[lld] fbae153 - Revert "[lld-macho] Add basic symbol table output"
Shoaib Meenai via llvm-commits
llvm-commits at lists.llvm.org
Tue Apr 28 11:34:34 PDT 2020
Author: Shoaib Meenai
Date: 2020-04-28T11:34:03-07:00
New Revision: fbae153ca583588de73d8fae84ec262c24d09025
URL: https://github.com/llvm/llvm-project/commit/fbae153ca583588de73d8fae84ec262c24d09025
DIFF: https://github.com/llvm/llvm-project/commit/fbae153ca583588de73d8fae84ec262c24d09025.diff
LOG: Revert "[lld-macho] Add basic symbol table output"
This reverts commit a3d95a50ee3397c89327fce6983624446cd8e9d7.
Reverting due to UBSan failures:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/40817/steps/check-lld%20ubsan/logs/stdio
Added:
Modified:
lld/MachO/SyntheticSections.cpp
lld/MachO/SyntheticSections.h
lld/MachO/Writer.cpp
Removed:
lld/test/MachO/symtab.s
################################################################################
diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
index 5f08547aa127..d4af5a706a80 100644
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -9,7 +9,6 @@
#include "SyntheticSections.h"
#include "InputFiles.h"
#include "OutputSegment.h"
-#include "SymbolTable.h"
#include "Symbols.h"
#include "Writer.h"
@@ -129,59 +128,6 @@ void BindingSection::writeTo(uint8_t *buf) {
memcpy(buf, contents.data(), contents.size());
}
-SymtabSection::SymtabSection(StringTableSection &stringTableSection)
- : stringTableSection(stringTableSection) {
- segname = segment_names::linkEdit;
- name = section_names::symbolTable;
-}
-
-size_t SymtabSection::getSize() const {
- return symbols.size() * sizeof(nlist_64);
-}
-
-void SymtabSection::finalizeContents() {
- // TODO: We should filter out some symbols.
- for (Symbol *sym : symtab->getSymbols())
- symbols.push_back({sym, stringTableSection.addString(sym->getName())});
-}
-
-void SymtabSection::writeTo(uint8_t *buf) {
- auto *nList = reinterpret_cast<nlist_64 *>(buf);
- for (const SymtabEntry &entry : symbols) {
- // TODO support other symbol types
- // TODO populate n_desc
- if (auto defined = dyn_cast<Defined>(entry.sym)) {
- nList->n_strx = entry.strx;
- nList->n_type = N_EXT | N_SECT;
- nList->n_sect = defined->isec->sectionIndex;
- // For the N_SECT symbol type, n_value is the address of the symbol
- nList->n_value = defined->value + defined->isec->addr;
- }
-
- ++nList;
- }
-}
-
-StringTableSection::StringTableSection() {
- segname = segment_names::linkEdit;
- name = section_names::stringTable;
-}
-
-uint32_t StringTableSection::addString(StringRef str) {
- uint32_t strx = size;
- strings.push_back(str);
- size += str.size() + 1; // account for null terminator
- return strx;
-}
-
-void StringTableSection::writeTo(uint8_t *buf) {
- uint32_t off = 0;
- for (StringRef str : strings) {
- memcpy(buf + off, str.data(), str.size());
- off += str.size() + 1; // account for null terminator
- }
-}
-
InStruct in;
} // namespace macho
diff --git a/lld/MachO/SyntheticSections.h b/lld/MachO/SyntheticSections.h
index 3988772906ec..2adc5754a7e8 100644
--- a/lld/MachO/SyntheticSections.h
+++ b/lld/MachO/SyntheticSections.h
@@ -23,8 +23,6 @@ namespace section_names {
constexpr const char *pageZero = "__pagezero";
constexpr const char *header = "__mach_header";
constexpr const char *binding = "__binding";
-constexpr const char *symbolTable = "__symbol_table";
-constexpr const char *stringTable = "__string_table";
} // namespace section_names
@@ -95,49 +93,6 @@ class BindingSection : public InputSection {
SmallVector<char, 128> contents;
};
-// Stores the strings referenced by the symbol table.
-class StringTableSection : public InputSection {
-public:
- StringTableSection();
- // Returns the start offset of the added string.
- uint32_t addString(StringRef);
- size_t getSize() const override { return size; }
- // Like other sections in __LINKEDIT, the string table section is special: its
- // offsets are recorded in the LC_SYMTAB load command, instead of in section
- // headers.
- bool isHidden() const override { return true; }
- void writeTo(uint8_t *buf) override;
-
-private:
- // An n_strx value of 0 always indicates the empty string, so we must locate
- // our non-empty string values at positive offsets in the string table.
- // Therefore we insert a dummy value at position zero.
- std::vector<StringRef> strings{"\0"};
- size_t size = 1;
-};
-
-struct SymtabEntry {
- Symbol *sym;
- size_t strx;
-};
-
-class SymtabSection : public InputSection {
-public:
- SymtabSection(StringTableSection &);
- void finalizeContents();
- size_t getNumSymbols() const { return symbols.size(); }
- size_t getSize() const override;
- // Like other sections in __LINKEDIT, the symtab section is special: its
- // offsets are recorded in the LC_SYMTAB load command, instead of in section
- // headers.
- bool isHidden() const override { return true; }
- void writeTo(uint8_t *buf) override;
-
-private:
- StringTableSection &stringTableSection;
- std::vector<SymtabEntry> symbols;
-};
-
struct InStruct {
GotSection *got = nullptr;
};
diff --git a/lld/MachO/Writer.cpp b/lld/MachO/Writer.cpp
index 7041df2d6e82..b6e5ed0c5e4d 100644
--- a/lld/MachO/Writer.cpp
+++ b/lld/MachO/Writer.cpp
@@ -52,8 +52,6 @@ class Writer {
uint64_t fileOff = 0;
MachHeaderSection *headerSection = nullptr;
BindingSection *bindingSection = nullptr;
- SymtabSection *symtabSection = nullptr;
- StringTableSection *stringTableSection = nullptr;
};
// LC_DYLD_INFO_ONLY stores the offsets of symbol import/export information.
@@ -165,23 +163,13 @@ class LCMain : public LoadCommand {
class LCSymtab : public LoadCommand {
public:
- LCSymtab(SymtabSection *symtabSection, StringTableSection *stringTableSection)
- : symtabSection(symtabSection), stringTableSection(stringTableSection) {}
-
uint32_t getSize() const override { return sizeof(symtab_command); }
void writeTo(uint8_t *buf) const override {
auto *c = reinterpret_cast<symtab_command *>(buf);
c->cmd = LC_SYMTAB;
c->cmdsize = getSize();
- c->symoff = symtabSection->getFileOffset();
- c->nsyms = symtabSection->getNumSymbols();
- c->stroff = stringTableSection->getFileOffset();
- c->strsize = stringTableSection->getFileSize();
}
-
- SymtabSection *symtabSection = nullptr;
- StringTableSection *stringTableSection = nullptr;
};
class LCLoadDylib : public LoadCommand {
@@ -250,12 +238,7 @@ class SectionComparator {
{defaultPosition, {}},
// Make sure __LINKEDIT is the last segment (i.e. all its hidden
// sections must be ordered after other sections).
- {segment_names::linkEdit,
- {
- section_names::binding,
- section_names::symbolTable,
- section_names::stringTable,
- }},
+ {segment_names::linkEdit, {section_names::binding}},
};
for (uint32_t i = 0, n = ordering.size(); i < n; ++i) {
@@ -311,8 +294,7 @@ void Writer::scanRelocations() {
void Writer::createLoadCommands() {
headerSection->addLoadCommand(make<LCDyldInfo>(bindingSection));
headerSection->addLoadCommand(make<LCLoadDylinker>());
- headerSection->addLoadCommand(
- make<LCSymtab>(symtabSection, stringTableSection));
+ headerSection->addLoadCommand(make<LCSymtab>());
headerSection->addLoadCommand(make<LCDysymtab>());
headerSection->addLoadCommand(make<LCMain>());
@@ -341,8 +323,6 @@ void Writer::createLoadCommands() {
void Writer::createHiddenSections() {
headerSection = createInputSection<MachHeaderSection>();
bindingSection = createInputSection<BindingSection>();
- stringTableSection = createInputSection<StringTableSection>();
- symtabSection = createInputSection<SymtabSection>(*stringTableSection);
createInputSection<PageZeroSection>();
}
@@ -425,7 +405,6 @@ void Writer::run() {
// Fill __LINKEDIT contents.
bindingSection->finalizeContents();
- symtabSection->finalizeContents();
// Now that __LINKEDIT is filled out, do a proper calculation of its
// addresses and offsets. We don't have to recalculate the other segments
diff --git a/lld/test/MachO/symtab.s b/lld/test/MachO/symtab.s
deleted file mode 100644
index 44a016912bd6..000000000000
--- a/lld/test/MachO/symtab.s
+++ /dev/null
@@ -1,54 +0,0 @@
-# REQUIRES: x86
-# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
-# RUN: lld -flavor darwinnew -o %t %t.o
-# RUN: llvm-readobj -symbols %t | FileCheck %s
-
-# CHECK: Symbols [
-# CHECK-NEXT: Symbol {
-# CHECK-NEXT: Name: _main
-# CHECK-NEXT: Extern
-# CHECK-NEXT: Type: Section (0xE)
-# CHECK-NEXT: Section: __text (0x1)
-# CHECK-NEXT: RefType:
-# CHECK-NEXT: Flags [ (0x0)
-# CHECK-NEXT: ]
-# CHECK-NEXT: Value:
-# CHECK-NEXT: }
-# CHECK-NEXT: Symbol {
-# CHECK-NEXT: Name: bar
-# CHECK-NEXT: Extern
-# CHECK-NEXT: Type: Section (0xE)
-# CHECK-NEXT: Section: __text (0x1)
-# CHECK-NEXT: RefType:
-# CHECK-NEXT: Flags [ (0x0)
-# CHECK-NEXT: ]
-# CHECK-NEXT: Value:
-# CHECK-NEXT: }
-# CHECK-NEXT: Symbol {
-# CHECK-NEXT: Name: foo
-# CHECK-NEXT: Extern
-# CHECK-NEXT: Type: Section (0xE)
-# CHECK-NEXT: Section: __data
-# CHECK-NEXT: RefType:
-# CHECK-NEXT: Flags [ (0x0)
-# CHECK-NEXT: ]
-# CHECK-NEXT: Value:
-# CHECK-NEXT: }
-# CHECK-NEXT: ]
-
-.data
-.global foo
-foo:
- .asciz "Hello world!\n"
-
-.text
-.global bar
-.global _main
-
-_main:
- mov $0, %rax
- ret
-
-bar:
- mov $2, %rax
- ret
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