Re: [PATCH 1/2] gdbsupport, gdb: add read_text_file_to_string, use it in linux_common_core_of_thread

[Simon Marchi <simark@simark.ca>]

On 11/8/22 12:13, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Simon> I would like to add more code to nat/linux-osdata.c that reads an entire
> Simon> file from /proc or /sys and processes it as a string afterwards.  I
> Simon> would like to avoid duplicating the somewhat error-prone code that reads
> Simon> an entire file to a buffer.  I think we should have a utility function
> Simon> that does that.
> 
> Makes sense.  source_cache::get_plain_source_lines could use this btw,
> though it would need some change for error reporting.

Ok, although it would need a bit of refactoring, because that uses
open_source_file, which returns a scoped_fd.

I also spotted xml_fetch_content_from_file.  The problem here is that it
returns a gdb::char_vector, not an std::string.  To change it, we would
have to change to std::string all the way to target_read_stralloc.  I
think it would be nice (it's nicer to use std::string for strings than
gdb::char_vector), but a bit too much just for this patch.

> 
> Simon> +
> Simon> +gdb::optional<std::string>
> Simon> +read_text_file_to_string (const char *path)
> 
> Should have a comment.
> 
>  
> Simon> +extern gdb::optional<std::string> read_text_file_to_string (const char *path);
> 
> Here too.

Oops, forgot.  Does that look good to you?

diff --git a/gdbsupport/filestuff.cc b/gdbsupport/filestuff.cc
index d003a7f39c4..cf5fb13bd0c 100644
--- a/gdbsupport/filestuff.cc
+++ b/gdbsupport/filestuff.cc
@@ -502,6 +502,8 @@ mkdir_recursive (const char *dir)
     }
 }

+/* See gdbsupport/filestuff.h.  */
+
 gdb::optional<std::string>
 read_text_file_to_string (const char *path)
 {
diff --git a/gdbsupport/filestuff.h b/gdbsupport/filestuff.h
index 3932710b5dc..33362901ab8 100644
--- a/gdbsupport/filestuff.h
+++ b/gdbsupport/filestuff.h
@@ -129,6 +129,8 @@ extern bool is_regular_file (const char *name, int *errno_ptr);

 extern bool mkdir_recursive (const char *dir);

+/* Read the entire content of file PATH into an std::string.  */
+
 extern gdb::optional<std::string> read_text_file_to_string (const char *path);

 #endif /* COMMON_FILESTUFF_H */

Simon