[clang] [KeyInstr] Add release note & update option (PR #148244)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Orlando Cazalet-Hyams (OCHyams)

<details>
<summary>Changes</summary>

Make the option visible, improve the help text, and add a release note.

---
Full diff: https://github.com/llvm/llvm-project/pull/148244.diff


2 Files Affected:

- (modified) clang/docs/ReleaseNotes.rst (+2) 
- (modified) clang/include/clang/Driver/Options.td (+3-3) 


``````````diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index bee71cf296ac3..9fa0d182ead25 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -354,6 +354,8 @@ New Compiler Flags
 
 - New option ``-ignore-pch`` added to disable precompiled headers. It overrides ``-emit-pch`` and ``-include-pch``. (#GH142409, `PCHDocs <https://clang.llvm.org/docs/UsersManual.html#ignoring-a-pch-file>`_).
 
+- New options ``-g[no-]key-instructions`` added, disabled by default. Reduces jumpiness of debug stepping for optimized code in some debuggers (not LLDB at this time). Not recommended for use without optimizations. DWARF only. Note both the positive and negative flags imply ``-g``.
+
 Deprecated Compiler Flags
 -------------------------
 
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 9911d752966e3..a6ff105d1b6a4 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4704,9 +4704,9 @@ def gno_embed_source : Flag<["-"], "gno-embed-source">, Group<g_flags_Group>,
 defm key_instructions : BoolGOption<"key-instructions",
     CodeGenOpts<"DebugKeyInstructions">, DefaultFalse,
     NegFlag<SetFalse>, PosFlag<SetTrue, [], [],
-        "Enable Key Instructions, which reduces the jumpiness of optimized code stepping (DWARF only)."
-        " Requires LLVM built with LLVM_EXPERIMENTAL_KEY_INSTRUCTIONS.">,
-    BothFlags<[HelpHidden], [ClangOption, CLOption, CC1Option]>>;
+        "Enable Key Instructions, which reduces the jumpiness of debug stepping in optimized C/C++ code"
+        " in some debuggers. DWARF only. Implies -g.">,
+    BothFlags<[], [ClangOption, CLOption, CC1Option]>>;
 def headerpad__max__install__names : Joined<["-"], "headerpad_max_install_names">;
 def help : Flag<["-", "--"], "help">,
     Visibility<[ClangOption, CC1Option, CC1AsOption,

``````````

</details>


https://github.com/llvm/llvm-project/pull/148244