[PATCH] D23112: [analyzer] Correctly add assumptions based on array bounds.

[Gábor Horváth via cfe-commits]

xazax.hun updated this revision to Diff 67135.
xazax.hun added a comment.

- Address review comments.


https://reviews.llvm.org/D23112

Files:
  lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
  test/Analysis/out-of-bounds.c

Index: test/Analysis/out-of-bounds.c
===================================================================
--- test/Analysis/out-of-bounds.c
+++ test/Analysis/out-of-bounds.c
@@ -1,4 +1,6 @@
-// RUN: %clang_cc1 -Wno-array-bounds -analyze -analyzer-checker=core,alpha.security.ArrayBoundV2 -verify %s
+// RUN: %clang_cc1 -Wno-array-bounds -analyze -analyzer-checker=core,alpha.security.ArrayBoundV2,debug.ExprInspection -verify %s
+
+void clang_analyzer_eval(int);
 
 // Tests doing an out-of-bounds access after the end of an array using:
 // - constant integer index
@@ -146,6 +148,14 @@
     buf[x] = 1; 
 }
 
+// *** FIXME ***
+// The result is unknown for the same reason as above.
+void test_asume_after_access(unsigned long x) {
+  int buf[100];
+  buf[x] = 1;
+  clang_analyzer_eval(x <= 99); // expected-warning{{UNKNOWN}}
+}
+
 // Don't warn when indexing below the start of a symbolic region's whose
 // base extent we don't know.
 int *get_symbolic();
@@ -166,3 +176,9 @@
   p[1] = 42; // no-warning
 }
 
+void test_asume_after_access2(unsigned long x) {
+  char buf[100];
+  buf[x] = 1;
+  clang_analyzer_eval(x <= 99); // expected-warning{{TRUE}}
+}
+
Index: lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
+++ lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
@@ -157,13 +157,13 @@
 
     // If we are under constrained and the index variables are tainted, report.
     if (state_exceedsUpperBound && state_withinUpperBound) {
-      if (state->isTainted(rawOffset.getByteOffset()))
+      if (state->isTainted(rawOffset.getByteOffset())) {
         reportOOB(checkerContext, state_exceedsUpperBound, OOB_Tainted);
         return;
-    }
-
-    // If we are constrained enough to definitely exceed the upper bound, report.
-    if (state_exceedsUpperBound) {
+      }
+    } else if (state_exceedsUpperBound) {
+      // If we are constrained enough to definitely exceed the upper bound,
+      // report.
       assert(!state_withinUpperBound);
       reportOOB(checkerContext, state_exceedsUpperBound, OOB_Excedes);
       return;


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