Commit Graph

1002 Commits

Author SHA1 Message Date
James Henderson
a3acf99e59 [DWARF] Rework debug line parsing to use llvm::Error and callbacks
Reviewed by: dblaikie, JDevlieghere, espindola

Differential Revision: https://reviews.llvm.org/D44560

Summary:
The .debug_line parser previously reported errors by printing to stderr and
return false. This is not particularly helpful for clients of the library code,
as it prevents them from handling the errors in a manner based on the calling
context. This change switches to using llvm::Error and callbacks to indicate
what problems were detected during parsing, and has updated clients to handle
the errors in a location-specific manner. In general, this means that they
continue to do the same thing to external users. Below, I have outlined what
the known behaviour changes are, relating to this change.

There are two levels of "errors" in the new error mechanism, to broadly
distinguish between different fail states of the parser, since not every
failure will prevent parsing of the unit, or of subsequent unit. Malformed
table errors that prevent reading the remainder of the table (reported by
returning them) and other minor issues representing problems with parsing that
do not prevent attempting to continue reading the table (reported by calling a
specified callback funciton). The only example of this currently is when the
last sequence of a unit is unterminated. However, I think it would be good to
change the handling of unrecognised opcodes to report as minor issues as well,
rather than just printing to the stream if --verbose is used (this would be a
subsequent change however).

I have substantially extended the DwarfGenerator to be able to handle
custom-crafted .debug_line sections, allowing for comprehensive unit-testing
of the parser code. For now, I am just adding unit tests to cover the basic
error reporting, and positive cases, and do not currently intend to test every
part of the parser, although the framework should be sufficient to do so at a
later point.

Known behaviour changes:
  - The dump function in DWARFContext now does not attempt to read subsequent
  tables when searching for a specific offset, if the unit length field of a
  table before the specified offset is a reserved value.
  - getOrParseLineTable now returns a useful Error if an invalid offset is
  encountered, rather than simply a nullptr.
  - The parse functions no longer use `WithColor::warning` directly to report
  errors, allowing LLD to call its own warning function.
  - The existing parse error messages have been updated to not specifically
  include "warning" in their message, allowing consumers to determine what
  severity the problem is.
  - If the line table version field appears to have a value less than 2, an
  informative error is returned, instead of just false.
  - If the line table unit length field uses a reserved value, an informative
  error is returned, instead of just false.
  - Dumping of .debug_line.dwo sections is now implemented the same as regular
  .debug_line sections.
  - Verbose dumping of .debug_line[.dwo] sections now prints the prologue, if
  there is a prologue error, just like non-verbose dumping.

As a helper for the generator code, I have re-added emitInt64 to the
AsmPrinter code. This previously existed, but was removed way back in r100296,
presumably because it was dead at the time.

This change also requires a change to LLD, which will be committed separately.

llvm-svn: 331971
2018-05-10 10:51:33 +00:00
Shiva Chen
801bf7ebbe [DebugInfo] Examine all uses of isDebugValue() for debug instructions.
Because we create a new kind of debug instruction, DBG_LABEL, we need to
check all passes which use isDebugValue() to check MachineInstr is debug
instruction or not. When expelling debug instructions, we should expel
both DBG_VALUE and DBG_LABEL. So, I create a new function,
isDebugInstr(), in MachineInstr to check whether the MachineInstr is
debug instruction or not.

This patch has no new test case. I have run regression test and there is
no difference in regression test.

Differential Revision: https://reviews.llvm.org/D45342

Patch by Hsiangkai Wang.

llvm-svn: 331844
2018-05-09 02:42:00 +00:00
Shiva Chen
cd070cdc94 [DebugInfo] Convert intrinsic llvm.dbg.label to MachineInstr.
In order to convert LLVM IR to MachineInstr, we need a new TargetOpcode,
DBG_LABEL, to ‘lower’ intrinsic llvm.dbg.label. The patch
creates this new TargetOpcode and convert intrinsic llvm.dbg.label to
MachineInstr through SelectionDAG.

In SelectionDAG, debug information is stored in SDDbgInfo. We create a
new data member of SDDbgInfo for labels and use the new data member,
SDDbgLabel, to create DBG_LABEL MachineInstr.

The new DBG_LABEL MachineInstr uses label metadata from LLVM IR as its
parameter. So, the backend could get metadata information of labels from
DBG_LABEL MachineInstr.

Differential Revision: https://reviews.llvm.org/D45341

Patch by Hsiangkai Wang.

llvm-svn: 331842
2018-05-09 02:41:08 +00:00
Martin Storsjo
966d34563f [AsmPrinter] Allow emitting codeview for any windows target
Before SVN r244158, codeview debug info was emitted always
emitted for msvc if debug info was enabled, but that commit
added a module flag.

Since it's still restricted by the flag, we can allow it
for any target if the user requests it, not only msvc (and
windows-itanium, added in SVN r287567).

Add a test for emitting it for a mingw target.

Differential Revision: https://reviews.llvm.org/D46303

llvm-svn: 331809
2018-05-08 20:56:04 +00:00
Krzysztof Parzyszek
5e3aba8251 Add assertion to padding size calculation, NFC
The size of an object cannot be less than the emitted size of all the
contained elements. This would cause an overflow in padding size
calculation. Add an assert to catch this.

Patch by Suyog Sarda.

llvm-svn: 331376
2018-05-02 17:20:22 +00:00
Adrian Prantl
5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Eric Christopher
aadbabc070 Remove unused argument from emitModuleMetadata.
NFCI.

llvm-svn: 330470
2018-04-20 19:07:57 +00:00
Michael Zolotukhin
8d052a0dd2 Remove MachineLoopInfo dependency from AsmPrinter.
Summary:
Currently MachineLoopInfo is used in only two places:
1) for computing IsBasicBlockInsideInnermostLoop field of MCCodePaddingContext, and it is never used.
2) in emitBasicBlockLoopComments, which is called only if `isVerbose()` is true.
Despite that, we currently have a dependency on MachineLoopInfo, which makes
pass manager to compute it and MachineDominator Tree. This patch removes the
use (1) and makes the use (2) lazy, thus avoiding some redundant
recomputations.

Reviewers: opaparo, gadi.haber, rafael, craig.topper, zvi

Subscribers: rengolin, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D44812

llvm-svn: 329542
2018-04-09 00:54:47 +00:00
Rafael Espindola
8c58750cc4 Align stubs for external and common global variables to pointer size.
This patch fixes PR36885: clang++ generates unaligned stub symbol
holding a pointer.

Patch by Rahul Chaudhry!

llvm-svn: 329030
2018-04-02 23:20:30 +00:00
Rafael Espindola
4b4d85fd4d Style update. NFC.
Rename 3 functions to start with lowercase letters. Don't repeat the
name in the comments.

llvm-svn: 328848
2018-03-29 23:32:54 +00:00
Rafael Espindola
78fdca3cd5 Use local symbols for creating .stack-size.
llvm-svn: 328581
2018-03-26 20:40:22 +00:00
David Blaikie
6054e650ff Move TargetLoweringObjectFile from CodeGen to Target to fix layering
It's implemented in Target & include from other Target headers, so the
header should be in Target.

llvm-svn: 328392
2018-03-23 23:58:19 +00:00
David Blaikie
8820929011 Sink Analysis/ObjectUtil(canBeOmittedFromSymbolTable) into IR so it can be legitimately be used by Object/IRSymtab
llvm-svn: 328135
2018-03-21 19:23:45 +00:00
Jonas Devlieghere
a6ef1abc09 [dsymutil] Rename llvm-dsymutil -> dsymutil
Now that almost all functionality of Apple's dsymutil has been
upstreamed, the open source variant can be used as a drop in
replacement. Hence we feel it's no longer necessary to have the llvm
prefix.

Differential revision: https://reviews.llvm.org/D44527

llvm-svn: 327790
2018-03-18 11:38:41 +00:00
Matt Arsenault
41e5ac4fa4 TargetMachine: Add address space to getPointerSize
llvm-svn: 327467
2018-03-14 00:36:23 +00:00
Alina Sbirlea
08fa594298 Avoid creating a Constant for each value in a ConstantDataSequential.
Summary: We create a ConstantDataSequential (ConstantDataArray or ConstantDataVector) to avoid creating a Constant for each element in an array of constants. But them in AsmPrinter, we do create a ConstantFP for each element in the ConstantDataSequential. This triggers excessive memory use when generating large global FP constants.

Reviewers: bogner, lhames, t.p.northover

Subscribers: jlebar, sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D44277

llvm-svn: 327161
2018-03-09 18:48:20 +00:00
Simi Pallipurath
ad96d9a373 test commit: fix typo in comment
This is  a simple change to do the test commit and verify commit access.

llvm-svn: 326800
2018-03-06 14:35:23 +00:00
Chih-Hung Hsieh
9f9e4681ac [TLS] use emulated TLS if the target supports only this mode
Emulated TLS is enabled by llc flag -emulated-tls,
which is passed by clang driver.
When llc is called explicitly or from other drivers like LTO,
missing -emulated-tls flag would generate wrong TLS code for targets
that supports only this mode.
Now use useEmulatedTLS() instead of Options.EmulatedTLS to decide whether
emulated TLS code should be generated.
Unit tests are modified to run with and without the -emulated-tls flag.

Differential Revision: https://reviews.llvm.org/D42999

llvm-svn: 326341
2018-02-28 17:48:55 +00:00
Heejin Ahn
9386bde11b [WebAssembly] Add exception handling option and feature
Summary:
Add a llc command line option and WebAssembly architecture feature for
exception handling.

Reviewers: dschuff

Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D43683

llvm-svn: 326004
2018-02-24 00:40:50 +00:00
Shoaib Meenai
63b6a0e5bc [CodeGen] Simplify conditional. NFC
Rafael pointed out that `hasInternalLinkage() || hasPrivateLinkage()` is
equivalent to `hasLocalLinkage()` in post-commit review.

I'm intentionally not updating the comment, partly because I like it
being explicit, and partly because "global symbols with local linkage"
sounds like an oxymoron.

llvm-svn: 323688
2018-01-29 20:28:04 +00:00
Shoaib Meenai
d8fd16b08f [CodeGen] Ignore private symbols in llvm.used for COFF
Similar to the existing handling for internal symbols, private symbols
are also not visible to the linker and should be ignored.

llvm-svn: 323483
2018-01-26 00:15:25 +00:00
Saleem Abdulrasool
99f479abcf CodeGen: handle llvm.used properly for COFF
`llvm.used` contains a list of pointers to named values which the
compiler, assembler, and linker are required to treat as if there is a
reference that they cannot see.  Ensure that the symbols are preserved
by adding an explicit `-include` reference to the linker command.

llvm-svn: 323017
2018-01-20 00:28:02 +00:00
Reid Kleckner
1aa9061c5f [CodeGen] Hoist common AsmPrinter code out of X86, ARM, and AArch64
Every known PE COFF target emits /EXPORT: linker flags into a .drective
section. The AsmPrinter should handle this.

While we're at it, use global_values() and emit each export flag with
its own .ascii directive. This should make the .s file output more
readable.

llvm-svn: 322788
2018-01-17 23:55:23 +00:00
Sean Eveson
2ae6037dd1 [MC] Fix -stack-size-section on ARM
Change symbol values in the stack_size section from being 8 bytes, to being a target dependent size.

Differential Revision: https://reviews.llvm.org/D42108

llvm-svn: 322619
2018-01-17 09:01:29 +00:00
Adrian McCarthy
db2736ddd8 Reland "Emit Function IDs table for Control Flow Guard"
Adds option /guard:cf to clang-cl and -cfguard to cc1 to emit function IDs
of functions that have their address taken into a section named .gfids$y for
compatibility with Microsoft's Control Flow Guard feature.

The original patch didn't have the lit.local.cfg file that restricts the new
test to x86, thus the new test was failing on the non-x86 bots.

Differential Revision: https://reviews.llvm.org/D40531

The reverts r322008, which was a revert of r322005.

This reverts commit a05b89f9aca70597dc79fe97bc49b50b51f525ba.

llvm-svn: 322136
2018-01-09 23:49:30 +00:00
Adrian McCarthy
ce63a925cc Revert "Emit Function IDs table for Control Flow Guard"
The new test fails on the Hexagon bot.  Reverting while I investigate.

This reverts https://reviews.llvm.org/rL322005

This reverts commit b7e0026b4385180c378edc658ec91a39566f2942.

llvm-svn: 322008
2018-01-08 17:12:01 +00:00
Adrian McCarthy
cf6e6c82c1 Emit Function IDs table for Control Flow Guard
Adds option /guard:cf to clang-cl and -cfguard to cc1 to emit function IDs
of functions that have their address taken into a section named .gfids$y for
compatibility with Microsoft's Control Flow Guard feature.

Differential Revision: https://reviews.llvm.org/D40531

llvm-svn: 322005
2018-01-08 16:33:42 +00:00
Adrian Prantl
0e6694d111 Silence a bunch of implicit fallthrough warnings
llvm-svn: 321114
2017-12-19 22:05:25 +00:00
Matthias Braun
f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Andrew V. Tischenko
22f0742dda Fix for bug PR35549 - Repeated schedule comments.
Differential Revision: https://reviews.llvm.org/D40960

llvm-svn: 320837
2017-12-15 18:13:05 +00:00
Matthias Braun
5dd72adbec MC/AsmPrinter: Reduce code duplication.
Factor out duplicated code emitting mach-o version-min specifiers.

This should be NFC but happens to fix a bug where the code in
MCMachoStreamer didn't take the version skew between darwin and macos
versions into account.

llvm-svn: 320666
2017-12-14 03:59:24 +00:00
Francis Visoiu Mistrih
a8a83d150f [CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.
Work towards the unification of MIR and debug output by refactoring the
interfaces.

For MachineOperand::print, keep a simple version that can be easily called
from `dump()`, and a more complex one which will be called from both the
MIRPrinter and MachineInstr::print.

Add extra checks inside MachineOperand for detached operands (operands
with getParent() == nullptr).

https://reviews.llvm.org/D40836

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g'

llvm-svn: 320022
2017-12-07 10:40:31 +00:00
Francis Visoiu Mistrih
25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Sean Eveson
a6bcd53d52 [MC] Function stack size section.
Re applying after fixing issues in the diff, sorry for any painful conflicts/merges!

Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html

This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).

The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.

There is a follow up change to add an option to clang.

Thanks.

Reviewers: hfinkel, MatzeB

Reviewed By: MatzeB

Subscribers: thegameg, asb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39788

llvm-svn: 319430
2017-11-30 13:05:14 +00:00
Sean Eveson
661e4fbf83 Revert r319423: [MC] Function stack size section.
I messed up the diff.

llvm-svn: 319429
2017-11-30 12:43:25 +00:00
Sean Eveson
f77b4d2f38 [MC] Function stack size section.
Summary:
Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html

I wasn't sure who to put as reviewers, so please add/remove people as appropriate.

This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).

The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.

There is a follow up change to add an option to clang.

Thanks.

Reviewers: hfinkel, MatzeB

Reviewed By: MatzeB

Subscribers: thegameg, asb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39788

llvm-svn: 319423
2017-11-30 12:01:16 +00:00
Francis Visoiu Mistrih
9d419d3b0c [CodeGen] Rename functions PrintReg* to printReg*
LLVM Coding Standards:
  Function names should be verb phrases (as they represent actions), and
  command-like function should be imperative. The name should be camel
  case, and start with a lower case letter (e.g. openFile() or isFoo()).

Differential Revision: https://reviews.llvm.org/D40416

llvm-svn: 319168
2017-11-28 12:42:37 +00:00
David Blaikie
b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
David Blaikie
3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00
David Blaikie
1be62f0327 Move TargetFrameLowering.h to CodeGen where it's implemented
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.

llvm-svn: 317379
2017-11-03 22:32:11 +00:00
Omer Paparo Bivas
2251c79aba [MC] Adding code padding for performance stability - infrastructure. NFC.
Infrastructure designed for padding code with nop instructions in key places such that preformance improvement will be achieved.
The infrastructure is implemented such that the padding is done in the Assembler after the layout is done and all IPs and alignments are known.
This patch by itself in a NFC. Future patches will make use of this infrastructure to implement required policies for code padding.

Reviewers:
aaboud
zvi
craig.topper
gadi.haber

Differential revision: https://reviews.llvm.org/D34393

Change-Id: I92110d0c0a757080a8405636914a93ef6f8ad00e
llvm-svn: 316413
2017-10-24 06:16:03 +00:00
Justin Bogner
fdf9bf4f16 CodeGen: Minor cleanups to use MachineInstr::getMF. NFC
Since r315388 we have a shorter way to say this, so we'll replace
MI->getParent()->getParent() with MI->getMF() in a few places.

llvm-svn: 315390
2017-10-10 23:50:49 +00:00
Eugene Zelenko
149178d92b [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 315380
2017-10-10 22:33:29 +00:00
Than McIntosh
dee2cf67ea [CodeGen] Emit necessary .note sections for -fsplit-stack
Summary:
According to https://gcc.gnu.org/wiki/SplitStacks, the linker expects a zero-sized .note.GNU-split-stack section if split-stack is used (and also .note.GNU-no-split-stack section if it also contains non-split-stack functions), so it can handle the cases where a split-stack function calls non-split-stack function.

This change adds the sections if needed.

Fixes PR #34670.

Reviewers: thanm, rnk, luqmana

Reviewed By: rnk

Subscribers: llvm-commits

Patch by Cherry Zhang <cherryyz@google.com>

Differential Revision: https://reviews.llvm.org/D38051

llvm-svn: 314335
2017-09-27 19:34:00 +00:00
Dean Michael Berris
01fd7c8bd4 [XRay][CodeGen] Use the current function symbol as the associated symbol for the instrumentation map
Summary:
XRay had been assuming that the previous section is the "text" section
of the function when lowering the instrumentation map. Unfortunately
this is not a safe assumption, because we may be coming from lowering
debug type information for the function being lowered.

This fixes an issue with combining -gsplit-dwarf, -generate-type-units,
-debug-compile and -fxray-instrument for sole member functions. When the
split dwarf section is stripped, we're left with references from the
xray_instr_map to the debug section. The change now uses the function's
symbol instead of the previous section's start symbol.

We found the bug while attempting to strip the split debug sections off
an XRay-instrumented object file, which had a peculiar edge-case for
single-function classes where the single function is being lowered.
Because XRay had assocaited the instrumentation map for a function to
the debug types section instead of the function's section, the objcopy
call will fail due to the misplaced reference from the xray_instr_map
section.

Reviewers: pcc, dblaikie, echristo

Subscribers: llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D37791

llvm-svn: 313233
2017-09-14 07:08:23 +00:00
Dean Michael Berris
ebc1659016 [XRay][CodeGen] Use PIC-friendly code in XRay sleds and remove synthetic references in .text
Summary:
This is a re-roll of D36615 which uses PLT relocations in the back-end
to the call to __xray_CustomEvent() when building in -fPIC and
-fxray-instrument mode.

Reviewers: pcc, djasper, bkramer

Subscribers: sdardis, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D37373

llvm-svn: 312466
2017-09-04 05:34:58 +00:00
Daniel Jasper
c0a976d417 Revert r311525: "[XRay][CodeGen] Use PIC-friendly code in XRay sleds; remove synthetic references in .text"
Breaks builds internally. Will forward repo instructions to author.

llvm-svn: 312243
2017-08-31 15:17:17 +00:00
Dean Michael Berris
0884b73220 [XRay][CodeGen] Use PIC-friendly code in XRay sleds; remove synthetic references in .text
Summary:
This change achieves two things:

  - Redefine the Custom Event handling instrumentation points emitted by
    the compiler to not require dynamic relocation of references to the
    __xray_CustomEvent trampoline.

  - Remove the synthetic reference we emit at the end of a function that
    we used to keep auxiliary sections alive in favour of SHF_LINK_ORDER
    associated with the section where the function is defined.

To achieve the custom event handling change, we've had to introduce the
concept of sled versioning -- this will need to be supported by the
runtime to allow us to understand how to turn on/off the new version of
the custom event handling sleds. That change has to land first before we
change the way we write the sleds.

To remove the synthetic reference, we rely on a relatively new linker
feature that preserves the sections that are associated with each other.
This allows us to limit the effects on the .text section of ELF
binaries.

Because we're still using absolute references that are resolved at
runtime for the instrumentation map (and function index) maps, we mark
these sections write-able. In the future we can re-define the entries in
the map to use relative relocations instead that can be statically
determined by the linker. That change will be a bit more invasive so we
defer this for later.

Depends on D36816.

Reviewers: dblaikie, echristo, pcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36615

llvm-svn: 311525
2017-08-23 04:49:41 +00:00
Taewook Oh
f5040b9685 Make .file directive to have basename only
Summary:
Currently LLVM puts directory along with the filename in .file directive, but this behavior doesn't match gcc. There's a no clear description about which one is right (https://sourceware.org/binutils/docs/as/File.html#File), but one document (https://sourceware.org/gdb/current/onlinedocs/stabs/ELF-Linker-Relocation.html) suggests that STT_FILE symbol in elf file is expected to have basename only, which should have a same sting file .file directive according to (https://docs.oracle.com/cd/E26502_01/html/E28388/eoiyg.html).

This also affects badly on the build system that uses hashing, as the directory info could be differnt from developer to developer even when they're working on same file.

Reviewers: pcc, mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36018

llvm-svn: 310642
2017-08-10 18:17:11 +00:00
Francis Visoiu Mistrih
9b97a31870 [AsmPrinter] Constify needsCFIMoves. NFC
llvm-svn: 308557
2017-07-19 23:47:33 +00:00