Option flag with string arguments

Option flag with string arguments

[Erick Ochoa]

Hello,

I am working on testing an optimization. I am starting to write
tests in the GCC testing suite. However, I want to develop some
fine grain testing for my own sake.

This optimization I am working on, is a variant of struct reordering.
One way I would like to test my pass is for example, making a test case
and guaranteeing that my pass is able to detect global variables of
a specific struct type.

For example, given the following C file

```
/* { dg-lto-options {{-flto -fipa-struct-reorg -fipa-struct-reorg-assert-has-structs=astruct_s}} } */

struct astruct_s { _Bool a; };
struct astruct_s astruct;

int main() { };
```

I would like to create the option flag that has a list of string arguments

-fipa-struct-reorg-assert-has-structs=<string>+

such that during the analysis time, I'd be able to have an assertion
to make sure that my pass has actually collected the types identified by the
strings.
I'm not very familiar on the DSL to specify option flags.
I've looked at gcc/common.opt for some examples and found this one:

```
frandom-seed=
Common Joined RejectNegative Var(common_deferred_options) Defer
-frandom-seed=<string>  Make compile reproducible using <string>.
```

Could anyone explain how to specify my flag? Or possibly
point to some documentation/source that explains Common, Joined, etc...?

Re: Option flag with string arguments

[Jozef Lawrynowicz]

On Thu, 19 Dec 2019 16:47:42 -0500
Erick Ochoa <erick.ochoa@theobroma-systems.com> wrote:

> Hello,
> 
> I am working on testing an optimization. I am starting to write
> tests in the GCC testing suite. However, I want to develop some
> fine grain testing for my own sake.
> 
> This optimization I am working on, is a variant of struct reordering.
> One way I would like to test my pass is for example, making a test case
> and guaranteeing that my pass is able to detect global variables of
> a specific struct type.
> 
> For example, given the following C file
> 
> ```
> /* { dg-lto-options {{-flto -fipa-struct-reorg -fipa-struct-reorg-assert-has-structs=astruct_s}} } */
> 
> struct astruct_s { _Bool a; };
> struct astruct_s astruct;
> 
> int main() { };
> ```
> 
> I would like to create the option flag that has a list of string arguments
> 
> -fipa-struct-reorg-assert-has-structs=<string>+
> 
> such that during the analysis time, I'd be able to have an assertion
> to make sure that my pass has actually collected the types identified by the
> strings.
> I'm not very familiar on the DSL to specify option flags.
> I've looked at gcc/common.opt for some examples and found this one:
> 
> ```
> frandom-seed=
> Common Joined RejectNegative Var(common_deferred_options) Defer
> -frandom-seed=<string>  Make compile reproducible using <string>.
> ```
> 
> Could anyone explain how to specify my flag? Or possibly
> point to some documentation/source that explains Common, Joined, etc...?

Have you looked at the GCC Internals Manual (gccint)? The section on option
specification files is online here:
https://gcc.gnu.org/onlinedocs/gccint/Option-properties.html#Option-properties

Jozef

Re: Option flag with string arguments

[Erick Ochoa]

On 2019-12-19 5:01 p.m., Jozef Lawrynowicz wrote:
> On Thu, 19 Dec 2019 16:47:42 -0500
> Erick Ochoa <erick.ochoa@theobroma-systems.com> wrote:
> 
>> Hello,
>>
>> I am working on testing an optimization. I am starting to write
>> tests in the GCC testing suite. However, I want to develop some
>> fine grain testing for my own sake.
>>
>> This optimization I am working on, is a variant of struct reordering.
>> One way I would like to test my pass is for example, making a test case
>> and guaranteeing that my pass is able to detect global variables of
>> a specific struct type.
>>
>> For example, given the following C file
>>
>> ```
>> /* { dg-lto-options {{-flto -fipa-struct-reorg -fipa-struct-reorg-assert-has-structs=astruct_s}} } */
>>
>> struct astruct_s { _Bool a; };
>> struct astruct_s astruct;
>>
>> int main() { };
>> ```
>>
>> I would like to create the option flag that has a list of string arguments
>>
>> -fipa-struct-reorg-assert-has-structs=<string>+
>>
>> such that during the analysis time, I'd be able to have an assertion
>> to make sure that my pass has actually collected the types identified by the
>> strings.
>> I'm not very familiar on the DSL to specify option flags.
>> I've looked at gcc/common.opt for some examples and found this one:
>>
>> ```
>> frandom-seed=
>> Common Joined RejectNegative Var(common_deferred_options) Defer
>> -frandom-seed=<string>  Make compile reproducible using <string>.
>> ```
>>
>> Could anyone explain how to specify my flag? Or possibly
>> point to some documentation/source that explains Common, Joined, etc...?
> 
> Have you looked at the GCC Internals Manual (gccint)? The section on option
> specification files is online here:
> https://gcc.gnu.org/onlinedocs/gccint/Option-properties.html#Option-properties> 
> Jozef

Thanks Jozef! This is exactly what I was looking for (and overlooked).

> 

Re: Option flag with string arguments

[David Malcolm]

On Thu, 2019-12-19 at 16:47 -0500, Erick Ochoa wrote:
> Hello,
> 
> I am working on testing an optimization. I am starting to write
> tests in the GCC testing suite. However, I want to develop some
> fine grain testing for my own sake.
> 
> This optimization I am working on, is a variant of struct reordering.
> One way I would like to test my pass is for example, making a test
> case
> and guaranteeing that my pass is able to detect global variables of
> a specific struct type.

For example, given the following C file
> 
> ```
> /* { dg-lto-options {{-flto -fipa-struct-reorg -fipa-struct-reorg-
> assert-has-structs=astruct_s}} } */
> 
> struct astruct_s { _Bool a; };
> struct astruct_s astruct;
> 
> int main() { };
> ```
> 
> I would like to create the option flag that has a list of string
> arguments
> 
> -fipa-struct-reorg-assert-has-structs=<string>+
> 
> such that during the analysis time, I'd be able to have an assertion
> to make sure that my pass has actually collected the types identified
> by the
> strings.
> I'm not very familiar on the DSL to specify option flags.
> I've looked at gcc/common.opt for some examples and found this one:
> 
> ```
> frandom-seed=
> Common Joined RejectNegative Var(common_deferred_options) Defer
> -frandom-seed=<string>  Make compile reproducible using <string>.
> ```
> 
> Could anyone explain how to specify my flag? Or possibly
> point to some documentation/source that explains Common, Joined,
> etc...?


It sounds like what you really want is a DejaGnu option to detect that
a specific struct type was handled by your pass, rather than a command-
line option for controlling that pass.

I think you want something like:

/* { dg-options "-fdump-ipa-your-pass" } */
/* { dg-lto-options {{-flto -fipa-struct-reorg }} } */

(not sure of the precise interaction of these two though)

and:

/* { dg-final { scan-ipa-dump "handling type: 'struct_s'"  "your-pass" } } */

then arranging for the dumpfile for your-pass to contain the message:
dg-final queues up a scan of the given dumpfile which will PASS/FAIL
based on whether it sees the message.

Try grepping the testsuite for dg-final to see more examples of the
idea.


Hope this is helpful
Dave