[PATCH v3 1/4] [gdb/cli] Skip string copy in source_cache::ensure

Tom de Vries
2023-10-16T09:18:13Z

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.
---
gdb/source-cache.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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 (...)
--
2.35.3