[lld] 6b4f86f - Reapply: [MachO] Add a test for detecting reserved unit length.

[Igor Kudrin via llvm-commits]

Author: Igor Kudrin
Date: 2020-01-21T16:59:44+07:00
New Revision: 6b4f86f65f165249cbea1d23611ac97aeec7a082

URL: https://github.com/llvm/llvm-project/commit/6b4f86f65f165249cbea1d23611ac97aeec7a082
DIFF: https://github.com/llvm/llvm-project/commit/6b4f86f65f165249cbea1d23611ac97aeec7a082.diff

LOG: Reapply: [MachO] Add a test for detecting reserved unit length.

The test in the origin patch did not create a __debug_str section.
An UBSan check triggered when the corresponding pointer was dereferenced.

Differential Revision: https://reviews.llvm.org/D72695

This reapplies fcc08aa835de1e0c1f3e7e479917575e55433b68
which was reverted in b16f82ad3b095070729cde2873bd3a2e8ab35c0e.

Added: 
    

Modified: 
    lld/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp

Removed: 
    


################################################################################
diff  --git a/lld/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp b/lld/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp
index cf9a845c4b26..19534eadaf5b 100644
--- a/lld/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp
+++ b/lld/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp
@@ -97,3 +97,44 @@ TEST(ToAtomsTest, basic_obj_x86_64) {
   EXPECT_TRUE(atom4->name().equals("_undef"));
   EXPECT_EQ(lld::Atom::definitionUndefined, atom4->definition());
 }
+
+TEST(ToAtomsTest, reservedUnitLength) {
+  static const uint8_t debugInfoWithReservedLengthContent[12] = {
+      0xf0, 0xff, 0xff, 0xff // Reserved length value
+  };
+  static const uint8_t debugInfoWithValidBigLengthContent[12] = {
+      0xef, 0xff, 0xff, 0xff, // The maximum valid length value for DWARF32
+      0x00, 0x00              // Wrong version
+  };
+  static const uint8_t dummyContent[] = {0x00};
+
+  NormalizedFile fReservedLength, fValidBigLength;
+  fReservedLength.arch = lld::MachOLinkingContext::arch_x86;
+  fValidBigLength.arch = lld::MachOLinkingContext::arch_x86;
+  Section section;
+  section.segmentName = "__DWARF";
+  section.sectionName = "__debug_info";
+  section.content = llvm::makeArrayRef(debugInfoWithReservedLengthContent);
+  fReservedLength.sections.push_back(section);
+  section.content = llvm::makeArrayRef(debugInfoWithValidBigLengthContent);
+  fValidBigLength.sections.push_back(section);
+  section.sectionName = "__debug_abbrev";
+  section.content = llvm::makeArrayRef(dummyContent);
+  fReservedLength.sections.push_back(section);
+  fValidBigLength.sections.push_back(section);
+  section.sectionName = "__debug_str";
+  fReservedLength.sections.push_back(section);
+  fValidBigLength.sections.push_back(section);
+
+  auto resultReservedLength = normalizedToAtoms(fReservedLength, "foo", false);
+  auto resultValidBigLength = normalizedToAtoms(fValidBigLength, "foo", false);
+
+  // Both cases should return errors, but 
diff erent.
+  ASSERT_FALSE(resultReservedLength);
+  ASSERT_FALSE(resultValidBigLength);
+
+  EXPECT_STREQ("Malformed DWARF in foo",
+               toString(resultReservedLength.takeError()).c_str());
+  EXPECT_STREQ("Unsupported DWARF version in foo",
+               toString(resultValidBigLength.takeError()).c_str());
+}