Support for position independent executables (PIE) on the native linux
backend, the gdbserver backend on linux and the core backend.
Also implemented in the windows native backend, but it can't be tested
because go doesn't support PIE on windows yet.
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.
Adds a test that compares the output of our state machine with the
output of the debug_line reader in the standard library and checks that
they produce the same output for the debug_line section of grafana as
compiled on macOS (which is the most interesting case since it uses cgo
and therefore goes through dsymutil).
A few bugs were uncovered and fixed:
1. is_stmt was reset improperly after a DW_LNS_end_sequence instruction
2. basic_block, prologue_end and epilogue_begin were not reset after a
DW_LNS_copy instruction
3. some opcodes were not decoded properly if the debug_line section
declares fewer standard opcodes than we know about.
Fixes#1282
There is no guarantee that files will end up stored contiguously in the
debug_line section which makes this optimization wrong in the general
case.
In particular with recent versions of go1.11 and a go.mod file present
the go compiler seems to sometimes produce executables that actually
violate this assumption.
Go1.11 switched to the zlib-gnu compression format for debug sections.
Change proc and and a test in dwarf/line to support this change.
Also deletes some dead code from pkg/proc/bininfo.go that hadn't been
used in a long time.
Implements structured logging via Logrus. This gives us a logger per
boundry that we care about, allowing for easier parsing of logs if users
have more than one log option enabled. Also, cleans up a lot of
conditionals in the code by simply silencing the logger at creation as
opposed to conditionally logging everywhere.
go1.11 adds a new extended attribute to all type DIEs containing the
address of the corresponding runtime._type struct, use this attribute
to find the DIE of the concrete type of interface variables when
available.
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'.
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.
debug_info entries can use DW_AT_abstract_origin to inherit the
attributes of another entry, supporting this attribute is necessary to
support DW_TAG_inlined_subroutine.
Go, starting with 1.10, emits DW_TAG_inlined_subroutine entries when
inlining is enabled.
Adds a configuration option (show-location-expr) that when activated
will cause the whatis command to also print the DWARF location
expression for a variable.
On macOS, externally linked programs will have an abbrev for
DW_TAG_subprogram without the haschildren flag set. We should handle
this case instead of expecting all DW_TAG_subprogram entries to have
list of children.
Fixes#1034
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
Instead of only tracking a few cherrypicked registers in stack.go track
all DWARF registers.
This is needed for cgo code and for the locationlists emitted by go in
1.10:
* The debug_frame sections emitted by C compilers can not be used
without tracking all registers
* the loclists emitted by go1.10 need all registers of a frame to be
interpreted.
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.
gosymtab and gopclntab only contain informations about go code, linked
C code isn't there, we should use debug_line instead to also cover C.
Updates #935
Splits out type parsing and go-specific Type hierarchy from
x/debug/dwarf, replace x/debug/dwarf with debug/dwarf everywhere,
remove x/debug/dwarf from vendoring.
* Fix various issues detected by megacheck
I've ran honnef.co/go/tools/cmd/megacheck and fixed a few of the
things that came up there.
* Cleanup using Gogland
* pkg/proc: use golang.org/x/arch/x86/x86asm
instead of rsc.io/x86/x86asm
* pkg/dwarf: migrate to github.com/pkg/profile
from github.com/davecheney/profile
* scripts: keep script go files from being considered for the build
scripts/gen-*.go files are scripts for generating documentation
files and don't follow the typical Go package layout. Expected
usage is like
go run scripts/gen-cli-docs.go
* vendor: update vendored packages
There were many changes in delve, and go tool chains since last
vendored package update. I just rerun godpes from scratch.
$ rm vendor/*
$ rm Godeps/Godeps.json
$ go list ./... | grep -v /vendor/ | grep -v /scripts/ | go get -u -t
$ go get -u github.com/mattn/go-colorable
$ go get -u github.com/mattn/go-isatty
$ go list ./... | grep -v /vendor/ | grep -v /scripts/ | godeps save
