Add support for --gtest_flagfile

[phajdan.jr, 2015-04-18 00:51:40]

See https://groups.google.com/d/msg/googletestframework/nstlT3Dv6ns/uazos4T-wd4J
for context.

[sbenza, 2015-04-21 19:50:29]

Thanks for the patch.

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc
File src/gtest.cc (right):

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc#newcode5191
src/gtest.cc:5191: std::vector<std::string> lines(SplitEscapedString(contents));
Is this the right split routine to use?
What are the contents of the file? Are the contents somehow escaped?
The format of the file has to be specified somewhere. I think the flag
description could mention it.

I think the simplest would be to keep commandline syntax (using --flag_name).
Treat space and newline as flag separators.
If you want to get fancy, you could allow comments, like in a shell.

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc#newcode5193
src/gtest.cc:5193: if (!ParseGoogleTestFlag(lines[i].c_str()))
I don't know if it is a good idea to have this function be recursive.
A config file pointing to itself could cause a stack overflow.

Maybe something like:

bool ParseGoogleTestFlag() only does the other names, and then in
ParseGoogleTestFlagsOnlyImpl() you could do:

if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
  return LoadFlagsFromFile();
} else {
  return ParseGoogleTestFlag(...);
}

And LoadFlagsFromFile() can also call ParseGoogleTestFlag(...)

[phajdan.jr, 2015-04-30 15:49:03]

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc
File src/gtest.cc (right):

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc#newcode5191
src/gtest.cc:5191: std::vector<std::string> lines(SplitEscapedString(contents));
On 2015/04/21 19:50:29, sbenza wrote:
> Is this the right split routine to use?
> What are the contents of the file? Are the contents somehow escaped?
> The format of the file has to be specified somewhere. I think the flag
> description could mention it.
> 
> I think the simplest would be to keep commandline syntax (using --flag_name).
> Treat space and newline as flag separators.
> If you want to get fancy, you could allow comments, like in a shell.

Done.

https://codereview.appspot.com/226420043/diff/1/src/gtest.cc#newcode5193
src/gtest.cc:5193: if (!ParseGoogleTestFlag(lines[i].c_str()))
On 2015/04/21 19:50:29, sbenza wrote:
> I don't know if it is a good idea to have this function be recursive.
> A config file pointing to itself could cause a stack overflow.
> 
> Maybe something like:
> 
> bool ParseGoogleTestFlag() only does the other names, and then in
> ParseGoogleTestFlagsOnlyImpl() you could do:
> 
> if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
>   return LoadFlagsFromFile();
> } else {
>   return ParseGoogleTestFlag(...);
> }
> 
> And LoadFlagsFromFile() can also call ParseGoogleTestFlag(...)

Done.

[phajdan.jr, 2015-05-07 13:14:38]

Please take another look. Added a test.