[llvm] 27033cc - Fix line table lookups in line tables with multiple lines with the sa… (#70879)
via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 6 10:10:04 PST 2023
Author: Greg Clayton
Date: 2023-11-06T10:09:59-08:00
New Revision: 27033cc66500b7578b2cbf297b7881eef0cafdac
URL: https://github.com/llvm/llvm-project/commit/27033cc66500b7578b2cbf297b7881eef0cafdac
DIFF: https://github.com/llvm/llvm-project/commit/27033cc66500b7578b2cbf297b7881eef0cafdac.diff
LOG: Fix line table lookups in line tables with multiple lines with the sa… (#70879)
Fix line table lookups in line tables with multiple lines with the same
address.
Compilers emit line tables that have multiple line table entries with
the same address. When doing lookups, we always need to use the last
line entry if a lookup address matches the address of one or more line
entries. This is because the size of an address range for a line uses
the next line entry to figure out how big the current line entry is. If
the next line entry has the same address, that means the current line
entry has a size of zero, so no bytes correspond to the line entry.
This patch ensures that lookups will always pick the last matching line
entry when the lookup address matches more than one line entry.
Added:
Modified:
llvm/lib/DebugInfo/GSYM/LineTable.cpp
llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
Removed:
################################################################################
diff --git a/llvm/lib/DebugInfo/GSYM/LineTable.cpp b/llvm/lib/DebugInfo/GSYM/LineTable.cpp
index a49a3ba9bf2ad1d..666d9f15f1b43d6 100644
--- a/llvm/lib/DebugInfo/GSYM/LineTable.cpp
+++ b/llvm/lib/DebugInfo/GSYM/LineTable.cpp
@@ -270,11 +270,6 @@ Expected<LineEntry> LineTable::lookup(DataExtractor &Data, uint64_t BaseAddr, ui
if (Addr < Row.Addr)
return false; // Stop parsing, result contains the line table row!
Result = Row;
- if (Addr == Row.Addr) {
- // Stop parsing, this is the row we are looking for since the address
- // matches.
- return false;
- }
return true; // Keep parsing till we find the right row.
});
if (Err)
diff --git a/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp b/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
index e5ee93ffa3c607c..bfc6efc1bbb44e4 100644
--- a/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
+++ b/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
@@ -4156,3 +4156,172 @@ TEST(GSYMTest, TestEmptyLinkageName) {
// Make sure we don't see spurious errors in the output:
EXPECT_TRUE(errors.find("error:") == std::string::npos);
}
+
+TEST(GSYMTest, TestLineTablesWithEmptyRanges) {
+ // Test that lookups find the right line table entry when there are multiple
+ // line entries with the same address. When we have multiple line table
+ // entries with the same address, we need to pick the last one in the line
+ // table. We do this because a line entry's start address in the defined by
+ // the line table entry's address and the size is determined by the
+ // subtracting the next line table's address. If the current line table
+ // entry's address is the same as the next one, then there is no code
+ // assiciated with the current line table entry and it should be ignored.
+ //
+ // 0x0000000b: DW_TAG_compile_unit
+ // DW_AT_name ("/tmp/main.cpp")
+ // DW_AT_language (DW_LANG_C)
+ // DW_AT_stmt_list (0x00000000)
+ //
+ // 0x00000015: DW_TAG_subprogram
+ // DW_AT_name ("foo")
+ // DW_AT_low_pc (0x0000000000001000)
+ // DW_AT_high_pc (0x0000000000001050)
+ //
+ // 0x0000002a: NULL
+ //
+ // The line table has a duplicate entry at 0x1010:
+ //
+ // Address Line Column File ISA Discriminator Flags
+ // ---------- ------ ------ ------ --- ------------- -------------
+ // 0x00001000 10 0 1 0 0 is_stmt
+ // 0x00001010 11 0 1 0 0 is_stmt
+ // 0x00001010 12 0 1 0 0 is_stmt
+ // 0x00001050 13 0 1 0 0 is_stmt end_sequence
+
+ StringRef yamldata = R"(
+ debug_str:
+ - ''
+ - '/tmp/main.cpp'
+ - foo
+ debug_abbrev:
+ - ID: 0
+ Table:
+ - Code: 0x1
+ Tag: DW_TAG_compile_unit
+ Children: DW_CHILDREN_yes
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_language
+ Form: DW_FORM_udata
+ - Attribute: DW_AT_stmt_list
+ Form: DW_FORM_sec_offset
+ - Code: 0x2
+ Tag: DW_TAG_subprogram
+ Children: DW_CHILDREN_no
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_low_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_high_pc
+ Form: DW_FORM_addr
+ debug_info:
+ - Length: 0x27
+ Version: 4
+ AbbrevTableID: 0
+ AbbrOffset: 0x0
+ AddrSize: 8
+ Entries:
+ - AbbrCode: 0x1
+ Values:
+ - Value: 0x1
+ - Value: 0x2
+ - Value: 0x0
+ - AbbrCode: 0x2
+ Values:
+ - Value: 0xF
+ - Value: 0x1000
+ - Value: 0x1050
+ - AbbrCode: 0x0
+ debug_line:
+ - Length: 71
+ Version: 2
+ PrologueLength: 36
+ MinInstLength: 1
+ DefaultIsStmt: 1
+ LineBase: 251
+ LineRange: 14
+ OpcodeBase: 13
+ StandardOpcodeLengths: [ 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 ]
+ IncludeDirs:
+ - '/tmp'
+ Files:
+ - Name: main.cpp
+ DirIdx: 1
+ ModTime: 0
+ Length: 0
+ Opcodes:
+ - Opcode: DW_LNS_extended_op
+ ExtLen: 9
+ SubOpcode: DW_LNE_set_address
+ Data: 4096
+ - Opcode: DW_LNS_advance_line
+ SData: 9
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 16
+ - Opcode: DW_LNS_advance_line
+ SData: 1
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_line
+ SData: 1
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 64
+ - Opcode: DW_LNS_advance_line
+ SData: 1
+ Data: 0
+ - Opcode: DW_LNS_extended_op
+ ExtLen: 1
+ SubOpcode: DW_LNE_end_sequence
+ Data: 0
+ )";
+ auto ErrOrSections = DWARFYAML::emitDebugSections(yamldata);
+ ASSERT_THAT_EXPECTED(ErrOrSections, Succeeded());
+ std::unique_ptr<DWARFContext> DwarfContext =
+ DWARFContext::create(*ErrOrSections, 8);
+ ASSERT_TRUE(DwarfContext.get() != nullptr);
+ std::string errors;
+ raw_string_ostream OS(errors);
+ GsymCreator GC;
+ DwarfTransformer DT(*DwarfContext, GC);
+ const uint32_t ThreadCount = 1;
+ ASSERT_THAT_ERROR(DT.convert(ThreadCount, &OS), Succeeded());
+ ASSERT_THAT_ERROR(GC.finalize(OS), Succeeded());
+ OS.flush();
+ SmallString<512> Str;
+ raw_svector_ostream OutStrm(Str);
+ const auto ByteOrder = llvm::endianness::native;
+ FileWriter FW(OutStrm, ByteOrder);
+ ASSERT_THAT_ERROR(GC.encode(FW), Succeeded());
+ Expected<GsymReader> GR = GsymReader::copyBuffer(OutStrm.str());
+ ASSERT_THAT_EXPECTED(GR, Succeeded());
+ // There should be one function in our GSYM.
+ EXPECT_EQ(GR->getNumAddresses(), 1u);
+ // Verify "foo" is present and has a line table and no inline info.
+ auto ExpFI = GR->getFunctionInfo(0x1000);
+ ASSERT_THAT_EXPECTED(ExpFI, Succeeded());
+ ASSERT_EQ(ExpFI->Range, AddressRange(0x1000, 0x1050));
+ EXPECT_TRUE(ExpFI->OptLineTable.has_value());
+ EXPECT_FALSE(ExpFI->Inline.has_value());
+ StringRef FuncName = GR->getString(ExpFI->Name);
+ EXPECT_EQ(FuncName, "foo");
+
+ // Make sure we don't see spurious errors in the output:
+ EXPECT_TRUE(errors.find("error:") == std::string::npos);
+
+ // Make sure that when we lookup address 0x1010, that we get the entry that
+ // matches line 12, the second line entry that also has the address of
+ // 0x1010.
+ auto LR = GR->lookup(0x1010);
+ ASSERT_THAT_EXPECTED(LR, Succeeded());
+ SourceLocation src_loc = {"foo", "/tmp", "main.cpp", 12, 16};
+ EXPECT_THAT(LR->Locations, testing::ElementsAre(src_loc));
+git}
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