[analyzer] Prevent AnalyzerStatsChecker from crash

The checker marks the locations where the analyzer creates sinks. However, it
can happen that the sink was created because of a loop which does not contain
condition statement, only breaks in the body. The exhausted block is the block
which should contain the condition but empty, in this case.
This change only emits this marking in order to avoid the undefined behavior.

Differential Revision: https://reviews.llvm.org/D42266

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@325693 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp b/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
index 64c30e7a82c1e1c0ef067e076ea8602ccabf38c6..aadc6bac8d00ffb1e0416ed57447f5ff3522d941 100644 (file)
--- a/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
@@ -122,6 +122,8 @@ void AnalyzerStatsChecker::checkEndAnalysis(ExplodedGraph &G,
       E = CE.blocks_exhausted_end(); I != E; ++I) {
     const BlockEdge &BE =  I->first;
     const CFGBlock *Exit = BE.getDst();
+    if (Exit->empty())
+      continue;
     const CFGElement &CE = Exit->front();
     if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) {
       SmallString<128> bufI;

diff --git a/test/Analysis/analyzer-stats.c b/test/Analysis/analyzer-stats.c
index 5a40d196bb1fde81068db4eeb3d86709c9e8bd09..b58e862f6c6599f4fee392320e6a6b54e63769a2 100644 (file)
--- a/test/Analysis/analyzer-stats.c
+++ b/test/Analysis/analyzer-stats.c
@@ -1,4 +1,4 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=core,deadcode.DeadStores,debug.Stats -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks %s
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,deadcode.DeadStores,debug.Stats -verify -Wno-unreachable-code -analyzer-opt-analyze-nested-blocks -analyzer-max-loop 4 %s
 
 int foo();
 
@@ -12,3 +12,19 @@ int test() { // expected-warning-re{{test -> Total CFGBlocks: {{[0-9]+}} | Unrea
   a /= 4;
   return a;
 }
+
+
+int sink() // expected-warning-re{{sink -> Total CFGBlocks: {{[0-9]+}} | Unreachable CFGBlocks: 1 | Exhausted Block: yes | Empty WorkList: yes}}
+{
+  for (int i = 0; i < 10; ++i) // expected-warning {{(sink): The analyzer generated a sink at this point}}
+    ++i;
+
+  return 0;
+}
+
+int emptyConditionLoop() // expected-warning-re{{emptyConditionLoop -> Total CFGBlocks: {{[0-9]+}} | Unreachable CFGBlocks: 0 | Exhausted Block: yes | Empty WorkList: yes}}
+{
+  int num = 1;
+  for (;;)
+    num++;
+}