Convert public char* to const char* for C++ compatibility.

.github/workflows/cmake_actions.yml

@@ -1,4 +1,4 @@
-name: Build with CMake
+name: Test CMake build
 
 on: [push, pull_request]
 
@@ -7,6 +7,7 @@ jobs:
     name:
       Cmake
     strategy:
+      fail-fast: false
       matrix:
         cc:          [gcc, clang]
         cmake_flags: ["",

.github/workflows/make_actions.yml

@@ -1,4 +1,4 @@
-name: Build with Make
+name: Test Make build
 
 on: [push, pull_request]
 
@@ -7,6 +7,7 @@ jobs:
     name:
       Make
     strategy:
+      fail-fast: false
       matrix:
         cc:         [gcc, clang]
         make_flags: ["",

.github/workflows/windows_build.yml

@@ -1,4 +1,4 @@
-name: Cmake on Windows
+name: Test Cmake build on Windows
 
 on: [push, pull_request]
 

.github/workflows/zig_build.yml

@@ -17,6 +17,6 @@ jobs:
       - uses: goto-bus-stop/setup-zig@v2
         with:
           version: master
-      
+
       - name: Build Summary
         run: zig build -DBUILD_TESTS -DBUILD_EXAMPLES -DUSE_SYSTEM_MINIZIP --summary all -freference-trace

Makefile

@@ -64,6 +64,10 @@ universal_binary :
 examples : all
 	$(Q)$(MAKE) -C examples
 
+# Build the example programs with CPP for compatibility checking.
+examples_cpp : all
+	$(Q)$(MAKE) -C examples CC=$(CXX)
+
 # Clean src and test directories.
 clean :
 	$(Q)$(MAKE) clean -C src

examples/autofilter.c

@@ -268,7 +268,7 @@ int main() {
     worksheet_autofilter(worksheet5, 0, 0, 50, 3);
 
     /* Add the filter criteria. */
-    char* list[] = {"East", "North", "South", NULL};
+    const char* list[] = {"East", "North", "South", NULL};
 
     worksheet_filter_list(worksheet5, 0, list);
 

examples/chart_styles.c

@@ -13,7 +13,7 @@
 int main() {
 
     int chart_types[]    = {LXW_CHART_COLUMN, LXW_CHART_AREA, LXW_CHART_LINE, LXW_CHART_PIE};
-    char *chart_names[]  = {"Column", "Area", "Line", "Pie"};
+    const char *chart_names[]  = {"Column", "Area", "Line", "Pie"};
     char chart_title[32] = {0};
     int row_num, col_num, chart_num, style_num;
     lxw_worksheet *worksheet;

examples/conditional_format1.c

@@ -32,7 +32,8 @@ int main() {
     format_set_font_color(custom_format, LXW_COLOR_RED);
 
     /* Create a conditional format object. A static object would also work. */
-    lxw_conditional_format *conditional_format = calloc(1, sizeof(lxw_conditional_format));
+    lxw_conditional_format *conditional_format =
+        (lxw_conditional_format *)calloc(1, sizeof(lxw_conditional_format));
 
     /* Set the format type: a cell conditional: */
     conditional_format->type     = LXW_CONDITIONAL_TYPE_CELL;

examples/conditional_format2.c

@@ -61,7 +61,8 @@ int main() {
     format_set_font_color(format2, 0x006100);
 
     /* Create a single conditional format object to reuse in the examples. */
-    lxw_conditional_format *conditional_format = calloc(1, sizeof(lxw_conditional_format));
+    lxw_conditional_format *conditional_format =
+        (lxw_conditional_format *)calloc(1, sizeof(lxw_conditional_format));
 
     /*
      * Example 1. Conditional formatting based on simple cell based criteria.

examples/data_validate.c

@@ -47,7 +47,8 @@ int main() {
 
     lxw_workbook        *workbook  = workbook_new("data_validate1.xlsx");
     lxw_worksheet       *worksheet = workbook_add_worksheet(workbook, NULL);
-    lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
+    lxw_data_validation *data_validation =
+        (lxw_data_validation *)calloc(1, sizeof(lxw_data_validation));
 
     /* Add a format to use to highlight the header cells. */
     lxw_format *format = workbook_add_format(workbook);
@@ -154,7 +155,7 @@ int main() {
                            "Select a value from a drop down list",
                            NULL);
 
-    char *list[] = {"open", "high", "close", NULL};
+    const char *list[] = {"open", "high", "close", NULL};
 
     data_validation->validate   = LXW_VALIDATION_TYPE_LIST;
     data_validation->value_list = list;

examples/dates_and_times04.c

@@ -18,7 +18,7 @@ int main() {
     /* Examples date and time formats. In the output file compare how changing
      * the format strings changes the appearance of the date.
      */
-    char *date_formats[] = {
+    const char *date_formats[] = {
         "dd/mm/yy",
         "mm/dd/yy",
         "dd m yy",

examples/format_num_format.c

@@ -62,7 +62,7 @@ int main() {
     /* Format a Zip code. */
     format_set_num_format(format11, "00000");
     worksheet_write_number(worksheet, 13, 0, 1209, format11);
-    
+
     /* Close the workbook, save the file and free any memory. */
     return workbook_close(workbook);
 }

examples/output_buffer.c

@@ -10,7 +10,7 @@
 #include "xlsxwriter.h"
 
 int main() {
-    char *output_buffer;
+    const char *output_buffer;
     size_t output_buffer_size;
 
     /* Set the worksheet options. */
@@ -36,7 +36,7 @@ int main() {
     FILE *file = fopen("output_buffer.xlsx", "wb");
     fwrite(output_buffer, output_buffer_size, 1, file);
     fclose(file);
-    free(output_buffer);
+    free((void *)output_buffer);
 
     return ferror(stdout);
 }

include/xlsxwriter/chart.h

@@ -699,7 +699,7 @@ typedef struct lxw_chart_pattern {
 typedef struct lxw_chart_font {
 
     /** The chart font name, such as "Arial" or "Calibri". */
-    char *name;
+    const char *name;
 
     /** The chart font size. The default is 11. */
     double size;
@@ -800,7 +800,7 @@ typedef struct lxw_chart_data_label {
 
     /** The string or formula value for the data label. See
      *  @ref chart_custom_labels. */
-    char *value;
+    const char *value;
 
     /** Option to hide/delete the data label from the chart series.
      *  See @ref chart_custom_labels. */

include/xlsxwriter/chartsheet.h

@@ -80,9 +80,9 @@ typedef struct lxw_chartsheet {
     struct lxw_protection_obj protection;
     uint8_t is_protected;
 
-    char *name;
-    char *quoted_name;
-    char *tmpdir;
+    const char *name;
+    const char *quoted_name;
+    const char *tmpdir;
     uint16_t index;
     uint8_t active;
     uint8_t selected;

include/xlsxwriter/packager.h

@@ -67,10 +67,10 @@ typedef struct lxw_packager {
     size_t output_buffer_size;
     zipFile zipfile;
     zip_fileinfo zipfile_info;
-    char *filename;
-    char *buffer;
+    const char *filename;
+    const char *buffer;
     char *output_buffer;
-    char *tmpdir;
+    const char *tmpdir;
     uint8_t use_zip64;
 
 } lxw_packager;
@@ -82,7 +82,7 @@ extern "C" {
 #endif
 /* *INDENT-ON* */
 
-lxw_packager *lxw_packager_new(const char *filename, char *tmpdir,
+lxw_packager *lxw_packager_new(const char *filename, const char *tmpdir,
                                uint8_t use_zip64);
 void lxw_packager_free(lxw_packager *packager);
 lxw_error lxw_create_package(lxw_packager *self);

include/xlsxwriter/styles.h

@@ -44,7 +44,7 @@ extern "C" {
 lxw_styles *lxw_styles_new(void);
 void lxw_styles_free(lxw_styles *styles);
 void lxw_styles_assemble_xml_file(lxw_styles *self);
-void lxw_styles_write_string_fragment(lxw_styles *self, char *string);
+void lxw_styles_write_string_fragment(lxw_styles *self, const char *string);
 void lxw_styles_write_rich_font(lxw_styles *styles, lxw_format *format);
 
 /* Declarations required for unit testing. */

include/xlsxwriter/utility.h

@@ -232,8 +232,8 @@ void lxw_str_tolower(char *str);
 #define lxw_strcasecmp strcasecmp
 #endif
 
-FILE *lxw_tmpfile(char *tmpdir);
-FILE *lxw_get_filehandle(char **buf, size_t *size, char *tmpdir);
+FILE *lxw_tmpfile(const char *tmpdir);
+FILE *lxw_get_filehandle(char **buf, size_t *size, const char *tmpdir);
 FILE *lxw_fopen(const char *filename, const char *mode);
 
 /* Use the third party dtoa function to avoid locale issues with sprintf

include/xlsxwriter/workbook.h

@@ -182,34 +182,34 @@ typedef struct lxw_defined_name {
  */
 typedef struct lxw_doc_properties {
     /** The title of the Excel Document. */
-    char *title;
+    const char *title;
 
     /** The subject of the Excel Document. */
-    char *subject;
+    const char *subject;
 
     /** The author of the Excel Document. */
-    char *author;
+    const char *author;
 
     /** The manager field of the Excel Document. */
-    char *manager;
+    const char *manager;
 
     /** The company field of the Excel Document. */
-    char *company;
+    const char *company;
 
     /** The category of the Excel Document. */
-    char *category;
+    const char *category;
 
     /** The keywords of the Excel Document. */
-    char *keywords;
+    const char *keywords;
 
     /** The comment field of the Excel Document. */
-    char *comments;
+    const char *comments;
 
     /** The status of the Excel Document. */
-    char *status;
+    const char *status;
 
     /** The hyperlink base URL of the Excel Document. */
-    char *hyperlink_base;
+    const char *hyperlink_base;
 
     /** The file creation date/time shown in Excel. This defaults to the
      * current time and date if set to 0. If you wish to create files that are
@@ -270,13 +270,13 @@ typedef struct lxw_workbook_options {
     uint8_t constant_memory;
 
     /** Directory to use for the temporary files created by libxlsxwriter. */
-    char *tmpdir;
+    const char *tmpdir;
 
     /** Allow ZIP64 extensions when creating the xlsx file zip container. */
     uint8_t use_zip64;
 
     /** Output buffer to use instead of writing to a file */
-    char **output_buffer;
+    const char **output_buffer;
 
     /** Used with output_buffer to get the size of the created buffer */
     size_t *output_buffer_size;

include/xlsxwriter/worksheet.h

@@ -979,7 +979,7 @@ typedef struct lxw_data_validation {
      * is applied using a cell reference. It is valid for any of the
      * `_FORMULA` validation types.
      */
-    char *value_formula;
+    const char *value_formula;
 
     /**
      * This parameter is used to set a list of strings for a drop down list.
@@ -998,7 +998,7 @@ typedef struct lxw_data_validation {
      * Note, the string list is restricted by Excel to 255 characters,
      * including comma separators.
      */
-    char **value_list;
+    const char **value_list;
 
     /**
      * This parameter is used to set the limiting value to which the date or
@@ -1016,7 +1016,7 @@ typedef struct lxw_data_validation {
      * This parameter is the same as `value_formula` but for the minimum value
      * when a `BETWEEN` criteria is used.
      */
-    char *minimum_formula;
+    const char *minimum_formula;
 
     /**
      * This parameter is the same as `value_datetime` but for the minimum value
@@ -1034,7 +1034,7 @@ typedef struct lxw_data_validation {
      * This parameter is the same as `value_formula` but for the maximum value
      * when a `BETWEEN` criteria is used.
      */
-    char *maximum_formula;
+    const char *maximum_formula;
 
     /**
      * This parameter is the same as `value_datetime` but for the maximum value
@@ -1050,7 +1050,7 @@ typedef struct lxw_data_validation {
      *
      * The maximum title length is 32 characters.
      */
-    char *input_title;
+    const char *input_title;
 
     /**
      * The input_message parameter is used to set the input message that is
@@ -1059,7 +1059,7 @@ typedef struct lxw_data_validation {
      * The message can be split over several lines using newlines. The maximum
      * message length is 255 characters.
      */
-    char *input_message;
+    const char *input_message;
 
     /**
      * The error_title parameter is used to set the title of the error message
@@ -1067,7 +1067,7 @@ typedef struct lxw_data_validation {
      * default error title is 'Microsoft Excel'. The maximum title length is
      * 32 characters.
      */
-    char *error_title;
+    const char *error_title;
 
     /**
      * The error_message parameter is used to set the error message that is
@@ -1078,7 +1078,7 @@ typedef struct lxw_data_validation {
      * The message can be split over several lines using newlines. The maximum
      * message length is 255 characters.
      */
-    char *error_message;
+    const char *error_message;
 
 } lxw_data_validation;
 
@@ -1142,7 +1142,7 @@ typedef struct lxw_conditional_format {
      *  value_string exists in the struct then the number value is
      *  ignored. Note, if the condition refers to a text string then it must
      *  be double quoted like this `"foo"`. */
-    char *value_string;
+    const char *value_string;
 
     /** The format field is used to specify the #lxw_format format that will
      *  be applied to the cell when the conditional formatting criterion is
@@ -1163,7 +1163,7 @@ typedef struct lxw_conditional_format {
 
     /** The minimum string value used for Cell, Color Scale and Data Bar conditional
      *  formats. Usually used to set ranges like `=A1`. */
-    char *min_value_string;
+    const char *min_value_string;
 
     /** The rule used for the minimum condition in Color Scale and Data Bar
      *  conditional formats. The rule types are defined in
@@ -1180,7 +1180,7 @@ typedef struct lxw_conditional_format {
 
     /** The middle string value used for Color Scale and Data Bar conditional
      *  formats. Usually used to set ranges like `=A1`. */
-    char *mid_value_string;
+    const char *mid_value_string;
 
     /** The rule used for the middle condition in Color Scale and Data Bar
      *  conditional formats. The rule types are defined in
@@ -1198,7 +1198,7 @@ typedef struct lxw_conditional_format {
 
     /** The maximum string value used for Cell, Color Scale and Data Bar conditional
      *  formats. Usually used to set ranges like `=A1`. */
-    char *max_value_string;
+    const char *max_value_string;
 
     /** The rule used for the maximum condition in Color Scale and Data Bar
      *  conditional formats. The rule types are defined in
@@ -1304,7 +1304,7 @@ typedef struct lxw_conditional_format {
      *  conditional format and any others separated by spaces. For example
      *  `"A1 C1:C5 E2 G1:G100"`.
      */
-    char *multi_range;
+    const char *multi_range;
 
     /** The stop_if_true parameter can be used to set the "stop if true"
      *  feature of a conditional formatting rule when more than one rule is
@@ -1389,13 +1389,13 @@ typedef struct lxw_table_column {
 
     /** Set the header name/caption for the column. If NULL the header defaults
      *  to  Column 1, Column 2, etc. */
-    char *header;
+    const char *header;
 
     /** Set the formula for the column. */
-    char *formula;
+    const char *formula;
 
     /** Set the string description for the column total.  */
-    char *total_string;
+    const char *total_string;
 
     /** Set the function for the column total.  */
     uint8_t total_function;
@@ -1437,7 +1437,7 @@ typedef struct lxw_table_options {
      * [Naming an Excel Table]
      * (https://support.microsoft.com/en-us/office/rename-an-excel-table-fbf49a4f-82a3-43eb-8ba2-44d21233b114).
      */
-    char *name;
+    const char *name;
 
     /**
      * The `no_header_row` parameter can be used to turn off the header row in
@@ -1666,7 +1666,7 @@ typedef struct lxw_filter_rule {
     uint8_t criteria;
 
     /** String value to which the criteria applies. */
-    char *value_string;
+    const char *value_string;
 
     /** Numeric value to which the criteria applies (if value_string isn't used). */
     double value;
@@ -1720,7 +1720,7 @@ typedef struct lxw_image_options {
      *  used to provide a text description of the image to help
      *  accessibility. Defaults to the image filename as in Excel. Set to ""
      *  to ignore the description field. */
-    char *description;
+    const char *description;
 
     /** Optional parameter to help accessibility. It is used to mark the image
      *  as decorative, and thus uninformative, for automated screen
@@ -1730,10 +1730,10 @@ typedef struct lxw_image_options {
 
     /** Add an optional hyperlink to the image. Follows the same URL rules
      *  and types as `worksheet_write_url()`. */
-    char *url;
+    const char *url;
 
     /** Add an optional mouseover tip for a hyperlink to the image. */
-    char *tip;
+    const char *tip;
 
 } lxw_image_options;
 
@@ -1765,7 +1765,7 @@ typedef struct lxw_chart_options {
      *  used to provide a text description of the chart to help
      *  accessibility. Defaults to the image filename as in Excel. Set to NULL
      *  to ignore the description field. */
-    char *description;
+    const char *description;
 
     /** Optional parameter to help accessibility. It is used to mark the chart
      *  as decorative, and thus uninformative, for automated screen
@@ -1832,7 +1832,7 @@ typedef struct lxw_comment_options {
      *  worksheet. The default author for all cell comments in a worksheet can
      *  be set using the `worksheet_set_comments_author()` function. Set to
      *  NULL if not required.  See also @ref ww_comments_author. */
-    char *author;
+    const char *author;
 
     /** This option is used to set the width of the cell comment box
      *  explicitly in pixels. The default width is 128 pixels. See also @ref
@@ -1859,7 +1859,7 @@ typedef struct lxw_comment_options {
 
     /** This option is used to set the font for the comment. The default font
      *  is 'Tahoma'.  See also @ref ww_comments_font_name. */
-    char *font_name;
+    const char *font_name;
 
      /** This option is used to set the font size for the comment. The default
       * is 8. See also @ref ww_comments_font_size. */
@@ -1902,16 +1902,16 @@ typedef struct lxw_button_options {
     /** Sets the caption on the button. The default is "Button n" where n is
      *  the current number of buttons in the worksheet, including this
      *  button. */
-    char *caption;
+    const char *caption;
 
     /** Name of the macro to run when the button is pressed. The macro must be
      *  included with workbook_add_vba_project(). */
-    char *macro;
+    const char *macro;
 
     /** Optional description or "Alt text" for the button. This field can be
      *  used to provide a text description of the button to help
      *  accessibility. Set to NULL to ignore the description field. */
-    char *description;
+    const char *description;
 
     /** This option is used to set the width of the cell button box
      *  explicitly in pixels. The default width is 64 pixels. */
@@ -1983,17 +1983,17 @@ typedef struct lxw_header_footer_options {
     /** The left header image filename, with path if required. This should
      * have a corresponding `&G/&[Picture]` placeholder in the `&L` section of
      * the header/footer string. See `worksheet_set_header_opt()`. */
-    char *image_left;
+    const char *image_left;
 
     /** The center header image filename, with path if required. This should
      * have a corresponding `&G/&[Picture]` placeholder in the `&C` section of
      * the header/footer string. See `worksheet_set_header_opt()`. */
-    char *image_center;
+    const char *image_center;
 
     /** The right header image filename, with path if required. This should
      * have a corresponding `&G/&[Picture]` placeholder in the `&R` section of
      * the header/footer string. See `worksheet_set_header_opt()`. */
-    char *image_right;
+    const char *image_right;
 
 } lxw_header_footer_options;
 
@@ -2094,7 +2094,7 @@ typedef struct lxw_rich_string_tuple {
     lxw_format *format;
 
     /** The string fragment. */
-    char *string;
+    const char *string;
 } lxw_rich_string_tuple;
 
 /**
@@ -2134,9 +2134,9 @@ typedef struct lxw_worksheet {
     lxw_col_t dim_colmax;
 
     lxw_sst *sst;
-    char *name;
-    char *quoted_name;
-    char *tmpdir;
+    const char *name;
+    const char *quoted_name;
+    const char *tmpdir;
 
     uint16_t index;
     uint8_t active;
@@ -2303,9 +2303,9 @@ typedef struct lxw_worksheet_init_data {
     uint16_t *active_sheet;
     uint16_t *first_sheet;
     lxw_sst *sst;
-    char *name;
-    char *quoted_name;
-    char *tmpdir;
+    const char *name;
+    const char *quoted_name;
+    const char *tmpdir;
     lxw_format *default_url_format;
     uint16_t max_url_length;
 
@@ -2340,7 +2340,7 @@ typedef struct lxw_cell {
     union {
         double number;
         int32_t string_id;
-        char *string;
+        const char *string;
     } u;
 
     double formula_result;
@@ -4149,7 +4149,7 @@ lxw_error worksheet_filter_column2(lxw_worksheet *worksheet, lxw_col_t col,
  * ww_autofilters_data for more details.
  */
 lxw_error worksheet_filter_list(lxw_worksheet *worksheet, lxw_col_t col,
-                                char **list);
+                                const char **list);
 
 /**
  * @brief Add a data validation to a cell.

src/chart.c

@@ -78,7 +78,7 @@ _chart_free_font(lxw_chart_font *font)
     if (!font)
         return;
 
-    free(font->name);
+    free((void *) font->name);
     free(font);
 }
 
@@ -5596,7 +5596,7 @@ chart_series_set_labels_custom(lxw_chart_series *series,
     for (i = 0; i < data_label_count; i++) {
         lxw_chart_data_label *user_label = data_labels[i];
         lxw_chart_custom_label *data_label = &series->data_labels[i];
-        char *src_value = user_label->value;
+        const char *src_value = user_label->value;
 
         data_label->hide = user_label->hide;
         data_label->font = _chart_convert_font_args(user_label->font);

src/chartsheet.c

@@ -66,8 +66,8 @@ lxw_chartsheet_free(lxw_chartsheet *chartsheet)
         return;
 
     lxw_worksheet_free(chartsheet->worksheet);
-    free(chartsheet->name);
-    free(chartsheet->quoted_name);
+    free((void *) chartsheet->name);
+    free((void *) chartsheet->quoted_name);
     free(chartsheet);
 }
 

src/packager.c

@@ -52,7 +52,7 @@
 STATIC lxw_error _add_file_to_zip(lxw_packager *self, FILE * file,
                                   const char *filename);
 
-STATIC lxw_error _add_buffer_to_zip(lxw_packager *self, char *buffer,
+STATIC lxw_error _add_buffer_to_zip(lxw_packager *self, const char *buffer,
                                     size_t buffer_size, const char *filename);
 
 STATIC lxw_error _add_to_zip(lxw_packager *self, FILE * file,
@@ -153,7 +153,7 @@ _fclose_memstream(voidpf opaque, voidpf stream)
         GOTO_LABEL_ON_MEM_ERROR(packager->output_buffer, mem_error);
 
         rewind(file);
-        if (fread(packager->output_buffer, size, 1, file) < 1)
+        if (fread((void *) packager->output_buffer, size, 1, file) < 1)
             goto mem_error;
 
         packager->output_buffer_size = size;
@@ -170,7 +170,7 @@ mem_error:
  * Create a new packager object.
  */
 lxw_packager *
-lxw_packager_new(const char *filename, char *tmpdir, uint8_t use_zip64)
+lxw_packager_new(const char *filename, const char *tmpdir, uint8_t use_zip64)
 {
     zlib_filefunc_def filefunc;
     lxw_packager *packager = calloc(1, sizeof(lxw_packager));
@@ -239,8 +239,8 @@ lxw_packager_free(lxw_packager *packager)
     if (!packager)
         return;
 
-    free(packager->buffer);
-    free(packager->filename);
+    free((void *) packager->buffer);
+    free((void *) packager->filename);
     free(packager);
 }
 
@@ -1792,7 +1792,7 @@ _add_file_to_zip(lxw_packager *self, FILE * file, const char *filename)
     fflush(file);
     rewind(file);
 
-    size_read = fread(self->buffer, 1, self->buffer_size, file);
+    size_read = fread((void *) self->buffer, 1, self->buffer_size, file);
 
     while (size_read) {
 
@@ -1811,7 +1811,8 @@ _add_file_to_zip(lxw_packager *self, FILE * file, const char *filename)
             RETURN_ON_ZIP_ERROR(error, LXW_ERROR_ZIP_FILE_ADD);
         }
 
-        size_read = fread(self->buffer, 1, self->buffer_size, file);
+        size_read =
+            fread((void *) (void *) self->buffer, 1, self->buffer_size, file);
     }
 
     error = zipCloseFileInZip(self->zipfile);
@@ -1824,7 +1825,7 @@ _add_file_to_zip(lxw_packager *self, FILE * file, const char *filename)
 }
 
 STATIC lxw_error
-_add_buffer_to_zip(lxw_packager *self, char *buffer, size_t buffer_size,
+_add_buffer_to_zip(lxw_packager *self, const char *buffer, size_t buffer_size,
                    const char *filename)
 {
     int16_t error = ZIP_OK;
@@ -1872,7 +1873,7 @@ _add_to_zip(lxw_packager *self, FILE * file, char **buffer,
 }
 
 /*
- * Write the xml files that make up the XLXS OPC package.
+ * Write the xml files that make up the XLSX OPC package.
  */
 lxw_error
 lxw_create_package(lxw_packager *self)

src/styles.c

@@ -85,7 +85,7 @@ lxw_styles_free(lxw_styles *styles)
  * Write the <t> element for rich strings.
  */
 void
-lxw_styles_write_string_fragment(lxw_styles *self, char *string)
+lxw_styles_write_string_fragment(lxw_styles *self, const char *string)
 {
     struct xml_attribute_list attributes;
     struct xml_attribute *attribute;

src/utility.c

@@ -572,7 +572,7 @@ lxw_quote_sheetname(const char *str)
  * version if required for safety or portability.
  */
 FILE *
-lxw_tmpfile(char *tmpdir)
+lxw_tmpfile(const char *tmpdir)
 {
 #ifndef USE_STANDARD_TMPFILE
     return tmpfileplus(tmpdir, NULL, NULL, 0);
@@ -586,7 +586,7 @@ lxw_tmpfile(char *tmpdir)
  * Return a memory-backed file if supported, otherwise a temporary one
  */
 FILE *
-lxw_get_filehandle(char **buf, size_t *size, char *tmpdir)
+lxw_get_filehandle(char **buf, size_t *size, const char *tmpdir)
 {
     static size_t s;
     if (!size)

src/workbook.c

@@ -66,16 +66,16 @@ STATIC void
 _free_doc_properties(lxw_doc_properties *properties)
 {
     if (properties) {
-        free(properties->title);
-        free(properties->subject);
-        free(properties->author);
-        free(properties->manager);
-        free(properties->company);
-        free(properties->category);
-        free(properties->keywords);
-        free(properties->comments);
-        free(properties->status);
-        free(properties->hyperlink_base);
+        free((void *) properties->title);
+        free((void *) properties->subject);
+        free((void *) properties->author);
+        free((void *) properties->manager);
+        free((void *) properties->company);
+        free((void *) properties->category);
+        free((void *) properties->keywords);
+        free((void *) properties->comments);
+        free((void *) properties->status);
+        free((void *) properties->hyperlink_base);
     }
 
     free(properties);
@@ -261,7 +261,7 @@ lxw_workbook_free(lxw_workbook *workbook)
     lxw_hash_free(workbook->used_xf_formats);
     lxw_hash_free(workbook->used_dxf_formats);
     lxw_sst_free(workbook->sst);
-    free(workbook->options.tmpdir);
+    free((void *) workbook->options.tmpdir);
     free(workbook->ordered_charts);
     free(workbook->vba_project);
     free(workbook->vba_project_signature);
@@ -1972,8 +1972,8 @@ workbook_add_worksheet(lxw_workbook *self, const char *sheetname)
     return worksheet;
 
 mem_error:
-    free(init_data.name);
-    free(init_data.quoted_name);
+    free((void *) init_data.name);
+    free((void *) init_data.quoted_name);
     free(worksheet_name);
     free(worksheet);
     return NULL;
@@ -2056,8 +2056,8 @@ workbook_add_chartsheet(lxw_workbook *self, const char *sheetname)
     return chartsheet;
 
 mem_error:
-    free(init_data.name);
-    free(init_data.quoted_name);
+    free((void *) init_data.name);
+    free((void *) init_data.quoted_name);
     free(chartsheet_name);
     free(chartsheet);
     return NULL;

src/worksheet.c

@@ -369,7 +369,7 @@ _free_cell(lxw_cell *cell)
     if (cell->type != NUMBER_CELL && cell->type != STRING_CELL
         && cell->type != BLANK_CELL && cell->type != BOOLEAN_CELL) {
 
-        free(cell->u.string);
+        free((void *) cell->u.string);
     }
 
     free(cell->user_data1);
@@ -486,9 +486,9 @@ _free_worksheet_table_column(lxw_table_column *column)
     if (!column)
         return;
 
-    free(column->header);
-    free(column->formula);
-    free(column->total_string);
+    free((void *) column->header);
+    free((void *) column->formula);
+    free((void *) column->total_string);
 
     free(column);
 }
@@ -785,8 +785,8 @@ lxw_worksheet_free(lxw_worksheet *worksheet)
 
     free(worksheet->hbreaks);
     free(worksheet->vbreaks);
-    free(worksheet->name);
-    free(worksheet->quoted_name);
+    free((void *) worksheet->name);
+    free((void *) worksheet->quoted_name);
     free(worksheet->vba_codename);
     free(worksheet->vml_data_id_str);
     free(worksheet->vml_header_id_str);
@@ -896,7 +896,7 @@ _new_inline_string_cell(lxw_row_t row_num,
  */
 STATIC lxw_cell *
 _new_inline_rich_string_cell(lxw_row_t row_num,
-                             lxw_col_t col_num, char *string,
+                             lxw_col_t col_num, const char *string,
                              lxw_format *format)
 {
     lxw_cell *cell = calloc(1, sizeof(lxw_cell));
@@ -1452,7 +1452,7 @@ lxw_basename(const char *path)
 /* Function to count the total concatenated length of the strings in a
  * validation list array, including commas. */
 size_t
-_validation_list_length(char **list)
+_validation_list_length(const char **list)
 {
     uint8_t i = 0;
     size_t length = 0;
@@ -1475,7 +1475,7 @@ _validation_list_length(char **list)
 /* Function to convert an array of strings into a CSV string for data
  * validation lists. */
 char *
-_validation_list_to_csv(char **list)
+_validation_list_to_csv(const char **list)
 {
     uint8_t i = 0;
     char *str;
@@ -1670,10 +1670,10 @@ _set_default_table_columns(lxw_table_obj *table_obj)
  *  "[#This Row]" in table formulas. This is the format that Excel uses to
  *  store the references. */
 char *
-_expand_table_formula(char *formula)
+_expand_table_formula(const char *formula)
 {
     char *expanded;
-    char *ptr;
+    const char *ptr;
     size_t i;
     size_t ref_count = 0;
     size_t expanded_len;
@@ -1753,7 +1753,7 @@ _set_custom_table_columns(lxw_table_obj *table_obj,
             RETURN_ON_MEM_ERROR(str, LXW_ERROR_MEMORY_MALLOC_FAILED);
 
             /* Free the default column header. */
-            free(table_column->header);
+            free((void *) table_column->header);
             table_column->header = str;
         }
 
@@ -4446,7 +4446,7 @@ STATIC void
 _write_inline_rich_string_cell(lxw_worksheet *self, char *range,
                                int32_t style_index, lxw_cell *cell)
 {
-    char *string = cell->u.string;
+    const char *string = cell->u.string;
 
     if (style_index)
         fprintf(self->file,
@@ -4743,7 +4743,7 @@ lxw_worksheet_write_single_row(lxw_worksheet *self)
 
 /* Process a header/footer image and store it in the correct slot. */
 lxw_error
-_worksheet_set_header_footer_image(lxw_worksheet *self, char *filename,
+_worksheet_set_header_footer_image(lxw_worksheet *self, const char *filename,
                                    uint8_t image_position)
 {
     FILE *image_stream;
@@ -8422,7 +8422,7 @@ worksheet_write_rich_string(lxw_worksheet *self,
     uint8_t i;
     long file_size;
     char *rich_string = NULL;
-    char *string_copy = NULL;
+    const char *string_copy = NULL;
     lxw_styles *styles = NULL;
     lxw_format *default_format = NULL;
     lxw_rich_string_tuple *rich_string_tuple = NULL;
@@ -8499,9 +8499,9 @@ worksheet_write_rich_string(lxw_worksheet *self,
 
         /* Rewind the file and read the data into the memory buffer. */
         rewind(tmpfile);
-        if (fread(rich_string, file_size, 1, tmpfile) < 1) {
+        if (fread((void *) rich_string, file_size, 1, tmpfile) < 1) {
             fclose(tmpfile);
-            free(rich_string);
+            free((void *) rich_string);
             return LXW_ERROR_READING_TMPFILE;
         }
     }
@@ -8510,14 +8510,14 @@ worksheet_write_rich_string(lxw_worksheet *self,
     fclose(tmpfile);
 
     if (lxw_utf8_strlen(rich_string) > LXW_STR_MAX) {
-        free(rich_string);
+        free((void *) rich_string);
         return LXW_ERROR_MAX_STRING_LENGTH_EXCEEDED;
     }
 
     if (!self->optimize) {
         /* Get the SST element and string id. */
         sst_element = lxw_get_sst_index(self->sst, rich_string, LXW_TRUE);
-        free(rich_string);
+        free((void *) rich_string);
 
         if (!sst_element)
             return LXW_ERROR_SHARED_STRING_INDEX_NOT_FOUND;
@@ -8530,7 +8530,7 @@ worksheet_write_rich_string(lxw_worksheet *self,
         /* Look for and escape control chars in the string. */
         if (lxw_has_control_characters(rich_string)) {
             string_copy = lxw_escape_control_characters(rich_string);
-            free(rich_string);
+            free((void *) rich_string);
         }
         else {
             string_copy = rich_string;
@@ -9152,7 +9152,7 @@ worksheet_filter_column2(lxw_worksheet *self, lxw_col_t col,
  * Set two autofilter rules for a filter column.
  */
 lxw_error
-worksheet_filter_list(lxw_worksheet *self, lxw_col_t col, char **list)
+worksheet_filter_list(lxw_worksheet *self, lxw_col_t col, const char **list)
 {
     lxw_filter_rule_obj *rule_obj;
     uint16_t rule_index;

test/functional/src/test_autofilter09.c

@@ -106,7 +106,7 @@ int main() {
 
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
-    char* list[] = {"East", "North", "South", NULL};
+    const char* list[] = {"East", "North", "South", NULL};
 
     worksheet_filter_list(worksheet, 0, list);
 

test/functional/src/test_autofilter10.c

@@ -107,7 +107,7 @@ int main() {
 
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
-    char* list[] = {"East", "North", "South", "Blanks", NULL};
+    const char* list[] = {"East", "North", "South", "Blanks", NULL};
 
     worksheet_filter_list(worksheet, 0, list);
 

test/functional/src/test_autofilter11.c

@@ -108,7 +108,7 @@ int main() {
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
 
-    char* list[] = {"3000", "5000", "8000", NULL};
+    const char* list[] = {"3000", "5000", "8000", NULL};
 
     worksheet_filter_list(worksheet, 2, list);
 

test/functional/src/test_data_validation01.c

@@ -13,7 +13,7 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation01.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list[] = {"Foo", "Bar", "Baz", NULL};
+    const char* list[] = {"Foo", "Bar", "Baz", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;

test/functional/src/test_data_validation02.c

@@ -13,7 +13,7 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation02.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list[] = {"Foo", "Bar", "Baz", NULL};
+    const char* list[] = {"Foo", "Bar", "Baz", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;

test/functional/src/test_data_validation03.c

@@ -13,8 +13,8 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation03.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list1[] = {"Foo", "Bar", "Baz", NULL};
-    char *list2[] = {
+    const char *list1[] = {"Foo", "Bar", "Baz", NULL};
+    const char *list2[] = {
         "Foobar", "Foobas", "Foobat", "Foobau", "Foobav", "Foobaw", "Foobax",
         "Foobay", "Foobaz", "Foobba", "Foobbb", "Foobbc", "Foobbd", "Foobbe",
         "Foobbf", "Foobbg", "Foobbh", "Foobbi", "Foobbj", "Foobbk", "Foobbl",

test/functional/src/test_data_validation04.c

@@ -13,8 +13,8 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation04.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list1[] = {"Foo", "Bar", "Baz", NULL};
-    char *list2[] = {
+    const char *list1[] = {"Foo", "Bar", "Baz", NULL};
+    const char *list2[] = {
         "Foobar", "Foobas", "Foobat", "Foobau", "Foobav", "Foobaw", "Foobax",
         "Foobay", "Foobaz", "Foobba", "Foobbb", "Foobbc", "Foobbd", "Foobbe",
         "Foobbf", "Foobbg", "Foobbh", "Foobbi", "Foobbj", "Foobbk", "Foobbl",

test/functional/src/test_data_validation05.c

@@ -13,8 +13,8 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation05.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list1[] = {"Foo", "Bar", "Baz", NULL};
-    char *list2[] = {
+    const char *list1[] = {"Foo", "Bar", "Baz", NULL};
+    const char *list2[] = {
         "Foobar", "Foobas", "Foobat", "Foobau", "Foobav", "Foobaw", "Foobax",
         "Foobay", "Foobaz", "Foobba", "Foobbb", "Foobbc", "Foobbd", "Foobbe",
         "Foobbf", "Foobbg", "Foobbh", "Foobbi", "Foobbj", "Foobbk", "Foobbl",

test/functional/src/test_data_validation06.c

@@ -13,8 +13,8 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation06.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list1[] = {"Foo", "Bar", "Baz", NULL};
-    char *list2[] = {
+    const char *list1[] = {"Foo", "Bar", "Baz", NULL};
+    const char *list2[] = {
         "Foobar", "Foobas", "Foobat", "Foobau", "Foobav", "Foobaw", "Foobax",
         "Foobay", "Foobaz", "Foobba", "Foobbb", "Foobbc", "Foobbd", "Foobbe",
         "Foobbf", "Foobbg", "Foobbh", "Foobbi", "Foobbj", "Foobbk", "Foobbl",

test/functional/src/test_data_validation07.c

@@ -13,7 +13,7 @@ int main() {
 
     lxw_workbook  *workbook  = workbook_new("test_data_validation07.xlsx");
     lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
-    char *list[] = {"coffee", "café", NULL};
+    const char* list[] = {"coffee", "café", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;

test/functional/src/test_output_buffer01.c

@@ -10,7 +10,7 @@
 #include "xlsxwriter.h"
 
 int main() {
-    char *output_buffer;
+    const char *output_buffer;
     size_t output_buffer_size;
     lxw_workbook_options options = {LXW_FALSE,
                                     ".",
@@ -31,7 +31,7 @@ int main() {
     FILE *file = fopen("test_output_buffer01.xlsx", "wb");
     fwrite(output_buffer, output_buffer_size, 1, file);
     fclose(file);
-    free(output_buffer);
+    free((void *)output_buffer);
 
     return 0;
 }

test/functional/src/test_properties01.c

@@ -33,15 +33,15 @@ int main() {
     worksheet_set_column(worksheet, 0, 0, 70, NULL);
     worksheet_write_string(worksheet, CELL("A1"), "Select 'Office Button -> Prepare -> Properties' to see the file properties." , NULL);
 
-    free(properties->title);
-    free(properties->subject);
-    free(properties->author);
-    free(properties->manager);
-    free(properties->company);
-    free(properties->category);
-    free(properties->keywords);
-    free(properties->comments);
-    free(properties->status);
+    free((void *)properties->title);
+    free((void *)properties->subject);
+    free((void *)properties->author);
+    free((void *)properties->manager);
+    free((void *)properties->company);
+    free((void *)properties->category);
+    free((void *)properties->keywords);
+    free((void *)properties->comments);
+    free((void *)properties->status);
     free(properties);
 
     return workbook_close(workbook);

test/functional/src/test_properties02.c

@@ -21,7 +21,7 @@ int main() {
 
     (void)worksheet;
 
-    free(properties->hyperlink_base);
+    free((void *)properties->hyperlink_base);
     free(properties);
 
     return workbook_close(workbook);

test/unit/worksheet/test_worksheet_write_auto_filter.c

@@ -458,7 +458,7 @@ CTEST(worksheet, write_write_auto_filter19) {
 
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
-    char* list[] = {"East", NULL};
+    const char* list[] = {"East", NULL};
 
     worksheet_filter_list(worksheet, 0, list);
 
@@ -481,7 +481,7 @@ CTEST(worksheet, write_write_auto_filter20) {
 
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
-    char* list[] = {"East", "North", NULL};
+    const char* list[] = {"East", "North", NULL};
 
     worksheet_filter_list(worksheet, 0, list);
 
@@ -504,7 +504,7 @@ CTEST(worksheet, write_write_auto_filter21) {
 
     worksheet_autofilter(worksheet, 0, 0, 50, 3);
 
-    char* list[] = {"February", "January", "July", "June", NULL};
+    const char* list[] = {"February", "January", "July", "June", NULL};
 
     worksheet_filter_list(worksheet, 3, list);
 

test/unit/worksheet/test_worksheet_write_data_validation1.c

@@ -128,7 +128,7 @@ CTEST(worksheet, write_data_validations04) {
     char* got;
     char exp[] = "<dataValidations count=\"1\"><dataValidation type=\"list\" allowBlank=\"1\" showInputMessage=\"1\" showErrorMessage=\"1\" sqref=\"A4\"><formula1>\"open,high,close\"</formula1></dataValidation></dataValidations>";
     FILE* testfile = lxw_tmpfile(NULL);
-    char *list[] = {"open", "high", "close", NULL};
+    const char* list[] = {"open", "high", "close", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;

test/unit/worksheet/test_worksheet_write_data_validation2.c

@@ -486,7 +486,7 @@ CTEST(worksheet, test_write_data_validations_220) {
     char* got;
     char exp[] = "<dataValidations count=\"1\"><dataValidation type=\"list\" allowBlank=\"1\" showInputMessage=\"1\" showErrorMessage=\"1\" sqref=\"B5\"><formula1>\"a,bb,ccc\"</formula1></dataValidation></dataValidations>";
     FILE* testfile = lxw_tmpfile(NULL);
-    char *list[] = {"a", "bb", "ccc", NULL};
+    const char* list[] = {"a", "bb", "ccc", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;
@@ -509,7 +509,7 @@ CTEST(worksheet, test_write_data_validations_221) {
     char* got;
     char exp[] = "<dataValidations count=\"1\"><dataValidation type=\"list\" allowBlank=\"1\" showDropDown=\"1\" showInputMessage=\"1\" showErrorMessage=\"1\" sqref=\"B5\"><formula1>\"a,bb,ccc\"</formula1></dataValidation></dataValidations>";
     FILE* testfile = lxw_tmpfile(NULL);
-    char *list[] = {"a", "bb", "ccc", NULL};
+    const char* list[] = {"a", "bb", "ccc", NULL};
 
     lxw_data_validation *data_validation = calloc(1, sizeof(lxw_data_validation));
     data_validation->validate = LXW_VALIDATION_TYPE_LIST;