[llvm] [Object] Provide operator< for ELFSymbolRef (PR #89861)
Amir Ayupov via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 26 10:28:26 PDT 2024
https://github.com/aaupov updated https://github.com/llvm/llvm-project/pull/89861
>From b6630e85ff5d4a35cf8d77fad63ba93791ffa806 Mon Sep 17 00:00:00 2001
From: Amir Ayupov <aaupov at fb.com>
Date: Tue, 23 Apr 2024 19:34:12 -0700
Subject: [PATCH 1/4] [Object] Provide operator< for ELFSymbolRef
Normally, operator< accepting DataRefImpl is used when comparing
SymbolRef/ELFSymbolRef. However, it uses std::memcmp which interprets
DataRefImpl union as char string. For ELFSymbolRef it's known that it
uses the struct view of the union, therefore a specialized operator< can
be used instead.
---
llvm/include/llvm/Object/ELFObjectFile.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/llvm/include/llvm/Object/ELFObjectFile.h b/llvm/include/llvm/Object/ELFObjectFile.h
index 1d457be93741f2..8ec0e3fe15dc9d 100644
--- a/llvm/include/llvm/Object/ELFObjectFile.h
+++ b/llvm/include/llvm/Object/ELFObjectFile.h
@@ -199,6 +199,14 @@ class ELFSymbolRef : public SymbolRef {
}
};
+inline bool operator<(const ELFSymbolRef &A, const ELFSymbolRef &B) {
+ const DataRefImpl &DRIA = A.getRawDataRefImpl();
+ const DataRefImpl &DRIB = B.getRawDataRefImpl();
+ if (DRIA.d.a == DRIB.d.a)
+ return DRIA.d.b < DRIB.d.b;
+ return DRIA.d.a < DRIB.d.b;
+}
+
class elf_symbol_iterator : public symbol_iterator {
public:
elf_symbol_iterator(const basic_symbol_iterator &B)
>From 0e9aab883f33caf9b2d8ec246f2f81bda63c2a5e Mon Sep 17 00:00:00 2001
From: Amir Ayupov <aaupov at fb.com>
Date: Wed, 24 Apr 2024 11:39:09 -0700
Subject: [PATCH 2/4] Add ELFObjectFileTest::ELFSymbolRefLess
---
llvm/unittests/Object/ELFObjectFileTest.cpp | 36 +++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/llvm/unittests/Object/ELFObjectFileTest.cpp b/llvm/unittests/Object/ELFObjectFileTest.cpp
index c4d2b4ae8b9acd..a4a0f6d4a7276d 100644
--- a/llvm/unittests/Object/ELFObjectFileTest.cpp
+++ b/llvm/unittests/Object/ELFObjectFileTest.cpp
@@ -1504,3 +1504,39 @@ TEST(ELFObjectFileTest, GetSectionAndRelocations) {
"SHT_RELA section with index 1: failed to get a "
"relocated section: invalid section index: 255");
}
+
+TEST(ELFObjectFileTest, ELFSymbolRefLess) {
+ SmallString<0> Storage;
+ Expected<ELFObjectFile<ELF64LE>> ElfOrErr = toBinary<ELF64LE>(Storage, R"(
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_DYN
+ Machine: EM_X86_64
+)");
+
+ ASSERT_THAT_EXPECTED(ElfOrErr, Succeeded());
+ const ELFObjectFile<ELF64LE> &Obj = *ElfOrErr;
+
+ llvm::object::DataRefImpl Data1;
+ Data1.d.a = 0x00000000;
+ Data1.d.b = 0x00000001;
+ SymbolRef Symbol1(Data1, &Obj);
+ ELFSymbolRef ELFSymbol1(Symbol1);
+
+ llvm::object::DataRefImpl Data2;
+ Data2.d.a = 0x00000000;
+ Data2.d.b = 0x00000100;
+ SymbolRef Symbol2(Data2, &Obj);
+ ELFSymbolRef ELFSymbol2(Symbol2);
+
+ // SymbolRef operator< uses std::memcmp treating the union as char string.
+ if (llvm::sys::IsLittleEndianHost)
+ EXPECT_FALSE(Symbol1 < Symbol2);
+ else
+ EXPECT_TRUE(Symbol1 < Symbol2);
+
+ // ELFSymbolRef operator< compares struct fields.
+ EXPECT_TRUE(ELFSymbol1 < ELFSymbol2);
+}
>From 978d8fb6582c65f28f76789c17a5d3b4f90f73e8 Mon Sep 17 00:00:00 2001
From: Amir Ayupov <aaupov at fb.com>
Date: Wed, 24 Apr 2024 18:56:02 -0700
Subject: [PATCH 3/4] Fix typo
---
llvm/include/llvm/Object/ELFObjectFile.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/include/llvm/Object/ELFObjectFile.h b/llvm/include/llvm/Object/ELFObjectFile.h
index 8ec0e3fe15dc9d..38d3a4f1732cf3 100644
--- a/llvm/include/llvm/Object/ELFObjectFile.h
+++ b/llvm/include/llvm/Object/ELFObjectFile.h
@@ -204,7 +204,7 @@ inline bool operator<(const ELFSymbolRef &A, const ELFSymbolRef &B) {
const DataRefImpl &DRIB = B.getRawDataRefImpl();
if (DRIA.d.a == DRIB.d.a)
return DRIA.d.b < DRIB.d.b;
- return DRIA.d.a < DRIB.d.b;
+ return DRIA.d.a < DRIB.d.a;
}
class elf_symbol_iterator : public symbol_iterator {
>From fb87c76a98c9dc4b14013a55210a4cd6482eecef Mon Sep 17 00:00:00 2001
From: Amir Ayupov <aaupov at fb.com>
Date: Fri, 26 Apr 2024 10:24:12 -0700
Subject: [PATCH 4/4] Added tests, addressed comments
---
llvm/unittests/Object/ELFObjectFileTest.cpp | 66 +++++++++++++++------
1 file changed, 47 insertions(+), 19 deletions(-)
diff --git a/llvm/unittests/Object/ELFObjectFileTest.cpp b/llvm/unittests/Object/ELFObjectFileTest.cpp
index a4a0f6d4a7276d..5b1062c07fdf58 100644
--- a/llvm/unittests/Object/ELFObjectFileTest.cpp
+++ b/llvm/unittests/Object/ELFObjectFileTest.cpp
@@ -1519,24 +1519,52 @@ TEST(ELFObjectFileTest, ELFSymbolRefLess) {
ASSERT_THAT_EXPECTED(ElfOrErr, Succeeded());
const ELFObjectFile<ELF64LE> &Obj = *ElfOrErr;
- llvm::object::DataRefImpl Data1;
- Data1.d.a = 0x00000000;
- Data1.d.b = 0x00000001;
- SymbolRef Symbol1(Data1, &Obj);
- ELFSymbolRef ELFSymbol1(Symbol1);
-
- llvm::object::DataRefImpl Data2;
- Data2.d.a = 0x00000000;
- Data2.d.b = 0x00000100;
- SymbolRef Symbol2(Data2, &Obj);
- ELFSymbolRef ELFSymbol2(Symbol2);
-
- // SymbolRef operator< uses std::memcmp treating the union as char string.
- if (llvm::sys::IsLittleEndianHost)
- EXPECT_FALSE(Symbol1 < Symbol2);
- else
- EXPECT_TRUE(Symbol1 < Symbol2);
-
- // ELFSymbolRef operator< compares struct fields.
+ const uint32_t Val1 = 0x00000001;
+ const uint32_t Val2 = 0x00000100;
+
+ DataRefImpl Data1, Data2, Data3, Data4;
+
+ // Symtab index
+ Data1.d.a = Data2.d.a = Val1;
+ Data3.d.a = Data4.d.a = Val2;
+
+ // Symbol index
+ Data1.d.b = Data3.d.b = Val1;
+ Data2.d.b = Data4.d.b = Val2;
+
+ SymbolRef Symbol1(Data1, &Obj), Symbol2(Data2, &Obj), Symbol3(Data3, &Obj),
+ Symbol4(Data4, &Obj);
+ ELFSymbolRef ELFSymbol1(Symbol1), ELFSymbol2(Symbol2), ELFSymbol3(Symbol3),
+ ELFSymbol4(Symbol4);
+
+ // Symtab index match
+ // left sym index is lower
EXPECT_TRUE(ELFSymbol1 < ELFSymbol2);
+ EXPECT_TRUE(ELFSymbol3 < ELFSymbol4);
+ // right sym index is lower
+ EXPECT_FALSE(ELFSymbol2 < ELFSymbol1);
+ EXPECT_FALSE(ELFSymbol4 < ELFSymbol3);
+ // sym indexes match
+ EXPECT_FALSE(ELFSymbol1 < ELFSymbol1);
+ EXPECT_FALSE(ELFSymbol2 < ELFSymbol2);
+ EXPECT_FALSE(ELFSymbol3 < ELFSymbol3);
+ EXPECT_FALSE(ELFSymbol4 < ELFSymbol4);
+
+ // Left symtab index is lower
+ // left sym index is lower
+ EXPECT_TRUE(ELFSymbol1 < ELFSymbol4);
+ // right sym index is lower
+ EXPECT_TRUE(ELFSymbol2 < ELFSymbol3);
+ // sym indexes match
+ EXPECT_TRUE(ELFSymbol1 < ELFSymbol3);
+ EXPECT_TRUE(ELFSymbol2 < ELFSymbol4);
+
+ // Right symtab index is lower
+ // left sym index is lower
+ EXPECT_FALSE(ELFSymbol3 < ELFSymbol2);
+ // right sym index is lower
+ EXPECT_FALSE(ELFSymbol4 < ELFSymbol1);
+ // sym indexes match
+ EXPECT_FALSE(ELFSymbol3 < ELFSymbol1);
+ EXPECT_FALSE(ELFSymbol4 < ELFSymbol2);
}
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