f12(long foo)
   else
     clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
 }
+
+void f13(int foo)
+{
+  unsigned short index = -1;
+  if (index < foo) index = foo;
+  if (index + 1 == 0)
+    clang_analyzer_warnIfReached(); // no-warning
+  else
+    clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
+}
 
 void f14(long foo)
 {