The -p flag specifies the import path of the package being compiled.
This CL makes it required when invoking the compiler and
adjusts tests that invoke the compiler directly to conform to this
new requirement. The go command already passes the flag, so it
is unmodified in this CL. It is expected that any other Go build systems
also already pass -p, or else they will need to arrange to do so before
updating to Go 1.19. Of particular note, Bazel already does for rules
with an importpath= attribute, which includes all Gazelle-generated rules.
There is more cleanup possible now in cmd/compile, cmd/link,
and other consumers of Go object files, but that is left to future CLs.
Additional historical background follows but can be ignored.
Long ago, before the go command, or modules, or any kind of
versioning, symbols in Go archive files were named using just the
package name, so that for example func F in math/rand and func F in
crypto/rand would both be the object file symbol 'rand.F'. This led to
collisions even in small source trees, which made certain packages
unusable in the presence of other packages and generally was a problem
for Go's goal of scaling to very large source trees.
Fixing this problem required changing from package names to import
paths in symbol names, which was mostly straightforward. One wrinkle,
though, is that the compiler did not know the import path of the
package being compiled; it only knew the package name. At the time,
there was no go command, just Makefiles that people had invoking 6g
(now “go tool compile”) and then copying the resulting object file to
an importable location. That is, everyone had a custom build setup for
Go, because there was no standard one. So it was not particularly
attractive to change how the compiler was invoked, since that would
break approximately every Go user at the time. Instead, we arranged
for the compiler to emit, and other tools reading object files to
recognize, a special import path (the empty string, it turned out)
denoting “the import path of this object file”. This worked well
enough at the time and maintained complete command-line compatibility
with existing Go usage.
The changes implementing this transition can be found by searching
the Git history for “package global name space”, which is what they
eliminated. In particular, CL 190076 (a6736fa4), CL 186263 (758f2bc5),
CL 193080 (1cecac81), CL 194053 (19126320), and CL 194071 (531e6b77)
did the bulk of this transformation in January 2010.
Later, in September 2011, we added the -p flag to the compiler for
diagnostic purposes. The problem was that it was easy to create import
cycles, especially in tests, and these could not be diagnosed until
link time. You'd really want the compiler to diagnose these, for
example if the compilation of package sort noticed it was importing a
package that itself imported "sort". But the compilation of package
sort didn't know its own import path, and so it could not tell whether
it had found itself as a transitive dependency. Adding the -p flag
solved this problem, and its use was optional, since the linker would
still diagnose the import cycle in builds that had not updated to
start passing -p. This was CL 4972057 (1e480cd1).
There was still no go command at this point, but when we introduced
the go command we made it pass -p, which it has for many years at this
point.
Over time, parts of the compiler began to depend on the presence of
the -p flag for various reasonable purposes. For example:
In CL 6497074 (041fc8bf; Oct 2012), the race detector used -p to
detect packages that should not have race annotations, such as
runtime/race and sync/atomic.
In CL 13367052 (7276c02b; Sep 2013), a bug fix used -p to detect the
compilation of package reflect.
In CL 30539 (8aadcc55; Oct 2016), the compiler started using -p to
identify package math, to be able to intrinsify calls to Sqrt inside
that package.
In CL 61019 (9daee931; Sep 2017), CL 71430 (2c1d2e06; Oct 2017), and
later related CLs, the compiler started using the -p value when
creating various DWARF debugging information.
In CL 174657 (cc5eaf93; May 2019), the compiler started writing
symbols without the magic empty string whenever -p was used, to reduce
the amount of work required in the linker.
In CL 179861 (dde7c770; Jun 2019), the compiler made the second
argument to //go:linkname optional when -p is used, because in that
case the compiler can derive an appropriate default.
There are more examples. Today it is impossible to compile the Go
standard library without using -p, and DWARF debug information is
incomplete without using -p.
All known Go build systems pass -p. In particular, the go command
does, which is what nearly all Go developers invoke to build Go code.
And Bazel does, for go_library rules that set the importpath
attribute, which is all rules generated by Gazelle.
Gccgo has an equivalent of -p and has required its use in order to
disambiguate packages with the same name but different import paths
since 2010.
On top of all this, various parts of code generation for generics
are made more complicated by needing to cope with the case where -p
is not specified, even though it's essentially always specified.
In summary, the current state is:
- Use of the -p flag with cmd/compile is required for building
the standard library, and for complete DWARF information,
and to enable certain linker speedups.
- The go command and Bazel, which we expect account for just
about 100% of Go builds, both invoke cmd/compile with -p.
- The code in cmd/compile to support builds without -p is
complex and has become more complex with generics, but it is
almost always dead code and therefore not worth maintaining.
- Gccgo already requires its equivalent of -p in any build
where two packages have the same name.
All this supports the change in this CL, which makes -p required
and adjusts tests that invoke cmd/compile to add -p appropriately.
Future CLs will be able to remove all the code dealing with the
possibility of -p not having been specified.
Change-Id: I6b95b9d4cffe59c7bac82eb273ef6c4a67bb0e43
Reviewed-on: https://go-review.googlesource.com/c/go/+/391014
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
When being used by the compiler, fix up types2 error messages to be more
like Go 1.17 compiler errors. In particular:
- add information about which method is missing when a type is not
assignable/convertible/etc. to an interface.
- add information about any existing method which has the same name,
but wrong type.
- add extra hint in the case that the source or destination type is a
pointer to an interface, rather than an interface.
- add extra hint "need type assertion" in the case that the source is
an interface that is implemented by the destination.
- the following change in the CL stack also adds information about any
existing method with a different name that only differs in case.
Include much of the new logic in a new common function
(*Checker).missingMethodReason().
types2 still adds a little more information in some cases then the Go
1.17 compiler. For example, it typically says "(value of type T)",
rather than "(type T)", where "value" could also be "constant",
"variable", etc.
I kept the types2 error messages almost all the same when types2 is not
used by the compiler. The only change (to reduce amount of compatibility
code) was to change "M method" phrasing in one case to "method M"
phrasing in one error message (which is the phrasing it uses in all
other cases). That is the reason that there are a few small changes in
types2/testdata/check/*.src.
Added new test test/fixedbugs/issue48471.go to test that the added
information is appearing correctly.
Also adjusted the pattern matching in a bunch of other
test/fixedbugs/*.go, now that types2 is producing error messages closer
to Go 1.17. Was able to remove a couple test files from the types2
exception list in run.go.
Updated #48471
Change-Id: I8af1eae6eb8a5541d8ea20b66f494e2e795e1956
Reviewed-on: https://go-review.googlesource.com/c/go/+/363436
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Agressively mark all LHS variables in assignments as used if there
is any error in the (entire) assignment. This reduces the number of
spurious "declared but not used" errors in programs that are invalid
in the first place. This behavior is closer to the behavior of the
compiler's original type checker (types1) and lets us remove lines
of the form "_ = variable" just to satisfy test cases. It also makes
more important errors visible by not crowding them out.
Remove the Checker.useLHS function and use Checker.use instead:
useLHS didn't evaluate top-level variables, but we actually want
them to be evaluated in an error scenario so that they are getting
used (and thus we don't get the "declared but not used" error).
Fixes#42937.
Change-Id: Idda460f6b81c66735bf9fd597c54188949bf12b8
Reviewed-on: https://go-review.googlesource.com/c/go/+/351730
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
The following files had merge conflicts and were merged manually:
src/cmd/compile/fmtmap_test.go
src/cmd/compile/internal/gc/noder.go
src/go/parser/error_test.go
test/assign.go
test/chan/perm.go
test/fixedbugs/issue22822.go
test/fixedbugs/issue4458.go
test/init.go
test/interface/explicit.go
test/map1.go
test/method2.go
The following files had manual changes to make tests pass:
test/run.go
test/used.go
src/cmd/compile/internal/types2/stdlib_test.go
Change-Id: Ia495aaaa80ce321ee4ec2a9105780fbe913dbd4c
If an interface contains a blank method, that's already an error. No
need for useless follow-up error messages about not implementing them.
Fixes#42964.
Change-Id: I5bf53a8f27d75d4c86c61588c5e2e3e95563d320
Reviewed-on: https://go-review.googlesource.com/c/go/+/275294
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
With this CL, the first ~500 errorcheck tests pass when running
go run run.go -v -G
in the $GOROOT/test directory (the log output includes a few dozen
tests that are currently skipped).
Change-Id: I9eaa2319fb39a090df54f8699ddc29ffe58b1bf1
Reviewed-on: https://go-review.googlesource.com/c/go/+/274975
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
These changes match the following gofrontend error messages:
blank1.go:16:1: error: may not define methods on non-local type
chan/perm.go:28:9: error: expected channel
chan/perm.go:29:11: error: left operand of ‘<-’ must be channel
chan/perm.go:69:9: error: argument must be channel
complit1.go:25:16: error: attempt to slice object that is not array, slice, or string
complit1.go:26:16: error: attempt to slice object that is not array, slice, or string
complit1.go:27:17: error: attempt to slice object that is not array, slice, or string
complit1.go:49:41: error: may only omit types within composite literals of slice, array, or map type
complit1.go:50:14: error: expected struct, slice, array, or map type for composite literal
convlit.go:24:9: error: invalid type conversion (cannot use type unsafe.Pointer as type string)
convlit.go:25:9: error: invalid type conversion (cannot use type unsafe.Pointer as type float64)
convlit.go:26:9: error: invalid type conversion (cannot use type unsafe.Pointer as type int)
ddd1.go:63:9: error: invalid use of ‘...’ calling non-variadic function
fixedbugs/bug176.go:12:18: error: index expression is not integer constant
fixedbugs/bug332.go:17:10: error: use of undefined type ‘T’
fixedbugs/issue4232.go:22:16: error: integer constant overflow
fixedbugs/issue4232.go:33:16: error: integer constant overflow
fixedbugs/issue4232.go:44:25: error: integer constant overflow
fixedbugs/issue4232.go:55:16: error: integer constant overflow
fixedbugs/issue4458.go:19:14: error: type has no method ‘foo’
fixedbugs/issue5172.go:24:14: error: too many expressions for struct
init.go:17:9: error: reference to undefined name ‘runtime’
initializerr.go:26:29: error: duplicate value for index 1
interface/explicit.go:60:14: error: type assertion only valid for interface types
label.go:64:9: error: reference to undefined label ‘go2’
label1.go:18:97: error: continue statement not within for
label1.go:22:97: error: continue statement not within for
label1.go:106:89: error: continue statement not within for
label1.go:108:26: error: invalid continue label ‘on’
label1.go:111:118: error: break statement not within for or switch or select
label1.go:113:23: error: invalid break label ‘dance’
map1.go:64:9: error: not enough arguments
map1.go:65:9: error: not enough arguments
map1.go:67:9: error: argument 1 must be a map
method2.go:36:11: error: reference to undefined field or method ‘val’
method2.go:37:11: error: reference to undefined field or method ‘val’
method2.go:41:12: error: method requires pointer (use ‘(*T).g’)
syntax/chan1.go:13:19: error: send statement used as value; use select for non-blocking send
syntax/chan1.go:17:11: error: send statement used as value; use select for non-blocking send
Change-Id: I98047b60a376e3d2788836300f7fcac3f2c285cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/273527
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
We seem to lack any tests for some corner cases of itab.init
(multiple methods with the same name, breaking itab.init doesn't
seem to fail any tests). We also lack tests that fix text of panics.
Add more tests for itab.init.
Change-Id: Id6b536179ba6b0d45c3cb9dc1c66b9311d0ab85e
Reviewed-on: https://go-review.googlesource.com/c/go/+/202451
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change adds line position tests for several yyerror calls in the
typechecker that are currently not tested in any way.
Untested yyerror calls were found by replacing them with
yerrorl(src.NoXPos, ...)
(thus destroying position information in the error), and then running
the test suite. No failures means no test coverage for the relevant
yyerror call.
For #19683
Change-Id: Iedb3d2f02141b332e9bfa76dbf5ae930ad2fddc3
Reviewed-on: https://go-review.googlesource.com/41477
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The code to do the conversion is smaller than the
call to the runtime.
The 1-result asserts need to call panic if they fail, but that
code is out of line.
The only conversions left in the runtime are those which
might allocate and those which might need to generate an itab.
Given the following types:
type E interface{}
type I interface { foo() }
type I2 iterface { foo(); bar() }
type Big [10]int
func (b Big) foo() { ... }
This CL inlines the following conversions:
was assertE2T
var e E = ...
b := i.(Big)
was assertE2T2
var e E = ...
b, ok := i.(Big)
was assertI2T
var i I = ...
b := i.(Big)
was assertI2T2
var i I = ...
b, ok := i.(Big)
was assertI2E
var i I = ...
e := i.(E)
was assertI2E2
var i I = ...
e, ok := i.(E)
These are the remaining runtime calls:
convT2E:
var b Big = ...
var e E = b
convT2I:
var b Big = ...
var i I = b
convI2I:
var i2 I2 = ...
var i I = i2
assertE2I:
var e E = ...
i := e.(I)
assertE2I2:
var e E = ...
i, ok := e.(I)
assertI2I:
var i I = ...
i2 := i.(I2)
assertI2I2:
var i I = ...
i2, ok := i.(I2)
Fixes#17405Fixes#8422
Change-Id: Ida2367bf8ce3cd2c6bb599a1814f1d275afabe21
Reviewed-on: https://go-review.googlesource.com/32313
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
When T is a scalar, there are no runtime calls
required, which makes this a clear win.
encoding/binary:
WriteInts-8 958ns ± 3% 864ns ± 2% -9.80% (p=0.000 n=15+15)
This also considerably shrinks a core fmt
routine:
Before: "".(*pp).printArg t=1 size=3952 args=0x20 locals=0xf0
After: "".(*pp).printArg t=1 size=2624 args=0x20 locals=0x98
Unfortunately, I find it very hard to get stable
numbers out of the fmt benchmarks due to thermal scaling.
Change-Id: I1278006b030253bf8e48dc7631d18985cdaa143d
Reviewed-on: https://go-review.googlesource.com/26659
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Try to provide hints for common areas, either *interface
were interface would have been better, and note incorrect
capitalization (but don't be more ambitious than that, at
least not today).
Added code and test for cases
ptrInterface.ExistingMethod
ptrInterface.unexportedMethod
ptrInterface.MissingMethod
ptrInterface.withwRongcASEdMethod
interface.withwRongcASEdMethod
ptrStruct.withwRongcASEdMethod
struct.withwRongcASEdMethod
also included tests for related errors to check for
unintentional changes and consistent wording.
Somewhat simplified from previous versions to avoid second-
guessing user errors, yet also biased to point out most-likely
root cause.
Fixes#10700
Change-Id: I16693e93cc8d8ca195e7742a222d640c262105b4
Reviewed-on: https://go-review.googlesource.com/9731
Reviewed-by: Russ Cox <rsc@golang.org>
These can be implemented with just a compare and a move instruction.
Do so, avoiding the overhead of a call into the runtime.
These assertions are a significant cost in Go code that uses interface{}
as a safe alternative to C's void* (or unsafe.Pointer), such as the
current version of the Go compiler.
*T here includes pointer to T but also any Go type represented as
a single pointer (chan, func, map). It does not include [1]*T or struct{*int}.
That requires more work in other parts of the compiler; there is a TODO.
Change-Id: I7ff681c20d2c3eb6ad11dd7b3a37b1f3dda23965
Reviewed-on: https://go-review.googlesource.com/7862
Reviewed-by: Rob Pike <r@golang.org>
The other tests either need a complex procedure
or are architecture- or OS-dependent.
Update #4139.
R=golang-dev, daniel.morsing, iant
CC=golang-dev
https://golang.org/cl/6618062
Today, if run.go doesn't understand a test header line it just ignores
the test, making it too easy to write or edit tests that are not actually
being run.
- expand errorcheck to accept flags, so that bounds.go and escape*.go can run.
- create a whitelist of skippable tests in run.go; skipping others is an error.
- mark all skipped tests at top of file.
Update #4139.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6549054
Accomplished by synchronizing the formatting of conversion errors between typecheck.c and subr.c
Fixes#3984.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6500064
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.
The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.
For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.
R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
Had been allowing it for use by fmt, but it is too hard to lock down.
Fix other packages not to depend on it.
R=r, r
CC=golang-dev
https://golang.org/cl/5266054
bug363.go:13:12: error: invalid context-determined non-integer type for shift operand
bug363.go:16:12: error: invalid context-determined non-integer type for shift operand
pointer.go:34:6: error: incompatible type in initialization (pointer to interface type has no methods)
pointer.go:36:6: error: incompatible type in initialization
method2.go:15:1: error: invalid pointer or interface receiver type
method2.go:16:1: error: invalid pointer or interface receiver type
method2.go:21:1: error: invalid pointer or interface receiver type
method2.go:22:1: error: invalid pointer or interface receiver type
method2.go:28:15: error: type ‘*Val’ has no method ‘val’
method2.go:33:11: error: reference to undefined field or method ‘val’
shift1.go:19:16: error: invalid context-determined non-integer type for shift operand
shift1.go:24:19: error: invalid context-determined non-integer type for shift operand
shift1.go:25:17: error: invalid context-determined non-integer type for shift operand
shift1.go:18:18: error: shift of non-integer operand
shift1.go:26:13: error: floating point constant truncated to integer
shift1.go:33:15: error: integer constant overflow
shift1.go:34:15: error: integer constant overflow
shift1.go:35:17: error: integer constant overflow
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5081051
// ERROR "pattern1" "pattern2"
means that there has to be one or more
lines matching pattern1 and then excluding
those, there have to be one or more lines
matching pattern2. So if you expect two
different error messages from a particular
line, writing two separate patterns checks
that both errors are produced.
Also, errchk now flags lines that produce
more errors than expected. Before, as long as
at least one error matched the pattern, all the
others were ignored.
Revise tests to expect or silence these
additional errors.
R=lvd, r, iant
CC=golang-dev
https://golang.org/cl/4869044
explicit.go:36:4: error: incompatible types in assignment (need explicit conversion)
explicit.go:41:4: error: incompatible types in assignment (type has no methods)
explicit.go:42:4: error: incompatible types in assignment (need explicit conversion)
explicit.go:45:5: error: incompatible types in assignment (need explicit conversion; missing method ‘N’)
explicit.go:48:9: error: invalid type conversion (need explicit conversion; missing method ‘N’)
explicit.go:51:4: error: incompatible types in assignment
explicit.go:51:7: error: invalid type conversion (need explicit conversion)
explicit.go:57:10: error: impossible type assertion: type does not implement interface (type has no methods)
explicit.go:62:10: error: impossible type assertion: type does not implement interface (incompatible type for method ‘M’ (different number of parameters))
explicit.go:67:5: error: incompatible type in initialization (type has no methods)
explicit.go:68:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different number of parameters))
explicit.go:70:11: error: invalid type conversion (type has no methods)
explicit.go:71:11: error: invalid type conversion (incompatible type for method ‘M’ (different number of parameters))
R=rsc
CC=golang-dev
https://golang.org/cl/2139044
* Code for assignment, conversions now mirrors spec.
* Changed some snprint -> smprint.
* Renamed runtime functions to separate
interface conversions from type assertions:
convT2I, assertI2T, etc.
* Correct checking of \U sequences.
Fixes#840.
Fixes#830.
Fixes#778.
R=ken2
CC=golang-dev
https://golang.org/cl/1303042
note that sortmain.go has been run through hg gofmt;
only the formatting of the day initializers changed.
i'm happy to revert that formatting if you'd prefer.
stop on error in doc/progs/run
R=r
CC=golang-dev
https://golang.org/cl/850041
