[llvm] [BOLT][DWARF] Add support to create path (PR #73884)

[Alexander Yermolovich via llvm-commits]

https://github.com/ayermolo created https://github.com/llvm/llvm-project/pull/73884

When option --dwarf-output-path is specified, if the path does not exist BOLT will now create it. This is what also happens when --plugin-opt=dwo_dir=<value> is specified to LLD.

>From fa97d78e6edd39b8986e51cd9154de7bcbfe328d Mon Sep 17 00:00:00 2001
From: Alexander Yermolovich <ayermolo at meta.com>
Date: Wed, 29 Nov 2023 16:55:49 -0800
Subject: [PATCH] [BOLT][DWARF] Add support to create path

When option --dwarf-output-path is specified, if the path does not exist BOLT
will now create it. This is what also happens when --plugin-opt=dwo_dir=<value>
is specified to LLD.
---
 bolt/lib/Rewrite/DWARFRewriter.cpp               |  2 ++
 .../test/X86/dwarf5-df-output-dir-same-name.test | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/bolt/lib/Rewrite/DWARFRewriter.cpp b/bolt/lib/Rewrite/DWARFRewriter.cpp
index 0beb865bd48cb1f..5580d85e3fa7716 100644
--- a/bolt/lib/Rewrite/DWARFRewriter.cpp
+++ b/bolt/lib/Rewrite/DWARFRewriter.cpp
@@ -679,6 +679,8 @@ void DWARFRewriter::updateDebugInfo() {
     assert(CompDirAttrInfo && "DW_AT_comp_dir is not in Skeleton CU.");
 
     if (!opts::DwarfOutputPath.empty()) {
+      if (!sys::fs::exists(opts::DwarfOutputPath))
+        sys::fs::create_directory(opts::DwarfOutputPath);
       addStringHelper(DIEBldr, UnitDIE, Unit, CompDirAttrInfo,
                       opts::DwarfOutputPath.c_str());
     }
diff --git a/bolt/test/X86/dwarf5-df-output-dir-same-name.test b/bolt/test/X86/dwarf5-df-output-dir-same-name.test
index 4fd42e287a11b71..1f78da2022b8ced 100644
--- a/bolt/test/X86/dwarf5-df-output-dir-same-name.test
+++ b/bolt/test/X86/dwarf5-df-output-dir-same-name.test
@@ -21,3 +21,19 @@
 ; BOLT: split.dwo1.dwo
 ; BOLT: DW_AT_dwo_name  ("split.dwo0.dwo")
 ; BOLT: DW_AT_dwo_name  ("split.dwo1.dwo")
+
+; Tests that when --dwarf-output-path is specified, but path do not exist BOLT creates it.
+
+; RUN: rm -rf dwo
+; RUN: llvm-bolt main.exe -o main.exe.bolt --update-debug-sections --dwarf-output-path=%t/dwo
+; RUN: ls -l %t/dwo > log
+; RUN: llvm-dwarfdump --debug-info main.exe.bolt >> log
+; RUN: cat log | FileCheck -check-prefix=BOLT1 %s
+
+; Tests that BOLT handles correctly writing out .dwo files to the same directory when input has input where part of path
+; is in DW_AT_dwo_name and the .dwo file names are the same.
+
+; BOLT1: split.dwo0.dwo
+; BOLT1: split.dwo1.dwo
+; BOLT1: DW_AT_dwo_name  ("split.dwo0.dwo")
+; BOLT1: DW_AT_dwo_name  ("split.dwo1.dwo")