Fix latent bug in test_gdb_complete_cmd_multiple

[deliverable/binutils-gdb.git] / gdb / source-cache.c

diff --git a/gdb/source-cache.c b/gdb/source-cache.c
index 3b15b3f28895dcd86632ee59fa66fd0fd4efd8a5..86efe83bf9a5679de9a58e2ff0ebe9a3dc37c11e 100644 (file)
--- a/gdb/source-cache.c
+++ b/gdb/source-cache.c
@@ -49,13 +49,10 @@ bool
 source_cache::get_plain_source_lines (struct symtab *s, int first_line,
                                      int last_line, std::string *lines)
 {
-  scoped_fd desc (open_source_file (s));
+  scoped_fd desc (open_source_file_with_line_charpos (s));
   if (desc.get () < 0)
     return false;
 
-  if (s->line_charpos == 0)
-    find_source_lines (s, desc.get ());
-
   if (first_line < 1 || first_line > s->nlines || last_line < 1)
     return false;
 
@@ -84,9 +81,9 @@ source_cache::get_plain_source_lines (struct symtab *s, int first_line,
 
 /* See source-cache.h.  */
 
-bool
+std::string
 source_cache::extract_lines (const struct source_text &text, int first_line,
-                            int last_line, std::string *lines)
+                            int last_line)
 {
   int lineno = 1;
   std::string::size_type pos = 0;
@@ -102,16 +99,17 @@ source_cache::extract_lines (const struct source_text &text, int first_line,
       pos = new_pos;
       if (lineno == last_line || pos == std::string::npos)
        {
+         if (first_pos == std::string::npos)
+           return {};
          if (pos == std::string::npos)
            pos = text.contents.size ();
-         *lines = text.contents.substr (first_pos, pos - first_pos);
-         return true;
+         return text.contents.substr (first_pos, pos - first_pos);
        }
       ++lineno;
       ++pos;
     }
 
-  return false;
+  return {};
 }
 
 #ifdef HAVE_SOURCE_HIGHLIGHT
@@ -180,14 +178,17 @@ source_cache::get_source_lines (struct symtab *s, int first_line,
     return false;
 
 #ifdef HAVE_SOURCE_HIGHLIGHT
-  if (source_styling && can_emit_style_escape (gdb_stdout))
+  if (source_styling && gdb_stdout->can_emit_style_escape ())
     {
       const char *fullname = symtab_to_fullname (s);
 
       for (const auto &item : m_source_map)
        {
          if (item.fullname == fullname)
-           return extract_lines (item, first_line, last_line, lines);
+           {
+             *lines = extract_lines (item, first_line, last_line);
+             return true;
+           }
        }
 
       const char *lang_name = get_language_name (SYMTAB_LANGUAGE (s));
@@ -196,11 +197,34 @@ source_cache::get_source_lines (struct symtab *s, int first_line,
          std::ifstream input (fullname);
          if (input.is_open ())
            {
-             srchilite::SourceHighlight highlighter ("esc.outlang");
-             highlighter.setStyleFile("esc.style");
+             /* The global source highlight object, or null if one
+                was never constructed.  This is stored here rather
+                than in the class so that we don't need to include
+                anything or do conditional compilation in
+                source-cache.h.  */
+             static srchilite::SourceHighlight *highlighter;
+
+             if (s->line_charpos == 0)
+               {
+                 scoped_fd desc (open_source_file_with_line_charpos (s));
+                 if (desc.get () < 0)
+                   return false;
+
+                 /* FULLNAME points to a value owned by the symtab
+                    (symtab::fullname).  Calling open_source_file reallocates
+                    that value, so we must refresh FULLNAME to avoid a
+                    use-after-free.  */
+                 fullname = symtab_to_fullname (s);
+               }
+
+             if (highlighter == nullptr)
+               {
+                 highlighter = new srchilite::SourceHighlight ("esc.outlang");
+                 highlighter->setStyleFile ("esc.style");
+               }
 
              std::ostringstream output;
-             highlighter.highlight (input, output, lang_name, fullname);
+             highlighter->highlight (input, output, lang_name, fullname);
 
              source_text result = { fullname, output.str () };
              m_source_map.push_back (std::move (result));
@@ -208,8 +232,9 @@ source_cache::get_source_lines (struct symtab *s, int first_line,
              if (m_source_map.size () > MAX_ENTRIES)
                m_source_map.erase (m_source_map.begin ());
 
-             return extract_lines (m_source_map.back (), first_line,
-                                   last_line, lines);
+             *lines = extract_lines (m_source_map.back (), first_line,
+                                     last_line);
+             return true;
            }
        }
     }