[llvm] r206564 - [asan] one more workaround for PR17409: don't do BB-level coverage instrumentation if there are more than N (=1500) basic blocks. This makes ASanCoverage work on libjpeg_turbo/jchuff.c used by Chrome, which has 1824 BBs

[Kostya Serebryany]

Author: kcc
Date: Fri Apr 18 03:02:42 2014
New Revision: 206564

URL: http://llvm.org/viewvc/llvm-project?rev=206564&view=rev
Log:
[asan] one more workaround for PR17409: don't do BB-level coverage instrumentation if there are more than N (=1500) basic blocks. This makes ASanCoverage work on libjpeg_turbo/jchuff.c used by Chrome, which has 1824 BBs

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
    llvm/trunk/test/Instrumentation/AddressSanitizer/coverage.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=206564&r1=206563&r2=206564&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Fri Apr 18 03:02:42 2014
@@ -135,6 +135,10 @@ static cl::opt<bool> ClGlobals("asan-glo
 static cl::opt<int> ClCoverage("asan-coverage",
        cl::desc("ASan coverage. 0: none, 1: entry block, 2: all blocks"),
        cl::Hidden, cl::init(false));
+static cl::opt<int> ClCoverageBlockThreshold("asan-coverage-block-threshold",
+       cl::desc("Add coverage instrumentation only to the entry block if there "
+                "are more than this number of blocks."),
+       cl::Hidden, cl::init(1500));
 static cl::opt<bool> ClInitializers("asan-initialization-order",
        cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
 static cl::opt<bool> ClMemIntrin("asan-memintrin",
@@ -1263,7 +1267,8 @@ bool AddressSanitizer::InjectCoverage(Fu
                                       const ArrayRef<BasicBlock *> AllBlocks) {
   if (!ClCoverage) return false;
 
-  if (ClCoverage == 1) {
+  if (ClCoverage == 1 ||
+      (unsigned)ClCoverageBlockThreshold < AllBlocks.size()) {
     InjectCoverageAtBlock(F, F.getEntryBlock());
   } else {
     for (size_t i = 0, n = AllBlocks.size(); i < n; i++)

Modified: llvm/trunk/test/Instrumentation/AddressSanitizer/coverage.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/coverage.ll?rev=206564&r1=206563&r2=206564&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/coverage.ll (original)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/coverage.ll Fri Apr 18 03:02:42 2014
@@ -1,5 +1,7 @@
 ; RUN: opt < %s -asan -asan-module -asan-coverage=1 -S | FileCheck %s --check-prefix=CHECK1
 ; RUN: opt < %s -asan -asan-module -asan-coverage=2 -S | FileCheck %s --check-prefix=CHECK2
+; RUN: opt < %s -asan -asan-module -asan-coverage=2 -asan-coverage-block-threshold=10 -S | FileCheck %s --check-prefix=CHECK2
+; RUN: opt < %s -asan -asan-module -asan-coverage=2 -asan-coverage-block-threshold=1  -S | FileCheck %s --check-prefix=CHECK1
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-unknown-linux-gnu"
 define void @foo(i32* %a) sanitize_address {