[llvm-dwp] Report the filename if it cannot be found

For now, we report nothing if the execution/dwo file is missing, which is confusing.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D133549

Author: qshanz373

llvm/lib/DWP/DWP.cpp

@@ -586,8 +586,12 @@ Error write(MCStreamer &Out, ArrayRef<std::string> Inputs) {
 
   for (const auto &Input : Inputs) {
     auto ErrOrObj = object::ObjectFile::createObjectFile(Input);
-    if (!ErrOrObj)
-      return ErrOrObj.takeError();
+    if (!ErrOrObj) {
+      return handleErrors(ErrOrObj.takeError(),
+                          [&](std::unique_ptr<ECError> EC) -> Error {
+                            return createFileError(Input, Error(std::move(EC)));
+                          });
+    }
 
     auto &Obj = *ErrOrObj->getBinary();
     Objects.push_back(std::move(*ErrOrObj));

llvm/test/tools/llvm-dwp/X86/diagnose_missing_dwos.test

@@ -0,0 +1,28 @@
+RUN: rm -rf %t
+RUN: mkdir %t
+RUN: cd %t
+RUN: cp %p/../Inputs/dwos_list_from_exec/b.dwo b.dwo
+RUN: cp %p/../Inputs/dwos_list_from_exec/main main
+RUN: not llvm-dwp -e binary -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK-BIN
+RUN: not llvm-dwp -e main -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK-1ST-DWO
+RUN: cp %p/../Inputs/dwos_list_from_exec/a.dwo a.dwo
+RUN: rm b.dwo
+RUN: not llvm-dwp -e main -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK-2ND-DWO
+
+Build commands for the test binaries:
+
+clang++ -Xclang -fdebug-compilation-dir -Xclang "./" -g -O0 -gsplit-dwarf a.cpp b.cpp -o main
+
+sources:
+a.cpp:
+  void a() {}
+
+b.cpp:
+  void b() {}
+  int main() {
+     return 0;
+  }
+
+CHECK-BIN: error: 'binary': {{[Nn]}}o such file or directory
+CHECK-1ST-DWO: error: './a.dwo': {{[Nn]}}o such file or directory
+CHECK-2ND-DWO: error: './b.dwo': {{[Nn]}}o such file or directory

llvm/tools/llvm-dwp/llvm-dwp.cpp

@@ -111,7 +111,13 @@ int main(int argc, char **argv) {
   for (const auto &ExecFilename : ExecFilenames) {
     auto DWOs = getDWOFilenames(ExecFilename);
     if (!DWOs) {
-      logAllUnhandledErrors(DWOs.takeError(), WithColor::error());
+      logAllUnhandledErrors(
+          handleErrors(DWOs.takeError(),
+                       [&](std::unique_ptr<ECError> EC) -> Error {
+                         return createFileError(ExecFilename,
+                                                Error(std::move(EC)));
+                       }),
+          WithColor::error());
       return 1;
     }
     DWOFilenames.insert(DWOFilenames.end(),
@@ -127,7 +133,13 @@ int main(int argc, char **argv) {
 
   auto ErrOrTriple = readTargetTriple(DWOFilenames.front());
   if (!ErrOrTriple) {
-    logAllUnhandledErrors(ErrOrTriple.takeError(), WithColor::error());
+    logAllUnhandledErrors(
+        handleErrors(ErrOrTriple.takeError(),
+                     [&](std::unique_ptr<ECError> EC) -> Error {
+                       return createFileError(DWOFilenames.front(),
+                                              Error(std::move(EC)));
+                     }),
+        WithColor::error());
     return 1;
   }