[RFC 3/6] Move mkdir_recursive to common/filestuff.c

[Tom Tromey <tom@tromey.com>]

This moves mkdir_recursive from dwarf-index-cache.c to
common/filestuff.c, and also changes it to return a boolean that says
whether or not it worked.

gdb/ChangeLog
2018-09-26  Tom Tromey  <tom@tromey.com>

	* unittests/mkdir-recursive-selftests.c: New file.
	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	unittests/mkdir-recursive-selftests.c.
	* dwarf-index-cache.c (mkdir_recursive): Move to
	common/filestuff.c.
	(index_cache::store): Check return value of mkdir_recursive.
	(create_dir_and_check, test_mkdir_recursive): Move to new file.
	(_initialize_index_cache): Don't register test.
	* common/filestuff.h (mkdir_recursive): Declare.
	* common/filestuff.c (mkdir_recursive): Move from
	dwarf-index-cache.c.  Return bool.
---
 gdb/ChangeLog           |  14 +++++
 gdb/Makefile.in         |   1 +
 gdb/common/filestuff.c  |  45 ++++++++++++++++
 gdb/common/filestuff.h  |  10 ++++
 gdb/dwarf-index-cache.c | 114 +++-------------------------------------
 5 files changed, 76 insertions(+), 108 deletions(-)

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 3b158fa1db..69c4c49a97 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -419,6 +419,7 @@ SUBDIR_UNITTESTS_SRCS = \
 	unittests/optional-selftests.c \
 	unittests/parse-connection-spec-selftests.c \
 	unittests/ptid-selftests.c \
+	unittests/mkdir-recursive-selftests.c \
 	unittests/rsp-low-selftests.c \
 	unittests/scoped_fd-selftests.c \
 	unittests/scoped_mmap-selftests.c \
diff --git a/gdb/common/filestuff.c b/gdb/common/filestuff.c
index fa10165a7c..763def7643 100644
--- a/gdb/common/filestuff.c
+++ b/gdb/common/filestuff.c
@@ -448,3 +448,48 @@ is_regular_file (const char *name, int *errno_ptr)
     *errno_ptr = EINVAL;
   return false;
 }
+
+/* See common/filestuff.h.  */
+
+bool
+mkdir_recursive (const char *dir)
+{
+  gdb::unique_xmalloc_ptr<char> holder (xstrdup (dir));
+  char * const start = holder.get ();
+  char *component_start = start;
+  char *component_end = start;
+
+  while (1)
+    {
+      /* Find the beginning of the next component.  */
+      while (*component_start == '/')
+	component_start++;
+
+      /* Are we done?  */
+      if (*component_start == '\0')
+	return true;
+
+      /* Find the slash or null-terminator after this component.  */
+      component_end = component_start;
+      while (*component_end != '/' && *component_end != '\0')
+	component_end++;
+
+      /* Temporarily replace the slash with a null terminator, so we can create
+         the directory up to this component.  */
+      char saved_char = *component_end;
+      *component_end = '\0';
+
+      /* If we get EEXIST and the existing path is a directory, then we're
+         happy.  If it exists, but it's a regular file and this is not the last
+         component, we'll fail at the next component.  If this is the last
+         component, the caller will fail with ENOTDIR when trying to
+         open/create a file under that path.  */
+      if (mkdir (start, 0700) != 0)
+	if (errno != EEXIST)
+	  return false;
+
+      /* Restore the overwritten char.  */
+      *component_end = saved_char;
+      component_start = component_end;
+    }
+}
diff --git a/gdb/common/filestuff.h b/gdb/common/filestuff.h
index e9328f5358..ecfc18d600 100644
--- a/gdb/common/filestuff.h
+++ b/gdb/common/filestuff.h
@@ -122,4 +122,14 @@ typedef std::unique_ptr<DIR, gdb_dir_deleter> gdb_dir_up;
    we're expecting a regular file.  */
 extern bool is_regular_file (const char *name, int *errno_ptr);
 
+
+/* A cheap (as in low-quality) recursive mkdir.  Try to create all the
+   parents directories up to DIR and DIR itself.  Stop if we hit an
+   error along the way.  There is no attempt to remove created
+   directories in case of failure.
+
+   Returns false on failure and sets errno.  */
+
+extern bool mkdir_recursive (const char *dir);
+
 #endif /* FILESTUFF_H */
diff --git a/gdb/dwarf-index-cache.c b/gdb/dwarf-index-cache.c
index 966630b60c..bac98f9db8 100644
--- a/gdb/dwarf-index-cache.c
+++ b/gdb/dwarf-index-cache.c
@@ -45,53 +45,6 @@ index_cache global_index_cache;
 static cmd_list_element *set_index_cache_prefix_list;
 static cmd_list_element *show_index_cache_prefix_list;
 
-/* A cheap (as in low-quality) recursive mkdir.  Try to create all the parents
-   directories up to DIR and DIR itself.  Stop if we hit an error along the way.
-   There is no attempt to remove created directories in case of failure.  */
-
-static void
-mkdir_recursive (const char *dir)
-{
-  gdb::unique_xmalloc_ptr<char> holder (xstrdup (dir));
-  char * const start = holder.get ();
-  char *component_start = start;
-  char *component_end = start;
-
-  while (1)
-    {
-      /* Find the beginning of the next component.  */
-      while (*component_start == '/')
-	component_start++;
-
-      /* Are we done?  */
-      if (*component_start == '\0')
-	return;
-
-      /* Find the slash or null-terminator after this component.  */
-      component_end = component_start;
-      while (*component_end != '/' && *component_end != '\0')
-	component_end++;
-
-      /* Temporarily replace the slash with a null terminator, so we can create
-         the directory up to this component.  */
-      char saved_char = *component_end;
-      *component_end = '\0';
-
-      /* If we get EEXIST and the existing path is a directory, then we're
-         happy.  If it exists, but it's a regular file and this is not the last
-         component, we'll fail at the next component.  If this is the last
-         component, the caller will fail with ENOTDIR when trying to
-         open/create a file under that path.  */
-      if (mkdir (start, 0700) != 0)
-	if (errno != EEXIST)
-	  return;
-
-      /* Restore the overwritten char.  */
-      *component_end = saved_char;
-      component_start = component_end;
-    }
-}
-
 /* Default destructor of index_cache_resource.  */
 index_cache_resource::~index_cache_resource () = default;
 
@@ -160,7 +113,12 @@ index_cache::store (struct dwarf2_per_objfile *dwarf2_per_objfile)
   TRY
     {
       /* Try to create the containing directory.  */
-      mkdir_recursive (m_dir.c_str ());
+      if (!mkdir_recursive (m_dir.c_str ()))
+	{
+	  warning (_("index cache: could not make cache directory: %s\n"),
+		   safe_strerror (errno));
+	  return;
+	}
 
       if (debug_index_cache)
         printf_unfiltered ("index cache: writing index cache for objfile %s\n",
@@ -346,62 +304,6 @@ show_index_cache_stats_command (const char *arg, int from_tty)
 		     indent, global_index_cache.n_misses ());
 }
 
-#if GDB_SELF_TEST && defined (HAVE_MKDTEMP)
-namespace selftests
-{
-
-/* Try to create DIR using mkdir_recursive and make sure it exists.  */
-
-static bool
-create_dir_and_check (const char *dir)
-{
-  mkdir_recursive (dir);
-
-  struct stat st;
-  if (stat (dir, &st) != 0)
-    perror_with_name (("stat"));
-
-  return (st.st_mode & S_IFDIR) != 0;
-}
-
-/* Test mkdir_recursive.  */
-
-static void
-test_mkdir_recursive ()
-{
-  char base[] = "/tmp/gdb-selftests-XXXXXX";
-
-  if (mkdtemp (base) == NULL)
-    perror_with_name (("mkdtemp"));
-
-  /* Try not to leave leftover directories.  */
-  struct cleanup_dirs {
-    cleanup_dirs (const char *base)
-      : m_base (base)
-    {}
-
-    ~cleanup_dirs () {
-      rmdir (string_printf ("%s/a/b/c/d/e", m_base).c_str ());
-      rmdir (string_printf ("%s/a/b/c/d", m_base).c_str ());
-      rmdir (string_printf ("%s/a/b/c", m_base).c_str ());
-      rmdir (string_printf ("%s/a/b", m_base).c_str ());
-      rmdir (string_printf ("%s/a", m_base).c_str ());
-      rmdir (m_base);
-    }
-
-  private:
-    const char *m_base;
-  } cleanup_dirs (base);
-
-  std::string dir = string_printf ("%s/a/b", base);
-  SELF_CHECK (create_dir_and_check (dir.c_str ()));
-
-  dir = string_printf ("%s/a/b/c//d/e/", base);
-  SELF_CHECK (create_dir_and_check (dir.c_str ()));
-}
-}
-#endif /*  GDB_SELF_TEST && defined (HAVE_MKDTEMP) */
-
 void
 _initialize_index_cache ()
 {
@@ -456,8 +358,4 @@ _initialize_index_cache ()
 When non-zero, debugging output for the index cache is displayed."),
 			    NULL, NULL,
 			    &setdebuglist, &showdebuglist);
-
-#if GDB_SELF_TEST && defined (HAVE_MKDTEMP)
-  selftests::register_test ("mkdir_recursive", selftests::test_mkdir_recursive);
-#endif
 }
-- 
2.17.1