From ffaebc199ed7b1f7e539c938e8b234d2a4ad9df9 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Wed, 20 Apr 2022 17:03:25 -0400 Subject: gdbsupport: add path_join function In this review [1], Eli pointed out that we should be careful when concatenating file names to avoid duplicated slashes. On Windows, a double slash at the beginning of a file path has a special meaning. So naively concatenating "/" and "foo/bar" would give "//foo/bar", which would not give the desired results. We already have a few spots doing: if (first_path ends with a slash) path = first_path + second_path else path = first_path + slash + second_path In general, I think it's nice to avoid superfluous slashes in file paths, since they might end up visible to the user and look a bit unprofessional. Introduce the path_join function that can be used to join multiple path components together (along with unit tests). I initially wanted to make it possible to join two absolute paths, to support the use case of prepending a sysroot path to a target file path, or the prepending the debug-file-directory to a target file path. But the code in solib_find_1 shows that it is more complex than this anyway (for example, when the right hand side is a Windows path with a drive letter). So I don't think we need to support that case in path_join. That also keeps the implementation simpler. Change a few spots to use path_join to show how it can be used. I believe that all the spots I changed are guarded by some checks that ensure the right hand side operand is not an absolute path. Regression-tested on Ubuntu 18.04. Built-tested on Windows, and I also ran the new unit-test there. [1] https://sourceware.org/pipermail/gdb-patches/2022-April/187559.html Change-Id: I0df889f7e3f644e045f42ff429277b732eb6c752 --- gdbsupport/pathstuff.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'gdbsupport/pathstuff.h') diff --git a/gdbsupport/pathstuff.h b/gdbsupport/pathstuff.h index f6c51e9..c859279 100644 --- a/gdbsupport/pathstuff.h +++ b/gdbsupport/pathstuff.h @@ -21,6 +21,7 @@ #define COMMON_PATHSTUFF_H #include "gdbsupport/byte-vector.h" +#include "gdbsupport/array-view.h" #include #include @@ -60,6 +61,28 @@ extern std::string gdb_abspath (const char *path); extern const char *child_path (const char *parent, const char *child); +/* Join elements in PATHS into a single path. + + The first element can be absolute or relative. All the others must be + relative. */ + +extern std::string path_join (gdb::array_view paths); + +/* Same as the above, but accept paths as distinct parameters. */ + +template +std::string +path_join (Args... paths) +{ + /* It doesn't make sense to join less than two paths. */ + gdb_static_assert (sizeof... (Args) >= 2); + + std::array views + { gdb::string_view (paths)... }; + + return path_join (gdb::array_view (views)); +} + /* Return whether PATH contains a directory separator character. */ extern bool contains_dir_separator (const char *path); -- cgit v1.1