LibELF: Remove ELF::Loader and move everyone to ELF::Image

This commit gets rid of ELF::Loader entirely since its very ambiguous
purpose was actually to load executables for the kernel, and that is
now handled by the kernel itself.

This patch includes some drive-by cleanup in LibDebug and CrashDaemon
enabled by the fact that we no longer need to keep the ref-counted
ELF::Loader around.

11 files changed, 118 insertions, 240 deletions

diff --git a/Libraries/LibDebug/DebugInfo.cpp b/Libraries/LibDebug/DebugInfo.cpp
index 6ceb72b455..10204f23d3 100644
--- a/Libraries/LibDebug/DebugInfo.cpp
+++ b/Libraries/LibDebug/DebugInfo.cpp
@@ -35,9 +35,9 @@
 
 namespace Debug {
 
-DebugInfo::DebugInfo(NonnullRefPtr<const ELF::Loader> elf)
-    : m_elf(elf)
-    , m_dwarf_info(Dwarf::DwarfInfo::create(m_elf))
+DebugInfo::DebugInfo(NonnullOwnPtr<const ELF::Image> elf)
+    : m_elf(move(elf))
+    , m_dwarf_info(*m_elf)
 {
     prepare_variable_scopes();
     prepare_lines();
@@ -45,7 +45,7 @@ DebugInfo::DebugInfo(NonnullRefPtr<const ELF::Loader> elf)
 
 void DebugInfo::prepare_variable_scopes()
 {
-    m_dwarf_info->for_each_compilation_unit([&](const Dwarf::CompilationUnit& unit) {
+    m_dwarf_info.for_each_compilation_unit([&](const Dwarf::CompilationUnit& unit) {
         auto root = unit.root_die();
         parse_scopes_impl(root);
     });
@@ -102,7 +102,7 @@ void DebugInfo::parse_scopes_impl(const Dwarf::DIE& die)
 
 void DebugInfo::prepare_lines()
 {
-    auto section = m_elf->image().lookup_section(".debug_line");
+    auto section = elf().lookup_section(".debug_line");
     if (section.is_undefined())
         return;
 
diff --git a/Libraries/LibDebug/DebugInfo.h b/Libraries/LibDebug/DebugInfo.h
index cb4fe30b8a..bcb5db3cbc 100644
--- a/Libraries/LibDebug/DebugInfo.h
+++ b/Libraries/LibDebug/DebugInfo.h
@@ -33,14 +33,16 @@
 #include <LibDebug/Dwarf/DIE.h>
 #include <LibDebug/Dwarf/DwarfInfo.h>
 #include <LibDebug/Dwarf/LineProgram.h>
-#include <LibELF/Loader.h>
+#include <LibELF/Image.h>
 #include <sys/arch/i386/regs.h>
 
 namespace Debug {
 
 class DebugInfo {
 public:
-    explicit DebugInfo(NonnullRefPtr<const ELF::Loader> elf);
+    explicit DebugInfo(NonnullOwnPtr<const ELF::Image>);
+
+    const ELF::Image& elf() const { return *m_elf; }
 
     struct SourcePosition {
         FlyString file_path;
@@ -117,8 +119,8 @@ private:
     void parse_scopes_impl(const Dwarf::DIE& die);
     OwnPtr<VariableInfo> create_variable_info(const Dwarf::DIE& variable_die, const PtraceRegisters&) const;
 
-    NonnullRefPtr<const ELF::Loader> m_elf;
-    NonnullRefPtr<Dwarf::DwarfInfo> m_dwarf_info;
+    NonnullOwnPtr<const ELF::Image> m_elf;
+    Dwarf::DwarfInfo m_dwarf_info;
 
     Vector<VariablesScope> m_scopes;
     Vector<Dwarf::LineProgram::LineInfo> m_sorted_lines;
diff --git a/Libraries/LibDebug/DebugSession.cpp b/Libraries/LibDebug/DebugSession.cpp
index 42f1ced66e..27fb35edc9 100644
--- a/Libraries/LibDebug/DebugSession.cpp
+++ b/Libraries/LibDebug/DebugSession.cpp
@@ -33,8 +33,7 @@ namespace Debug {
 DebugSession::DebugSession(pid_t pid)
     : m_debuggee_pid(pid)
     , m_executable(map_executable_for_process(pid))
-    , m_elf(ELF::Loader::create(reinterpret_cast<const u8*>(m_executable.data()), m_executable.size()))
-    , m_debug_info(m_elf)
+    , m_debug_info(make<ELF::Image>(reinterpret_cast<const u8*>(m_executable.data()), m_executable.size()))
 {
 }
 
diff --git a/Libraries/LibDebug/DebugSession.h b/Libraries/LibDebug/DebugSession.h
index 6912eb59dc..ff0c90fab5 100644
--- a/Libraries/LibDebug/DebugSession.h
+++ b/Libraries/LibDebug/DebugSession.h
@@ -35,7 +35,6 @@
 #include <AK/String.h>
 #include <LibC/sys/arch/i386/regs.h>
 #include <LibDebug/DebugInfo.h>
-#include <LibELF/Loader.h>
 #include <signal.h>
 #include <stdio.h>
 #include <sys/ptrace.h>
@@ -99,8 +98,7 @@ public:
     template<typename Callback>
     void run(Callback callback);
 
-    const ELF::Loader& elf() const { return *m_elf; }
-    NonnullRefPtr<const ELF::Loader> elf_ref() const { return m_elf; }
+    const ELF::Image& elf() const { return m_debug_info.elf(); }
     const MappedFile& executable() const { return m_executable; }
     const DebugInfo& debug_info() const { return m_debug_info; }
 
@@ -130,7 +128,6 @@ private:
     bool m_is_debuggee_dead { false };
 
     MappedFile m_executable;
-    NonnullRefPtr<const ELF::Loader> m_elf;
     DebugInfo m_debug_info;
 
     HashMap<void*, BreakPoint> m_breakpoints;
diff --git a/Libraries/LibDebug/Dwarf/DwarfInfo.cpp b/Libraries/LibDebug/Dwarf/DwarfInfo.cpp
index c1bd4a39c6..09717cfc71 100644
--- a/Libraries/LibDebug/Dwarf/DwarfInfo.cpp
+++ b/Libraries/LibDebug/Dwarf/DwarfInfo.cpp
@@ -30,7 +30,7 @@
 
 namespace Debug::Dwarf {
 
-DwarfInfo::DwarfInfo(NonnullRefPtr<const ELF::Loader> elf)
+DwarfInfo::DwarfInfo(const ELF::Image& elf)
     : m_elf(elf)
 {
     m_debug_info_data = section_data(".debug_info");
@@ -42,7 +42,7 @@ DwarfInfo::DwarfInfo(NonnullRefPtr<const ELF::Loader> elf)
 
 ReadonlyBytes DwarfInfo::section_data(const String& section_name) const
 {
-    auto section = m_elf->image().lookup_section(section_name);
+    auto section = m_elf.lookup_section(section_name);
     if (section.is_undefined())
         return {};
     return section.bytes();
diff --git a/Libraries/LibDebug/Dwarf/DwarfInfo.h b/Libraries/LibDebug/Dwarf/DwarfInfo.h
index 0a0222a78b..59496e0e3b 100644
--- a/Libraries/LibDebug/Dwarf/DwarfInfo.h
+++ b/Libraries/LibDebug/Dwarf/DwarfInfo.h
@@ -32,13 +32,13 @@
 #include <AK/NonnullRefPtr.h>
 #include <AK/RefCounted.h>
 #include <AK/String.h>
-#include <LibELF/Loader.h>
+#include <LibELF/Image.h>
 
 namespace Debug::Dwarf {
 
-class DwarfInfo : public RefCounted<DwarfInfo> {
+class DwarfInfo {
 public:
-    static NonnullRefPtr<DwarfInfo> create(NonnullRefPtr<const ELF::Loader> elf) { return adopt(*new DwarfInfo(move(elf))); }
+    explicit DwarfInfo(const ELF::Image&);
 
     ReadonlyBytes debug_info_data() const { return m_debug_info_data; }
     ReadonlyBytes abbreviation_data() const { return m_abbreviation_data; }
@@ -48,12 +48,11 @@ public:
     void for_each_compilation_unit(Callback) const;
 
 private:
-    explicit DwarfInfo(NonnullRefPtr<const ELF::Loader> elf);
     void populate_compilation_units();
 
     ReadonlyBytes section_data(const String& section_name) const;
 
-    NonnullRefPtr<const ELF::Loader> m_elf;
+    const ELF::Image& m_elf;
     ReadonlyBytes m_debug_info_data;
     ReadonlyBytes m_abbreviation_data;
     ReadonlyBytes m_debug_strings_data;
diff --git a/Libraries/LibELF/Image.cpp b/Libraries/LibELF/Image.cpp
index 085cb97aa3..f455a7d98b 100644
--- a/Libraries/LibELF/Image.cpp
+++ b/Libraries/LibELF/Image.cpp
@@ -26,6 +26,7 @@
 
 #include <AK/Demangle.h>
 #include <AK/Memory.h>
+#include <AK/QuickSort.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <LibELF/Image.h>
@@ -323,4 +324,84 @@ Optional<Image::Symbol> Image::find_demangled_function(const String& name) const
     return found;
 }
 
+Optional<Image::Symbol> Image::find_symbol(u32 address, u32* out_offset) const
+{
+    auto symbol_count = this->symbol_count();
+    if (!symbol_count)
+        return {};
+
+    SortedSymbol* sorted_symbols = nullptr;
+    if (m_sorted_symbols.is_empty()) {
+        m_sorted_symbols.ensure_capacity(symbol_count);
+        for_each_symbol([this](auto& symbol) {
+            m_sorted_symbols.append({ symbol.value(), symbol.name(), {}, symbol });
+            return IterationDecision::Continue;
+        });
+        quick_sort(m_sorted_symbols, [](auto& a, auto& b) {
+            return a.address < b.address;
+        });
+    }
+    sorted_symbols = m_sorted_symbols.data();
+
+    for (size_t i = 0; i < symbol_count; ++i) {
+        if (sorted_symbols[i].address > address) {
+            if (i == 0)
+                return {};
+            auto& symbol = sorted_symbols[i - 1];
+            if (out_offset)
+                *out_offset = address - symbol.address;
+            return symbol.symbol;
+        }
+    }
+    return {};
+}
+
+String Image::symbolicate(u32 address, u32* out_offset) const
+{
+    auto symbol_count = this->symbol_count();
+    if (!symbol_count) {
+        if (out_offset)
+            *out_offset = 0;
+        return "??";
+    }
+    SortedSymbol* sorted_symbols = nullptr;
+
+    if (m_sorted_symbols.is_empty()) {
+        m_sorted_symbols.ensure_capacity(symbol_count);
+        for_each_symbol([this](auto& symbol) {
+            m_sorted_symbols.append({ symbol.value(), symbol.name(), {}, {} });
+            return IterationDecision::Continue;
+        });
+        quick_sort(m_sorted_symbols, [](auto& a, auto& b) {
+            return a.address < b.address;
+        });
+    }
+    sorted_symbols = m_sorted_symbols.data();
+
+    for (size_t i = 0; i < symbol_count; ++i) {
+        if (sorted_symbols[i].address > address) {
+            if (i == 0) {
+                if (out_offset)
+                    *out_offset = 0;
+                return "!!";
+            }
+            auto& symbol = sorted_symbols[i - 1];
+
+            auto& demangled_name = symbol.demangled_name;
+            if (demangled_name.is_null()) {
+                demangled_name = demangle(symbol.name);
+            }
+
+            if (out_offset) {
+                *out_offset = address - symbol.address;
+                return demangled_name;
+            }
+            return String::format("%s +%u", demangled_name.characters(), address - symbol.address);
+        }
+    }
+    if (out_offset)
+        *out_offset = 0;
+    return "??";
+}
+
 } // end namespace ELF
diff --git a/Libraries/LibELF/Image.h b/Libraries/LibELF/Image.h
index 4cb941c019..eb444ab412 100644
--- a/Libraries/LibELF/Image.h
+++ b/Libraries/LibELF/Image.h
@@ -210,6 +210,10 @@ public:
 
     Optional<Symbol> find_demangled_function(const String& name) const;
 
+    bool has_symbols() const { return symbol_count(); }
+    String symbolicate(u32 address, u32* offset = nullptr) const;
+    Optional<Image::Symbol> find_symbol(u32 address, u32* offset = nullptr) const;
+
 private:
     const char* raw_data(unsigned offset) const;
     const Elf32_Ehdr& header() const;
@@ -227,6 +231,15 @@ private:
     bool m_valid { false };
     unsigned m_symbol_table_section_index { 0 };
     unsigned m_string_table_section_index { 0 };
+
+    struct SortedSymbol {
+        u32 address;
+        StringView name;
+        String demangled_name;
+        Optional<Image::Symbol> symbol;
+    };
+
+    mutable Vector<SortedSymbol> m_sorted_symbols;
 };
 
 template<typename F>
diff --git a/Libraries/LibELF/Loader.cpp b/Libraries/LibELF/Loader.cpp
deleted file mode 100644
index 4b0bd25279..0000000000
--- a/Libraries/LibELF/Loader.cpp
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "Loader.h"
-#include <AK/Demangle.h>
-#include <AK/Memory.h>
-#include <AK/QuickSort.h>
-
-//#define Loader_DEBUG
-
-namespace ELF {
-
-Loader::Loader(const u8* buffer, size_t size, String&&, bool verbose_logging)
-    : m_image(buffer, size, verbose_logging)
-{
-    if (m_image.is_valid())
-        m_symbol_count = m_image.symbol_count();
-}
-
-Loader::~Loader()
-{
-}
-
-#ifndef KERNEL
-Optional<Image::Symbol> Loader::find_symbol(u32 address, u32* out_offset) const
-{
-    if (!m_symbol_count)
-        return {};
-
-    SortedSymbol* sorted_symbols = nullptr;
-    if (m_sorted_symbols.is_empty()) {
-        m_sorted_symbols.ensure_capacity(m_symbol_count);
-        m_image.for_each_symbol([this](auto& symbol) {
-            m_sorted_symbols.append({ symbol.value(), symbol.name(), {}, symbol });
-            return IterationDecision::Continue;
-        });
-        quick_sort(m_sorted_symbols, [](auto& a, auto& b) {
-            return a.address < b.address;
-        });
-    }
-    sorted_symbols = m_sorted_symbols.data();
-
-    for (size_t i = 0; i < m_symbol_count; ++i) {
-        if (sorted_symbols[i].address > address) {
-            if (i == 0)
-                return {};
-            auto& symbol = sorted_symbols[i - 1];
-            if (out_offset)
-                *out_offset = address - symbol.address;
-            return symbol.symbol;
-        }
-    }
-    return {};
-}
-
-String Loader::symbolicate(u32 address, u32* out_offset) const
-{
-    if (!m_symbol_count) {
-        if (out_offset)
-            *out_offset = 0;
-        return "??";
-    }
-    SortedSymbol* sorted_symbols = nullptr;
-
-    if (m_sorted_symbols.is_empty()) {
-        m_sorted_symbols.ensure_capacity(m_symbol_count);
-        m_image.for_each_symbol([this](auto& symbol) {
-            m_sorted_symbols.append({ symbol.value(), symbol.name(), {}, {} });
-            return IterationDecision::Continue;
-        });
-        quick_sort(m_sorted_symbols, [](auto& a, auto& b) {
-            return a.address < b.address;
-        });
-    }
-    sorted_symbols = m_sorted_symbols.data();
-
-    for (size_t i = 0; i < m_symbol_count; ++i) {
-        if (sorted_symbols[i].address > address) {
-            if (i == 0) {
-                if (out_offset)
-                    *out_offset = 0;
-                return "!!";
-            }
-            auto& symbol = sorted_symbols[i - 1];
-
-            auto& demangled_name = symbol.demangled_name;
-            if (demangled_name.is_null()) {
-                demangled_name = demangle(symbol.name);
-            }
-
-            if (out_offset) {
-                *out_offset = address - symbol.address;
-                return demangled_name;
-            }
-            return String::format("%s +%u", demangled_name.characters(), address - symbol.address);
-        }
-    }
-    if (out_offset)
-        *out_offset = 0;
-    return "??";
-}
-
-#endif
-
-} // end namespace ELF
diff --git a/Libraries/LibELF/Loader.h b/Libraries/LibELF/Loader.h
deleted file mode 100644
index afa6c391a5..0000000000
--- a/Libraries/LibELF/Loader.h
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#pragma once
-
-#include <AK/Function.h>
-#include <AK/HashMap.h>
-#include <AK/NonnullRefPtr.h>
-#include <AK/OwnPtr.h>
-#include <AK/StringView.h>
-#include <AK/Vector.h>
-#include <LibELF/Image.h>
-
-#ifdef KERNEL
-#    include <Kernel/VirtualAddress.h>
-namespace Kernel {
-class Region;
-}
-#endif
-
-namespace ELF {
-
-class Loader : public RefCounted<Loader> {
-public:
-    static NonnullRefPtr<Loader> create(const u8* data, size_t size, String&& name = String::empty(), bool verbose_logging = true) { return adopt(*new Loader(data, size, move(name), verbose_logging)); }
-    ~Loader();
-
-    VirtualAddress entry() const
-    {
-        return m_image.entry();
-    }
-    const Image& image() const { return m_image; }
-    Optional<Image::Symbol> find_demangled_function(const String& name) const
-    {
-        return m_image.find_demangled_function(name);
-    }
-
-    bool has_symbols() const { return m_symbol_count; }
-
-    String symbolicate(u32 address, u32* offset = nullptr) const;
-    Optional<Image::Symbol> find_symbol(u32 address, u32* offset = nullptr) const;
-
-private:
-    explicit Loader(const u8*, size_t, String&& name, bool verbose_logging);
-
-    bool layout();
-
-    Image m_image;
-
-    size_t m_symbol_count { 0 };
-
-    struct SortedSymbol {
-        u32 address;
-        StringView name;
-        String demangled_name;
-        Optional<Image::Symbol> symbol;
-    };
-
-    mutable Vector<SortedSymbol> m_sorted_symbols;
-};
-
-} // end namespace ELF
diff --git a/Libraries/LibX86/ELFSymbolProvider.h b/Libraries/LibX86/ELFSymbolProvider.h
index 3a9b94a40c..f208cec0a0 100644
--- a/Libraries/LibX86/ELFSymbolProvider.h
+++ b/Libraries/LibX86/ELFSymbolProvider.h
@@ -26,23 +26,23 @@
 
 #pragma once
 
-#include <LibELF/Loader.h>
+#include <LibELF/Image.h>
 
 namespace X86 {
 
 class ELFSymbolProvider final : public SymbolProvider {
 public:
-    ELFSymbolProvider(ELF::Loader& loader)
-        : m_loader(loader)
+    ELFSymbolProvider(const ELF::Image& elf)
+        : m_elf(elf)
     {
     }
 
     virtual String symbolicate(FlatPtr address, u32* offset = nullptr) const override
     {
-        return m_loader.symbolicate(address, offset);
+        return m_elf.symbolicate(address, offset);
     }
 
 private:
-    ELF::Loader& m_loader;
+    const ELF::Image& m_elf;
 };
 }