Capture the current directory and debug directory in DWARF reader

This changes the DWARF reader to capture the current working directory
and the current debug directory.  This avoids races when the DWARF
reader is working in the background.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31716

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 95498bf01ed4caa48c2243fc2826975ca572cbbe..bd2de028d1d26175f281c0c4db434391d46057be 100644 (file)
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -1252,7 +1252,9 @@ line_header_eq_voidp (const void *item_lhs, const void *item_rhs)
 dwarf2_per_bfd::dwarf2_per_bfd (bfd *obfd, const dwarf2_debug_sections *names,
                                bool can_copy_)
   : obfd (obfd),
-    can_copy (can_copy_)
+    can_copy (can_copy_),
+    captured_cwd (current_directory),
+    captured_debug_dir (debug_file_directory)
 {
   if (names == NULL)
     names = &dwarf2_elf_names;
@@ -9046,10 +9048,12 @@ try_open_dwop_file (dwarf2_per_objfile *per_objfile,
   gdb::unique_xmalloc_ptr<char> search_path_holder;
   if (search_cwd)
     {
-      if (!debug_file_directory.empty ())
+      const std::string &debug_dir = per_objfile->per_bfd->captured_debug_dir;
+
+      if (!debug_dir.empty ())
        {
          search_path_holder.reset (concat (".", dirname_separator_string,
-                                           debug_file_directory.c_str (),
+                                           debug_dir.c_str (),
                                            (char *) NULL));
          search_path = search_path_holder.get ();
        }
@@ -9057,7 +9061,7 @@ try_open_dwop_file (dwarf2_per_objfile *per_objfile,
        search_path = ".";
     }
   else
-    search_path = debug_file_directory.c_str ();
+    search_path = per_objfile->per_bfd->captured_debug_dir.c_str ();
 
   /* Add the path for the executable binary to the list of search paths.  */
   std::string objfile_dir = ldirname (objfile_name (per_objfile->objfile));
@@ -9072,7 +9076,8 @@ try_open_dwop_file (dwarf2_per_objfile *per_objfile,
 
   gdb::unique_xmalloc_ptr<char> absolute_name;
   desc = openp (search_path, flags, file_name,
-               O_RDONLY | O_BINARY, &absolute_name);
+               O_RDONLY | O_BINARY, &absolute_name,
+               per_objfile->per_bfd->captured_cwd.c_str ());
   if (desc < 0)
     return NULL;
 
@@ -9126,7 +9131,7 @@ open_dwo_file (dwarf2_per_objfile *per_objfile,
   /* That didn't work, try debug-file-directory, which, despite its name,
      is a list of paths.  */
 
-  if (debug_file_directory.empty ())
+  if (per_objfile->per_bfd->captured_debug_dir.empty ())
     return NULL;
 
   return try_open_dwop_file (per_objfile, file_name,
@@ -9407,7 +9412,7 @@ open_dwp_file (dwarf2_per_objfile *per_objfile, const char *file_name)
      [IWBN if the dwp file name was recorded in the executable, akin to
      .gnu_debuglink, but that doesn't exist yet.]
      Strip the directory from FILE_NAME and search again.  */
-  if (!debug_file_directory.empty ())
+  if (!per_objfile->per_bfd->captured_debug_dir.empty ())
     {
       /* Don't implicitly search the current directory here.
         If the user wants to search "." to handle this case,

diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 7c42017c3d62f227604f0afe18e69af46a157307..728f2b552244b758c59101d91dffaf58659a3b78 100644 (file)
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -558,6 +558,12 @@ public:
   std::unordered_map<sect_offset, std::vector<sect_offset>,
                     gdb::hash_enum<sect_offset>>
     abstract_to_concrete;
+
+  /* Current directory, captured at the moment that object this was
+     created.  */
+  std::string captured_cwd;
+  /* Captured copy of debug_file_directory.  */
+  std::string captured_debug_dir;
 };
 
 /* An iterator for all_units that is based on index.  This