a0572f0bc7
Previously we stored the source position table, which stored a mapping
of pc offsets to line numbers, and the inline_locations, which stored a
mapping of pc offsets to stacks of {CodeEntry, line_number} pairs. This
was slightly wasteful because we had two different tables which were
both keyed on the pc offset and contained some overlapping information.
This CL combines the two tables in a way. The source position table now
maps a pc offset to a pair of {line_number, inlining_id}. If the
inlining_id is valid, then it can be used to look up the inlining stack
which is stored in inline_locations, but is now keyed by inlining_id
rather than pc offset. This also has the nice effect of de-duplicating
inline stacks which we previously duplicated.
The new structure is similar to how this data is stored by the compiler,
except that we convert 'source positions' (char offset in a file) into
line numbers as we go, because we only care about attributing ticks to
a given line.
Also remove the helper RecordInliningInfo() as this is only actually
used to add inline stacks by one caller (where it is now inlined). The
other callers would always bail out or are only called from
test-cpu-profiler.
Remove AddInlineStack and replace it with SetInlineStacks which adds all
of the stacks at once. We need to do it this way because the source pos
table is passed into the constructor of CodeEntry, so we need to create
it before the CodeEntry, but the inline stacks are not (they are part of
rare_data which is not always present), so we need to add them after
construction. Given that we calculate both the source pos table and the
inline stacks before construction, it's just easier to add them all at
once.
Also add a print() method to CodeEntry to make future debugging easier
as I'm constantly rewriting this locally.
Bug: v8:8575, v8:7719, v8:7203
Change-Id: I39324d6ea13d116d5da5d0a0d243cae76a749c79
Reviewed-on: https://chromium-review.googlesource.com/c/1392195
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58554}
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| build_overrides | ||
| custom_deps | ||
| docs | ||
| gni | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party | ||
| tools | ||
| .clang-format | ||
| .clang-tidy | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
| .vpython | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| CODE_OF_CONDUCT.md | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.fdlibm | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| snapshot_toolchain.gni | ||
| WATCHLISTS | ||
V8 JavaScript Engine
V8 is Google's open source JavaScript engine.
V8 implements ECMAScript as specified in ECMA-262.
V8 is written in C++ and is used in Google Chrome, the open source browser from Google.
V8 can run standalone, or can be embedded into any C++ application.
V8 Project page: https://github.com/v8/v8/wiki
Getting the Code
Checkout depot tools, and run
fetch v8
This will checkout V8 into the directory v8 and fetch all of its dependencies.
To stay up to date, run
git pull origin
gclient sync
For fetching all branches, add the following into your remote
configuration in .git/config:
fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
fetch = +refs/tags/*:refs/tags/*
Contributing
Please follow the instructions mentioned on the V8 wiki.