1 files changed, 78 insertions, 0 deletions
diff --git a/js/src/util/CompleteFile.cpp b/js/src/util/CompleteFile.cpp
new file mode 100644
index 0000000000..bdef8b4cf4
--- /dev/null
+++ b/js/src/util/CompleteFile.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "util/CompleteFile.h"
+
+#include <cstring>     // std::strcmp
+#include <stdio.h>     // FILE, fileno, fopen, getc, getc_unlocked, _getc_nolock
+#include <sys/stat.h>  // stat, fstat
+
+#include "jsapi.h"  // JS_ReportErrorNumberLatin1
+
+#include "js/friend/ErrorMessages.h"  // js::GetErrorMessage, JSMSG_CANT_OPEN
+
+bool js::ReadCompleteFile(JSContext* cx, FILE* fp, FileContents& buffer) {
+  /* Get the complete length of the file, if possible. */
+  struct stat st;
+  int ok = fstat(fileno(fp), &st);
+  if (ok != 0) {
+    return false;
+  }
+  if (st.st_size > 0) {
+    if (!buffer.reserve(st.st_size)) {
+      return false;
+    }
+  }
+
+  /* Use the fastest available getc. */
+  auto fast_getc =
+#if defined(HAVE_GETC_UNLOCKED)
+      getc_unlocked
+#elif defined(HAVE__GETC_NOLOCK)
+      _getc_nolock
+#else
+      getc
+#endif
+      ;
+
+  // Read in the whole file. Note that we can't assume the data's length
+  // is actually st.st_size, because 1) some files lie about their size
+  // (/dev/zero and /dev/random), and 2) reading files in text mode on
+  // Windows collapses "\r\n" pairs to single \n characters.
+  for (;;) {
+    int c = fast_getc(fp);
+    if (c == EOF) {
+      break;
+    }
+    if (!buffer.append(c)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+/*
+ * Open a source file for reading. Supports "-" and nullptr to mean stdin. The
+ * return value must be fclosed unless it is stdin.
+ */
+bool js::AutoFile::open(JSContext* cx, const char* filename) {
+  if (!filename || std::strcmp(filename, "-") == 0) {
+    fp_ = stdin;
+  } else {
+    fp_ = fopen(filename, "r");
+    if (!fp_) {
+      /*
+       * Use Latin1 variant here because the encoding of filename is
+       * platform dependent.
+       */
+      JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_CANT_OPEN,
+                                 filename, "No such file or directory");
+      return false;
+    }
+  }
+  return true;
+}