Add basic error checking to MemoryBuffer::getSTDIN.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104855 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/MemoryBuffer.h

@@ -89,7 +89,8 @@ public:
                                              StringRef BufferName = "");
 
   /// getSTDIN - Read all of stdin into a file buffer, and return it.
-  static MemoryBuffer *getSTDIN();
+  /// If an error occurs, this returns null and fills in *ErrStr with a reason.
+  static MemoryBuffer *getSTDIN(std::string *ErrStr = 0);
 
 
   /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin

lib/Linker/LinkItems.cpp

@@ -160,16 +160,17 @@ bool Linker::LinkInFile(const sys::Path &File, bool &is_native) {
   // Check for a file of name "-", which means "read standard input"
   if (File.str() == "-") {
     std::auto_ptr<Module> M;
-    MemoryBuffer *Buffer = MemoryBuffer::getSTDIN();
-    if (!Buffer->getBufferSize()) {
-      delete Buffer;
-      Error = "standard input is empty";
-    } else {
-      M.reset(ParseBitcodeFile(Buffer, Context, &Error));
-      delete Buffer;
-      if (M.get())
-        if (!LinkInModule(M.get(), &Error))
-          return false;
+    if (MemoryBuffer *Buffer = MemoryBuffer::getSTDIN(&Error)) {
+      if (!Buffer->getBufferSize()) {
+        delete Buffer;
+        Error = "standard input is empty";
+      } else {
+        M.reset(ParseBitcodeFile(Buffer, Context, &Error));
+        delete Buffer;
+        if (M.get())
+          if (!LinkInModule(M.get(), &Error))
+            return false;
+      }
     }
     return error("Cannot link stdin: " + Error);
   }

lib/Support/MemoryBuffer.cpp

@@ -137,7 +137,7 @@ MemoryBuffer *MemoryBuffer::getFileOrSTDIN(StringRef Filename,
                                            int64_t FileSize,
                                            struct stat *FileInfo) {
   if (Filename == "-")
-    return getSTDIN();
+    return getSTDIN(ErrStr);
   return getFile(Filename, ErrStr, FileSize, FileInfo);
 }
 
@@ -263,7 +263,7 @@ public:
 };
 }
 
-MemoryBuffer *MemoryBuffer::getSTDIN() {
+MemoryBuffer *MemoryBuffer::getSTDIN(std::string *ErrStr) {
   char Buffer[4096*4];
 
   std::vector<char> FileData;
@@ -279,6 +279,11 @@ MemoryBuffer *MemoryBuffer::getSTDIN() {
     FileData.insert(FileData.end(), Buffer, Buffer+ReadBytes);
   } while (ReadBytes == sizeof(Buffer));
 
+  if (!feof(stdin)) {
+    if (ErrStr) *ErrStr = "error reading from stdin";
+    return 0;
+  }
+
   FileData.push_back(0); // &FileData[Size] is invalid. So is &*FileData.end().
   size_t Size = FileData.size();
   MemoryBuffer *B = new STDINBufferFile();

lib/VMCore/Core.cpp

@@ -2205,15 +2205,14 @@ LLVMBool LLVMCreateMemoryBufferWithContentsOfFile(
 
 LLVMBool LLVMCreateMemoryBufferWithSTDIN(LLVMMemoryBufferRef *OutMemBuf,
                                          char **OutMessage) {
-  MemoryBuffer *MB = MemoryBuffer::getSTDIN();
-  if (!MB->getBufferSize()) {
-    delete MB;
-    *OutMessage = strdup("stdin is empty.");
-    return 1;
+  std::string Error;
+  if (MemoryBuffer *MB = MemoryBuffer::getSTDIN(&Error)) {
+    *OutMemBuf = wrap(MB);
+    return 0;
   }
 
-  *OutMemBuf = wrap(MB);
-  return 0;
+  *OutMessage = strdup(Error.c_str());
+  return 1;
 }
 
 void LLVMDisposeMemoryBuffer(LLVMMemoryBufferRef MemBuf) {