[clang] [flang] [libcxx] [llvm] [llvm-reduce]: print short form, actionable names in the log (PR #132813)

[via llvm-commits]

YLChenZ wrote:

@arsenm Based on your tips, I have the following in mind:
First, the function pointer field of structure DeltaPass needs to be modified to void (Oracle &, ReducerWorkItem &). 
Second, instead of using reduceXXXDeltaPass to call runDeltaPass indirectly, the function pointer provided by DeltaPass is called directly in DeltaManager.

For example:
before:
```c++
//===- ReduceAliases.h - Specialized Delta Pass -----------------*- C++ -*-===//

#ifndef LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEALIASES_H
#define LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEALIASES_H

#include "Delta.h"

namespace llvm {
void reduceAliasesDeltaPass(TestRunner &Test);
void reduceIFuncsDeltaPass(TestRunner &Test);
} // namespace llvm

#endif
```
```c++
//===- ReduceAliases.cpp - Specialized Delta Pass -------------------------===//

#include "ReduceAliases.h"
...

using namespace llvm;

/// Removes all aliases aren't inside any of the
/// desired Chunks.
static void extractAliasesFromModule(Oracle &O, ReducerWorkItem &Program) {
...
}

static void extractIFuncsFromModule(Oracle &O, ReducerWorkItem &WorkItem) {
  ...
}

void llvm::reduceAliasesDeltaPass(TestRunner &Test, StringRef PassMessage) {
  runDeltaPass(Test, extractAliasesFromModule, PassMessage);
}

void llvm::reduceIFuncsDeltaPass(TestRunner &Test, StringRef PassMessage) {
  runDeltaPass(Test, extractIFuncsFromModule, PassMessage);
}
```
after:
```c++
//===- ReduceAliases.h - Specialized Delta Pass -----------------*- C++ -*-===//

#ifndef LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEALIASES_H
#define LLVM_TOOLS_LLVM_REDUCE_DELTAS_REDUCEALIASES_H

#include "Delta.h"

namespace llvm {
void extractAliasesFromModule(Oracle &O, ReducerWorkItem &Program);
void extractIFuncsFromModule(Oracle &O, ReducerWorkItem &WorkItem);
} // namespace llvm

#endif
```
```c++
//===- ReduceAliases.cpp - Specialized Delta Pass -------------------------===//

#include "ReduceAliases.h"
...

using namespace llvm;

/// Removes all aliases aren't inside any of the
/// desired Chunks.
void llvm::extractAliasesFromModule(Oracle &O, ReducerWorkItem &Program) {
...
}

void llvm::extractIFuncsFromModule(Oracle &O, ReducerWorkItem &WorkItem) {
  ...
}

```

Call runDeltaPass directly in DeltaManager:
```c++
...
static void runAllDeltaPasses(TestRunner &Tester,
                              const SmallStringSet &SkipPass) {
  if (Tester.getProgram().isMIR()) {
    for(const DeltaPass &Pass : MIR_Passes) {
      if (!SkipPass.count(Pass.Name)) {
        SmallString<64> Message = Pass.Desc;
        Message += " (";
        Message += Pass.Name;
        Message += ')';
        runDeltaPass(Tester,Pass.Func,Message);
      } 
    }
  }
...
```

https://github.com/llvm/llvm-project/pull/132813