Make it possible to redirect not only errs() but also outs()

This change is for those who use lld as a library. Context:
https://reviews.llvm.org/D70287

This patch adds a new parmeter to lld::*::link() so that we can pass
an raw_ostream object representing stdout. Previously, lld::*::link()
took only an stderr object.

Justification for making stdoutOS and stderrOS mandatory: I wanted to
make link() functions to take stdout and stderr in that order.
However, if we change the function signature from

  bool link(ArrayRef<const char *> args, bool canExitEarly,
            raw_ostream &stderrOS = llvm::errs());

to

  bool link(ArrayRef<const char *> args, bool canExitEarly,
            raw_ostream &stdoutOS = llvm::outs(),
            raw_ostream &stderrOS = llvm::errs());

, then the meaning of existing code that passes stderrOS silently
changes (stderrOS would be interpreted as stdoutOS). So, I chose to
make existing code not to compile, so that developers can fix their
code.

Differential Revision: https://reviews.llvm.org/D70292

7 files changed, 36 insertions, 44 deletions

diff --git a/lld/lib/Core/Resolver.cpp b/lld/lib/Core/Resolver.cpp
index 7e6d95f8223..182f9caa985 100644
--- a/lld/lib/Core/Resolver.cpp
+++ b/lld/lib/Core/Resolver.cpp
@@ -223,8 +223,8 @@ bool Resolver::resolveUndefines() {
     if (!file)
       return true;
     if (std::error_code ec = file->parse()) {
-      llvm::errs() << "Cannot open " + file->path()
-                   << ": " << ec.message() << "\n";
+      lld::errs() << "Cannot open " + file->path() << ": " << ec.message()
+                  << "\n";
       return false;
     }
     DEBUG_WITH_TYPE("resolver",
@@ -252,8 +252,8 @@ bool Resolver::resolveUndefines() {
       if (auto EC = undefAddedOrError.takeError()) {
         // FIXME: This should be passed to logAllUnhandledErrors but it needs
         // to be passed a Twine instead of a string.
-        llvm::errs() << "Error in " + file->path() << ": ";
-        logAllUnhandledErrors(std::move(EC), llvm::errs(), std::string());
+        lld::errs() << "Error in " + file->path() << ": ";
+        logAllUnhandledErrors(std::move(EC), lld::errs(), std::string());
         return false;
       }
       undefAdded = undefAddedOrError.get();
@@ -266,8 +266,8 @@ bool Resolver::resolveUndefines() {
       if (auto EC = undefAddedOrError.takeError()) {
         // FIXME: This should be passed to logAllUnhandledErrors but it needs
         // to be passed a Twine instead of a string.
-        llvm::errs() << "Error in " + file->path() << ": ";
-        logAllUnhandledErrors(std::move(EC), llvm::errs(), std::string());
+        lld::errs() << "Error in " + file->path() << ": ";
+        logAllUnhandledErrors(std::move(EC), lld::errs(), std::string());
         return false;
       }
       undefAdded = undefAddedOrError.get();
@@ -279,8 +279,8 @@ bool Resolver::resolveUndefines() {
       if (auto EC = handleSharedLibrary(*file)) {
         // FIXME: This should be passed to logAllUnhandledErrors but it needs
         // to be passed a Twine instead of a string.
-        llvm::errs() << "Error in " + file->path() << ": ";
-        logAllUnhandledErrors(std::move(EC), llvm::errs(), std::string());
+        lld::errs() << "Error in " + file->path() << ": ";
+        logAllUnhandledErrors(std::move(EC), lld::errs(), std::string());
         return false;
       }
       break;
@@ -424,15 +424,14 @@ bool Resolver::checkUndefines() {
     // Seems like this symbol is undefined. Warn that.
     foundUndefines = true;
     if (_ctx.printRemainingUndefines()) {
-      llvm::errs() << "Undefined symbol: " << undef->file().path()
-                   << ": " << _ctx.demangle(undef->name())
-                   << "\n";
+      lld::errs() << "Undefined symbol: " << undef->file().path() << ": "
+                  << _ctx.demangle(undef->name()) << "\n";
     }
   }
   if (!foundUndefines)
     return false;
   if (_ctx.printRemainingUndefines())
-    llvm::errs() << "symbol(s) not found\n";
+    lld::errs() << "symbol(s) not found\n";
   return true;
 }
 
diff --git a/lld/lib/Core/SymbolTable.cpp b/lld/lib/Core/SymbolTable.cpp
index 55cc27c38a6..7ccd1ce0ab2 100644
--- a/lld/lib/Core/SymbolTable.cpp
+++ b/lld/lib/Core/SymbolTable.cpp
@@ -157,21 +157,15 @@ bool SymbolTable::addByName(const Atom &newAtom) {
         useNew = true;
         break;
       }
-      llvm::errs() << "Size mismatch: "
-                   << existing->name() << " (" << existingSize << ") "
-                   << newAtom.name() << " (" << newSize << ")\n";
+      lld::errs() << "Size mismatch: " << existing->name() << " ("
+                  << existingSize << ") " << newAtom.name() << " (" << newSize
+                  << ")\n";
       LLVM_FALLTHROUGH;
     }
     case MCR_Error:
-      llvm::errs() << "Duplicate symbols: "
-                   << existing->name()
-                   << ":"
-                   << existing->file().path()
-                   << " and "
-                   << newAtom.name()
-                   << ":"
-                   << newAtom.file().path()
-                   << "\n";
+      lld::errs() << "Duplicate symbols: " << existing->name() << ":"
+                  << existing->file().path() << " and " << newAtom.name() << ":"
+                  << newAtom.file().path() << "\n";
       llvm::report_fatal_error("duplicate symbol error");
       break;
     }
@@ -193,7 +187,7 @@ bool SymbolTable::addByName(const Atom &newAtom) {
     break;
   }
   case NCR_Error:
-    llvm::errs() << "SymbolTable: error while merging " << name << "\n";
+    lld::errs() << "SymbolTable: error while merging " << name << "\n";
     llvm::report_fatal_error("duplicate symbol error");
     break;
   }
diff --git a/lld/lib/Driver/DarwinLdDriver.cpp b/lld/lib/Driver/DarwinLdDriver.cpp
index 8566ababc65..60515d21a92 100644
--- a/lld/lib/Driver/DarwinLdDriver.cpp
+++ b/lld/lib/Driver/DarwinLdDriver.cpp
@@ -232,7 +232,7 @@ static std::error_code parseOrderFile(StringRef orderFilePath,
      sym = prefixAndSym.first;
     if (!sym.empty()) {
       ctx.appendOrderedSymbol(sym, prefix);
-      //llvm::errs() << sym << ", prefix=" << prefix << "\n";
+      // lld::errs() << sym << ", prefix=" << prefix << "\n";
     }
   }
   return std::error_code();
@@ -382,7 +382,7 @@ bool parse(llvm::ArrayRef<const char *> args, MachOLinkingContext &ctx) {
         !parsedArgs.getLastArg(OPT_test_file_usage)) {
       // If no -arch and no options at all, print usage message.
       if (parsedArgs.size() == 0) {
-        table.PrintHelp(llvm::outs(),
+        table.PrintHelp(lld::outs(),
                         (std::string(args[0]) + " [options] file...").c_str(),
                         "LLVM Linker", false);
       } else {
@@ -1144,14 +1144,16 @@ static void createFiles(MachOLinkingContext &ctx, bool Implicit) {
 
 /// This is where the link is actually performed.
 bool link(llvm::ArrayRef<const char *> args, bool CanExitEarly,
-          raw_ostream &Error) {
+          raw_ostream &StdoutOS, raw_ostream &StderrOS) {
   errorHandler().logName = args::getFilenameWithoutExe(args[0]);
   errorHandler().errorLimitExceededMsg =
       "too many errors emitted, stopping now (use "
       "'-error-limit 0' to see all errors)";
-  errorHandler().errorOS = &Error;
   errorHandler().exitEarly = CanExitEarly;
-  enableColors(Error.has_colors());
+  enableColors(StderrOS.has_colors());
+
+  lld::stdoutOS = &StdoutOS;
+  lld::stderrOS = &StderrOS;
 
   MachOLinkingContext ctx;
   if (!parse(args, ctx))
@@ -1196,10 +1198,9 @@ bool link(llvm::ArrayRef<const char *> args, bool CanExitEarly,
   if (auto ec = pm.runOnFile(*merged)) {
     // FIXME: This should be passed to logAllUnhandledErrors but it needs
     // to be passed a Twine instead of a string.
-    *errorHandler().errorOS << "Failed to run passes on file '"
-                            << ctx.outputPath() << "': ";
-    logAllUnhandledErrors(std::move(ec), *errorHandler().errorOS,
-                          std::string());
+    lld::errs() << "Failed to run passes on file '" << ctx.outputPath()
+                << "': ";
+    logAllUnhandledErrors(std::move(ec), lld::errs(), std::string());
     return false;
   }
 
@@ -1210,10 +1211,8 @@ bool link(llvm::ArrayRef<const char *> args, bool CanExitEarly,
   if (auto ec = ctx.writeFile(*merged)) {
     // FIXME: This should be passed to logAllUnhandledErrors but it needs
     // to be passed a Twine instead of a string.
-    *errorHandler().errorOS << "Failed to write file '" << ctx.outputPath()
-                            << "': ";
-    logAllUnhandledErrors(std::move(ec), *errorHandler().errorOS,
-                          std::string());
+    lld::errs() << "Failed to write file '" << ctx.outputPath() << "': ";
+    logAllUnhandledErrors(std::move(ec), lld::errs(), std::string());
     return false;
   }
 
diff --git a/lld/lib/ReaderWriter/FileArchive.cpp b/lld/lib/ReaderWriter/FileArchive.cpp
index 98f4d06ee21..d73711cfb3d 100644
--- a/lld/lib/ReaderWriter/FileArchive.cpp
+++ b/lld/lib/ReaderWriter/FileArchive.cpp
@@ -145,7 +145,7 @@ private:
                            + mb.getBufferIdentifier() + ")").str();
 
     if (_logLoading)
-      llvm::errs() << memberPath << "\n";
+      lld::errs() << memberPath << "\n";
 
     std::unique_ptr<MemoryBuffer> memberMB(MemoryBuffer::getMemBuffer(
         mb.getBuffer(), mb.getBufferIdentifier(), false));
diff --git a/lld/lib/ReaderWriter/MachO/LayoutPass.cpp b/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
index 8db6ffb958a..ea54c2d4cc3 100644
--- a/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
+++ b/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
@@ -241,8 +241,8 @@ static bool compareAtomsSub(const LayoutPass::SortKey &lc,
     return leftOrdinal < rightOrdinal;
   }
 
-  llvm::errs() << "Unordered: <" << left->name() << "> <"
-               << right->name() << ">\n";
+  lld::errs() << "Unordered: <" << left->name() << "> <" << right->name()
+              << ">\n";
   llvm_unreachable("Atoms with Same Ordinal!");
 }
 
diff --git a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
index 221d895a40d..812f89696f6 100644
--- a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
@@ -825,7 +825,7 @@ bool MachOLinkingContext::sectionAligned(StringRef seg, StringRef sect,
 void MachOLinkingContext::addExportSymbol(StringRef sym) {
   // Support old crufty export lists with bogus entries.
   if (sym.endswith(".eh") || sym.startswith(".objc_category_name_")) {
-    llvm::errs() << "warning: ignoring " << sym << " in export list\n";
+    lld::errs() << "warning: ignoring " << sym << " in export list\n";
     return;
   }
   // Only i386 MacOSX uses old ABI, so don't change those.
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
index f34857b9967..3e70a1db7b1 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -316,8 +316,8 @@ llvm::Error processSymboledSection(DefinedAtom::ContentType atomType,
             });
 
   // Debug logging of symbols.
-  //for (const Symbol *sym : symbols)
-  //  llvm::errs() << "  sym: "
+  // for (const Symbol *sym : symbols)
+  //  lld::errs() << "  sym: "
   //    << llvm::format("0x%08llx ", (uint64_t)sym->value)
   //    << ", " << sym->name << "\n";