Commit Graph

15 Commits

Author SHA1 Message Date
Shu-yu Guo
627b6b2f06 Reland^2 "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
This is a reland of e28dadc207

The original failure was due to a stale Win32 bot. The reland failure
was due to idempotent task deduplication returning the exact same
failure. See crbug/1196064

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}

Bug: v8:11460
No-Try: true
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: Id69311cf3267ebe1297fff159de0be48b15b65a3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806546
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73795}
2021-04-06 01:55:28 +00:00
Shu-yu Guo
562c42511a Revert "Reland "[ptr-cage] Rename IsolateRoot to PtrComprCageBase""
This reverts commit 15c78b45a6.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32277/overview

Original change's description:
> Reland "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
>
> This is a reland of e28dadc207
>
> Relanding to see if Win32 rel failures from
> https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
> were infra flakes. Could not repro on try bots.
>
> Original change's description:
> > [ptr-cage] Rename IsolateRoot to PtrComprCageBase
> >
> > Currently, IsolateRoot is both the address of the Isolate root and the
> > base address of the pointer compression reservation. This CL teases the
> > two uses apart by renaming IsolateRoot to PtrComprCageBase.
> >
> > - In addition to V8_COMPRESS_POINTERS, add a
> >   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
> >
> > - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> >   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> >   aliases to GetPtrComprCageBase.
> >
> > - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
> >
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> > Reviewed-by: Igor Sheludko <ishell@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
>
> No-Try: true
> Bug: v8:11460
> Tbr: ishell@chromium.org
> Tbr: rmcilroy@chromium.org
> Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169
> Reviewed-by: Shu-yu Guo <syg@chromium.org>
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73792}

Bug: v8:11460
Change-Id: Ifee92d622c43a91c15f45ef94ff739237bd2024b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806545
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73793}
2021-04-05 23:17:00 +00:00
Shu-yu Guo
15c78b45a6 Reland "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
This is a reland of e28dadc207

Relanding to see if Win32 rel failures from
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
were infra flakes. Could not repro on try bots.

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>

No-Try: true
Bug: v8:11460
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73792}
2021-04-05 23:08:15 +00:00
Francis McCabe
07a9ff4dbb Revert "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
This reverts commit e28dadc207.

Reason for revert: failed test262 tests;; see https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/steps?succeeded=true&debug=false

Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
>   V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
>   aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}

Bug: v8:11460
Change-Id: I19d0e28194fcdb28e89f129a7694ca3fe29fa17a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806168
Auto-Submit: Francis McCabe <fgm@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#73791}
2021-04-05 21:55:11 +00:00
Shu-yu Guo
e28dadc207 [ptr-cage] Rename IsolateRoot to PtrComprCageBase
Currently, IsolateRoot is both the address of the Isolate root and the
base address of the pointer compression reservation. This CL teases the
two uses apart by renaming IsolateRoot to PtrComprCageBase.

- In addition to V8_COMPRESS_POINTERS, add a
  V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).

- Rename GetIsolate* helpers to GetPtrComprCageBase. When
  V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
  aliases to GetPtrComprCageBase.

- Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.

Bug: v8:11460
Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73790}
2021-04-05 20:54:55 +00:00
Tobias Tebbi
21b585165f Reland "[torque] refactor: use -tq only in filenames derived from .tq files"
This is a reland of 64caf2b0b2

Original change's description:
> [torque] refactor: use -tq only in filenames derived from .tq files
>
> This is to establish a naming rule for Torque-generated files:
> - If the file is called foo/bar-tq..., then it is derived from a
>   file foo/bar.tq
> - Otherwise it doesn't belong to a specific .tq file.
>
> So far, we attached -tq to all Torque-generated file names, where it
> sometimes corresponded to a .tq file name and sometimes not.
> It is not necessary to add -tq to file names to indicate that they are
> Torque-generated, since they are already in a directory called
> torque-generated, and we always refer to them as
> "torque-generated/filename", so there is no confusion even though some
> files now have the same name as a corresponding hand-written file, for
> example factory.cc.
>
> TBR: hpayer@chromium.org
> Bug: v8:7793
> Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70060}

Bug: v8:7793
TBR: hpayer@chromium.org jgruber@chromium.org
Change-Id: I6c492bc64aee1ff167e7ef401825eca9097a7f38
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2431565
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70137}
2020-09-25 15:04:18 +00:00
Francis McCabe
92aaace1a9 Revert "[torque] refactor: use -tq only in filenames derived from .tq files"
This reverts commit 64caf2b0b2.

Reason for revert: Seems to be causing a failure:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux/38809?

Original change's description:
> [torque] refactor: use -tq only in filenames derived from .tq files
> 
> This is to establish a naming rule for Torque-generated files:
> - If the file is called foo/bar-tq..., then it is derived from a
>   file foo/bar.tq
> - Otherwise it doesn't belong to a specific .tq file.
> 
> So far, we attached -tq to all Torque-generated file names, where it
> sometimes corresponded to a .tq file name and sometimes not.
> It is not necessary to add -tq to file names to indicate that they are
> Torque-generated, since they are already in a directory called
> torque-generated, and we always refer to them as
> "torque-generated/filename", so there is no confusion even though some
> files now have the same name as a corresponding hand-written file, for
> example factory.cc.
> 
> TBR: hpayer@chromium.org
> Bug: v8:7793
> Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70060}

TBR=jgruber@chromium.org,tebbi@chromium.org

Change-Id: I6960fe540861947536c6ddfc0f4887ea80899fae
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2424486
Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Francis McCabe <fgm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70065}
2020-09-22 17:20:30 +00:00
Tobias Tebbi
64caf2b0b2 [torque] refactor: use -tq only in filenames derived from .tq files
This is to establish a naming rule for Torque-generated files:
- If the file is called foo/bar-tq..., then it is derived from a
  file foo/bar.tq
- Otherwise it doesn't belong to a specific .tq file.

So far, we attached -tq to all Torque-generated file names, where it
sometimes corresponded to a .tq file name and sometimes not.
It is not necessary to add -tq to file names to indicate that they are
Torque-generated, since they are already in a directory called
torque-generated, and we always refer to them as
"torque-generated/filename", so there is no confusion even though some
files now have the same name as a corresponding hand-written file, for
example factory.cc.

TBR: hpayer@chromium.org
Bug: v8:7793
Change-Id: Ie172babad1fc7422fd1059c48f5dafaa53e50c8b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414218
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70060}
2020-09-22 15:52:58 +00:00
Seth Brenith
8b1a5681de [tools] Fix v8windbg behavior on Map's bit_field2
Bill kindly pointed out to me that v8windbg was not handling bit_field2
correctly. The issue was that the constexpr type for ElementsKind was,
somewhat unsurprisingly, "ElementsKind", but v8windbg expected a fully-
qualified type name like "v8::internal::ElementsKind". This change
addresses the problem in two ways:
1. Update v8windbg's type resolution logic to resolve type names as if
   they were used in the v8::internal namespace. This makes it more
   consistent with how those type names are used in other generated
   Torque code, reducing surprises and the number of times we have to
   write `v8::internal::` in .tq files.
2. Add compile-time verification that any constexpr type name used as a
   string in class-debug-readers-tq.cc can also resolve as a type name.

Bug: v8:9376
Change-Id: I349cd6ab586fd8345a1fa8bfc3989bb8e6376ab8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2063769
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#66633}
2020-03-09 17:36:27 +00:00
Seth Brenith
386ed8a9a0 Update postmortem tools to use unsigned compressed pointers
The tests were already passing because they happened to use objects
allocated in the lower half of the heap reservation, but this small
change should make behavior more consistent.

Change-Id: Ib6be3123d347234f4771c213f2209bfe6e19c569
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1860332
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#64294}
2019-10-15 14:39:10 +00:00
Seth Brenith
1d3c4975be [tools] Use instance types of known Maps in v8_debug_helper
If we can read an object's Map pointer but not any data from the Map
itself, we may still be able to accurately describe the object's type if
the Map pointer matches one of the known Maps from the snapshot.
GetObjectProperties uses that data in one of two ways:
- If it is sure that the Map pointer matches a known Map, then it uses
  the type from that Map and continues as if it read the type normally.
- If the Map pointer is at the right offset within a heap page to match
  a known Map, but the caller didn't provide the addresses of the first
  pages in Map space or read-only space, then the type of that Map is
  just a guess and gets returned in a separate array. This gives the
  caller the opportunity to present guessed types to the user, and
  perhaps call again using the guessed type as the type hint.

Bug: v8:9376
Change-Id: I187f67b77e76699863a14534a9d635b79f654124
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1787986
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63908}
2019-09-20 16:00:59 +00:00
Seth Brenith
2ccca6c5ac [tools][torque] Include string values in GetObjectProperties responses
This change provides a quick way to see string contents in postmortem
debugging sessions, without digging through a (possibly very large, in
the case of ConsString) tree of properties. As well as being convenient
for inspecting String objects, this functionality will also be necessary
for displaying property names on JSReceiver objects. In order to support
custom behaviors for specific classes, this change extends the existing
generated debug reader classes with a visitor pattern.

Bug: v8:9376
Change-Id: I70eab9ea4e74ca0fab39bf5998d6a602716a4202
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1771939
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63485}
2019-08-30 21:56:06 +00:00
Seth Brenith
0921e8f28b Reland "Add postmortem debugging helper library"
This is a reland of 517ab73fd7

Updates since original: now compressed pointers passed to the function
GetObjectProperties are required to be sign-extended. Previously, the
function allowed zero-extended values, but that led to ambiguity on
pointers like 0x88044919: is it compressed or is the heap range actually
centered on 0x100000000?

Original change's description:
> Add postmortem debugging helper library
>
> This change begins to implement the functionality described in
> https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
> for investigating V8 state in crash dumps.
>
> This change adds a new library, v8_debug_helper, for providing platform-
> agnostic assistance with postmortem debugging. This library can be used
> by extensions built for debuggers such as WinDbg or lldb. Its public API
> is described by debug-helper.h; currently the only method it exposes is
> GetObjectProperties, but we'd like to add more functionality over time.
> The API surface is restricted to plain C-style structs and pointers, so
> that it's easy to link from a debugger extension built with a different
> toolchain.
>
> This change also adds a new cctest file to exercise some basic
> interaction with the new library.
>
> The API function GetObjectProperties takes an object pointer (which
> could be compressed, or weak, or a SMI), and returns a string
> description of the object and a list of properties the object contains.
> For now, the list of properties is entirely based on Torque object
> definitions, but we expect to add custom properties in future updates so
> that it can be easier to make sense of complex data structures such as
> dictionaries.
>
> GetObjectProperties does several things that are intended to generate
> somewhat useful results even in cases where memory may be corrupt or
> unavailable:
> - The caller may optionally provide a type string which will be used if
>   the memory for the object's Map is inaccessible.
> - All object pointers are compared against the list of known objects
>   generated by mkgrokdump. The caller may optionally provide the
>   pointers for the first pages of various heap spaces, to avoid spurious
>   matches. If those pointers are not provided, then any matches are
>   prefixed with "maybe" in the resulting description string, such as
>   "maybe UndefinedValue (0x4288000341 <Oddball>)".
>
> Bug: v8:9376
>
> Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62882}

Bug: v8:9376
Change-Id: I866a1cc9d4c34bfe10c7b98462451fe69763cf3f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1717090
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63008}
2019-07-31 14:30:19 +00:00
Zhi An Ng
6747e3a186 Revert "Add postmortem debugging helper library"
This reverts commit 517ab73fd7.

Reason for revert: Test failures https://bugs.chromium.org/p/v8/issues/detail?id=9538

Original change's description:
> Add postmortem debugging helper library
> 
> This change begins to implement the functionality described in
> https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
> for investigating V8 state in crash dumps.
> 
> This change adds a new library, v8_debug_helper, for providing platform-
> agnostic assistance with postmortem debugging. This library can be used
> by extensions built for debuggers such as WinDbg or lldb. Its public API
> is described by debug-helper.h; currently the only method it exposes is
> GetObjectProperties, but we'd like to add more functionality over time.
> The API surface is restricted to plain C-style structs and pointers, so
> that it's easy to link from a debugger extension built with a different
> toolchain.
> 
> This change also adds a new cctest file to exercise some basic
> interaction with the new library.
> 
> The API function GetObjectProperties takes an object pointer (which
> could be compressed, or weak, or a SMI), and returns a string
> description of the object and a list of properties the object contains.
> For now, the list of properties is entirely based on Torque object
> definitions, but we expect to add custom properties in future updates so
> that it can be easier to make sense of complex data structures such as
> dictionaries.
> 
> GetObjectProperties does several things that are intended to generate
> somewhat useful results even in cases where memory may be corrupt or
> unavailable:
> - The caller may optionally provide a type string which will be used if
>   the memory for the object's Map is inaccessible.
> - All object pointers are compared against the list of known objects
>   generated by mkgrokdump. The caller may optionally provide the
>   pointers for the first pages of various heap spaces, to avoid spurious
>   matches. If those pointers are not provided, then any matches are
>   prefixed with "maybe" in the resulting description string, such as
>   "maybe UndefinedValue (0x4288000341 <Oddball>)".
> 
> Bug: v8:9376
> 
> Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62882}

TBR=yangguo@chromium.org,mvstanton@chromium.org,jgruber@chromium.org,tebbi@chromium.org,seth.brenith@microsoft.com

Change-Id: Ia078f2e8d101d2375b5db88021b2d65d28f1b075
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9376
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1716033
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62899}
2019-07-24 16:31:54 +00:00
Seth Brenith
517ab73fd7 Add postmortem debugging helper library
This change begins to implement the functionality described in
https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
for investigating V8 state in crash dumps.

This change adds a new library, v8_debug_helper, for providing platform-
agnostic assistance with postmortem debugging. This library can be used
by extensions built for debuggers such as WinDbg or lldb. Its public API
is described by debug-helper.h; currently the only method it exposes is
GetObjectProperties, but we'd like to add more functionality over time.
The API surface is restricted to plain C-style structs and pointers, so
that it's easy to link from a debugger extension built with a different
toolchain.

This change also adds a new cctest file to exercise some basic
interaction with the new library.

The API function GetObjectProperties takes an object pointer (which
could be compressed, or weak, or a SMI), and returns a string
description of the object and a list of properties the object contains.
For now, the list of properties is entirely based on Torque object
definitions, but we expect to add custom properties in future updates so
that it can be easier to make sense of complex data structures such as
dictionaries.

GetObjectProperties does several things that are intended to generate
somewhat useful results even in cases where memory may be corrupt or
unavailable:
- The caller may optionally provide a type string which will be used if
  the memory for the object's Map is inaccessible.
- All object pointers are compared against the list of known objects
  generated by mkgrokdump. The caller may optionally provide the
  pointers for the first pages of various heap spaces, to avoid spurious
  matches. If those pointers are not provided, then any matches are
  prefixed with "maybe" in the resulting description string, such as
  "maybe UndefinedValue (0x4288000341 <Oddball>)".

Bug: v8:9376

Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62882}
2019-07-23 20:02:16 +00:00