Reapply [llvm-ar] Include a line number when failing to parse an MRI script

Reapply r372309

Errors that occur when reading an MRI script now include a corresponding
line number.

Differential Revision: https://reviews.llvm.org/D67449

llvm-svn: 372374

1 files changed, 16 insertions, 3 deletions

diff --git a/llvm/tools/llvm-ar/llvm-ar.cpp b/llvm/tools/llvm-ar/llvm-ar.cpp
index 65a86192091..4eb50a12490 100644
--- a/llvm/tools/llvm-ar/llvm-ar.cpp
+++ b/llvm/tools/llvm-ar/llvm-ar.cpp
@@ -116,10 +116,19 @@ void printHelpMessage() {
     outs() << ArHelp;
 }
 
+static unsigned MRILineNumber;
+static bool ParsingMRIScript;
+
 // Show the error message and exit.
 LLVM_ATTRIBUTE_NORETURN static void fail(Twine Error) {
-  WithColor::error(errs(), ToolName) << Error << "\n";
-  printHelpMessage();
+  if (ParsingMRIScript) {
+    WithColor::error(errs(), ToolName)
+        << "script line " << MRILineNumber << ": " << Error << "\n";
+  } else {
+    WithColor::error(errs(), ToolName) << Error << "\n";
+    printHelpMessage();
+  }
+
   exit(1);
 }
 
@@ -958,8 +967,10 @@ static void runMRIScript() {
   const MemoryBuffer &Ref = *Buf.get();
   bool Saved = false;
   std::vector<NewArchiveMember> NewMembers;
+  ParsingMRIScript = true;
 
   for (line_iterator I(Ref, /*SkipBlanks*/ false), E; I != E; ++I) {
+    ++MRILineNumber;
     StringRef Line = *I;
     Line = Line.split(';').first;
     Line = Line.split('*').first;
@@ -1021,7 +1032,9 @@ static void runMRIScript() {
       fail("unknown command: " + CommandStr);
     }
   }
-
+  
+  ParsingMRIScript = false;
+  
   // Nothing to do if not saved.
   if (Saved)
     performOperation(ReplaceOrInsert, &NewMembers);