This change detects concatenated profiles by checking if time_nanos appears more than once in the profile being parsed.

Fixes #273

Debian builds packages with HOME set to a bogus value and this causes tests to
fail when packaging Go 1.10...

When pprof symbolizes kernel addresses in vmlinux binary for a profile
converted using https://github.com/google/perf_data_converter, the
addresses need to be adjusted if kernel ASLR is in effect. So far the
call to GetBase did not pass text segment info to GetBase which
shortcircuited the code to merely return zero adjustment. This change
fixes the call to GetBase to address that.

The added test case is a simulation of what happens with vmlinux, but it
should be pretty close. Including a vmlinux file into the test data does
not appear practical due to the binary size. I verified that the test
failed before the fix and passes after.

Note that the fixed issue is specific to the kernel ASLR as user-mode
ASRL-enabled binaries (i.e. built with -pie / -fpie) have ET_DYN type
which takes a different code path in GetBase which did not have issues
before this fix in practice.

The current version of go vet does not flag these as noted in
golang/go#23539. A fix is in the works, and will likely be included in
Go 1.11. Make the updated vet tool happy, so that the vendored copy of
pprof in the Go tree can be updated and make the vet trybot happy.

Fixes #297.

* Support parsing of is_folded bit

* Include folded bit lin (*Location).string() and in profile mergining

* address comments

* Set IsFolded to false during symbolization when Line is reset

* simplify tests

On an instance of the Android emulator running x86_64, $HOME points
to / which is not writable. Add Android to the list of GOOS where
the temp dir error is skipped.

Fixes the android/amd64 and android/386 builders on build.golang.org.

* Fix panic on merge when one profile missing mappings

* Simplify fix for merge panics

Pull request #263 disabled the refine menu for any views other than
Graph, but that's not expected - it's perfectly fine to use it for Flame
and Top, so just keep it enabled.

Fixes #285.

The third_party svg directory has been a mix of pprof-specific code and
svgpan itself. This change moves the pprof-specific code out and adds a
license file. It also updates svgpan to 1.2.2 from
https://github.com/aleofreddi/svgpan while we are here. It also renames
the directory to svgpan to have all directories under third_party be
named precisely over the third party package they hold.

Change URL matching code to restore compatibility with old pprof (#276)

* Add documentation on getting the source.

* Update the doc more.

Add semicolons to all of JS

Indenting the JS and HTML sources for readability

Implements https://github.com/google/pprof/issues/166.

Update the web user interface aesthetically.
The Refine menu is greyed-out for pages besides the Graph.
The description box now opens upon clicking the filename in the top-right.

This will in turn fix golang.org/issues/22612 for the Go iOS
builders.

* Handle "listen hungup" error on Plan 9 in TestHttpsInsecure

Plan 9 returns the "listen hungup" error when closing a closed listener.

See https://github.com/0intro/plan9/blob/4225c3e/sys/src/9/ip/devip.c#L476

Fixes #253.

* Handle empty profile on Plan 9 in TestHttpsInsecure

CPU profiling isn't implemented on Plan 9.

See golang.org/issues/22564.

Fixes #253.

* Improve POST URL status error

* Mirror the connection error string

* Locate symbol endpoints with deeper paths

* Remove unnecessarily named return value

* Add test for deeper symbol path

Add tests for CheckValid, fix a couple crashers.

* Show menu on click, not hover.

Previously, users had to be careful to not move the mouse
outside the menu (otherwise it would disappear unintentionally).

Also fixed a minor bug where we were not overwriting URL
parameters correctly when no selection was made.

* Use vendor prefixes for user-select.

weblist output disassembly now contains inlined source.

In addition, fixed the line number assigned to instructions from inlined calls.

As an illustration, see the before and after output for a "pprof -weblist" command for a simple function:

[before](https://ghemawat.github.io/scratch/tmp/list1.html)
[after](https://ghemawat.github.io/scratch/tmp/list2.html)

Note that in the "before" page, the 7.26 second line cannot be expanded, but in the "after" page clicking on it reveals a wealth of information.

* Add support for tag units

Updated tests for adding tag units

* updated proto docs to describe tag units

* fixed formatting

* added additional test

* require specific units for graph tag to be recognixed

* updated tests and formatting

* Fixed formatting

* Fixed style error

* modify proto_test to be sure tag units not overwritten

* Clarified label docs

* call legacy profile memory allocations size, not byte

* updated tests to call bytes tags in legacy profile size

* Revert "updated tests to call bytes tags in legacy profile size"

This reverts commit 9289378af2.

* Revert "call legacy profile memory allocations size, not byte"

This reverts commit 6b18973562.

* Updated so units not modified when profile written out

* Fixed formatting errors

* Removed field for inferred numeric label units from profile

* Modified profile String() output

* fixed formatting error

* changed name of function used to identify units for numeric labels

* Refactor String() for profile

* Modified for clarity and address comments

* renamed function for clarity

* Made numeric label units field seperate in profile

* Modified test

* Refactored identifyNumLabelUnits()

* Updated comments

* Fixed formatting error

* Addressed comments

* Fixed style error

* clarify comment

* Refactored to address comments

* addressed comments

* addressed comments

* addressed comments

Added some multi-threaded tests that allow the race detector
to detect race conditions in pprof internals.

* Make binutils thread safe.

binutils is now used from multiple goroutines when the
web interface is enabled (since http server spins up a new
goroutine for each request). Added appropriate synchronization
to various objects in binutils to provide the appropriate
thread-safety.

In addition, added a bunch of tests:

. Test parsing of nm output.
. Tests for Binutils methods.
. Test llvm-symbolizer interface (using an llvm-symbolizer emulator).

* Fix go vet errors about unkeyed literals.

* copy stderr to figure out test failures

* Make shell script portable.

* Update comments to match new var name.

* Give a name to the embedded Mutex field in addr2Liner.

Replaced http wrapper field in plugin Options with HTTPServer.

HTTPServer allows somebody embedding pprof to control how the
hosting HTTP server is constructed which makes pprof work in
more environments.

Add a flag to append a comment to a profile.