[PATCH v2 3/4] [gdb/cli] Keep track of styling failures in source_cache

Tom de Vries
2023-10-13T12:20:14Z

In source_cache::ensure, keep track of which files failed to be styled, and
don't attempt to style them again in case the file dropped out of the cache.

Tested on x86_64-linux.
---
gdb/source-cache.c | 24 ++++++++++++++++++++++--
gdb/source-cache.h | 4 ++++
2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/gdb/source-cache.c b/gdb/source-cache.c
index 9757721e932..f8c98d7e23f 100644
--- a/gdb/source-cache.c
+++ b/gdb/source-cache.c
@@ -285,7 +285,8 @@ source_cache::ensure (struct symtab *s)
return false;
}

- if (source_styling && gdb_stdout->can_emit_style_escape ())
+ if (source_styling && gdb_stdout->can_emit_style_escape ()
+ && m_no_styling_files.count (fullname) == 0)
{
bool already_styled
= try_source_highlight (contents, s->language (), fullname);
@@ -295,7 +296,26 @@ source_cache::ensure (struct symtab *s)
gdb::optional<std::string> ext_contents;
ext_contents = ext_lang_colorize (fullname, contents);
if (ext_contents.has_value ())
- contents = std::move (*ext_contents);
+ {
+ contents = std::move (*ext_contents);
+ already_styled = true;
+ }
+ }
+
+ if (!already_styled)
+ {
+ /* Styling failed. Styling can fail for instance for these
+ reasons:
+ - the language is not supported.
+ - the language cannot not be auto-detected from the file name.
+ - no stylers available.
+
+ Since styling failed, don't try styling the file again after it
+ drops from the cache.
+
+ Note that clearing the source cache also clears
+ m_no_styling_files. */
+ m_no_styling_files.insert (fullname);
}
}

diff --git a/gdb/source-cache.h b/gdb/source-cache.h
index bec6598ff9f..f1d30b43ce0 100644
--- a/gdb/source-cache.h
+++ b/gdb/source-cache.h
@@ -66,6 +66,7 @@ class source_cache
{
m_source_map.clear ();
m_offset_cache.clear ();
+ m_no_styling_files.clear ();
}

private:
@@ -95,6 +96,9 @@ class source_cache
/* The file offset cache. The key is the full name of the source
file. */
std::unordered_map<std::string, std::vector<off_t>> m_offset_cache;
+
+ /* The list of files where styling failed. */
+ std::unordered_set<std::string> m_no_styling_files;
};

/* The global source cache. */
--
2.35.3