One mildly interesting thing I noticed while writing this patch is
that gcc will give the following warning, but clang will not:
table.rows[table.nrows++] = xinmalloc (table.ncolumns,
sizeof *table.rows[0]);
src/df.c: In function 'alloc_table_row':
src/df.c:381:25: warning: operation on 'table.nrows' may be undefined
[-Wsequence-point]
381 | table.rows[table.nrows++] = xinmalloc (table.ncolumns,
| ~~~~~~~~~~~^~
It only shows up when COUNTED_BY is in use. Whether it is correct to
warn is unclear to me. My memory of that area of the standard is poor.
-- 8< --
* src/df.c (table): Define as a struct containing the previously global
variables. Use COUNTED_BY.
(columns, ncolumns, ncolumns_alloc, nrows, nrows_alloc): Move into the
table struct.
(alloc_table_row, print_table, alloc_field, get_field_list, get_header)
(get_dev): Update uses of the previously existing globals to reference
the table struct.
---
src/df.c | 87 ++++++++++++++++++++++++++++++++------------------------
1 file changed, 50 insertions(+), 37 deletions(-)
diff --git a/src/df.c b/src/df.c
index b3d83f505..969d09aab 100644
--- a/src/df.c
+++ b/src/df.c
@@ -216,11 +216,26 @@ static char const *all_args_string =
"source,fstype,itotal,iused,iavail,ipcent,size,"
"used,avail,pcent,file,target";
-/* Storage for the definition of output columns. */
-static struct field_data_t **columns;
+static struct
+{
+ /* The current number of processed rows (including header). */
+ idx_t nrows;
+
+ /* The number of slots allocated for rows. */
+ idx_t nrows_alloc;
+
+ /* Storage for pointers for each string (cell of table). */
+ char ***rows COUNTED_BY (nrows);
+
+ /* The current number of output columns. */
+ idx_t ncolumns;
-/* The current and allocated number of output columns. */
-static idx_t ncolumns, ncolumns_alloc;
+ /* The allocated number of output columns. */
+ idx_t ncolumns_alloc;
+
+ /* Storage for the definition of output columns. */
+ struct field_data_t **columns COUNTED_BY (ncolumns);
+} table;
/* Field values. */
struct field_values_t
@@ -235,13 +250,6 @@ struct field_values_t
bool negate_used;
};
-/* Storage for pointers for each string (cell of table). */
-static char ***table;
-
-/* The current number of processed rows (including header),
- and the number of slots allocated for rows. */
-static idx_t nrows, nrows_alloc;
-
/* For long options that have no equivalent short option, use a
non-character as a pseudo short option, starting with CHAR_MAX + 1. */
enum
@@ -361,15 +369,17 @@ replace_problematic_chars (char *cell)
}
-/* Dynamically allocate a row of pointers in TABLE, which
+/* Dynamically allocate a row of pointers in TABLE.ROWS, which
can then be accessed with standard 2D array notation. */
static void
alloc_table_row (void)
{
- if (nrows == nrows_alloc)
- table = xpalloc (table, &nrows_alloc, 1, -1, sizeof *table);
- table[nrows++] = xinmalloc (ncolumns, sizeof *table[0]);
+ if (table.nrows == table.nrows_alloc)
+ table.rows = xpalloc (table.rows, &table.nrows_alloc, 1, -1,
+ sizeof *table.rows);
+ idx_t const row_idx = table.nrows++;
+ table.rows[row_idx] = xinmalloc (table.ncolumns, sizeof *table.rows[0]);
}
/* Output each cell in the table, accounting for the
@@ -378,11 +388,11 @@ alloc_table_row (void)
static void
print_table (void)
{
- for (idx_t row = 0; row < nrows; row++)
+ for (idx_t row = 0; row < table.nrows; row++)
{
- for (idx_t col = 0; col < ncolumns; col++)
+ for (idx_t col = 0; col < table.ncolumns; col++)
{
- char *cell = table[row][col];
+ char *cell = table.rows[row][col];
/* Note the SOURCE_FIELD used to be displayed on it's own line
if (!posix_format && mbswidth (cell) > 20), but that
@@ -392,12 +402,12 @@ print_table (void)
putchar (' ');
int width = mbswidth (cell, MBSWIDTH_FLAGS);
- int fill = width < 0 ? 0 : columns[col]->width - width;
- if (columns[col]->align_right)
+ int fill = width < 0 ? 0 : table.columns[col]->width - width;
+ if (table.columns[col]->align_right)
for (; 0 < fill; fill--)
putchar (' ');
fputs (cell, stdout);
- if (col + 1 < ncolumns)
+ if (col + 1 < table.ncolumns)
for (; 0 < fill; fill--)
putchar (' ');
}
@@ -405,15 +415,17 @@ print_table (void)
}
}
-/* Dynamically allocate a struct field_t in COLUMNS, which
+/* Dynamically allocate a struct field_t in TABLE.COLUMNS, which
can then be accessed with standard array notation. */
static void
alloc_field (int f, char const *c)
{
- if (ncolumns == ncolumns_alloc)
- columns = xpalloc (columns, &ncolumns_alloc, 1, -1, sizeof *columns);
- columns[ncolumns++] = &field_data[f];
+ if (table.ncolumns == table.ncolumns_alloc)
+ table.columns = xpalloc (table.columns, &table.ncolumns_alloc, 1, -1,
+ sizeof *table.columns);
+ idx_t const column_idx = table.ncolumns++;
+ table.columns[column_idx] = &field_data[f];
if (c != NULL)
field_data[f].caption = c;
@@ -550,7 +562,7 @@ get_field_list (void)
break;
case OUTPUT_MODE:
- if (!ncolumns)
+ if (!table.ncolumns)
{
/* Add all fields if --output was given without a field list. */
decode_output_arg (all_args_string);
@@ -569,12 +581,12 @@ get_header (void)
{
alloc_table_row ();
- for (idx_t col = 0; col < ncolumns; col++)
+ for (idx_t col = 0; col < table.ncolumns; col++)
{
char *cell;
- char const *header = _(columns[col]->caption);
+ char const *header = _(table.columns[col]->caption);
- if (columns[col]->field == SIZE_FIELD
+ if (table.columns[col]->field == SIZE_FIELD
&& (header_mode == DEFAULT_MODE
|| (header_mode == OUTPUT_MODE
&& !(human_output_opts & human_autoscale))))
@@ -616,7 +628,8 @@ get_header (void)
/* TRANSLATORS: this is the "1K-blocks" header in "df" output. */
cell = xasprintf (_("%s-%s"), num, header);
}
- else if (header_mode == POSIX_MODE && columns[col]->field == SIZE_FIELD)
+ else if (header_mode == POSIX_MODE
+ && table.columns[col]->field == SIZE_FIELD)
{
/* TRANSLATORS: this is the "1024-blocks" header in "df -P". */
cell = xasprintf (_("%ju-%s"), output_block_size, header);
@@ -626,10 +639,10 @@ get_header (void)
replace_problematic_chars (cell);
- table[nrows - 1][col] = cell;
+ table.rows[table.nrows - 1][col] = cell;
int cell_width = mbswidth (cell, MBSWIDTH_FLAGS);
- columns[col]->width = MAX (columns[col]->width, cell_width);
+ table.columns[col]->width = MAX (table.columns[col]->width, cell_width);
}
}
@@ -1109,13 +1122,13 @@ get_dev (char const *device, char const *mount_point,
char const *file,
if (print_grand_total && ! force_fsu)
add_to_grand_total (&block_values, &inode_values);
- for (idx_t col = 0; col < ncolumns; col++)
+ for (idx_t col = 0; col < table.ncolumns; col++)
{
char buf[LONGEST_HUMAN_READABLE + 2];
char *cell;
struct field_values_t *v;
- switch (columns[col]->field_type)
+ switch (table.columns[col]->field_type)
{
case BLOCK_FLD:
v = &block_values;
@@ -1130,7 +1143,7 @@ get_dev (char const *device, char const *mount_point,
char const *file,
affirm (!"bad field_type");
}
- switch (columns[col]->field)
+ switch (table.columns[col]->field)
{
case SOURCE_FIELD:
cell = xstrdup (dev_name);
@@ -1227,8 +1240,8 @@ get_dev (char const *device, char const *mount_point,
char const *file,
replace_problematic_chars (cell);
int cell_width = mbswidth (cell, MBSWIDTH_FLAGS);
- columns[col]->width = MAX (columns[col]->width, cell_width);
- table[nrows - 1][col] = cell;
+ table.columns[col]->width = MAX (table.columns[col]->width, cell_width);
+ table.rows[table.nrows - 1][col] = cell;
}
free (dev_name);
}
--
2.56.0
