r347981 - lyzer] [HOTFIX!] SValBuilder crash when `aggressive-binary-operation-simplification` enabled

[Adam Balogh via cfe-commits]

Author: baloghadamsoftware
Date: Fri Nov 30 02:37:44 2018
New Revision: 347981

URL: http://llvm.org/viewvc/llvm-project?rev=347981&view=rev
Log:
lyzer] [HOTFIX!] SValBuilder crash when `aggressive-binary-operation-simplification` enabled

During the review of D41938 a condition check with an early exit accidentally
slipped into a branch, leaving the other branch unprotected. This may result in
an assertion later on. This hotfix moves this contition check outside of the
branch.

Differential Revision: https://reviews.llvm.org/D55051


Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
    cfe/trunk/test/Analysis/svalbuilder-rearrange-comparisons.c

Modified: cfe/trunk/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp?rev=347981&r1=347980&r2=347981&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp Fri Nov 30 02:37:44 2018
@@ -475,9 +475,6 @@ static Optional<NonLoc> tryRearrange(Pro
     SingleTy = ResultTy;
     if (LSym->getType() != SingleTy)
       return None;
-    // Substracting unsigned integers is a nightmare.
-    if (!SingleTy->isSignedIntegerOrEnumerationType())
-      return None;
   } else {
     // Don't rearrange other operations.
     return None;
@@ -485,6 +482,10 @@ static Optional<NonLoc> tryRearrange(Pro
 
   assert(!SingleTy.isNull() && "We should have figured out the type by now!");
 
+  // Rearrange signed symbolic expressions only
+  if (!SingleTy->isSignedIntegerOrEnumerationType())
+    return None;
+
   SymbolRef RSym = Rhs.getAsSymbol();
   if (!RSym || RSym->getType() != SingleTy)
     return None;

Modified: cfe/trunk/test/Analysis/svalbuilder-rearrange-comparisons.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/svalbuilder-rearrange-comparisons.c?rev=347981&r1=347980&r2=347981&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/svalbuilder-rearrange-comparisons.c (original)
+++ cfe/trunk/test/Analysis/svalbuilder-rearrange-comparisons.c Fri Nov 30 02:37:44 2018
@@ -979,3 +979,20 @@ int mixed_integer_types(int x, int y) {
   short a = x - 1U;
   return a - y;
 }
+
+unsigned gu();
+unsigned fu() {
+  unsigned x = gu();
+  // Assert that no overflows occur in this test file.
+  // Assuming that concrete integers are also within that range.
+  assert(x <= ((unsigned)UINT_MAX / 4));
+  return x;
+}
+
+void unsigned_concrete_int_no_crash() {
+  unsigned x = fu() + 1U, y = fu() + 1U;
+  clang_analyzer_denote(x - 1U, "$x");
+  clang_analyzer_denote(y - 1U, "$y");
+  clang_analyzer_express(y); // expected-warning {{$y}}
+  clang_analyzer_express(x == y); // expected-warning {{$x + 1U == $y + 1U}}
+}