[llvm] r231577 - Make the assertion macros in Verifier and Linter truly variadic.

[Duncan P. N. Exon Smith]

> On 2015 Mar 14, at 03:34, Benjamin Kramer <benny.kra at gmail.com> wrote:
> 
>> 
>> On 14.03.2015, at 04:14, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote:
>> 
>> 
>>> On 2015 Mar 7, at 13:15, Benjamin Kramer <benny.kra at googlemail.com> wrote:
>>> 
>>> Author: d0k
>>> Date: Sat Mar  7 15:15:40 2015
>>> New Revision: 231577
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=231577&view=rev
>>> Log:
>>> Make the assertion macros in Verifier and Linter truly variadic.
>>> 
>> 
>> Nice cleanup!
>> 
>>> NFC.
>> 
>> Actually... (see below)
>> 
>>> 
>>> Modified:
>>>  llvm/trunk/lib/Analysis/Lint.cpp
>>>  llvm/trunk/lib/IR/Verifier.cpp
>>> 
>>> Modified: llvm/trunk/lib/Analysis/Lint.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/Lint.cpp?rev=231577&r1=231576&r2=231577&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/lib/Analysis/Lint.cpp (original)
>>> +++ llvm/trunk/lib/Analysis/Lint.cpp Sat Mar  7 15:15:40 2015
>>> @@ -129,27 +129,26 @@ namespace {
>>>   }
>>>   void print(raw_ostream &O, const Module *M) const override {}
>>> 
>>> -    void WriteValue(const Value *V) {
>>> -      if (!V) return;
>>> -      if (isa<Instruction>(V)) {
>>> -        MessagesStr << *V << '\n';
>>> -      } else {
>>> -        V->printAsOperand(MessagesStr, true, Mod);
>>> -        MessagesStr << '\n';
>>> +    void WriteValues(ArrayRef<const Value *> Vs) {
>>> +      for (const Value *V : Vs) {
>>> +        if (!V)
>>> +          continue;
>>> +        if (isa<Instruction>(V)) {
>>> +          MessagesStr << *V << '\n';
>>> +        } else {
>>> +          V->printAsOperand(MessagesStr, true, Mod);
>>> +          MessagesStr << '\n';
>>> +        }
>>>     }
>>>   }
>>> 
>>>   // CheckFailed - A check failed, so print out the condition and the message
>>>   // that failed.  This provides a nice place to put a breakpoint if you want
>>>   // to see why something is not correct.
>> 
>> This is no longer true.  I was playing with a similar patch myself
>> while I was on holiday -- strange timing -- and I noticed that
>> `b CheckFailed` no longer works (at least, not in `lldb`).  The
>> problem is that you need to specify `CheckFailed<...>` as the
>> breakpoint target.
>> 
>> My workaround was to add a `CheckFailedMsg()` function:
>> 
>>   void CheckFailedMsg(const Twine &Message) {
>>     MessagesStr << Message.str() << "\n";
>>   }
>> 
>> and have `CheckFailed()` call it.  Then `CheckFailedMsg()` serves
>> as a nice target for a breakpoint.
>> 
>> Any other ideas?
> 
> That would be one possibility.

I committed a variation on this in r232268 that adds an overload
for `CheckFailed`.  Tested it with both `-verify` and `-lint`.

> My usual hackaround for issues like this is to place a breakpoint on the first line in the templated function instead of using the name. LLDB also supports regex breakpoints, but I never tried that.

IMO we shouldn't need hacks (or advanced debugger features) for
this.