This piggy-backs on top of existing precise and best-effort coverage to expose
block coverage through the inspector protocol.
Coverage collection now implicitly reports block-granularity coverage when
available. A new 'isBlockCoverage' property on Inspector's FunctionCoverage
type specifies the granularity of reported coverage.
For now, only count-based block coverage is supported, but binary block
coverage should follow soon.
Support is still gated behind the --block-coverage flag.
Bug: v8:6000
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I9c4d64e1d2a098e66178b3a68dcee800de0081af
Reviewed-on: https://chromium-review.googlesource.com/532975
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46157}
This CL improves reported source range precision in a couple of ways:
Source ranges are now standardized to consist of an inclusive start
index and an exclusive end index (similar to what's reported for
functions). For example:
0123456789 // Offset.
{ f(); } // Block represented as range {0,8}.
Duplicate singleton ranges (i.e. same start and end offsets) are now
merged (this only becomes relevant once jump statement coverage is
added). For example:
for (.) break; // Break- and loop continuation have same positions.
SourceRangeScope incorrectly collected starting position
(unconditionally) and end position (when no semi-colon was present).
01234567890123 // Offset.
for (.) break // Loop body range is {8,13}, was {6,9}.
Bug: v8:6000
Change-Id: I62e7c70cc894a20f318330a2fbbcedc47da2b5db
Reviewed-on: https://chromium-review.googlesource.com/541358
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46095}
Track execution counts of the continuations of block structures (e.g.
IfStatements) to capture cases in which execution does not continue after a
block. For example:
for (;;) {
return;
}
// Never reached, tracked by continuation counter.
A continuation counter only has a start position; it's range is implicitly
until the next sibling range or the end of the parent range.
Bug: v8:6000
Change-Id: I8e8f1f5b140b64c86754b916e626eb50f0707d70
Reviewed-on: https://chromium-review.googlesource.com/530846
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46006}
This CL implements general infrastructure for block coverage together with
initial support for if-statements.
Coverage output can be generated in lcov format by d8 as follows:
$ d8 --block-coverage --lcov=$(echo ~/simple-if.lcov) ~/simple-if.js
$ genhtml ~/simple-if.lcov -o ~/simple-if
$ chrome ~/simple-if/index.html
A high level overview of the implementation follows:
The parser now collects source ranges unconditionally for relevant AST nodes.
Memory overhead is very low and this seemed like the cleanest and simplest
alternative.
Bytecode generation uses these ranges to allocate coverage slots and insert
IncBlockCounter instructions (e.g. at the beginning of then- and else blocks
for if-statements). The slot-range mapping is generated here and passed on
through CompilationInfo, and is later accessible through the
SharedFunctionInfo.
The IncBlockCounter bytecode fetches the slot-range mapping (called
CoverageInfo) from the shared function info and simply increments the counter.
We don't collect native-context-specific counts as they are irrelevant to our
use-cases.
Coverage information is finally generated on-demand through Coverage::Collect.
The only current consumer is a d8 front-end with lcov-style output, but the
short-term goal is to expose this through the inspector protocol.
BUG=v8:6000
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng
Review-Url: https://codereview.chromium.org/2882973002
Cr-Commit-Position: refs/heads/master@{#45737}
With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.
Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.
Also change best effort coverage to be implicitly binary.
R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2766573003
Cr-Commit-Position: refs/heads/master@{#44074}
We used to clear invocation counts when enabling precise coverage.
This is not necessary, and we could continue to use the existing
invocation counts on the heap. The old behavior can be achieved
by explicitly resetting the counts by polling coverage data.
R=jgruber@chromium.org,caseq@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2768453002
Cr-Commit-Position: refs/heads/master@{#43964}
If the top-level function cannot be found, we previously assumed an
invocation count of 1. This is wrong when we expect the invocation
counts to be reset for precise coverage.
TBR=jgruber@chromium.orgR=caseq@chromium.org,pfeldman@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2723003007
Cr-Commit-Position: refs/heads/master@{#43620}
Collecting precise invocation counts need to be explicitly
enabled. Once enabled, we disable optimization (optimized
code does not increment invocation count, and may inline
callees), and make sure feedback vectors interesting for
code coverage is not garbage-collected.
R=hpayer@chromium.org, jgruber@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2686063002
Cr-Commit-Position: refs/heads/master@{#43082}
Collect code coverage from the available invocation counts.
The granularity is at function level, and invocation counts may
be lost to GC.
Coverage::Collect returns a std::vector of Coverage::ScriptData.
Each ScriptData contains a script ID and a std::vector of
Coverage::RangeEntry.
Each RangeEntry consists of a end position and the invocation
count. The start position is implicit from the end position of
the previous RangeEntry, or 0 if it's the first RangeEntry.
R=jgruber@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2689493002
Cr-Commit-Position: refs/heads/master@{#43072}
