From: Lancelot SIX <lsix@lancelotsix.com>
Date: Thu, 25 Feb 2021 00:30:49 +0000 (+0000)
Subject: [PR gdb/27393] set directories: handle empty dirs.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=bb3a4efe13c0bd9a7b15ecd02ddb966870a03bd0;p=binutils-gdb.git

[PR gdb/27393] set directories: handle empty dirs.

As reported in gdb/27393, the 'directory' and 'set directories' commands
fail when parsing an empty dir name:

    (gdb) set directories ""
    /home/lsix/dev/gnu/binutils-gdb/gdbsupport/pathstuff.cc:132: internal-error: gdb::unique_xmalloc_ptr<char> gdb_abspath(const char*): Assertion `path != NULL && path[0] != '\0'' failed.

or

    (gdb) dir :
    /home/lsix/dev/gnu/binutils-gdb/gdbsupport/pathstuff.cc:132: internal-error: gdb::unique_xmalloc_ptr<char> gdb_abspath(const char*): Assertion `path != NULL && path[0] != '\0'' failed.

This patch fixes this issue by ignoring any attempt to add an empty
name to the source directories list.  'set dir ""' will reset the
directories list the same way 'set dir' would do it.

Tested on x86_64.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8a2725368e3..bb7b2de0b58 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-02-27  Lancelot Six  <lsix@lancelotsix.com>
+
+	PR gdb/27393
+	* source.c (add_path): Skip empty dirnames.
+
 2021-02-25  Kevin Buettner  <kevinb@redhat.com>
 
 	* nat/aarch64-sve-linux-ptrace.h: Add comment regarding
diff --git a/gdb/source.c b/gdb/source.c
index dc30dac6d78..3a8f829759b 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -572,6 +572,8 @@ add_path (const char *dirname, char **which_path, int parse_separators)
 	    break;
 	}
 
+      if (name[0] == '\0')
+        goto skip_dup;
       if (name[0] == '~')
 	new_name_holder.reset (tilde_expand (name));
 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 625c4ecf493..b92e67c9557 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2021-02-27  Lancelot Six  <lsix@lancelotix.com>
+
+	PR gdb/27393
+	* gdb.base/source-dir.exp: Test that empty dirnames are skipped.
+
+
 2021-02-26  Tom Tromey  <tom@tromey.com>
 
 	* lib/gdb.exp (skip_ctf_tests): Use expr on result.
diff --git a/gdb/testsuite/gdb.base/source-dir.exp b/gdb/testsuite/gdb.base/source-dir.exp
index 988ea59afb5..eff683199be 100644
--- a/gdb/testsuite/gdb.base/source-dir.exp
+++ b/gdb/testsuite/gdb.base/source-dir.exp
@@ -163,5 +163,46 @@ proc test_truncated_comp_dir {} {
 	"info source after setting directory search list"
 }
 
+proc test_change_search_directory_with_empty_dirname {} {
+    gdb_start
+
+    # Add 3 entries to the source directories list:
+    # - ""
+    # - "/foo"
+    # - "/bar"
+    # Since /foo and /bar probably do not exist, ignore the warnings printed by
+    # GDB.
+    if { [ishost *-*-mingw*] } {
+	gdb_test "set directories ;/foo;/bar" ".*"
+    } else {
+	gdb_test "set directories :/foo:/bar" ".*"
+    }
+
+    # The first entry added ("") should be ignored, only /foo and /bar are
+    # effectively added.
+    with_test_prefix "initial_directory_state" {
+	gdb_test "show directories" \
+	    [search_dir_list [list \
+				  "/foo" \
+				  "/bar" \
+				  "\\\$cdir" \
+				  "\\\$cwd"]]
+    }
+
+    # Arguments can be quoted.  Check a empty string has the same effect as
+    # 'set directory' (i.e. reset to $cdir:$cwd)
+    gdb_test_no_output "set directories \"\""
+
+    with_test_prefix "directory_after_reset" {
+	gdb_test "show directories" \
+	    [search_dir_list [list \
+				  "\\\$cdir" \
+				  "\\\$cwd"]]
+    }
+
+    gdb_exit
+}
+
 test_changing_search_directory
+test_change_search_directory_with_empty_dirname
 test_truncated_comp_dir