[llvm] r239379 - [asan] Prevent __attribute__((annotate)) triggering errors on Darwin

[Anna Zaks]

Author: zaks
Date: Mon Jun  8 19:58:08 2015
New Revision: 239379

URL: http://llvm.org/viewvc/llvm-project?rev=239379&view=rev
Log:
[asan] Prevent __attribute__((annotate)) triggering errors on Darwin

The following code triggers a fatal error in the compiler instrumentation
of ASan on Darwin because we place the attribute into llvm.metadata section,
which does not have the proper MachO section name.

void foo() __attribute__((annotate("custom")));
void foo() {;}

This commit reorders the checks so that we skip everything in llvm.metadata
first. It also removes the hard failure in case the section name does not
parse. That check will be done lower in the compilation pipeline anyway.

(Reviewed in http://reviews.llvm.org/D9093.)

Added:
    llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=239379&r1=239378&r2=239379&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Mon Jun  8 19:58:08 2015
@@ -1133,6 +1133,18 @@ bool AddressSanitizerModule::ShouldInstr
   if (G->hasSection()) {
     StringRef Section(G->getSection());
 
+    // Globals from llvm.metadata aren't emitted, do not instrument them.
+    if (Section == "llvm.metadata") return false;
+
+    // Callbacks put into the CRT initializer/terminator sections
+    // should not be instrumented.
+    // See https://code.google.com/p/address-sanitizer/issues/detail?id=305
+    // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
+    if (Section.startswith(".CRT")) {
+      DEBUG(dbgs() << "Ignoring a global initializer callback: " << *G << "\n");
+      return false;
+    }
+
     if (TargetTriple.isOSBinFormatMachO()) {
       StringRef ParsedSegment, ParsedSection;
       unsigned TAA = 0, StubSize = 0;
@@ -1140,8 +1152,8 @@ bool AddressSanitizerModule::ShouldInstr
       std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(
           Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize);
       if (!ErrorCode.empty()) {
-        report_fatal_error("Invalid section specifier '" + ParsedSection +
-                           "': " + ErrorCode + ".");
+        assert(false && "Invalid section specifier.");
+        return false;
       }
 
       // Ignore the globals from the __OBJC section. The ObjC runtime assumes
@@ -1171,18 +1183,6 @@ bool AddressSanitizerModule::ShouldInstr
         return false;
       }
     }
-
-    // Callbacks put into the CRT initializer/terminator sections
-    // should not be instrumented.
-    // See https://code.google.com/p/address-sanitizer/issues/detail?id=305
-    // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
-    if (Section.startswith(".CRT")) {
-      DEBUG(dbgs() << "Ignoring a global initializer callback: " << *G << "\n");
-      return false;
-    }
-
-    // Globals from llvm.metadata aren't emitted, do not instrument them.
-    if (Section == "llvm.metadata") return false;
   }
 
   return true;

Added: llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll?rev=239379&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll (added)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll Mon Jun  8 19:58:08 2015
@@ -0,0 +1,12 @@
+; This test checks that we are not instrumenting globals in llvm.metadata.
+; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+ at .str_noinst = private unnamed_addr constant [4 x i8] c"aaa\00", section "llvm.metadata"
+ at .str_inst = private unnamed_addr constant [4 x i8] c"aaa\00"
+
+; CHECK-NOT: {{asan_gen.*str_noinst}}
+; CHECK: {{asan_gen.*str_inst}}
+; CHECK: @asan.module_ctor