[PATCH] [analyzer] Fix a crash by division by zero

Takeshi Yoshimura yos at sslab.ics.keio.ac.jp
Sat May 30 00:31:38 PDT 2015


http://reviews.llvm.org/D10145

Files:
  lib/StaticAnalyzer/Core/BasicValueFactory.cpp
  test/Analysis/division-by-zero.c

Index: lib/StaticAnalyzer/Core/BasicValueFactory.cpp
===================================================================
--- lib/StaticAnalyzer/Core/BasicValueFactory.cpp
+++ lib/StaticAnalyzer/Core/BasicValueFactory.cpp
@@ -154,9 +154,13 @@
       return &getValue( V1 * V2 );
 
     case BO_Div:
+      if (V2 == 0) // Avoid division by zero
+        return nullptr;
       return &getValue( V1 / V2 );
 
     case BO_Rem:
+      if (V2 == 0) // Avoid division by zero
+        return nullptr;
       return &getValue( V1 % V2 );
 
     case BO_Add:
Index: test/Analysis/division-by-zero.c
===================================================================
--- /dev/null
+++ test/Analysis/division-by-zero.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=unix.Malloc -verify %s
+// Do not crash due to division by zero
+
+int f(unsigned int a) {
+  if (a <= 0) return 1 / a;
+  return a;
+}

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D10145.26845.patch
Type: text/x-patch
Size: 910 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20150530/fb3aae0a/attachment.bin>


More information about the cfe-commits mailing list