Commit Graph

187 Commits

Author SHA1 Message Date
aarzilli
d7d4c144c8 cmd/dlv,terminal: fix accept-multiclient behavior
1. Check IsMulticlient and send stop request before doing anything
   else.
2. Allow init file to call 'exit'

Fixes #1430
2018-12-03 09:58:29 -08:00
aarzilli
85e4ba439c proc/core: add support for windows minidumps
Minidumps are the windows equivalent of unix core files.
This commit updates pkg/proc/core so that it can open and read windows
minidumps.

Updates #794
2018-11-21 12:17:16 -08:00
aarzilli
f813520e9b tests: minor fixes for Go 1.12 2018-11-20 12:57:25 -08:00
aarzilli
73d636f7d7 tests: rename _fixtures/vendor to _fixtures/internal
Some tests used a fake vendor directory placed inside _fixtures to
import some support packages.
In go.mod mode vendor directory are only supported on the root of the
project, which breaks some of our tests.
Since vendor directories outside the root of the project are so rare
anyway it's possible that a future version of go will stop supporting
it even in GOPATH mode.
Also it was weird and unnecessary in the first place anyawy.
2018-11-06 08:52:06 -08:00
aarzilli
f72c48c034 proc: Continue should always work after CallFunction
Continue did not resume execution after a call to CallFunction if the
point where the process was stopped, before the call CallFunction, was
a breakpoint.

Fixes #1374
2018-10-17 09:07:36 -07:00
aarzilli
b59032516e proc,service,terminal: eval expressions in the scope of a deferred call
Add ability to evaluate variables on the scope of a deferred call's
argument frame.
2018-10-16 08:40:07 -07:00
aarzilli
d2904322fa proc: add flag to disable escape checking in function calls
Fix escape checking in function calls  and add a flag to disable it.
2018-10-15 09:31:35 -07:00
chainhelen
143cf6aebf pkg/proc: extend conversion about string for array/str
Extend `string()`
1.convert `byte/rune array`(not only `slice`) to string.
2.convert string to string(itself), just like `string(str)` in go language.
2018-10-15 09:27:39 -07:00
aarzilli
79a0e216ab proc: add iface.(data) syntax to access concrete value of an interface
With this syntax users do not need to type the concrete type of an
interface variable to access its contents. This also sidesteps the
problem where the serialization of a type by go/printer is different
from the one used for debug_info type names.

Updates #1328
2018-09-27 14:09:26 -07:00
aarzilli
0461af8392 proc: fix type of some struct global variables
Normally variables that have a named struct as a type will get a
typedef entry as their type, sometimes however the Go linker will
decide to use the DW_TAG_structure_type entry instead.

For consistency always wrap a struct type into a typedef when we are
creating a new variables (see comment in newVariable for exceptions).

This fixes a bug where it would be impossible to call methods on a
global variable.
2018-08-29 16:16:20 -07:00
aarzilli
cab09a4bbb proc: fix next when disassembly fails
Next should work even if one or more instructions in the current
function can not be disassembled.
2018-08-29 16:11:18 -07:00
aarzilli
19ba86c0c9 proc: support calls through function pointers 2018-08-16 12:44:02 -07:00
aarzilli
7c42fc51d7 proc: support calls to methods directly and through interface 2018-08-16 12:44:02 -07:00
aarzilli
51994aafd3 proc: evaluate var.method expressions
Evaluates var.method expressions into a variable holding the
corresponding method with the receiver variable as a child, in
preparation for extending CallFunction so that it can call methods.
2018-08-16 12:44:02 -07:00
aarzilli
9335c54014 proc: use (*Variable).setValue in fncall 2018-08-15 10:29:16 -07:00
aarzilli
12a3f8bb97 proc: change (*Variable).setValue for use in CallFunction
Changes (*Variable).setValue so that it can be used in CallFunction to
set up the argument frame for the function call, adding the ability to:
- nil nillable types
- set strings to the empty string
- copy from one structure to another (including strings and slices)
- convert any interface type to interface{}
- convert pointer shaped types (map, chan, pointers, and structs
  consisting of a single pointer field) to interface{}

This covers all cases where an assignment statement can be evaluated
without allocating memory or calling functions in the target process.
2018-08-15 10:29:16 -07:00
aarzilli
8f1fc63da8 proc,service,terminal: read defer list
Adds -defer flag to the stack command that decorates the stack traces
by associating each stack frame with its deferred calls.

Reworks proc.next to use this feature instead of using proc.DeferPC,
laying the groundwork to implement #1240.
2018-07-24 14:58:56 -07:00
aarzilli
2925c0310a *: function call injection for go 1.11
Implements the function call injection protocol introduced in go 1.11
by https://go-review.googlesource.com/c/go/+/109699.

This is only the basic support, see TODO comments in pkg/proc/fncall.go
for a list of missing features.

Updates #119
2018-07-13 13:37:54 -07:00
aarzilli
0c15ca5f19 proc: allow breakpoint conditions to contain a single boolean variable
Fixes a bug where breakpoint condition evaluation would never load the
value if the breakpoint condition consisted of just a single variable.

Fix #1264
2018-07-09 17:25:47 -07:00
aarzilli
2a2d1040e9 proc: allow "package/path".varname syntax
If the application being debugged imports two packages with the same
name (but different paths) there was no way to disambiguate the two,
since the character '/' can not appear inside a go identifier.

By allowing users to use a string literal as the package name a package
path can be specified.
2018-06-14 09:29:23 -07:00
aarzilli
60c58acb8e proc,service: display return values when stepping out of a function
Displays the return values of the current function when we step out of
it after executing a step, next or stepout command.

Implementation of this feature is tricky: when the function has
returned the return variables are not in scope anymore. Implementing
this feature requires evaluating variables that are out of scope, using
a stack frame that doesn't exist anymore.

We can't calculate the address of these variables when the
next/step/stepout command is initiated either, because between that
point and the time where the stepout breakpoint is actually hit the
goroutine stack could grow and be moved to a different memory address.
2018-06-12 11:35:56 +02:00
aarzilli
5155ef047f proc,dwarf/line: support is_stmt and prologue_end flags
Go1.11 uses the is_stmt flag of .debug_line to communicate which
assembly instructions are good places for breakpoints, we should
respect this flag.

These changes were introduced by:
* https://go-review.googlesource.com/c/go/+/102435/

Additionally when setting next breakpoints ignore all PC addresses that
belong to the same line as the one currently under at the cursor. This
matches the behavior of gdb and avoids stopping multiple times at the
heading line of a for statement with go1.11.

Change: https://go-review.googlesource.com/c/go/+/110416 adds the
prologue_end flag to the .debug_line section to communicate the end of
the stack-split prologue. We should use it instead of pattern matching
the disassembly when available.

Fixes #550

type of interfaces
'c7cde8b'.
2018-06-11 11:09:02 -07:00
Sergio Lopez
bafa512067 proc_test: implement test for DWZ compressed DWARF
If dwz binary is available in the system, test delve's ability to find
deduplicated symbols in the DWARF information.

dwzcompression.go contains a small C function (void fortytwo()) which
calls glibc's fprintf with stdin as first argument. Normally, stdin
will be present as a DW_TAG_variable as part of a DW_TAG_compile_unit
named dwzcompression.cgo2.c.

After running dwz on the binary, stdin is moved to a
DW_TAG_partial_unit, which is imported from dwzcompression.cgo2.c with
a DW_TAG_imported_unit.

This test verifies that delve is able to find stdin symbol's type, as a
way to confirm it understands dwz's compressed/deduplicated DWARF
information.
2018-05-23 13:59:45 -07:00
aarzilli
7fd47749ef proc: Flag shadowed arguments as shadowed
Fixes #951
2018-04-23 10:13:21 -07:00
aarzilli
b9c4a1d68c proc: Short circuit evaluation of && and || like go does
Change evaluation of binary operators so that both && and || only
evaluate their second argument conditionally, like go does.
2018-04-13 15:34:03 -07:00
aarzilli
a708d00e78 proc/eval: strings of different length are never equal 2018-04-10 14:46:31 -07:00
aarzilli
290e8e7528 proc: support inlining
Go 1.10 added inlined calls to debug_info, this commit adds support
for DW_TAG_inlined_call to delve, both for stack traces (where
inlined calls will appear as normal stack frames) and to correct
the behavior of next, step and stepout.

The calls to Next and Frame of stackIterator continue to work
unchanged and only return real stack frames, after reading each line
appendInlinedCalls is called to unpacked all the inlined calls that
involve the current PC.

The fake stack frames produced by appendInlinedCalls are
distinguished from real stack frames by having the Inlined attribute
set to true. Also their Current and Call locations are treated
differently. The Call location will be changed to represent the
position inside the inlined call, while the Current location will
always reference the real stack frame. This is done because:

* next, step and stepout need to access the debug_info entry of
the real function they are stepping through
* we are already manipulating Call in different ways while Current
is just what we read from the call stack

The strategy remains mostly the same, we disassemble the function
and we set a breakpoint on each instruction corresponding to a
different file:line. The function in question will be the one
corresponding to the first real (i.e. non-inlined) stack frame.

* If the current function contains inlined calls, 'next' will not
set any breakpoints on instructions that belong to inlined calls. We
do not do this for 'step'.

* If we are inside an inlined call that makes other inlined
functions, 'next' will not set any breakpoints that belong to
inlined calls that are children of the current inlined call.

* If the current function is inlined the breakpoint on the return
address won't be set, because inlined frames don't have a return
address.

* The code we use for stepout doesn't work at all if we are inside
an inlined call, instead we call 'next' but instruct it to remove
all PCs belonging to the current inlined call.
2018-03-26 14:30:38 -04:00
Yasushi Saito
82aff3f18a Extend the "frame" command to set the current frame. (#1110)
* Extend the "frame" command to set the current frame.

Command

  frame 3

sets up so that subsequent "print", "set", "whatis" command
will operate on frame 3.

  frame 3 print foo

continues to work.

Added "up", "down". They move the current frame up or down.

Implementation note:

This changes removes "scopePrefix" mode from the terminal/command.go and instead
have the command examine the goroutine/frame value to see if it is invoked in a
scoped context.

* Rename Command.Frame -> Command.frame.
2018-03-22 10:02:15 -07:00
aarzilli
84ce278352 proc: allow evaluating constants specified with a partial package path
Fixes #1151
2018-03-20 09:46:35 -07:00
aarzilli
918ab760a4 proc/core: Make TestCoreFpTest less flaky
Registers XMM1 and XMM2 get sometimes clobbered between the time we set
them and the panic. There is no guarantee that they won't in the go
spec so we shouldn't expect any register to keep its value. However
since this seems to only affect 1 and 2 let's try to use 9 and 10
instead.
2018-03-20 09:34:05 -07:00
Josh Soref
1d3b41f64e all: Spelling 2018-03-20 11:05:35 +01:00
aarzilli
449b3cedef proc: manual stop requests should clear internal breakpoints
Fixes #1145
2018-03-08 12:02:29 -08:00
aarzilli
cd5203e305 proc: fix reading of empty strings in core files
Every time we read an empty string we accidentally issue a read for 0
bytes at address 0, this is fine for real memory but the core file
reader doesn't like it.

Fixes an issue reported on the mailing list.
2018-03-08 11:58:03 -08:00
aarzilli
f32ce1b21d proc/native: fix race condition between Halt and process death (linux)
If a breakpoint is hit close to process death on a thread that isn't
the group leader the process could die while we are trying to stop it.

This can be easily reproduced by having the goroutine that's executing
main.main (which will almost always run on the thread group leader)
wait for a second goroutine before exiting, then setting a breakpoint
on the second goroutine and stepping through it (see TestIssue1101 in
proc_test.go).

When stepping over the return instruction of main.f the deferred
wg.Done() call will be executed which will cause the main goroutine to
resume and proceed to exit. Both the temporary breakpoint on wg.Done
and the temporary breakpoint on the return address of main.f will be in
close proximity to main.main calling os.Exit() and causing the death of
the thread group leader.

Under these circumstances the call to native.(*Thread).waitFast in
native.(*Thread).halt can hang forever due to a bug similar to
https://sourceware.org/bugzilla/show_bug.cgi?id=12702 (see comment in
native.(*Thread).wait for an explanation).

Replacing waitFast with a normal wait work in most circumstances,
however, besides the performance hit, it looks like in this
circumstances trapWait sometimes receives a spurious SIGTRAP on the
dying group leader which would cause the subsequent call to wait in
halt to accidentally reap the process without noting that it did exit.

Instead this patch removes the call to wait from halt and instead calls
trapWait in a loop in setCurrentBreakpoints until all threads are set
to running=false. This is also a better fix than the workaround to
ESRCH error while setting current breakpoints implemented in 94b50d.

Fixes #1101
2018-03-06 09:06:19 -08:00
aarzilli
dc7a4ccb16 proc: support interface type resolution for packages containing a dot
If the last entry of the package path contains a '.' the corresponding
DIEs for its types will replace the '.' character with '%2e'. We must
do the same when resolving the package path of the concrete type of an
interface variable.

Fixes #1137
2018-03-05 10:07:11 -08:00
Alessandro Arzilli
bec6a65b15
proc,prettyprint: guard against autodereferenced escaped pointers (#1077)
Much like the bug in issue #1031 and commit
f6f6f0bf13e4c708cb501202b83a6327a0f00e31 pointers can also escape to
the heap and then have a zero address (and no children) when we
autodereference.

1. Mark autodereferenced escaped variables with a 0 address as
   unreadable.
2. Add guards to the pretty printers for unsafe.Pointer and pointers.

Fixes #1075
2018-01-19 15:50:28 +01:00
Yasushi Saito
c5c41f6352 command/terminal: allow restart to change process args (#1060)
* command/terminal: allow restart to change process args

Add -args flag to "restart" command. For example, "restart -args a b c" will
pass args a b c to the new process.

Add "-c" flag to pass the checkpoint name. This is needed to disambiguate the
checkpoint name and arglist.

Reverted unnecessary changes.

* Applied reviewer comments.

Vendored argv.

Change the syntax of restart. When the target is is in recording mode, it always
interprets the args as a checkpoint. Otherwise, it interprets the args as
commandline args. The flag "-args" is still there, to handle the case in which
the user wants to pass an empty args on restart.

* Add restartargs.go.

Change "restart -args" to "restart -noargs" to clarify that this flag is used to
start a process with an empty arg.
2018-01-18 14:16:11 -08:00
Florin Patan
480fc02d50 Remove limitation of exit notification only for specific API calls 2018-01-02 11:28:43 -08:00
aarzilli
8b4392dc46 pkg/proc: use constants to describe variable value 2017-12-13 12:18:18 -08:00
aarzilli
85669434f6 pkg/proc: use DW_AT_decl_line to determine var visibility
Fixes #186, #83
2017-12-13 12:18:18 -08:00
aarzilli
5372588c61 proc: support cgo stacktraces
When creating a stack trace we should switch between the goroutine
stack and the system stack (where cgo code is executed) as appropriate
to reconstruct the logical stacktrace.

Goroutines that are currently executing on the system stack will have
the SystemStack flag set, frames of the goroutine stack will have a
negative FrameOffset (like always) and frames of the system stack will
have a positive FrameOffset (which is actually just the CFA value for
the frame).

Updates #935
2017-11-28 11:00:53 -08:00
aarzilli
844762a853 proc: support access to chan buffers
Replace the unsafe.Pointer type of the buf field of channels with the
appropriate array type, allow expressions accessing member field of the
channel struct.

Fixes #962
2017-11-20 12:03:35 -08:00
aarzilli
1ced7c3a60 proc: next should not skip lines with conditional bps
Conditional breakpoints with unmet conditions would cause next and step
to skip the line.

This breakpoint changes the Kind field of proc.Breakpoint from a single
value to a bit field, each breakpoint object can represent
simultaneously a user breakpoint and one internal breakpoint (of which
we have several different kinds).

The breakpoint condition for internal breakpoints is stored in the new
internalCond field of proc.Breakpoint so that it will not conflict with
user specified conditions.

The breakpoint setting code is changed to allow overlapping one
internal breakpoint on a user breakpoint, or a user breakpoint on an
existing internal breakpoint. All other combinations are rejected. The
breakpoint clearing code is changed to clear the UserBreakpoint bit and
only remove the phisical breakpoint if no other bits are set in the
Kind field. ClearInternalBreakpoints does the same thing but clearing
all bits that aren't the UserBreakpoint bit.

Fixes #844
2017-11-20 11:25:35 -08:00
aarzilli
40ae277ab2 pkg/prog/test: add flag to run target with -race flag
Adds test command line flag to compile target fixtures using the -race flag.
Multiple tests will fail because of https://github.com/golang/go/issues/22600
but eventually this should work.
2017-11-15 08:51:57 -08:00
aarzilli
73a39b985a pkg/dwarf/line: improve performance
1. Use a slice instead of a map to access standard and extended opcodes
   (reduces BenchmarkStateMachine from ~12ms/op to ~7ms/op)

2. Cache StateMachine values for the entry point of functions.
2017-11-03 20:57:04 +01:00
aarzilli
8f16b371d1 proc/eval: support more type casts
* string to []rune
* string to []byte
* []rune to string
* []byte to string
* any pointer to uintptr

The string, []rune, []byte conversion pairs aligns this to the go
language.
The pointer -> uintptr conversion pair is symmetric to the uintptr ->
pointer that we already have.

Also lets the user specify any size for byte array types instead of
just the ones already used by the program, this can be used to read
arbitrary memory.

Fixes #548, #867
2017-10-25 13:20:25 +02:00
aarzilli
25765063fc proc/variables: distinguish between nil and empty slices and maps
Fixes #959
2017-09-11 11:43:37 -07:00
aarzilli
2ad9ce6fe3 proc: lexical block support
Fixes #106
2017-08-01 11:20:25 -06:00
aarzilli
731829c349 proc: auto-dereference local variables that escape to the heap
The compiler a variable 'v' that escapes to the heap with a '&v' entry.
Auto dereference those local variables.

Fixe #871
2017-08-01 11:20:25 -06:00
Alessandro Arzilli
e0ac447a75 debugger/locations: if locspec isn't found try interpreting it as expr (#858)
If the user tries to list the contents of a function pointer but
forgets the '*' operator the location lookup will fail and result in a
unhelpful "location not found" error.

Instead if the location lookup fails we should try interpreting the
locspec as if it was preceded by '*'.
2017-07-26 12:52:51 -06:00