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llvm-6502/test/MC/ELF/compression.s

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Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
// RUN: llvm-mc -filetype=obj -compress-debug-sections -triple x86_64-pc-linux-gnu %s -o %t
// RUN: llvm-objdump -s %t | FileCheck %s
// RUN: llvm-dwarfdump -debug-dump=abbrev %t | FileCheck --check-prefix=ABBREV %s
Revert debug info compression support. To support compression for debug_line and debug_frame a different approach is required. To simplify review, revert the old implementation and XFAIL the test case. New implementation to follow shortly. Reverts r205059 and r204958. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205989 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:47 +00:00
Only test compression when linked with zlib. I'll implement error handling and a negative test in both llvm-mc and Clang soon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205016 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 17:04:53 +00:00
// REQUIRES: zlib
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
// CHECK: Contents of section .zdebug_line:
// Check for the 'ZLIB' file magic at the start of the section only
// CHECK-NEXT: ZLIB
Debug Compression: Avoid compression debug_frame for now Turns out debug_frame does use multiple fragments, so it doesn't compress correctly with the current approach. Disable compressing it for now while I figure out what's the best solution for it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 21:48:31 +00:00
// CHECK-NOT: ZLIB
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
// CHECK: Contents of
Debug Compression: Avoid compression debug_frame for now Turns out debug_frame does use multiple fragments, so it doesn't compress correctly with the current approach. Disable compressing it for now while I figure out what's the best solution for it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 21:48:31 +00:00
// CHECK: Contents of section .zdebug_abbrev:
DebugInfo: Support for compressed debug info sections 1) When creating a .debug_* section and instead create a .zdebug_ section. 2) When creating a fragment in a .zdebug_* section, make it a compressed fragment. 3) When computing the size of a compressed section, compress the data and use the size of the compressed data. 4) Emit the compressed bytes. Also, check that only if a section has a compressed fragment, then that is the only fragment in the section. Assert-fail if the fragment's data is modified after it is compressed. Initial review on llvm-commits by Eric Christopher and Rafael Espindola. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 20:45:58 +00:00
// CHECK-NEXT: ZLIB
Debug Compression: Avoid compression debug_frame for now Turns out debug_frame does use multiple fragments, so it doesn't compress correctly with the current approach. Disable compressing it for now while I figure out what's the best solution for it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 21:48:31 +00:00
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
// FIXME: Handle compressing alignment fragments to support compressing debug_frame
// CHECK: Contents of section .debug_frame:
DebugInfo: Support for compressed debug info sections 1) When creating a .debug_* section and instead create a .zdebug_ section. 2) When creating a fragment in a .zdebug_* section, make it a compressed fragment. 3) When computing the size of a compressed section, compress the data and use the size of the compressed data. 4) Emit the compressed bytes. Also, check that only if a section has a compressed fragment, then that is the only fragment in the section. Assert-fail if the fragment's data is modified after it is compressed. Initial review on llvm-commits by Eric Christopher and Rafael Espindola. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 20:45:58 +00:00
// CHECK-NOT: ZLIB
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
// CHECK: Contents of
// Decompress one valid dwarf section just to check that this roundtrips
// ABBREV: Abbrev table for offset: 0x00000000
// ABBREV: [1] DW_TAG_compile_unit DW_CHILDREN_no
DebugInfo: Support for compressed debug info sections 1) When creating a .debug_* section and instead create a .zdebug_ section. 2) When creating a fragment in a .zdebug_* section, make it a compressed fragment. 3) When computing the size of a compressed section, compress the data and use the size of the compressed data. 4) Emit the compressed bytes. Also, check that only if a section has a compressed fragment, then that is the only fragment in the section. Assert-fail if the fragment's data is modified after it is compressed. Initial review on llvm-commits by Eric Christopher and Rafael Espindola. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 20:45:58 +00:00
.section .debug_line,"",@progbits
Debug Compression: Avoid compression debug_frame for now Turns out debug_frame does use multiple fragments, so it doesn't compress correctly with the current approach. Disable compressing it for now while I figure out what's the best solution for it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 21:48:31 +00:00
.section .debug_abbrev,"",@progbits
.byte 1 # Abbreviation Code
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
.byte 17 # DW_TAG_compile_unit
.byte 0 # DW_CHILDREN_no
.byte 0 # EOM(1)
.byte 0 # EOM(2)
DebugInfo: Support for compressed debug info sections 1) When creating a .debug_* section and instead create a .zdebug_ section. 2) When creating a fragment in a .zdebug_* section, make it a compressed fragment. 3) When computing the size of a compressed section, compress the data and use the size of the compressed data. 4) Emit the compressed bytes. Also, check that only if a section has a compressed fragment, then that is the only fragment in the section. Assert-fail if the fragment's data is modified after it is compressed. Initial review on llvm-commits by Eric Christopher and Rafael Espindola. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 20:45:58 +00:00
.text
foo:
.cfi_startproc
.file 1 "Driver.ii"
.loc 1 2 0
nop
.cfi_endproc
.cfi_sections .debug_frame
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