Increases the maximum string length from 64 to 1MB when loading strings
for a binary operator, also delays the loading until it's necessary.
This ensures that comparison between strings will always succeed in
reasonable situations.
Fixes#1615
Backports debug/dwarf commit: 535741a69a1300d1fe2800778b99c8a1b75d7fdd
CL: https://go-review.googlesource.com/18459
The x/debug/dwarf that we used for dwarf/godwarf/type.go was forked
from debug/dwarf long before this commit.
Original description:
Currently readType simultaneously constructs a type graph and resolves
the sizes of the types. However, these two operations are
fundamentally at odds: the order we parse a cyclic structure in may be
different than the order we need to resolve type sizes in. As a
result, it's possible that when readType attempts to resolve the size
of a typedef, it may dereference a nil Type field of another typedef
retrieved from the type cache that's only partially constructed.
To fix this, we delay resolving typedef sizes until the end of the
readType recursion, when the full type graph is constructed.
Fixes#1601
If the argument of 'source' ends in '.star' it will be interpreted as a
starlark script.
If the argument of 'source' is '-' an interactive starlark repl will be
started.
For documentation on how the starlark execution environment works see
Documentation/cli/starlark.md.
The starlark API is autogenerated from the JSON-RPC API by
script/gen-starlark-bindings.go.
In general for each JSON-RPC API a single global starlark function is
created.
When one of those functions is called (through a starlark script) the
arguments are converted to go structs using reflection. See
unmarshalStarlarkValue in pkg/terminal/starbind/conv.go.
If there are no type conversion errors the JSON-RPC call is executed.
The return value of the JSON-RPC call is converted back into a starlark
value by interfaceToStarlarkValue (same file):
* primitive types (such as integers, floats or strings) are converted
by creating the corresponding starlark value.
* compound types (such as structs and slices) are converted by wrapping
their reflect.Value object into a type that implements the relevant
starlark interfaces.
* api.Variables are treated specially so that their Value field can be
of the proper type instead of always being a string.
Implements #1415, #1443
* proc: allow simultaneous call injection to multiple goroutines
Changes the call injection code so that we can have multiple call
injections going on at the same time as long as they happen on distinct
goroutines.
* proc: fix EvalExpressionWithCalls for constant expressions
The lack of address of constant expressions would confuse EvalExpressionWithCalls
Fixes#1577
* tests: fix tests for Go 1.13
- Go 1.13 doesn't autogenerate init functions anymore, tests that
expected that now fail and should be skipped.
- Plugin tests now need -gcflags'all=-N -l' now, we were probably
getting lucky with -gcflags='-N -l' before.
* proc: allow signed integers as shift counts
Go1.13 allows signed integers to be used as the right hand side of a
shift operator, change eval to match.
* goversion: update maximum supported version
* travis: force Go to use vendor directory
Travis scripts get confused by "go: downloading" lines, the exact
reason is not clear. Testing that the vendor directory is up to date is
a good idea anyway.
Support for bulk queries makes the DWARF quality checker
(github.com/dr2chase/dwarf-goodness/cmd/dwarf-goodness)
run much more efficiently (replace quadratic cost with
linear).
The location specified '<fnname>:0' could be used to set a breakpoint
on the entry point of the function (as opposed to locspec '<fnname>'
which sets it after the prologue).
Setting a breakpoint on an entry point is almost never useful, the way
this feature was implemented could cause it to be used accidentally and
there are other ways to accomplish the same task (by setting a
breakpoint on the PC address directly).
Also fixes findCompileUnitForOffset which was broken in some edge cases
(when looking up an offset inside the last child of the compilation
unit) which don't happen in normal executables (we only look up types, and those
are always direct childs of compile units).
Allow changing the value of a string variable to a new literal string,
which requires calling runtime.mallocgc to allocate the string into the
target process.
This means that a command like:
call f("some string")
is now supported.
Additionally the command:
call s = "some string"
is also supported.
Fixes#826
The bitmasks for transforming a 64-bit register into it's lower-bit
counterparts (e.g. RAX -> EAX -> AX -> AH/AL) were incorrect. This patch
fixes the bitmasks and adds an additional test.
Childless compile units would confuse loadDebugInfoMaps.
No test because I don't know what causes go to invoke GNU As in such a
way that it produces a childless compile unit.
Fixes#1572
Without this a client calling an method on a version of Delve that
doesn't have that method (for example because it's old) will never get
a response back.
Instead of reading partial units as we see them skip them entirely and
then re-read them when they are imported, directly into the destination
compile unit.
This avoids a lot of duplicate code in the loadDebugInfoMaps function
and will simplify implementing logical breakpoints and support for the
new DW_AT_go_package_name attribute added in Go 1.13.
The current wording is confusing - the file exists and the line exists, so what is the problem? I suspect this ambiguity is behind #1496 and likely others.
Also I updated the style to return values like the rest of the code in the file, which is also more readable (IMO and per https://github.com/golang/go/wiki/CodeReviewComments#named-result-parameters)
* proc: support nested function calls
Changes the code in fncall.go to support nested function calls.
This changes delays argument evaluation until after we have used
the call injection protocol to allocate an argument frame. When
evaluating the parse tree of an expression we'll initiate each
function call we find on the way down and then complete the function
call on the way up.
For example. in:
f(g(x))
we will:
1. initiate the call injection protocol for f(...)
2. progress it until the point where we have space for the arguments
of 'f' (i.e. when we receive the debugCallAXCompleteCall message
from the target runtime)
3. inititate the call injection protocol for g(...)
4. progress it until the point where we have space for the arguments
of 'g'
5. copy the value of x into the argument frame of 'g'
6. finish the call to g(...)
7. copy the return value of g(x) into the argument frame of 'f'
8. finish the call to f(...)
Updates #119
* proc: bugfix: closure addr was wrong for non-closure functions
The initial implementation of the 'call' command required the
function call to be the root expression, i.e. something like:
double(3) + 1
was not allowed, because the root expression was the binary operator
'+', not the function call.
With this change expressions like the one above and others are
allowed.
This is the first step necessary to implement nested function calls
(where the result of a function call is used as argument to another
function call).
This is implemented by replacing proc.CallFunction with
proc.EvalExpressionWithCalls. EvalExpressionWithCalls will run
proc.(*EvalScope).EvalExpression in a different goroutine. This
goroutine, the 'eval' goroutine, will communicate with the main
goroutine of the debugger by means of two channels: continueRequest
and continueCompleted.
The eval goroutine evaluates the expression recursively, when
a function call is encountered it takes care of setting up the
function call on the target program and writes a request to the
continueRequest channel, this causes the 'main' goroutine to restart
the target program by calling proc.Continue.
Whenever Continue encounters a breakpoint that belongs to the
function call injection protocol (runtime.debugCallV1 and associated
functions) it writes to continueCompleted which resumes the 'eval'
goroutine.
The 'eval' goroutine takes care of implementing the function call
injection protocol.
When the expression is fully evaluated the 'eval' goroutine will
write a special message to 'continueRequest' signaling that the
expression evaluation is terminated which will cause Continue to
return to the user.
Updates #119
This change splits the BinaryInfo object into a slice of Image objects
containing information about the base executable and each loaded shared
library (note: go plugins are shared libraries).
Delve backens are supposed to call BinaryInfo.AddImage whenever they
detect that a new shared library has been loaded.
Member fields of BinaryInfo that are used to speed up access to dwarf
(Functions, packageVars, consts, etc...) remain part of BinaryInfo and
are updated to reference the correct image object. This simplifies this
change.
This approach has a few shortcomings:
1. Multiple shared libraries can define functions or globals with the
same name and we have no way to disambiguate between them.
2. We don't have a way to handle library unloading.
Both of those affect C shared libraries much more than they affect go
plugins. Go plugins can't be unloaded at all and a lot of name
collisions are prevented by import paths.
There's only one problem that is concerning: if two plugins both import
the same package they will end up with multiple definition for the same
function.
For example if two plugins use fmt.Printf the final in-memory image
(and therefore our BinaryInfo object) will end up with two copies of
fmt.Printf at different memory addresses. If a user types
break fmt.Printf
a breakpoint should be created at *both* locations.
Allowing this is a relatively complex change that should be done in a
different PR than this.
For this reason I consider this approach an acceptable and sustainable
stopgap.
Updates #865
Remove the breakpoint set in TestCallConcurrent so that it doesn't
interfere with the call injection protocol.
The fact that it can is a bug but that bug is better addressed after
PRs #1503 and #1504 are merged, this keeps tests happy in the meantime.
Fixes#1542
Before doing anything check that the version of Go is compatible with
the current version of Delve.
This will improve the error message in the case that another change as
disruptive as Go1.11 dwarf compression, happens.
Go 1.12 introduced a change to the internal map representation where
empty map cells can be marked with a tophash value of 1 instead of just
0.
Fixes#1531
RestoreRegisters on linux would also restore FS_BASE and GS_BASE, if
the target goroutine migrated to a different thread during the call
injection this would result in two threads of the target process
pointing to the same TLS area which would greatly confuse the target
runtime, leading to fatal panics with nonsensical stack traces.
Other backends are unaffected:
- native/windows doesn't store the TLS in the same CONTEXT struct as
the other register values.
- native/darwin doesn't support function calls (and wouldn't store the
TLS value in the same struct)
- gdbserial/rr doesn't support function calls (because it's a
recording)
- gsdbserial/lldb extracts the value of TLS by executing code in the
target process.
* *: use loglevel to control what gets logged instead of output redirection
This stops logrus from doing all the formatting just to discard it
immediately afterwards.
* logflags: replace default formatter of logrus
The default formatter of logrus emits logs in two different formats
depending on whether or not the output is going to a terminal. The
output format for non-terminals is indented to be machine readable, but
we mostly read logs ourselves and the excessive quoting makes that
format unreadable.
When outputting to terminals it uses ANSI escape codes unconditionally,
without checking whether the terminal it is connected to actually
supports colors.
This commit replaces the default formatter with a much simpler
formatter that always uses a more readable format, doesn't use colors
and places the key-value pairs at the beginning of the line (which is a
better match for how we use them).
* cmd/dlv: add command line options to redirect logs
Adds two options, --log-to-file and --log-to-fd, to redirect logs to a
file or to a file descriptor.
When one of those two options is specified the "API server listening
at:" message will also be redirected to the specified file/file
descriptor.
This allows clients that want to use the "API server listening at:"
message to do so even if they want to redirect the target's stdout to
another file or device.
Implements #1179, #1523
Adds initial support for plugins, this is only the code needed to keep
track of loaded plugins on linux (both native and gdbserial backend).
It does not actually implement support for debugging plugins on linux.
Updates #865
Like we do with unrecovered panics, create a default breakpoint to
catch runtime errors that will cause the program to terminate.
Primarily intended to give users the opportunity to examine the state
of a deadlocked process.
runtime.clone (on some operating systems?) work similarly to fork:
when a thread calls runtime.clone a new thread is created. For a
short period of time both the parent thread and the child thread
appear to be running the same goroutine, until the child thread
adjusts its TLS to point to the correct goroutine.
This means that proc.GetG for a thread that's currently running
'runtime.clone' could be wrong and, consequently, the field
proc.(G).thread of a G struct returned by GoroutinesInfo could be
also wrong. And, finally, that FindGoroutine could sometimes return
a *G with a bad associated thread if the goroutine of interest
recently called 'runtime.clone'.
To work around this problem this commit makes two changes:
1. proc.GetG will return nil for all threads executing runtime.clone.
2. FindGoroutine will return the selected goroutine as long as the
ID matches the one requested.
Change (1) takes care of the 'runtime.clone' problem. If we stop
the target process shortly after a thread executed the SYSCALL
instruction in 'runtime.clone' there are three possibilities:
a. Both the parent thread and the child thread are stopped inside
'runtime.clone'. In this case the state we report is slightly
incorrect, because both threads will be reported as not running any
goroutine when we do know which goorutine one of them (the parent)
is running. This doesn't actually matter since runtime.clone is
always called on the system stack and therefore the goroutine in
runtime.allgs will have the correct location.
b. The child thread managed to exit 'runtime.clone' but the parent
thread didn't. This is similar to (a) but in this case GetG on the
child thread will return the correct goroutine. GetG on the parent
thread will still return (incorrectly) nil but this doesn't matter
for the samer reason as described in (a).
c. The parent thread managed to exit 'runtime.clone' but the child
thread didn't. In this case GetG will return the correct goroutine
both for the parent thread (because it's not executing runtime.clone)
and the child thread.
Change (2) means that even if a thread has a completely nonsensical
TLS (for example because it's set through cgo) evaluating a variable
with a valid GoroutineID will still work as long as it's the current
goroutine (which is the most common case). This change also doubles
as an optimization for FindGoroutine.
Fixes#1469
