[PATCH] D39538: [llvm-ar] Support an options string that start with a dash

[Martin Storsjö via llvm-commits]

On Thu, 2 Nov 2017, Rafael Avila de Espindola wrote:

> Martin Storsjö via Phabricator <reviews at reviews.llvm.org> writes:
>
>> mstorsjo updated this revision to Diff 121361.
>> mstorsjo added a comment.
>>
>> Break out of the loop on '--' and once an argument with a stripped dash is found.
>>
>>
>> https://reviews.llvm.org/D39538
>>
>> Files:
>>   test/tools/llvm-ar/default-add.test
>>   tools/llvm-ar/llvm-ar.cpp
>>
>>
>> Index: tools/llvm-ar/llvm-ar.cpp
>> ===================================================================
>> --- tools/llvm-ar/llvm-ar.cpp
>> +++ tools/llvm-ar/llvm-ar.cpp
>> @@ -127,6 +127,8 @@
>>    "  [v] - be verbose about actions taken\n"
>>  );
>>
>> +static const char OptionChars[] = "dmpqrtxabiosSTucv";
>> +
>>  // This enumeration delineates the kinds of operations on an archive
>>  // that are permitted.
>>  enum ArchiveOperation {
>> @@ -879,6 +881,23 @@
>>        Stem.find("lib") != StringRef::npos)
>>      return libDriverMain(makeArrayRef(argv, argc));
>>
>> +  for (int i = 1; i < argc; i++) {
>> +    // If an argument starts with a dash and only contains chars
>> +    // that belong to the options chars set, remove the dash.
>> +    // We can't handle it after the command line options parsing
>> +    // is done, since it will error out on an unrecognized string
>> +    // starting with a dash.
>> +    // Make sure this doesn't match the actual llvm-ar specific options
>> +    // that start with a dash.
>> +    if (argv[i][0] == '-' &&
>> +        strspn(&argv[i][1], OptionChars) + 1 == strlen(argv[i])) {
>> +      argv[i]++;
>> +      break;
>> +    }
>> +    if (!strcmp(argv[i], "--"))
>> +      break;
>> +  }
>
> The intention is to not support "--format=gnu -rc"?

No, that should work (since this is strcmp, not strncmp).

The intention is to avoid issues with "llvm-ar rc foo.a -- -obj", where 
"-obj" is an object file name that would otherwise be interpreted as a 
potential ar command string, starting with a dash.

// Martin