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Commit Graph

99 Commits

Author SHA1 Message Date
Yury Smolsky
669676b7b3 text/template: fix the documentation of the block action
Fixes #23520

Change-Id: Ia834819f3260691a1a0181034ef4b4b945965688
Reviewed-on: https://go-review.googlesource.com/94761
Reviewed-by: Andrew Gerrand <adg@golang.org>
2018-02-21 20:57:47 +00:00
Kunpei Sakai
af7fc752b1 text/template: avoid assiging unnecessary variable
This follows up CL95235

Change-Id: I62652654e5bb46d2f8f37af468e1fbcc1835bb8a
Reviewed-on: https://go-review.googlesource.com/95295
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-20 15:42:01 +00:00
Daniel Martí
eb5925f5ff text/template: remove associate's error return
It's always nil, so simplify its signature. Found with unparam.

Change-Id: I45dd0f868ec2f5de98a970776be686417c8d73b6
Reviewed-on: https://go-review.googlesource.com/95235
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-02-19 22:43:56 +00:00
Daniel Martí
3cb54c8604 text/template: differentiate nil from missing arg
reflect.Value is a struct and does not have a kind nor any flag for
untyped nils. As a result, it is tricky to differentiate when we're
missing a value, from when we have one but it is untyped nil.

We could start using *reflect.Value instead, to add one level of
indirection, using nil for missing values and new(reflect.Value) for
untyped nils. However, that is a fairly invasive change, and would also
mean unnecessary allocations.

Instead, use a special reflect.Value that depicts when a value is
missing. This is the case for the "final" reflect.Value in multiple
scenarios, such as the start of a pipeline. Give it a specific,
unexported type too, to make sure it cannot be mistaken for any other
valid value.

Finally, replace "final.IsValid()" with "final != missingVal", since
final.IsValid() will be false when final is an untyped nil.

Also add a few test cases, all different variants of the untyped nil
versus missing value scenario.

Fixes #18716.

Change-Id: Ia9257a84660ead5a7007fd1cced7782760b62d9d
Reviewed-on: https://go-review.googlesource.com/95215
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2018-02-19 21:32:13 +00:00
Daniel Martí
618f88d847 text/template: never call reflect.Zero(nil)
It makes no sense to try to get the zero value of a nil type, hence the
panic. When we have a nil type, use reflect.ValueOf(nil) instead.

This was showing itself if one used a missing field on the data between
parentheses, when the data was a nil interface:

	t := template.Must(template.New("test").Parse(`{{ (.).foo }}`))
	var v interface{}
	t.Execute(os.Stdout, v)

Resulting in:

	panic: reflect: Zero(nil) [recovered]
		panic: reflect: Zero(nil)

Fixes #21171.

Change-Id: Ifcc4a0c67e6df425b65bc9f82fde6fcf03828579
Reviewed-on: https://go-review.googlesource.com/84482
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2018-02-13 22:18:21 +00:00
Ian Lance Taylor
fd7331a821 text/template: revert CL 66410 "add break, continue actions in ranges"
The new break and continue actions do not work in html/template, and
fixing them requires thinking about security issues that seem too
tricky at this stage of the release. We will try again for 1.11.

Original CL description:

    text/template: add break, continue actions in ranges

    Adds the two range control actions "break" and "continue". They act the
    same as the Go keywords break and continue, but are simplified in that
    only the innermost range statement can be broken out of or continued.

    Fixes #20531

Updates #20531
Updates #23683

Change-Id: Ia7fd3c409163e3bcb5dc42947ae90b15bdf89853
Reviewed-on: https://go-review.googlesource.com/92155
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2018-02-06 05:00:01 +00:00
Ariel Mashraki
3e97c42f77 text/template: remove unnecessary lexer field
this change removes the state field from the lexer,
because it's only used by the run method and can be
replaced with a local variable

Change-Id: Ib7a90ab6e9a894716cba2c7d9ed71bf2ad1240c0
Reviewed-on: https://go-review.googlesource.com/47338
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-11-10 04:13:30 +00:00
Ariel Mashraki
2f53fb58a8 text/template: remove unused lexer field
The lastPos field used in the past to track the line number of a token.
it's irrelevant anymore, and we can remove it.

Change-Id: I42c0bf55e884b79574a7da4926489f2d77618cd0
Reviewed-on: https://go-review.googlesource.com/49591
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-11-09 21:24:21 +00:00
Daniel Martí
7cb3e4fb1d all: unindent some if bodies by exiting early
All of these had a return or break in the else body, so flipping the
condition means we can unindent and simplify.

Change-Id: If93e97504480d18a0dac3f2c8ffe57ab8bcb929c
Reviewed-on: https://go-review.googlesource.com/74190
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-31 20:07:46 +00:00
Tim Cooper
3be5d55180 text/template: add break, continue actions in ranges
Adds the two range control actions "break" and "continue". They act the
same as the Go keywords break and continue, but are simplified in that
only the innermost range statement can be broken out of or continued.

Fixes #20531

Change-Id: I4412b3bbfd4dadb0ab74ae718e308c1ac7a0a1e9
Reviewed-on: https://go-review.googlesource.com/66410
Reviewed-by: Rob Pike <r@golang.org>
2017-10-17 02:06:15 +00:00
Daniel Martí
57e7d62455 all: use sort.Slice in a few more places
Do the low-hanging fruit - tiny Less functions that are used exactly
once. This reduces the amount of code and puts the logic in a single
place.

Change-Id: I9d4544cd68de5a95e55019bdad1fca0a1dbfae9c
Reviewed-on: https://go-review.googlesource.com/63171
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-22 12:39:14 +00:00
Daniel Martí
de22318888 text/template: check ignored error in a test
Found with staticcheck. Not terribly important since the test would
likely fail anyway, but at least it will fail with a better explanation
now.

Change-Id: Ic3f9a94a2152404b7873cc8cd47b6db79d78c2e6
Reviewed-on: https://go-review.googlesource.com/62990
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-13 15:06:31 +00:00
Daniel Martí
eb2dc3d3d0 all: remove strings.Contains check around Replace
It doesn't change the outcome. It might have been useful at some point
to avoid Replace from doing work or allocating. However, nowadays the
func returns early without doing any work if Count returns 0.

Change-Id: Id69dc74042a6e39672b405016484db8b50f43d58
Reviewed-on: https://go-review.googlesource.com/62991
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
2017-09-12 08:58:28 +00:00
Daniel Martí
9b8964bf2d text/template: fix pos info when trimming newlines
The lexer keeps the byte offset and the line for the rune it's currently
on. This was simple enough up until whitespace trimming was introduced.

With whitespace trimming, we might skip over newlines. In that case, the
lexer wasn't properly updating the line counter. Fix it.

Also, TestPos now checks that the line is correct too, which it was
ignoring before. This was necessary to test this scenario in the lexer.

Fixes #21778.

Change-Id: I3880f3adf02662eac8f818d5caa6935cca9cb33b
Reviewed-on: https://go-review.googlesource.com/61870
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-09-07 14:50:23 +00:00
Daniel Martí
fbc8973a6b all: join some chained ifs to unindent code
Found with mvdan.cc/unindent. It skipped the cases where parentheses
would need to be added, where comments would have to be moved elsewhere,
or where actions and simple logic would mix.

One of them was of the form "err != nil && err == io.EOF", so the first
part was removed.

Change-Id: Ie504c2b03a2c87d10ecbca1b9270069be1171b91
Reviewed-on: https://go-review.googlesource.com/57690
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-29 20:57:41 +00:00
Daniel Martí
59413d34c9 all: unindent some big chunks of code
Found with mvdan.cc/unindent. Prioritized the ones with the biggest wins
for now.

Change-Id: I2b032e45cdd559fc9ed5b1ee4c4de42c4c92e07b
Reviewed-on: https://go-review.googlesource.com/56470
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-18 06:59:48 +00:00
Emmanuel Odeke
590c5b0807 text/template: support indexing into *int* maps
Ensure that we can index maps whose key types are:
* int
* uint
* int32
* uint32
* int64
* uint64
* uintptr

Fixes #20439

Change-Id: I8fa96b14073c8af72786482ff4ffc3508064ea86
Reviewed-on: https://go-review.googlesource.com/43850
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-08-12 00:21:16 +00:00
Brad Fitzpatrick
af2ac479fc all: single space after period
Done with grep & interactive search & replace, to double-check
replacements. Not many remained after CL 20022.

Fixes #18572

Change-Id: Idbe90ba3b584f9b9661d2bbd141607daaadfa41a
Reviewed-on: https://go-review.googlesource.com/45270
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2017-06-09 20:29:09 +00:00
Robert Griesemer
fca6ad45e2 text/scanner: clarify documentation on Pos and Position
For #20292. (See discussion in that issue.)

Change-Id: I44cd69394fc47a01776905ec34305ba524c89883
Reviewed-on: https://go-review.googlesource.com/43452
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-05-14 20:24:34 +00:00
Robert Griesemer
8f06e217ea text/scanner: use correct token position in example
While at it, unindent source text so column values are easier
to read, remove unnecessary text in output, and simplify the
loop.

Fixes #20346.

Change-Id: I0fde02b9e4242383da427f4cf4c6c13dd0ab3b47
Reviewed-on: https://go-review.googlesource.com/43450
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-12 19:45:59 +00:00
Samuel Tan
3a2fee0389 html/template: allow safe usage of predefined escapers in pipelines
Allow the predefined escapers "html", "urlquery", and "js" to be used
in pipelines when they have no potential to affect the correctness or
safety of the escaped pipeline output. Specifically:
- "urlquery" may be used if it is the last command in the pipeline.
- "html" may be used if it is the last command in the pipeline, and
  the pipeline does not occur in an unquoted HTML attribute value
  context.
- "js" may be used in any pipeline, since it does not affect the
  merging of contextual escapers.

This change will loosens the restrictions on predefined escapers
introduced in golang.org/cl/37880, which will hopefully ease the
upgrade path for existing template users.

This change brings back the escaper-merging logic, and associated
unit tests, that were removed in golang.org/cl/37880. However, a
few notable changes have been made:
- "_html_template_nospaceescaper" is no longer considered
  equivalent to "html", since the former escapes spaces, while
  the latter does not (see #19345). This change should not silently
  break any templates, since pipelines where this substituion will
  happen will already trigger an explicit error.
- An "_eval_args_" internal directive has been added to
  handle pipelines containing a single explicit call to a
  predefined escaper, e.g. {{html .X}} (see #19353).

Also, the HTMLEscape function called by the predefined
text/template "html" function now escapes the NULL character as
well. This effectively makes it as secure as the internal
html/template HTML escapers (see #19345). While this change is
backward-incompatible, it will only affect illegitimate uses
of this escaper, since the NULL character is always illegal in
valid HTML.

Fixes #19952

Change-Id: I9b5570a80a3ea284b53901e6a1f842fc59b33d3a
Reviewed-on: https://go-review.googlesource.com/40936
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-05-05 18:56:31 +00:00
Dieter Plaetinck
1acff5fe61 template: warn about interleaved nature of writes
Execute incurs separate writes for each "step", e.g. each
variable that needs to be printed, and the final newline.
While it is correct to state that templates can be executed
concurrently, there is a more subtle nuance that is easily missed:
when writing to the same writer, the writes from concurrent execute
calls can be interleaved, leading to unexpected output.

Change-Id: I0abbd7960d8a8d15e109a8a3eeff3b43b852bbbf
Reviewed-on: https://go-review.googlesource.com/37444
Reviewed-by: Rob Pike <r@golang.org>
2017-05-05 17:58:56 +00:00
Daniel Martí
516e6f6d5d all: remove some unused parameters in test code
Mostly unnecessary *testing.T arguments.

Found with github.com/mvdan/unparam.

Change-Id: Ifb955cb88f2ce8784ee4172f4f94d860fa36ae9a
Reviewed-on: https://go-review.googlesource.com/41691
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-25 14:38:10 +00:00
Daniel Martí
ff7994ac10 all: remove redundant returns
Returns at the end of func bodies where the funcs have no return values
are pointless.

Change-Id: I0da5ea78671503e41a9f56dd770df8c919310ce5
Reviewed-on: https://go-review.googlesource.com/41093
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-19 20:03:51 +00:00
Rob Pike
be5a201e2a text/template: fix handling of empty blocks
This was a subtle bug introduced in the previous release's fix for
issue 16156.

The definition of empty template was broken, causing the answer
to depend on the order of templates in the map.

Fixes #16156 (for real).
Fixes #19294.
Fixes #19204.

Change-Id: I1cd915c94534cad3116d83bd158cbc28700510b9
Reviewed-on: https://go-review.googlesource.com/38420
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-04 15:46:02 +00:00
Rob Pike
5c5a10690e text/template,html/template: state that Funcs must happen before parsing
Any method that affects the parse must happen before parsing.
This obvious point is clear, but it's not clear to some that the
set of defined functions affect the parse.

Fixes #18971

Change-Id: I8b7f8c8cf85b028c18e5ca3b9797de92ea910669
Reviewed-on: https://go-review.googlesource.com/38413
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-03-21 04:07:35 +00:00
Russ Cox
06637fb314 text/template: fix method lookup on addressable nil pointer
Fixes #18816.

Change-Id: I4f8f1cac2680dbde492c56d3a5a038577605e7c1
Reviewed-on: https://go-review.googlesource.com/36542
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-02-09 14:58:40 +00:00
Seth Vargo
50c7783f59 text/template: remove duplicate logic in conditional
It looks like this conditional may have been refactored at some point,
but the logic was still very confusing. The outer conditional checks if
the function is variadic, so there's no need to verify that in the
result. Additionally, since the function isn't variadic, there is no
reason to permit the function call if the number of input arguments is
less than the function signature requires.

Change-Id: Ia957cf83d1c900c08dd66384efcb74f0c368422e
Reviewed-on: https://go-review.googlesource.com/35491
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-07 15:10:25 +00:00
Özgür Kesim
277bcbbdcd text/template: handle option missingkey=error consistently
The existing implementation of text/template handles the option
"missingkey=error" in an inconsitent manner:  If the provided data is
a nil-interface, no error is returned (despite the fact that no key
can be found in it).

This patch makes text/template return an error if "missingkey=error"
is set and the provided data is a not a valid reflect.Value.

Fixes #15356

Change-Id: Ia0a83da48652ecfaf31f18bdbd78cb21dbca1164
Reviewed-on: https://go-review.googlesource.com/31638
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-18 15:56:02 +00:00
Rob Pike
24a088d20a text/template: efficient reporting of line numbers
Instead of scanning the text to count newlines, which is n², keep track as we go
and store the line number in the token.

benchmark                 old ns/op      new ns/op     delta
BenchmarkParseLarge-4     1589721293     38783310      -97.56%

Fixes #17851

Change-Id: I231225c61e667535e2ce55cd2facea6d279cc59d
Reviewed-on: https://go-review.googlesource.com/33234
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-15 00:42:33 +00:00
Brad Fitzpatrick
b83350a2e0 Revert "text/template: efficient reporting of line numbers"
This reverts commit 794fb71d9c.

Reason for revert: submitted without TryBots and it broke all three race builders.

Change-Id: I80a1e566616f0ee8fa3529d4eeee04268f8a713b
Reviewed-on: https://go-review.googlesource.com/33232
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-14 22:23:24 +00:00
Rob Pike
794fb71d9c text/template: efficient reporting of line numbers
Instead of scanning the text to count newlines, which is n², keep track as we go
and store the line number in the token.

benchmark                 old ns/op      new ns/op     delta
BenchmarkParseLarge-4     1589721293     38783310      -97.56%

Fixes #17851

Change-Id: Ieaf89a35e371b405ad92e38baa1e3fa98d18cfb4
Reviewed-on: https://go-review.googlesource.com/32923
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-11-14 18:42:48 +00:00
Russ Cox
39e3cbfff6 text/template: reintroduce implicit indirect of interface values in builtin funcs
CL 31462 made it possible to operate directly on reflect.Values
instead of always forcing a round trip to interface{} and back.
The round trip was losing addressability, which hurt users.

The round trip was also losing "interface-ness", which helped users.
That is, using reflect.ValueOf(v.Interface()) instead of v was doing
an implicit indirect any time v was itself an interface{} value: the result
was the reflect.Value for the underlying concrete value contained in the
interface, not the interface itself.

CL 31462 eliminated some "unnecessary" reflect.Value round trips
in order to preserve addressability, but in doing so it lost this implicit
indirection. This CL adds the indirection back.

It may help to compare the changes in this CL against funcs.go from CL 31462:
https://go-review.googlesource.com/#/c/31462/4/src/text/template/funcs.go

Everywhere CL 31462 changed 'v := reflect.ValueOf(x)' to 'v := x',
this CL changes 'v := x' to 'v := indirectInterface(x)'.

Fixes #17714.

Change-Id: I67cec4eb41fed1d56e1c19f12b0abbd0e59d35a2
Reviewed-on: https://go-review.googlesource.com/33139
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2016-11-11 19:46:17 +00:00
Russ Cox
ef3a9f2dd4 html/template, text/template: drop defined template list from errors
The report in #17414 points out that if you have many many templates,
then this is an overwhelming list and just hurts the signal-to-noise ratio of the error.

Even the test of the old behavior also supports the idea that this is noise:

	template: empty: "empty" is an incomplete or empty template; defined templates are: "secondary"

The chance that someone mistyped "secondary" as "empty" is slim at best.

Similarly, the compiler does not augment an error like 'unknown variable x'
by dumping the full list of all the known variables.

For all these reasons, drop the list.

Fixes #17414.

Change-Id: I78f92d2c591df7218385fe723a4abc497913acf8
Reviewed-on: https://go-review.googlesource.com/32116
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2016-10-28 17:10:55 +00:00
Rob Pike
f9027d61ab all: freeze net/rpc and reword the 'frozen' message in other frozen packages
Make the messages grammatically korrect and consistent.

Fixes #16844

Change-Id: I7c137b4dc25c0c875ed07b0c64c67ae984c39cbc
Reviewed-on: https://go-review.googlesource.com/32112
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-26 16:11:07 +00:00
Brad Fitzpatrick
6e78f76974 testing/quick, text/tabwriter: freeze packages
Fixes #15557

Change-Id: I02ad98068894e75d4e08e271fdd16cb420519460
Reviewed-on: https://go-review.googlesource.com/31910
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-10-24 23:31:50 +00:00
Josh Bleecher Snyder
accf5cc386 all: minor vet fixes
Change-Id: I22f0f3e792052762499f632571155768b4052bc9
Reviewed-on: https://go-review.googlesource.com/31759
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-24 17:27:37 +00:00
Russ Cox
604146ce89 html/template, text/template: docs and fixes for template redefinition
All prior versions of Go have allowed redefining empty templates
to become non-empty. Unfortunately, that has never consistently
taken effect in html/template after the first execution:

	// define and execute
	t := template.New("root")
	t.Parse(`{{define "T"}}{{end}}<a href="{{template "T"}}">`)
	t.Execute(w, nil) // <a href="">

	// redefine
	t.Parse(`{{define "T"}}my.url{{end}}`) // succeeds, but ignored
	t.Execute(w, nil) // <a href="">

When Go 1.6 added {{block...}} to text/template, that loosened the
redefinition rules to allow redefinition at any time. The loosening was
undone a bit in html/template, although inconsistently:

	// define and execute
	t := template.New("root")
	t.Parse(`{{define "T"}}body{{end}}`)
	t.Lookup("T").Execute(ioutil.Discard, nil)

	// attempt to redefine
	t.Parse(`{{define "T"}}body{{end}}`) // rejected in all Go versions
	t.Lookup("T").Parse("body") // OK as of Go 1.6, likely unintentionally

Like in the empty->non-empty case, whether future execution takes
notice of a redefinition basically can't be explained without going into
the details of the template escape analysis.

Address both the original inconsistencies in whether a redefinition
would have any effect and the new inconsistencies about whether a
redefinition is allowed by adopting a new rule: no parsing or modifying
any templates after the first execution of any template in the same set.
Template analysis begins at first execution, and once template analysis
has begun, we simply don't have the right logic to update the analysis
for incremental modifications (and never have).

If this new rule breaks existing uses of templates that we decide need
to be supported, we can try to invalidate all escape analysis for the
entire set after any modifications. But let's wait on that until we know
we need to and why.

Also fix documentation of text/template redefinition policy
(redefinition is always OK).

Fixes #15761.

Change-Id: I7d58d7c08a7d9df2440ee0d651a5b2ecaff3006c
Reviewed-on: https://go-review.googlesource.com/31464
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-10-24 15:43:24 +00:00
Russ Cox
5378dd7768 text/template: add support for reflect.Value args, results in funcs
Add support for passing reflect.Values to and returning reflect.Values from
any registered functions in the FuncMap, much as if they were
interface{} values. Keeping the reflect.Value instead of round-tripping
to interface{} preserves addressability of the value, which is important
for method lookup.

Change index and a few other built-in functions to use reflect.Values,
making a loop using explicit indexing now match the semantics that
range has always had.

Fixes #14916.

Change-Id: Iae1a2fd9bb426886a7fcd9204f30a2d6ad4646ad
Reviewed-on: https://go-review.googlesource.com/31462
Reviewed-by: Rob Pike <r@golang.org>
2016-10-19 18:20:35 +00:00
Russ Cox
2f7f679c79 html/template, text/template: clarify template redefinition behavior
Make two important points clearer:

 - Giving a template definition containing
   nothing but spaces has no effect.
 - Giving a template definition containing
   non-spaces can only be done once per template.

Fixes #16912.
Fixes #16913.
Fixes #17360.

Change-Id: Ie3971b83ab148b7c8bb800fe4a21579566378e3e
Reviewed-on: https://go-review.googlesource.com/31459
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-10-19 12:57:09 +00:00
Paul Borman
07b8011393 text/template: improve lexer performance in finding left delimiters.
The existing implementation calls l.next for each run up to the next
instance of the left delimiter ({{).  For ascii text, this is multiple
function calls per byte.  Change to use strings.Index to find the left
delimiter.  The performace improvement ranges from 1:1 (no text outside
of {{}}'s) to multiple times faster (9:1 was seen on 8K of text with no
{{ }}'s).

Change-Id: I2f82bea63b78b6714f09a725f7b2bbb00a3448a3
Reviewed-on: https://go-review.googlesource.com/24863
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
2016-09-13 12:51:13 +00:00
Jess Frazelle
c3f05d9593 text/template: remove unused Tree.parse return value
Fixes #13993

Change-Id: Ic61b2bcd9f4f71457d3a8581574633d505d5750e
Reviewed-on: https://go-review.googlesource.com/27240
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2016-08-17 22:36:27 +00:00
Jess Frazelle
2b583a190e text/template: fix Parse when called twice with empty text
Fixes #16156

Change-Id: I6989db4fd392583a2d490339cefc525b07c11b90
Reviewed-on: https://go-review.googlesource.com/24380
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Andrew Gerrand <adg@golang.org>
2016-08-16 23:49:42 +00:00
Rob Pike
86b0310185 text/template: clarify the default formatting used for values
Fixes #16105.

Change-Id: I94467f2adf861eb38f3119ad30d46a87456d5305
Reviewed-on: https://go-review.googlesource.com/24281
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-06-21 02:15:44 +00:00
Robert Griesemer
824e1f2e08 text/scanner: better error message if no error handler is installed
This is reverting golang.org/cl/19622 and introducing "<input>"
as filename if no filename is specified.

Fixes #15813.

Change-Id: Iafc74b789fa33f48ee639c42d4aebc6f06435f95
Reviewed-on: https://go-review.googlesource.com/23402
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-25 15:44:28 +00:00
Andrew Gerrand
eb69476c66 text/template: detect pathologically recursive template invocations
Return an error message instead of eating memory and eventually
triggering a stack overflow.

Fixes #15618

Change-Id: I3dcf1d669104690a17847a20fbfeb6d7e39e8751
Reviewed-on: https://go-review.googlesource.com/23091
Reviewed-by: Rob Pike <r@golang.org>
2016-05-12 22:32:30 +00:00
Johan Sageryd
114051aa1d text/template: fix typo in documentation
Change-Id: I4ccfaa16e153aad001d670891b3848264e63cf6f
Reviewed-on: https://go-review.googlesource.com/23031
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-05-11 21:24:16 +00:00
Andrew Gerrand
7085fb31df html/template, text/template: clarify Parse{Files,Glob} semantics
Document the subtle property that files with equivalent base names
will overwrite extant templates with those same names.

Fixes golang/go#14320

Change-Id: Ie9ace1b08e6896ea599836e31582123169aa7a25
Reviewed-on: https://go-review.googlesource.com/21824
Reviewed-by: Rob Pike <r@golang.org>
2016-04-22 02:01:54 +00:00
Andrew Gerrand
0fd270ab7a text/template: emit field error over nil pointer error where appropriate
When evaluating "{{.MissingField}}" on a nil *T, Exec returns
"can't evaluate field MissingField in type *T" instead of
"nil pointer evaluating *T.MissingField".

Fixes golang/go#15125

Change-Id: I6e73f61b8a72c694179c1f8cdc808766c90b6f57
Reviewed-on: https://go-review.googlesource.com/21705
Reviewed-by: Rob Pike <r@golang.org>
2016-04-10 23:29:29 +00:00
Dominik Honnef
fdba5a7544 all: delete dead non-test code
This change removes a lot of dead code. Some of the code has never been
used, not even when it was first commited. The rest shouldn't have
survived refactors.

This change doesn't remove unused routines helpful for debugging, nor
does it remove code that's used in commented out blocks of code that are
only unused temporarily. Furthermore, unused constants weren't removed
when they were part of a set of constants from specifications.

One noteworthy omission from this CL are about 1000 lines of unused code
in cmd/fix, 700 lines of which are the typechecker, which hasn't been
used ever since the pre-Go 1 fixes have been removed. I wasn't sure if
this code should stick around for future uses of cmd/fix or be culled as
well.

Change-Id: Ib714bc7e487edc11ad23ba1c3222d1fd02e4a549
Reviewed-on: https://go-review.googlesource.com/20926
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25 06:28:13 +00:00