[llvm-branch-commits] [llvm] release/18.x: [llvm-readobj, ELF] Support --decompress/-z (#82594) (PR #82693)
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llvm-branch-commits at lists.llvm.org
Thu Feb 22 13:54:25 PST 2024
https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/82693
Backport 26d71d9ed56c4c23e6284dac7a9bdf603a5801f3
Requested by: @brad0
>From 6ab419cea064195460c56a9e38e05fc25b8dc8c9 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i at maskray.me>
Date: Thu, 22 Feb 2024 09:24:21 -0800
Subject: [PATCH] [llvm-readobj,ELF] Support --decompress/-z (#82594)
When a section has the SHF_COMPRESSED flag, -p/-x dump the compressed
content by default. In GNU readelf, if --decompress/-z is specified,
-p/-x will dump the decompressed content. This patch implements the
option.
Close #82507
(cherry picked from commit 26d71d9ed56c4c23e6284dac7a9bdf603a5801f3)
---
llvm/docs/CommandGuide/llvm-readelf.rst | 5 ++
llvm/docs/CommandGuide/llvm-readobj.rst | 5 ++
.../ELF/decompress-zlib-unsupported.test | 32 ++++++++
.../llvm-readobj/ELF/decompress-zlib.test | 76 +++++++++++++++++++
.../ELF/decompress-zstd-unsupported.test | 31 ++++++++
.../llvm-readobj/ELF/decompress-zstd.test | 28 +++++++
llvm/tools/llvm-readobj/ObjDumper.cpp | 26 ++++++-
llvm/tools/llvm-readobj/ObjDumper.h | 4 +-
llvm/tools/llvm-readobj/Opts.td | 2 +
llvm/tools/llvm-readobj/llvm-readobj.cpp | 6 +-
10 files changed, 209 insertions(+), 6 deletions(-)
create mode 100644 llvm/test/tools/llvm-readobj/ELF/decompress-zlib-unsupported.test
create mode 100644 llvm/test/tools/llvm-readobj/ELF/decompress-zlib.test
create mode 100644 llvm/test/tools/llvm-readobj/ELF/decompress-zstd-unsupported.test
create mode 100644 llvm/test/tools/llvm-readobj/ELF/decompress-zstd.test
diff --git a/llvm/docs/CommandGuide/llvm-readelf.rst b/llvm/docs/CommandGuide/llvm-readelf.rst
index 6ee4a5dfb15917..675628fdda45ec 100644
--- a/llvm/docs/CommandGuide/llvm-readelf.rst
+++ b/llvm/docs/CommandGuide/llvm-readelf.rst
@@ -38,6 +38,11 @@ OPTIONS
Display the contents of the basic block address map section(s), which contain the
address of each function, along with the relative offset of each basic block.
+.. option:: --decompress, -z
+
+ Dump decompressed section content when used with ``-x`` or ``-p``.
+ If the section(s) are not compressed, they are displayed as is.
+
.. option:: --demangle, -C
Display demangled symbol names in the output.
diff --git a/llvm/docs/CommandGuide/llvm-readobj.rst b/llvm/docs/CommandGuide/llvm-readobj.rst
index cb9232ef5e560a..6d78a038723445 100644
--- a/llvm/docs/CommandGuide/llvm-readobj.rst
+++ b/llvm/docs/CommandGuide/llvm-readobj.rst
@@ -56,6 +56,11 @@ file formats.
Display the address-significance table.
+.. option:: --decompress, -z
+
+ Dump decompressed section content when used with ``-x`` or ``-p``.
+ If the section(s) are not compressed, they are displayed as is.
+
.. option:: --expand-relocs
When used with :option:`--relocs`, display each relocation in an expanded
diff --git a/llvm/test/tools/llvm-readobj/ELF/decompress-zlib-unsupported.test b/llvm/test/tools/llvm-readobj/ELF/decompress-zlib-unsupported.test
new file mode 100644
index 00000000000000..f4c73de7ca6c9d
--- /dev/null
+++ b/llvm/test/tools/llvm-readobj/ELF/decompress-zlib-unsupported.test
@@ -0,0 +1,32 @@
+# UNSUPPORTED: zlib
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readobj -z -p .a -x .b %t 2>&1 | FileCheck %s -DFILE=%t
+
+# CHECK: String dump of section '.a':
+# CHECK-NEXT: warning: '[[FILE]]': LLVM was not built with LLVM_ENABLE_ZLIB or did not find zlib at build time
+# CHECK-NEXT: [ 0] .
+# CHECK-NEXT: [ 8] .
+# CHECK-NEXT: [ 10] .
+# CHECK-NEXT: [ 18] x.c.
+# CHECK-NEXT: [ 1e] .
+# CHECK-NEXT: [ 20] .
+# CHECK-NEXT: Hex dump of section '.b':
+# CHECK-NEXT: warning: '[[FILE]]': LLVM was not built with LLVM_ENABLE_ZLIB or did not find zlib at build time
+# CHECK-NEXT: 0x00000000 01000000 00000000 01000000 00000000 ................
+# CHECK-NEXT: 0x00000010 01000000 00000000 789c6304 00000200 ........x.c.....
+# CHECK-NEXT: 0x00000020 02 .
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+Sections:
+ - Name: .a
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 010000000000000001000000000000000100000000000000789c63040000020002
+ - Name: .b
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 010000000000000001000000000000000100000000000000789c63040000020002
diff --git a/llvm/test/tools/llvm-readobj/ELF/decompress-zlib.test b/llvm/test/tools/llvm-readobj/ELF/decompress-zlib.test
new file mode 100644
index 00000000000000..ea7a8854eb1a0c
--- /dev/null
+++ b/llvm/test/tools/llvm-readobj/ELF/decompress-zlib.test
@@ -0,0 +1,76 @@
+# REQUIRES: zlib
+## Test --decompress/-z.
+
+# RUN: yaml2obj %s -o %t
+
+# RUN: llvm-readelf -z -x .strings -x .not_null_terminated %t | FileCheck %s --check-prefix=HEX
+# RUN: llvm-readobj --decompress -p .strings -p .not_null_terminated %t | FileCheck %s --check-prefix=STR
+
+# HEX: Hex dump of section '.strings':
+# HEX-NEXT: 0x00000000 68657265 00617265 00736f6d 65007374 here.are.some.st
+# HEX-NEXT: 0x00000010 72696e67 7300 rings.
+# HEX: Hex dump of section '.not_null_terminated':
+# HEX-NEXT: 0x00000000 6e6f006e 756c6c no.null
+
+# STR: String dump of section '.strings':
+# STR-NEXT: [ 0] here
+# STR-NEXT: [ 5] are
+# STR-NEXT: [ 9] some
+# STR-NEXT: [ e] strings
+# STR-EMPTY:
+# STR-NEXT: String dump of section '.not_null_terminated':
+# STR-NEXT: [ 0] no
+# STR-NEXT: [ 3] null{{$}}
+# STR-NOT: {{.}}
+
+# RUN: llvm-readobj -x .strings -p .not_null_terminated %t | FileCheck %s --check-prefix=COMPRESSED
+
+# COMPRESSED: String dump of section '.not_null_terminated':
+# COMPRESSED-NEXT: [ 0] no
+# COMPRESSED-NEXT: [ 3] null
+# COMPRESSED-NEXT: Hex dump of section '.strings':
+# COMPRESSED-NEXT: 0x00000000 01000000 00000000 16000000 00000000 ................
+# COMPRESSED-NEXT: 0x00000010 00000000 00000000 789ccb48 2d4a6548 ........x..H-JeH
+# COMPRESSED-NEXT: 0x00000020 04e2e2fc 5c205152 9499975e cc000058 ....\ QR...^...X
+# COMPRESSED-NEXT: 0x00000030 2e079b ...
+
+# RUN: llvm-readelf -z -p .invalid1 -x .invalid2 -x .invalid3 %t 2>&1 | FileCheck %s -DFILE=%t --check-prefix=INVALID
+
+# INVALID: String dump of section '.invalid1':
+# INVALID-NEXT: warning: '[[FILE]]': corrupted compressed section header
+# INVALID-NEXT: [ 0] .
+# INVALID-NEXT: Hex dump of section '.invalid2':
+# INVALID-NEXT: warning: '[[FILE]]': zlib error: Z_DATA_ERROR
+# INVALID-NEXT: 0x00000000 01000000 00000000 16000000 00000000 ................
+# INVALID-NEXT: 0x00000010 00000000 00000000 78 ........x
+# INVALID-EMPTY:
+# INVALID-NEXT: Hex dump of section '.invalid3':
+# INVALID-NEXT: warning: '[[FILE]]': unsupported compression type (3)
+# INVALID-NEXT: 0x00000000 03000000 00000000 04000000 00000000 ................
+# INVALID-NEXT: 0x00000010 00000000 00000000 789c6360 ........x.c`
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+Sections:
+ - Name: .strings
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 010000000000000016000000000000000000000000000000789ccb482d4a654804e2e2fc5c2051529499975ecc0000582e079b
+ - Name: .not_null_terminated
+ Type: SHT_PROGBITS
+ Content: 6e6f006e756c6c
+ - Name: .invalid1
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 01
+ - Name: .invalid2
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 01000000000000001600000000000000000000000000000078
+ - Name: .invalid3
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 030000000000000004000000000000000000000000000000789c6360
diff --git a/llvm/test/tools/llvm-readobj/ELF/decompress-zstd-unsupported.test b/llvm/test/tools/llvm-readobj/ELF/decompress-zstd-unsupported.test
new file mode 100644
index 00000000000000..65da952687f526
--- /dev/null
+++ b/llvm/test/tools/llvm-readobj/ELF/decompress-zstd-unsupported.test
@@ -0,0 +1,31 @@
+# UNSUPPORTED: zstd
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readobj -z -p .a -x .b %t 2>&1 | FileCheck %s -DFILE=%t
+
+# CHECK: String dump of section '.a':
+# CHECK-NEXT: warning: '[[FILE]]': LLVM was not built with LLVM_ENABLE_ZSTD or did not find zstd at build time
+# CHECK-NEXT: [ 0] .
+# CHECK-NEXT: [ 8] .
+# CHECK-NEXT: [ 10] .
+# CHECK-NEXT: [ 18] (./. ..
+# CHECK-NEXT: [ 21] .
+# CHECK-NEXT: Hex dump of section '.b':
+# CHECK-NEXT: warning: '[[FILE]]': LLVM was not built with LLVM_ENABLE_ZSTD or did not find zstd at build time
+# CHECK-NEXT: 0x00000000 02000000 00000000 01000000 00000000 ................
+# CHECK-NEXT: 0x00000010 01000000 00000000 28b52ffd 20010900 ........(./. ...
+# CHECK-NEXT: 0x00000020 0001 ..
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+Sections:
+ - Name: .a
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 02000000000000000100000000000000010000000000000028b52ffd200109000001
+ - Name: .b
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 02000000000000000100000000000000010000000000000028b52ffd200109000001
diff --git a/llvm/test/tools/llvm-readobj/ELF/decompress-zstd.test b/llvm/test/tools/llvm-readobj/ELF/decompress-zstd.test
new file mode 100644
index 00000000000000..519db879b18c17
--- /dev/null
+++ b/llvm/test/tools/llvm-readobj/ELF/decompress-zstd.test
@@ -0,0 +1,28 @@
+# REQUIRES: zstd
+## Test --decompress/-z for zstd.
+
+# RUN: yaml2obj %s -o %t
+
+# RUN: llvm-readelf -z -x .strings %t | FileCheck %s --check-prefix=HEX
+# RUN: llvm-readobj --decompress -p .strings %t | FileCheck %s --check-prefix=STR
+
+# HEX: Hex dump of section '.strings':
+# HEX-NEXT: 0x00000000 68657265 00617265 00736f6d 65007374 here.are.some.st
+# HEX-NEXT: 0x00000010 72696e67 7300 rings.
+
+# STR: String dump of section '.strings':
+# STR-NEXT: [ 0] here
+# STR-NEXT: [ 5] are
+# STR-NEXT: [ 9] some
+# STR-NEXT: [ e] strings
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+Sections:
+ - Name: .strings
+ Type: SHT_PROGBITS
+ Flags: [SHF_COMPRESSED]
+ Content: 02000000000000001600000000000000000000000000000028b52ffd2016b10000686572650061726500736f6d6500737472696e677300
diff --git a/llvm/tools/llvm-readobj/ObjDumper.cpp b/llvm/tools/llvm-readobj/ObjDumper.cpp
index 59060ac217e32f..0d3fea71aafd42 100644
--- a/llvm/tools/llvm-readobj/ObjDumper.cpp
+++ b/llvm/tools/llvm-readobj/ObjDumper.cpp
@@ -14,6 +14,7 @@
#include "ObjDumper.h"
#include "llvm-readobj.h"
#include "llvm/Object/Archive.h"
+#include "llvm/Object/Decompressor.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FormatVariadic.h"
@@ -142,8 +143,23 @@ getSectionRefsByNameOrIndex(const object::ObjectFile &Obj,
return Ret;
}
+static void maybeDecompress(const object::ObjectFile &Obj,
+ StringRef SectionName, StringRef &SectionContent,
+ SmallString<0> &Out) {
+ Expected<object::Decompressor> Decompressor = object::Decompressor::create(
+ SectionName, SectionContent, Obj.isLittleEndian(), Obj.is64Bit());
+ if (!Decompressor)
+ reportWarning(Decompressor.takeError(), Obj.getFileName());
+ else if (auto Err = Decompressor->resizeAndDecompress(Out))
+ reportWarning(std::move(Err), Obj.getFileName());
+ else
+ SectionContent = Out;
+}
+
void ObjDumper::printSectionsAsString(const object::ObjectFile &Obj,
- ArrayRef<std::string> Sections) {
+ ArrayRef<std::string> Sections,
+ bool Decompress) {
+ SmallString<0> Out;
bool First = true;
for (object::SectionRef Section :
getSectionRefsByNameOrIndex(Obj, Sections)) {
@@ -156,12 +172,16 @@ void ObjDumper::printSectionsAsString(const object::ObjectFile &Obj,
StringRef SectionContent =
unwrapOrError(Obj.getFileName(), Section.getContents());
+ if (Decompress && Section.isCompressed())
+ maybeDecompress(Obj, SectionName, SectionContent, Out);
printAsStringList(SectionContent);
}
}
void ObjDumper::printSectionsAsHex(const object::ObjectFile &Obj,
- ArrayRef<std::string> Sections) {
+ ArrayRef<std::string> Sections,
+ bool Decompress) {
+ SmallString<0> Out;
bool First = true;
for (object::SectionRef Section :
getSectionRefsByNameOrIndex(Obj, Sections)) {
@@ -174,6 +194,8 @@ void ObjDumper::printSectionsAsHex(const object::ObjectFile &Obj,
StringRef SectionContent =
unwrapOrError(Obj.getFileName(), Section.getContents());
+ if (Decompress && Section.isCompressed())
+ maybeDecompress(Obj, SectionName, SectionContent, Out);
const uint8_t *SecContent = SectionContent.bytes_begin();
const uint8_t *SecEnd = SecContent + SectionContent.size();
diff --git a/llvm/tools/llvm-readobj/ObjDumper.h b/llvm/tools/llvm-readobj/ObjDumper.h
index 1d679453581bc8..3958dd3a333332 100644
--- a/llvm/tools/llvm-readobj/ObjDumper.h
+++ b/llvm/tools/llvm-readobj/ObjDumper.h
@@ -175,9 +175,9 @@ class ObjDumper {
void printAsStringList(StringRef StringContent, size_t StringDataOffset = 0);
void printSectionsAsString(const object::ObjectFile &Obj,
- ArrayRef<std::string> Sections);
+ ArrayRef<std::string> Sections, bool Decompress);
void printSectionsAsHex(const object::ObjectFile &Obj,
- ArrayRef<std::string> Sections);
+ ArrayRef<std::string> Sections, bool Decompress);
std::function<Error(const Twine &Msg)> WarningHandler;
void reportUniqueWarning(Error Err) const;
diff --git a/llvm/tools/llvm-readobj/Opts.td b/llvm/tools/llvm-readobj/Opts.td
index e2d93c6ec229e9..018facc278e891 100644
--- a/llvm/tools/llvm-readobj/Opts.td
+++ b/llvm/tools/llvm-readobj/Opts.td
@@ -20,6 +20,7 @@ def all : FF<"all", "Equivalent to setting: --file-header, --program-headers, --
def arch_specific : FF<"arch-specific", "Display architecture-specific information">;
def bb_addr_map : FF<"bb-addr-map", "Display the BB address map section">;
def cg_profile : FF<"cg-profile", "Display call graph profile section">;
+def decompress : FF<"decompress", "Dump decompressed section content when used with -x or -p">;
defm demangle : BB<"demangle", "Demangle symbol names", "Do not demangle symbol names (default)">;
def dependent_libraries : FF<"dependent-libraries", "Display the dependent libraries section">;
def dyn_relocations : FF<"dyn-relocations", "Display the dynamic relocation entries in the file">;
@@ -139,3 +140,4 @@ def : F<"u", "Alias for --unwind">, Alias<unwind>;
def : F<"X", "Alias for --extra-sym-info">, Alias<extra_sym_info>, Group<grp_elf>;
def : F<"V", "Alias for --version-info">, Alias<version_info>, Group<grp_elf>;
def : JoinedOrSeparate<["-"], "x">, Alias<hex_dump_EQ>, HelpText<"Alias for --hex-dump">, MetaVarName<"<name or index>">;
+def : F<"z", "Alias for --decompress">, Alias<decompress>;
diff --git a/llvm/tools/llvm-readobj/llvm-readobj.cpp b/llvm/tools/llvm-readobj/llvm-readobj.cpp
index f9d605d35244bf..979433d69011c3 100644
--- a/llvm/tools/llvm-readobj/llvm-readobj.cpp
+++ b/llvm/tools/llvm-readobj/llvm-readobj.cpp
@@ -97,6 +97,7 @@ static bool ArchSpecificInfo;
static bool BBAddrMap;
bool ExpandRelocs;
static bool CGProfile;
+static bool Decompress;
bool Demangle;
static bool DependentLibraries;
static bool DynRelocs;
@@ -212,6 +213,7 @@ static void parseOptions(const opt::InputArgList &Args) {
opts::ArchSpecificInfo = Args.hasArg(OPT_arch_specific);
opts::BBAddrMap = Args.hasArg(OPT_bb_addr_map);
opts::CGProfile = Args.hasArg(OPT_cg_profile);
+ opts::Decompress = Args.hasArg(OPT_decompress);
opts::Demangle = Args.hasFlag(OPT_demangle, OPT_no_demangle, false);
opts::DependentLibraries = Args.hasArg(OPT_dependent_libraries);
opts::DynRelocs = Args.hasArg(OPT_dyn_relocations);
@@ -439,9 +441,9 @@ static void dumpObject(ObjectFile &Obj, ScopedPrinter &Writer,
Dumper->printSymbols(opts::Symbols, opts::DynamicSymbols,
opts::ExtraSymInfo, SymComp);
if (!opts::StringDump.empty())
- Dumper->printSectionsAsString(Obj, opts::StringDump);
+ Dumper->printSectionsAsString(Obj, opts::StringDump, opts::Decompress);
if (!opts::HexDump.empty())
- Dumper->printSectionsAsHex(Obj, opts::HexDump);
+ Dumper->printSectionsAsHex(Obj, opts::HexDump, opts::Decompress);
if (opts::HashTable)
Dumper->printHashTable();
if (opts::GnuHashTable)
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