Add 'inspect' alias for dwim-print

[mdko]

People on my team coming from GDB continually try to use "inspect" to examine data, but this command doesn't exist. In GDB, "inspect" is a synonym for "print" (https://sourceware.org/gdb/current/onlinedocs/gdb.html/Data.html#Data), so I thought it was help with ergonomics if we additionally had an "inspect" alias in LLDB (mapping to "dwim-print", which is what LLDB's "print" alias maps to as well).

michristensen@my-machine build/Debug (inspect-alias-dwim) » ./bin/lldb
(lldb) help inspect
Print a variable or expression.  Expects 'raw' input (see 'help raw-input'.)

Syntax: inspect <variable-name>
  inspect <variable-name>
'inspect' is an abbreviation for 'dwim-print --'
(lldb) inspect 3+4
(int) 7

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Michael Christensen (mdko)

Changes

People on my team coming from GDB continually try to use "inspect" to examine data, but this command doesn't exist. In GDB, "inspect" is a synonym for "print" (https://sourceware.org/gdb/current/onlinedocs/gdb.html/Data.html#Data), so I thought it was help with ergonomics if we additionally had an "inspect" alias in LLDB (mapping to "dwim-print", which is what LLDB's "print" alias maps to as well).

---

Full diff: https://github.com/llvm/llvm-project/pull/155039.diff

2 Files Affected:

• (modified) lldb/source/Interpreter/CommandInterpreter.cpp (+1)
• (modified) lldb/test/API/commands/dwim-print/TestDWIMPrint.py (+13)

diff --git a/lldb/source/Interpreter/CommandInterpreter.cpp b/lldb/source/Interpreter/CommandInterpreter.cpp
index 650b754fd8ace..7ebcba6ffc8c9 100644
--- a/lldb/source/Interpreter/CommandInterpreter.cpp
+++ b/lldb/source/Interpreter/CommandInterpreter.cpp
@@ -432,6 +432,7 @@ void CommandInterpreter::Initialize() {
   if (cmd_obj_sp) {
     AddAlias("p", cmd_obj_sp, "--")->SetHelpLong("");
     AddAlias("print", cmd_obj_sp, "--")->SetHelpLong("");
+    AddAlias("inspect", cmd_obj_sp, "--")->SetHelpLong("");
     if (auto *po = AddAlias("po", cmd_obj_sp, "-O --")) {
       po->SetHelp("Evaluate an expression on the current thread.  Displays any "
                   "returned value with formatting "
diff --git a/lldb/test/API/commands/dwim-print/TestDWIMPrint.py b/lldb/test/API/commands/dwim-print/TestDWIMPrint.py
index 492d49f008a9e..d1ebdc1eb1564 100644
--- a/lldb/test/API/commands/dwim-print/TestDWIMPrint.py
+++ b/lldb/test/API/commands/dwim-print/TestDWIMPrint.py
@@ -185,3 +185,16 @@ def test_direct_child_access(self):
             self, "break inside", lldb.SBFileSpec("main.cpp")
         )
         self._expect_cmd("dwim-print number", "frame variable")
+
+    def test_aliases(self):
+        interp = self.dbg.GetCommandInterpreter()
+        for alias in ["p", "print", "inspect"]:
+            result = lldb.SBCommandReturnObject()
+            interp.ResolveCommand(alias, result)
+            self.assertTrue(result.Succeeded(), result.GetError())
+            self.assertEqual(result.GetOutput(), "dwim-print --")
+
+        result = lldb.SBCommandReturnObject()
+        interp.ResolveCommand("po", result)
+        self.assertTrue(result.Succeeded(), result.GetError())
+        self.assertEqual(result.GetOutput(), "dwim-print -O  --")

[mdko]

CC @clayborg @jeffreytan81 @youngd007

[jimingham]

This seems a slippery slope. gdb generally has 3 or 4 different ways of spelling every command; I really don't want to add them all to lldb and make it harder to spell the native lldb commands. The lldb command set isn't that hard to learn...

I'm not super excited about adding this, but in any case I'd really rather not have this or any future additions of this sort be on by default. If we feel we really need to do this, then we should add an interpreter.emulate-gdb setting and have these additions gated by that. We should also make sure i is image not inspect so we don't make people have to change what they have been typing.

[jimingham]

I don't think we should add this for all lldb users.

[mdko]

@jimingham Fair point, thanks for the quick feedback. I will abandon these changes and stick with making this a local alias.