From 0cccba71d41afee519d0000eb719f8c95f288166 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Tue, 2 Apr 2019 15:21:08 -0400
Subject: [PATCH] better error message when os_file_overwrite fails

---
 src/error.cpp |  5 +++++
 src/error.hpp |  5 +++++
 src/os.cpp    | 18 +++++++++++++++---
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/error.cpp b/src/error.cpp
index 86f807de2b..84b78aba1b 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -45,6 +45,11 @@ const char *err_str(Error err) {
         case ErrorUnknownOperatingSystem: return "unrecognized operating system";
         case ErrorUnknownABI: return "unrecognized C ABI";
         case ErrorInvalidFilename: return "invalid filename";
+        case ErrorDiskQuota: return "disk space quota exceeded";
+        case ErrorDiskSpace: return "out of disk space";
+        case ErrorUnexpectedWriteFailure: return "unexpected write failure";
+        case ErrorUnexpectedSeekFailure: return "unexpected seek failure";
+        case ErrorUnexpectedFileTruncationFailure: return "unexpected file truncation failure";
     }
     return "(invalid error)";
 }
diff --git a/src/error.hpp b/src/error.hpp
index 8af0d86154..d943703268 100644
--- a/src/error.hpp
+++ b/src/error.hpp
@@ -47,6 +47,11 @@ enum Error {
     ErrorUnknownOperatingSystem,
     ErrorUnknownABI,
     ErrorInvalidFilename,
+    ErrorDiskQuota,
+    ErrorDiskSpace,
+    ErrorUnexpectedWriteFailure,
+    ErrorUnexpectedSeekFailure,
+    ErrorUnexpectedFileTruncationFailure,
 };
 
 const char *err_str(Error err);
diff --git a/src/os.cpp b/src/os.cpp
index 1dd22b7183..470d222307 100644
--- a/src/os.cpp
+++ b/src/os.cpp
@@ -2048,9 +2048,9 @@ Error os_file_overwrite(OsFile file, Buf *contents) {
     return ErrorNone;
 #else
     if (lseek(file, 0, SEEK_SET) == -1)
-        return ErrorFileSystem;
+        return ErrorUnexpectedSeekFailure;
     if (ftruncate(file, 0) == -1)
-        return ErrorFileSystem;
+        return ErrorUnexpectedFileTruncationFailure;
     for (;;) {
         if (write(file, buf_ptr(contents), buf_len(contents)) == -1) {
             switch (errno) {
@@ -2060,8 +2060,20 @@ Error os_file_overwrite(OsFile file, Buf *contents) {
                     zig_unreachable();
                 case EBADF:
                     zig_unreachable();
-                default:
+                case EFAULT:
+                    zig_unreachable();
+                case EDQUOT:
+                    return ErrorDiskQuota;
+                case ENOSPC:
+                    return ErrorDiskSpace;
+                case EFBIG:
+                    return ErrorFileTooBig;
+                case EIO:
                     return ErrorFileSystem;
+                case EPERM:
+                    return ErrorAccess;
+                default:
+                    return ErrorUnexpectedWriteFailure;
             }
         }
         return ErrorNone;