ELF: Report multiple errors from the driver.

This patch let the driver keep going until it parses all
command line options.

http://reviews.llvm.org/D16645

llvm-svn: 259143

7 files changed, 59 insertions, 28 deletions

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index a0fc13af472..7909336f44b 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -55,8 +55,10 @@ static std::pair<ELFKind, uint16_t> parseEmulation(StringRef S) {
   if (S == "aarch64linux")
     return {ELF64LEKind, EM_AARCH64};
   if (S == "i386pe" || S == "i386pep" || S == "thumb2pe")
-    fatal("Windows targets are not supported on the ELF frontend: " + S);
-  fatal("Unknown emulation: " + S);
+    error("Windows targets are not supported on the ELF frontend: " + S);
+  else
+    error("Unknown emulation: " + S);
+  return {ELFNoneKind, 0};
 }
 
 // Returns slices of MB by parsing MB as an archive file.
@@ -84,7 +86,8 @@ void LinkerDriver::addFile(StringRef Path) {
   if (Config->Verbose)
     llvm::outs() << Path << "\n";
   auto MBOrErr = MemoryBuffer::getFile(Path);
-  fatal(MBOrErr, "cannot open " + Path);
+  if (error(MBOrErr, "cannot open " + Path))
+    return;
   std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
   MemoryBufferRef MBRef = MB->getMemBufferRef();
   OwningMBs.push_back(std::move(MB)); // take MB ownership
@@ -109,6 +112,15 @@ void LinkerDriver::addFile(StringRef Path) {
   }
 }
 
+// Add a given library by searching it from input search paths.
+void LinkerDriver::addLibrary(StringRef Name) {
+  StringRef Path = searchLibrary(Name);
+  if (Path.empty())
+    error("Unable to find library -l" + Name);
+  else
+    addFile(Path);
+}
+
 // Some command line options or some combinations of them are not allowed.
 // This function checks for such errors.
 static void checkOptions(opt::InputArgList &Args) {
@@ -116,15 +128,15 @@ static void checkOptions(opt::InputArgList &Args) {
   // of executables or DSOs. We don't support that since the feature
   // does not seem to provide more value than the static archiver.
   if (Args.hasArg(OPT_relocatable))
-    fatal("-r option is not supported. Use 'ar' command instead.");
+    error("-r option is not supported. Use 'ar' command instead.");
 
   // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
   // table which is a relatively new feature.
   if (Config->EMachine == EM_MIPS && Config->GnuHash)
-    fatal("The .gnu.hash section is not compatible with the MIPS target.");
+    error("The .gnu.hash section is not compatible with the MIPS target.");
 
   if (Config->EMachine == EM_AMDGPU && !Config->Entry.empty())
-    fatal("-e option is not valid for AMDGPU.");
+    error("-e option is not valid for AMDGPU.");
 }
 
 static StringRef
@@ -148,6 +160,8 @@ void LinkerDriver::main(ArrayRef<const char *> ArgsArr) {
   readConfigs(Args);
   createFiles(Args);
   checkOptions(Args);
+  if (HasError)
+    return;
 
   switch (Config->EKind) {
   case ELF32LEKind:
@@ -163,7 +177,7 @@ void LinkerDriver::main(ArrayRef<const char *> ArgsArr) {
     link<ELF64BE>(Args);
     return;
   default:
-    fatal("-m or at least a .o file required");
+    error("-m or at least a .o file required");
   }
 }
 
@@ -219,7 +233,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   if (auto *Arg = Args.getLastArg(OPT_O)) {
     StringRef Val = Arg->getValue();
     if (Val.getAsInteger(10, Config->Optimize))
-      fatal("Invalid optimization level");
+      error("Invalid optimization level");
   }
 
   if (auto *Arg = Args.getLastArg(OPT_hash_style)) {
@@ -230,7 +244,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
     } else if (S == "both") {
       Config->GnuHash = true;
     } else if (S != "sysv")
-      fatal("Unknown hash style: " + S);
+      error("Unknown hash style: " + S);
   }
 
   for (auto *Arg : Args.filtered(OPT_undefined))
@@ -241,7 +255,7 @@ void LinkerDriver::createFiles(opt::InputArgList &Args) {
   for (auto *Arg : Args) {
     switch (Arg->getOption().getID()) {
     case OPT_l:
-      addFile(searchLibrary(Arg->getValue()));
+      addLibrary(Arg->getValue());
       break;
     case OPT_INPUT:
     case OPT_script:
@@ -268,8 +282,8 @@ void LinkerDriver::createFiles(opt::InputArgList &Args) {
     }
   }
 
-  if (Files.empty())
-    fatal("no input files.");
+  if (Files.empty() && !HasError)
+    error("no input files.");
 }
 
 template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
diff --git a/lld/ELF/Driver.h b/lld/ELF/Driver.h
index 95b6d968c86..adcf4571375 100644
--- a/lld/ELF/Driver.h
+++ b/lld/ELF/Driver.h
@@ -27,6 +27,7 @@ class LinkerDriver {
 public:
   void main(ArrayRef<const char *> Args);
   void addFile(StringRef Path);
+  void addLibrary(StringRef Name);
 
 private:
   void readConfigs(llvm::opt::InputArgList &Args);
diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
index 52e463350f0..bbe5f9fc903 100644
--- a/lld/ELF/DriverUtils.cpp
+++ b/lld/ELF/DriverUtils.cpp
@@ -66,7 +66,7 @@ opt::InputArgList elf2::parseArgs(llvm::BumpPtrAllocator *A,
   // Parse options and then do error checking.
   opt::InputArgList Args = Table.ParseArgs(Vec, MissingIndex, MissingCount);
   if (MissingCount)
-    fatal(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
+    error(Twine("missing arg value for \"") + Args.getArgString(MissingIndex) +
           "\", expected " + Twine(MissingCount) +
           (MissingCount == 1 ? " argument.\n" : " arguments"));
 
@@ -74,8 +74,7 @@ opt::InputArgList elf2::parseArgs(llvm::BumpPtrAllocator *A,
   for (auto *Arg : Unknowns)
     warning("warning: unknown argument: " + Arg->getSpelling());
   if (Unknowns.begin() != Unknowns.end())
-    fatal("unknown argument(s) found");
-
+    error("unknown argument(s) found");
   return Args;
 }
 
@@ -104,7 +103,7 @@ std::string elf2::searchLibrary(StringRef Path) {
     if (!S.empty())
       return S;
   }
-  fatal("Unable to find library -l" + Path);
+  return "";
 }
 
 // Makes a path by concatenating Dir and File.
diff --git a/lld/ELF/Error.cpp b/lld/ELF/Error.cpp
index 327bb26a4f1..e3add1b4068 100644
--- a/lld/ELF/Error.cpp
+++ b/lld/ELF/Error.cpp
@@ -24,14 +24,18 @@ void error(const Twine &Msg) {
   HasError = true;
 }
 
-void error(std::error_code EC, const Twine &Prefix) {
-  if (EC)
-    error(Prefix + ": " + EC.message());
+bool error(std::error_code EC, const Twine &Prefix) {
+  if (!EC)
+    return false;
+  error(Prefix + ": " + EC.message());
+  return true;
 }
 
-void error(std::error_code EC) {
-  if (EC)
-    error(EC.message());
+bool error(std::error_code EC) {
+  if (!EC)
+    return false;
+  error(EC.message());
+  return true;
 }
 
 void fatal(const Twine &Msg) {
diff --git a/lld/ELF/Error.h b/lld/ELF/Error.h
index 3b6aa693ec8..546e1d348f2 100644
--- a/lld/ELF/Error.h
+++ b/lld/ELF/Error.h
@@ -20,13 +20,16 @@ extern bool HasError;
 void warning(const Twine &Msg);
 
 void error(const Twine &Msg);
-void error(std::error_code EC, const Twine &Prefix);
-void error(std::error_code EC);
+bool error(std::error_code EC, const Twine &Prefix);
+bool error(std::error_code EC);
 
-template <typename T> void error(const ErrorOr<T> &V, const Twine &Prefix) {
-  error(V.getError(), Prefix);
+template <typename T> bool error(const ErrorOr<T> &V, const Twine &Prefix) {
+  return error(V.getError(), Prefix);
+}
+
+template <typename T> bool error(const ErrorOr<T> &V) {
+  return error(V.getError());
 }
-template <typename T> void error(const ErrorOr<T> &V) { error(V.getError()); }
 
 LLVM_ATTRIBUTE_NORETURN void fatal(const Twine &Msg);
 void fatal(std::error_code EC, const Twine &Prefix);
@@ -35,6 +38,7 @@ void fatal(std::error_code EC);
 template <typename T> void fatal(const ErrorOr<T> &V, const Twine &Prefix) {
   fatal(V.getError(), Prefix);
 }
+
 template <typename T> void fatal(const ErrorOr<T> &V) { fatal(V.getError()); }
 
 } // namespace elf2
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index d9f98e9bbff..cbf422d25b4 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -178,7 +178,7 @@ void LinkerScript::addFile(StringRef S) {
     else
       Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)));
   } else if (S.startswith("-l")) {
-    Driver->addFile(searchLibrary(S.substr(2)));
+    Driver->addLibrary(S.substr(2));
   } else if (sys::fs::exists(S)) {
     Driver->addFile(S);
   } else {
diff --git a/lld/test/ELF/driver.test b/lld/test/ELF/driver.test
new file mode 100644
index 00000000000..13f040e4f9c
--- /dev/null
+++ b/lld/test/ELF/driver.test
@@ -0,0 +1,9 @@
+# RUN: not ld.lld -unknown1 -unknown2 -m foo /no/such/file -lnosuchlib \
+# RUN:   2>&1 | FileCheck %s
+
+# CHECK: warning: unknown argument: -unknown1
+# CHECK: warning: unknown argument: -unknown2
+# CHECK: unknown argument(s) found
+# CHECK: Unknown emulation: foo
+# CHECK: cannot open /no/such/file
+# CHECK: Unable to find library -lnosuchlib