[LLD][COFF] Support /ignore:4099. Support /ignore with comma-separated arguments.

[aganea]

Summary

Ditto.

[[ https://docs.microsoft.com/en-us/previous-versions/b7whw3f3(v=vs.140) | /ignore:4099 ]] corresponds to "PDB 'filename' was not found with 'object/library' or at 'path'; linking object as if no debug info".

Without /ignore:4099, we can't enable /WX (treat warnings as errors).

Also, providing multiple arguments such as /ignore:4037,4049,4065,4098,4099,4217,4221 now works.

[thakis]

Lgtm

[aganea]

Thank you!

[ruiu]

COFF/Driver.cpp

991

What StringRef::split returns is not an iterator, so I think It is not a very good name. Since this is not a performance-critical path, maybe this is the simplest code I could think of:

SmallVector<StringRef, 1> Vec;
StringRef(Arg->getValue())->split(Vec, ',');
for (StringRef S : Vec) {
  if (S == "4037") {
    ...

You can find the same pattern in the code handling OPT_opt.

COFF/PDB.cpp

1309

Flip the condition to return early.

1310

Please avoid using auto unless its type is obvious from the right-hand side (for example, if the rhs is a dyn_cast, then auto is fine, but in this case the actual type is not obvious).

1311

I don't know if adding [LNK4099] is the right thing. We have a lot of warnings and error messages in lld, but no one includes such error code. If we want to do this (I personally don't want though), we should do for everything, but this needs to be discussed first.

[aganea]

COFF/PDB.cpp

1311

This is how other /ignore are handled (look for "[LNK4037]" and "[LNK4217]" in lld/trunk/COFF/Driver.cpp and lld/trunk/COFF/SymbolTable.cpp). This has been discussed in D44297.

[aganea]

Updated as requested by @ruiu
Please let me know if that sounds better.

[aganea]

Sorry I missed one line in PDB.cpp. Should be good now.

[ruiu]

LGTM

test/COFF/ignore-many.yaml

1

This file is not a YAML file, so let's not use the .yaml file extension. Please name this ignore-many.test.

17

Remove the extraneous last '\n'. (Your file ends with "\n\n", so you should remove the last '\n").

COFF/Config.h

struct Configuration {
   bool AllowIsolation = true;
   bool TerminalServerAware = true;
   bool LargeAddressAware = false;
   bool HighEntropyVA = false;
   bool AppContainer = false;
   bool MinGW = false;
   bool WarnMissingOrderSymbol = true;
   bool WarnLocallyDefinedImported = true;
+  bool WarnDebugInfoUnusable = true;
   bool Incremental = true;
   bool IntegrityCheck = false;
   bool KillAt = false;
   bool Repro = false;
 };
 
 extern Configuration *Config;
 
 } // namespace coff
 } // namespace lld
 
 #endif

COFF/Driver.cpp

void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   // Construct search path list.
   SearchPaths.push_back("");
   for (auto *Arg : Args.filtered(OPT_libpath))
     SearchPaths.push_back(Arg->getValue());
   addLibSearchPaths();
 
   // Handle /ignore
   for (auto *Arg : Args.filtered(OPT_ignore)) {
-    if (StringRef(Arg->getValue()) == "4037")
+    SmallVector<StringRef, 8> Vec;
+    StringRef(Arg->getValue()).split(Vec, ',');
+    for (StringRef S : Vec) {
+      if (S == "4037")
         Config->WarnMissingOrderSymbol = false;
-    else if (StringRef(Arg->getValue()) == "4217")
+      else if (S == "4099")
+        Config->WarnDebugInfoUnusable = false;
+      else if (S == "4217")
         Config->WarnLocallyDefinedImported = false;
       // Other warning numbers are ignored.
     }
+  }
 
   // Handle /out
   if (auto *Arg = Args.getLastArg(OPT_out))
     Config->OutputFile = Arg->getValue();
 
   // Handle /verbose
   if (Args.hasArg(OPT_verbose))
     Config->Verbose = true;

COFF/PDB.cpp

void PDBLinker::addObjFile(ObjFile *File, CVIndexMap *ExternIndexMap) {
   // the PDB first, so that we can get the map from object file type and item
   // indices to PDB type and item indices.
   CVIndexMap ObjectIndexMap;
   auto IndexMapResult =
       mergeDebugT(File, ExternIndexMap ? ExternIndexMap : &ObjectIndexMap);
 
   // If the .debug$T sections fail to merge, assume there is no debug info.
   if (!IndexMapResult) {
-    auto FileName = sys::path::filename(Path);
-    warn("Cannot use debug info for '" + FileName + "'\n" +
+    if (!Config->WarnDebugInfoUnusable)
+      return;
+    StringRef FileName = sys::path::filename(Path);
+    warn("Cannot use debug info for '" + FileName + "' [LNK4099]\n" +
          ">>> failed to load reference " +
          StringRef(toString(IndexMapResult.takeError())));
     return;
   }
 
   ScopedTimer T(SymbolMergingTimer);
 
   DebugSHandler DSH(*this, *File, *IndexMapResult);
   // Now do all live .debug$S and .debug$F sections.
   for (SectionChunk *DebugChunk : File->getDebugChunks()) {
     if (!DebugChunk->Live || DebugChunk->getSize() == 0)
       continue;

test/COFF/ignore-many.yaml

+Tests /ignore with more than one argument.
+
+RUN: yaml2obj %S/ignore4217.yaml > %t1.obj
+RUN: yaml2obj %S/Inputs/pdb-type-server-missing-2.yaml > %t2.obj
+RUN: echo foo > %t3.order
+
+RUN: lld-link /entry:main /out:%t.exe %t1.obj %t2.obj /order:@%t3.order /debug 2>&1 | FileCheck -check-prefix=WARNINGS %s
+RUN: lld-link /entry:main /out:%t.exe %t1.obj %t2.obj /order:@%t3.order /debug /ignore:4217,4099,4037 2>&1 | FileCheck -allow-empty -check-prefix=SUPPRESSED %s
+
+WARNINGS: locally defined symbol imported
+WARNINGS: missing symbol: foo
+WARNINGS: warning: Cannot use debug info for
+
+SUPPRESSED-NOT: locally defined symbol imported
+SUPPRESSED-NOT: missing symbol: foo
+SUPPRESSED-NOT: warning: Cannot use debug info for
+

test/COFF/pdb-type-server-missing.yaml

 # This is an object compiled with /Zi (see the LF_TYPESERVER2 record) without an
 # adjacent type server PDB. Test that LLD fails gracefully on it.
 # Also try linking another OBJ with a reference to the same PDB
 
 # RUN: yaml2obj %s -o %t1.obj
 # RUN: yaml2obj %p/Inputs/pdb-type-server-missing-2.yaml -o %t2.obj
 # RUN: lld-link %t1.obj %t2.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main 2>&1 | FileCheck %s
+# RUN: lld-link %t1.obj %t2.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main /ignore:4099 2>&1 | FileCheck %s -check-prefix=IGNORE -allow-empty
+# RUN: not lld-link %t1.obj %t2.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main /WX 2>&1 | FileCheck %s -check-prefix=ERR
+# RUN: lld-link %t1.obj %t2.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main /ignore:4099 /WX 2>&1 | FileCheck %s -check-prefix=IGNORE-ERR -allow-empty
 
 # CHECK: warning: Cannot use debug info for {{.*}}.obj
 # CHECK-NEXT: {{N|n}}o such file or directory
-
 # CHECK: warning: Cannot use debug info for {{.*}}.obj
 # CHECK-NEXT: {{N|n}}o such file or directory
 
+# IGNORE-NOT: warning: Cannot use debug info for {{.*}}.obj
+# IGNORE-NOT: {{N|n}}o such file or directory
+
+# ERR: error: Cannot use debug info for {{.*}}.obj
+# ERR-NEXT: {{N|n}}o such file or directory
+# ERR: error: Cannot use debug info for {{.*}}.obj
+# ERR-NEXT: {{N|n}}o such file or directory
+
+# IGNORE-ERR-NOT: error: Cannot use debug info for {{.*}}.obj
+# IGNORE-ERR-NOT: {{N|n}}o such file or directory
+
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_AMD64
   Characteristics: [  ]
 sections:
   - Name:            '.debug$S'
     Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE, IMAGE_SCN_MEM_READ ]
     Alignment:       1