r303546 - [mips] Support `micromips` attribute

[Simon Atanasyan via cfe-commits]

On Mon, May 22, 2017 at 3:57 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
> On Mon, May 22, 2017 at 8:47 AM, Simon Atanasyan via cfe-commits
> <cfe-commits at lists.llvm.org> wrote:
>> Author: atanasyan
>> Date: Mon May 22 07:47:43 2017
>> New Revision: 303546
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=303546&view=rev
>> Log:
>> [mips] Support `micromips` attribute
>>
>> This patch adds support for the `micromips` and `nomicromips` attributes
>> for MIPS targets.
>>
>> Differential revision: https://reviews.llvm.org/D33363

[...]

>> Modified: cfe/trunk/include/clang/Basic/Attr.td
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=303546&r1=303545&r2=303546&view=diff
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/Attr.td (original)
>> +++ cfe/trunk/include/clang/Basic/Attr.td Mon May 22 07:47:43 2017
>> @@ -1179,6 +1179,12 @@ def MipsInterrupt : InheritableAttr, Tar
>>    let Documentation = [MipsInterruptDocs];
>>  }
>>
>> +def MicroMips : InheritableAttr, TargetSpecificAttr<TargetMips> {
>> +  let Spellings = [GCC<"micromips">];
>> +  let Subjects = SubjectList<[Function], ErrorDiag>;
>
> Why is this an error rather than a warning? Same question below.

Because GCC shows the error in this case. And I cannot imagine any
reason why micromips attribute added to non-function declaration.

% mips-mti-linux-gnu-gcc --version
mips-mti-linux-gnu-gcc (Codescape GNU Tools 2016.05-01 for MIPS MTI Linux) 4.9.2

% mips-mti-linux-gnu-gcc -c attr-micromips.c
tools/clang/test/Sema/attr-micromips.c:6:1: error: ‘nomicromips’
attribute only applies to functions
 __attribute((nomicromips)) int a; // expected-error {{attribute only
applies to functions}}
 ^
tools/clang/test/Sema/attr-micromips.c:7:1: error: ‘micromips’
attribute only applies to functions
 __attribute((micromips)) int b;   // expected-error {{attribute only
applies to functions}}

>> Modified: cfe/trunk/include/clang/Basic/AttrDocs.td
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=303546&r1=303545&r2=303546&view=diff
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/AttrDocs.td (original)
>> +++ cfe/trunk/include/clang/Basic/AttrDocs.td Mon May 22 07:47:43 2017
>> @@ -1269,6 +1269,19 @@ The semantics are as follows:
>>    }];
>>  }
>>
>> +def MicroMipsDocs : Documentation {
>> +  let Category = DocCatFunction;
>> +  let Content = [{
>> +Clang supports the GNU style ``__attribute__((micromips))`` and
>> +``__attribute__((nomicromips))`` attributes on MIPS targets. These attributes
>> +may be attached to a function definition and instructs the backend to generate
>> +or not to generate microMIPS code for that function.
>> +
>> +These attributes override the -mmicromips and -mno-micromips options
>
> Please quote the command line options with ``.

Fixed at r303564.

>> Added: cfe/trunk/test/Sema/attr-micromips.c
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-micromips.c?rev=303546&view=auto
>> ==============================================================================
>> --- cfe/trunk/test/Sema/attr-micromips.c (added)
>> +++ cfe/trunk/test/Sema/attr-micromips.c Mon May 22 07:47:43 2017
>> @@ -0,0 +1,15 @@
>> +// RUN: %clang_cc1 -triple mips-linux-gnu -fsyntax-only -verify %s
>> +
>> +__attribute__((nomicromips(0))) void foo1();  // expected-error {{'nomicromips' attribute takes no arguments}}
>> +__attribute__((micromips(1))) void foo2();    // expected-error {{'micromips' attribute takes no arguments}}
>> +
>> +__attribute((nomicromips)) int a; // expected-error {{attribute only applies to functions}}
>> +__attribute((micromips)) int b;   // expected-error {{attribute only applies to functions}}
>> +
>> +__attribute__((micromips,mips16)) void foo5();  // expected-error {{'micromips' and 'mips16' attributes are not compatible}} \
>> +                                                // expected-note {{conflicting attribute is here}}
>> +__attribute__((mips16,micromips)) void foo6();  // expected-error {{'mips16' and 'micromips' attributes are not compatible}} \
>> +                                                // expected-note {{conflicting attribute is here}}
>
> Can you also add a test like:
>
> __attribute__((mips16)) void foo9(void) __attribute__((micromips));

Fixed at r303565.

-- 
Simon Atanasyan