[Lldb-commits] [PATCH] D106985: [lldb] [gdb-remote] Sync vFile:open mode constants with GDB

[Michał Górny via Phabricator via lldb-commits]

mgorny created this revision.
mgorny added reviewers: krytarowski, labath, emaste, jasonmolenda, JDevlieghere, clayborg.
mgorny requested review of this revision.

Sync the mode constants used to drive vFile:open requests with these
used by GDB and defined for the gdb remote protocol.  This makes it
possible to use 'platform file open' after connecting to gdbremote
server (and to some degree to operate on the open file modulo other
incompatibilities).


https://reviews.llvm.org/D106985

Files:
  lldb/docs/lldb-platform-packets.txt
  lldb/include/lldb/Host/File.h
  lldb/source/Host/common/File.cpp


Index: lldb/source/Host/common/File.cpp
===================================================================
--- lldb/source/Host/common/File.cpp
+++ lldb/source/Host/common/File.cpp
@@ -90,8 +90,8 @@
           .Cases("a+", "ab+", "a+b",
                  eOpenOptionReadWrite | eOpenOptionAppend |
                      eOpenOptionCanCreate)
-          .Default(OpenOptions());
-  if (opts)
+          .Default(eOpenOptionInvalid);
+  if (opts != eOpenOptionInvalid)
     return opts;
   return llvm::createStringError(
       llvm::inconvertibleErrorCode(),
Index: lldb/include/lldb/Host/File.h
===================================================================
--- lldb/include/lldb/Host/File.h
+++ lldb/include/lldb/Host/File.h
@@ -39,27 +39,29 @@
   // NB this enum is used in the lldb platform gdb-remote packet
   // vFile:open: and existing values cannot be modified.
   //
-  // FIXME
-  // These values do not match the values used by GDB
+  // The first set of values is defined by gdb headers and can be found
+  // in the documentation at:
   // * https://sourceware.org/gdb/onlinedocs/gdb/Open-Flags.html#Open-Flags
-  // * rdar://problem/46788934
+  //
+  // The second half are LLDB extensions and use the highest uint32_t bits
+  // to avoid risk of collisions with future gdb remote protocol changes.
   enum OpenOptions : uint32_t {
-    eOpenOptionReadOnly = (1u << 0),  // Open file for reading (only)
-    eOpenOptionWriteOnly = (1u << 1), // Open file for writing (only)
-    eOpenOptionReadWrite =
-        eOpenOptionReadOnly |
-        eOpenOptionWriteOnly, // Open file for both reading and writing
+    eOpenOptionReadOnly = 0x0,  // Open file for reading (only)
+    eOpenOptionWriteOnly = 0x1, // Open file for writing (only)
+    eOpenOptionReadWrite = 0x2, // Open file for both reading and writing
     eOpenOptionAppend =
-        (1u << 2), // Don't truncate file when opening, append to end of file
-    eOpenOptionTruncate = (1u << 3),    // Truncate file when opening
-    eOpenOptionNonBlocking = (1u << 4), // File reads
-    eOpenOptionCanCreate = (1u << 5),   // Create file if doesn't already exist
+        0x8, // Don't truncate file when opening, append to end of file
+    eOpenOptionCanCreate = 0x200, // Create file if doesn't already exist
+    eOpenOptionTruncate = 0x400,  // Truncate file when opening
     eOpenOptionCanCreateNewOnly =
-        (1u << 6), // Can create file only if it doesn't already exist
-    eOpenOptionDontFollowSymlinks = (1u << 7),
+        0x800, // Can create file only if it doesn't already exist
+
+    eOpenOptionNonBlocking = (1u << 28), // File reads
+    eOpenOptionDontFollowSymlinks = (1u << 29),
     eOpenOptionCloseOnExec =
-        (1u << 8), // Close the file when executing a new process
-    LLVM_MARK_AS_BITMASK_ENUM(/* largest_value= */ eOpenOptionCloseOnExec)
+        (1u << 30), // Close the file when executing a new process
+    eOpenOptionInvalid = (1u << 31), // Used as invalid value
+    LLVM_MARK_AS_BITMASK_ENUM(/* largest_value= */ eOpenOptionInvalid)
   };
 
   static mode_t ConvertOpenOptionsForPOSIXOpen(OpenOptions open_options);
Index: lldb/docs/lldb-platform-packets.txt
===================================================================
--- lldb/docs/lldb-platform-packets.txt
+++ lldb/docs/lldb-platform-packets.txt
@@ -372,12 +372,6 @@
 //  response is F followed by the opened file descriptor in base 10.
 //  "F-1,errno" with the errno if an error occurs.
 //
-//  COMPATIBILITY
-//    The gdb-remote serial protocol documentatio defines a vFile:open:
-//    packet which uses incompatible flag values, e.g. 1 means O_WRONLY
-//    in gdb's vFile:open:, but it means eOpenOptionReadOnly to lldb's
-//    implementation.
-
 //----------------------------------------------------------------------
 // vFile:close:
 //


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