Add a --markdown flag to GN to be able to output help in markdown.

Add a --markdown flag to GN to be able to output help in markdown.

With this change, we can now generate a markdown page containing all
of the built-in help from GN, so that it will be visible on the web.

The changes to GN to support markdown are, so far, minimal, but the
resulting format is also pretty lame: we just wrap the body of the each
help command in a code block (markdown's equivalent of <pre>).

R=brettw@chromium.org
BUG=468851
Committed: https://crrev.com/e7700dd26912bcab168b6f4795a05fd9b5b1cb22
Cr-Commit-Position: refs/heads/master@{#325730}

[Dirk Pranke, 2015-04-15 03:21:55]

Patchset #2 (id:20001) has been deleted

[Dirk Pranke, 2015-04-15 03:22:01]

Patchset #1 (id:1) has been deleted

[Dirk Pranke, 2015-04-15 03:25:35]

Please take a look.

This patch depends on https://codereview.chromium.org/1021923002/.

I think we could get substantially better output if we decided just to
consistently indent anything we wanted to be formatted as code. If you like, I
can work up a few reformatted commands as examples (in a separate CL, we can
start with this one as-is).

[brettw, 2015-04-17 00:01:53]

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/docs/reference.md
File tools/gn/docs/reference.md (right):

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/docs/reference...
tools/gn/docs/reference.md:861: **  # both a .cc and a .h file for each input.
These are a bug. I think you will need to handle the case where the outputted
string ends in a newline.

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.cc
File tools/gn/standard_out.cc (right):

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:79: // The markdown rendering turns "dim" text to
italics and any
I think it would be better to replace this with:
  WriteMarkdownDecoration(dec);
and have that function implement the decoration checking and output, to avoid
all the duplication you have in here.

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:259: if (is_markdown && in_body) {
No {}

[Dirk Pranke, 2015-04-17 00:08:16]

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/docs/reference.md
File tools/gn/docs/reference.md (right):

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/docs/reference...
tools/gn/docs/reference.md:861: **  # both a .cc and a .h file for each input.
On 2015/04/17 00:01:53, brettw wrote:
> These are a bug. I think you will need to handle the case where the outputted
> string ends in a newline.

Good catch. Will look.

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.cc
File tools/gn/standard_out.cc (right):

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:79: // The markdown rendering turns "dim" text to
italics and any
On 2015/04/17 00:01:53, brettw wrote:
> I think it would be better to replace this with:
>   WriteMarkdownDecoration(dec);
> and have that function implement the decoration checking and output, to avoid
> all the duplication you have in here.

Acknowledged.

https://codereview.chromium.org/1024783002/diff/40001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:259: if (is_markdown && in_body) {
On 2015/04/17 00:01:53, brettw wrote:
> No {}

Acknowledged.

[Dirk Pranke, 2015-04-17 01:36:50]

Updated, please take another look?

[brettw, 2015-04-17 02:38:56]

LGTM

https://codereview.chromium.org/1024783002/diff/60001/tools/gn/standard_out.cc
File tools/gn/standard_out.cc (right):

https://codereview.chromium.org/1024783002/diff/60001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:41: // output help in Markdown's syntax, not
color-highlighted.
Capitalize "output"

https://codereview.chromium.org/1024783002/diff/60001/tools/gn/standard_out.c...
tools/gn/standard_out.cc:261: if (is_markdown && in_body) {
No {}

[Dirk Pranke, 2015-04-17 02:51:01]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2015-04-17 02:51:01]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1024783002/#ps80001
(title: "Update w/ more review feedback")

[commit-bot: I haz the power, 2015-04-17 02:52:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1024783002/80001

[commit-bot: I haz the power, 2015-04-17 03:19:20]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-17 03:19:20]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Dirk Pranke, 2015-04-17 16:46:14]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2015-04-17 16:47:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1024783002/80001

[commit-bot: I haz the power, 2015-04-17 17:11:31]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-17 17:11:32]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Dirk Pranke, 2015-04-17 20:35:45]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2015-04-17 20:35:46]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1024783002/#ps100001
(title: "fix typo in OutputMarkdownDec for win")

[commit-bot: I haz the power, 2015-04-17 20:36:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1024783002/100001

[commit-bot: I haz the power, 2015-04-17 21:15:27]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-17 21:15:28]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Dirk Pranke, 2015-04-17 21:18:02]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2015-04-17 21:18:03]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1024783002/#ps120001
(title: "fix dropped variable")

[commit-bot: I haz the power, 2015-04-17 21:18:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1024783002/120001

[commit-bot: I haz the power, 2015-04-17 22:55:54]

Committed patchset #6 (id:120001)

[commit-bot: I haz the power, 2015-04-17 22:57:33]

Patchset 6 (id:??) landed as
https://crrev.com/e7700dd26912bcab168b6f4795a05fd9b5b1cb22
Cr-Commit-Position: refs/heads/master@{#325730}