From: Tom de Vries <tdevries@suse.de>
Date: Tue, 17 Oct 2023 09:38:06 +0000 (+0200)
Subject: [gdb/cli] Skip string copy in source_cache::ensure
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7e5649156720ec6c3aa5e2036b27811bc8195ab9;p=binutils-gdb.git

[gdb/cli] Skip string copy in source_cache::ensure

In function source_cache::ensure we have:
...
 	      std::ostringstream output;
	      ...
	      contents = output.str ();
...
The last line causes an unnecessary string copy.

C++20 allows us to skip it, like this:
...
	      contents = std::move (output).str ();
...

Use the more efficient solution.

Tested on x86_64-linux.

Reviewed-By: Lancelot Six <lancelot.six@amd.com>
---

diff --git a/gdb/source-cache.c b/gdb/source-cache.c
index 77b357cb42b..ae02d2516d9 100644
--- a/gdb/source-cache.c
+++ b/gdb/source-cache.c
@@ -252,7 +252,7 @@ source_cache::ensure (struct symtab *s)
 	      std::istringstream input (contents);
 	      std::ostringstream output;
 	      highlighter->highlight (input, output, lang_name, fullname);
-	      contents = output.str ();
+	      contents = std::move (output).str ();
 	      already_styled = true;
 	    }
 	  catch (...)