[llvm-ar] Support * as comment char in MRI scripts

[mstorsjo]

Summary

MRI scripts have two comment chars, * and ;, but only the latter was supported before.

Also allow leading spaces before comment chars (and before any command string), and allow comments after a command.

[pcc]

tools/llvm-ar/llvm-ar.cpp

819

What should happen if a line contains both a command and a comment?

[mstorsjo]

tools/llvm-ar/llvm-ar.cpp

819

I'm not sure I'm following, can you elaborate?

If the first word of the line starts with either ; or *, the whole line is a comment.

[pcc]

tools/llvm-ar/llvm-ar.cpp

819

I mean what should be the interpretation of the line addlib foo.a ; comment? Does it add a library named foo.a or foo.a ; comment or is it an error?

[mstorsjo]

tools/llvm-ar/llvm-ar.cpp

819

Oh, good point. When checking with GNU 'ar', it creates a library named foo.a only.

I'll see if I can amend the code to handle this as well.

[mstorsjo]

Handle the comment char appearing anywhere in a command line - by discarding anything after the comment char.

[mstorsjo]

Ping

[pcc]

tools/llvm-ar/llvm-ar.cpp

807

Don't pass /*SkipBlanks*/ true, ';' here because you're already handling them below.

810

Perhaps more succinctly Line = Line.split(';').first;?

[mstorsjo]

tools/llvm-ar/llvm-ar.cpp

807

Ok, will change.

810

Ah, of course - yes.

[mstorsjo]

Avoided needless use of std::tie, passing SkipBlanks = false as we handle that skipping locally anyway now.

[pcc]

LGTM

tools/llvm-ar/llvm-ar.cpp

809–814

Move this decl next to line 815.

[mstorsjo]

tools/llvm-ar/llvm-ar.cpp

809–814

Sorry, I missed this comment before - will fix this as well.

test/tools/llvm-ar/mri-delete.test

 RUN: yaml2obj %S/Inputs/elf.yaml -o %t.o
 RUN: rm -f %t.ar
 
-RUN: echo "create %t.ar" > %t.mri
-RUN: echo "addmod %t.o" >> %t.mri
+RUN: echo "create %t.ar;comment" > %t.mri
+RUN: echo "addmod %t.o * comment" >> %t.mri
+RUN: echo "; comment" >> %t.mri
+RUN: echo " ;comment" >> %t.mri
+RUN: echo "* comment" >> %t.mri
+RUN: echo " *comment" >> %t.mri
 RUN: echo "addmod %S/Inputs/elf.yaml" >> %t.mri
 RUN: echo "delete %t.o" >> %t.mri
-RUN: echo "save" >> %t.mri
+RUN: echo " save" >> %t.mri
 RUN: echo "end" >> %t.mri
 
 RUN: llvm-ar -M < %t.mri
 RUN: llvm-ar tv %t.ar | FileCheck %s
 
 CHECK-NOT: mri-delete.test{{.*}}.o

tools/llvm-ar/llvm-ar.cpp

static void runMRIScript() {
   ErrorOr<std::unique_ptr<MemoryBuffer>> Buf = MemoryBuffer::getSTDIN();
   failIfError(Buf.getError());
   const MemoryBuffer &Ref = *Buf.get();
   bool Saved = false;
   std::vector<NewArchiveMember> NewMembers;
   std::vector<std::unique_ptr<MemoryBuffer>> ArchiveBuffers;
   std::vector<std::unique_ptr<object::Archive>> Archives;
 
   for (line_iterator I(Ref, /*SkipBlanks*/ true, ';'), E; I != E; ++I) {
     StringRef Line = *I;
     StringRef CommandStr, Rest;
+    std::tie(Line, Rest) = Line.split(';');
+    std::tie(Line, Rest) = Line.split('*');
+    Line = Line.trim();
+    if (Line.empty())
+      continue;
     std::tie(CommandStr, Rest) = Line.split(' ');
     Rest = Rest.trim();
     if (!Rest.empty() && Rest.front() == '"' && Rest.back() == '"')
       Rest = Rest.drop_front().drop_back();
     auto Command = StringSwitch<MRICommand>(CommandStr.lower())
                        .Case("addlib", MRICommand::AddLib)
                        .Case("addmod", MRICommand::AddMod)
                        .Case("create", MRICommand::Create)
                        .Case("delete", MRICommand::Delete)
                        .Case("save", MRICommand::Save)
                        .Case("end", MRICommand::End)
                        .Default(MRICommand::Invalid);