Fix Wvarargs warning in XFA error code.

Fix Wvarargs warning in XFA error code.

Chrome has enabled the -Wvarargs warning that was added to clang, this fails
with PDFium XFA builds due to two warnings:

../../xfa/fxfa/fm2js/xfa_lexer.cpp:539:16: error: passing an object that
undergoes default argument promotion to 'va_start' has undefined behavior
[-Werror,-Wvarargs]
  va_start(ap, msg);
               ^
../../xfa/fxfa/fm2js/xfa_lexer.cpp:535:40: note: parameter of type
'XFA_FM_ERRMSG' is declared here
void CXFA_FMLexer::Error(XFA_FM_ERRMSG msg, ...) {

The issue is that XFA_FM_ERRMSG is an enum and we violate the promotion rules
for passing the value to va_start.

I removed the enum and named the flags explicitly then pass in the string as
the argument.

BUG=chromium:606726
Committed: https://pdfium.googlesource.com/pdfium/+/76c53794b6202ec37f6dcace5f2ae86870e953b6

[dsinclair, 2016-04-26 15:39:40]

dsinclair@chromium.org changed reviewers:
+ thakis@chromium.org, thestig@chromium.org, tsepez@chromium.org

[dsinclair, 2016-04-26 15:39:40]

PTAL.

In order to get a clang with -Wvararg I had to update //build. That forced an
update to //v8 as some files had changed. That forced the addition to
build_overrides/v8.gni and the disabling of the warning.

[Nico, 2016-04-26 15:45:20]

lgtm

I don't understand why we didn't see this on Chromium's waterfall though -- are
these files only built in libfuzzer builds? If so, are they needed at all?

[Tom Sepez, 2016-04-26 15:51:04]

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h
File xfa/fxfa/fm2js/xfa_error.h (left):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h#...
xfa/fxfa/fm2js/xfa_error.h:12: 
what if you did

enum XFA_FM_ERRMSG : uint32_t {

does that resolve the ambiguity?

[dsinclair, 2016-04-26 15:54:26]

On 2016/04/26 15:45:20, Nico wrote:
> lgtm
> 
> I don't understand why we didn't see this on Chromium's waterfall though --
are
> these files only built in libfuzzer builds? If so, are they needed at all?


We're trying to enable the XFA build in Chrome. It was disabled due to a crash
bug. Currently only libfuzzer is building the XFA branch (we build it on our
waterfall, but our clang version was different).

[dsinclair, 2016-04-26 15:57:39]

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h
File xfa/fxfa/fm2js/xfa_error.h (left):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h#...
xfa/fxfa/fm2js/xfa_error.h:12: 
On 2016/04/26 15:51:04, Tom Sepez wrote:
> what if you did
> 
> enum XFA_FM_ERRMSG : uint32_t {
> 
> does that resolve the ambiguity? 

Nope, same error.

[Tom Sepez, 2016-04-26 16:03:58]

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.cpp
File xfa/fxfa/fm2js/xfa_error.cpp (left):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.cp...
xfa/fxfa/fm2js/xfa_error.cpp:9: static const FX_WCHAR* const
gs_lpStrErrorMsgInfo[] = {
Then this becomes

const FX_WCHAR kFMErrUnsupportedChar[] = L"unsupported char '%c'";

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h
File xfa/fxfa/fm2js/xfa_error.h (right):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h#...
xfa/fxfa/fm2js/xfa_error.h:13: #define FMERR_UNSUPPORTED_CHAR L"unsupported char
'%c'"
I think I'd be happier if we had
extern const FX_WCHAR kFMErrUnsupportedChar[];

[dsinclair, 2016-04-26 16:36:46]

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.cpp
File xfa/fxfa/fm2js/xfa_error.cpp (left):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.cp...
xfa/fxfa/fm2js/xfa_error.cpp:9: static const FX_WCHAR* const
gs_lpStrErrorMsgInfo[] = {
On 2016/04/26 16:03:58, Tom Sepez wrote:
> Then this becomes
> 
> const FX_WCHAR kFMErrUnsupportedChar[] = L"unsupported char '%c'";

Done.

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h
File xfa/fxfa/fm2js/xfa_error.h (right):

https://codereview.chromium.org/1921323002/diff/1/xfa/fxfa/fm2js/xfa_error.h#...
xfa/fxfa/fm2js/xfa_error.h:13: #define FMERR_UNSUPPORTED_CHAR L"unsupported char
'%c'"
On 2016/04/26 16:03:58, Tom Sepez wrote:
> I think I'd be happier if we had
> extern const FX_WCHAR kFMErrUnsupportedChar[];

Done.

[Tom Sepez, 2016-04-26 17:58:28]

lgtm

[dsinclair, 2016-04-26 18:05:05]

The CQ bit was checked by dsinclair@chromium.org

[dsinclair, 2016-04-26 18:05:06]

The patchset sent to the CQ was uploaded after l-g-t-m from thakis@chromium.org
Link to the patchset: https://codereview.chromium.org/1921323002/#ps20001
(title: " ")

[commit-bot: I haz the power, 2016-04-26 18:05:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1921323002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1921323002/20001

[commit-bot: I haz the power, 2016-04-26 18:05:31]

Description was changed from

==========
Fix Wvarargs warning in XFA error code.

Chrome has enabled the -Wvarargs warning that was added to clang, this fails
with PDFium XFA builds due to two warnings:

../../xfa/fxfa/fm2js/xfa_lexer.cpp:539:16: error: passing an object that
undergoes default argument promotion to 'va_start' has undefined behavior
[-Werror,-Wvarargs]
  va_start(ap, msg);
               ^
../../xfa/fxfa/fm2js/xfa_lexer.cpp:535:40: note: parameter of type
'XFA_FM_ERRMSG' is declared here
void CXFA_FMLexer::Error(XFA_FM_ERRMSG msg, ...) {

The issue is that XFA_FM_ERRMSG is an enum and we violate the promotion rules
for passing the value to va_start.

I removed the enum and named the flags explicitly then pass in the string as
the argument.

BUG=chromium:606726
==========

to

==========
Fix Wvarargs warning in XFA error code.

Chrome has enabled the -Wvarargs warning that was added to clang, this fails
with PDFium XFA builds due to two warnings:

../../xfa/fxfa/fm2js/xfa_lexer.cpp:539:16: error: passing an object that
undergoes default argument promotion to 'va_start' has undefined behavior
[-Werror,-Wvarargs]
  va_start(ap, msg);
               ^
../../xfa/fxfa/fm2js/xfa_lexer.cpp:535:40: note: parameter of type
'XFA_FM_ERRMSG' is declared here
void CXFA_FMLexer::Error(XFA_FM_ERRMSG msg, ...) {

The issue is that XFA_FM_ERRMSG is an enum and we violate the promotion rules
for passing the value to va_start.

I removed the enum and named the flags explicitly then pass in the string as
the argument.

BUG=chromium:606726

Committed:
https://pdfium.googlesource.com/pdfium/+/76c53794b6202ec37f6dcace5f2ae86870e9...
==========

[commit-bot: I haz the power, 2016-04-26 18:05:32]

Committed patchset #2 (id:20001) as
https://pdfium.googlesource.com/pdfium/+/76c53794b6202ec37f6dcace5f2ae86870e9...