Print warnings

Signed-off-by: Mattias Andrée <maandree@kth.se>

7 files changed, 64 insertions, 17 deletions

diff --git a/common.h b/common.h
index fe0d5ad..1047e2f 100644
--- a/common.h
+++ b/common.h
@@ -6,6 +6,7 @@
 #include <inttypes.h>
 #include <limits.h>
 #include <pwd.h>
+#include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -124,6 +125,18 @@
 
 
 static inline void
+warning(struct libfonts_context *ctx, int err, const char *function, const char *fmt, ...)
+{
+	va_list args;
+	if (ctx && ctx->warning) {
+		va_start(args, fmt);
+		ctx->warning(err, function, fmt, args, ctx->user);
+		va_end(args);
+	}
+}
+
+
+static inline void
 transform(double *x_out, double *y_out, double x, double y, const struct libfonts_transformation *transformation)
 {
 	double a = transformation->m[0][0], b = transformation->m[0][1], c = transformation->m[0][2];
diff --git a/libfonts.h b/libfonts.h
index 2c7202a..f45c203 100644
--- a/libfonts.h
+++ b/libfonts.h
@@ -2,6 +2,7 @@
 #ifndef LIBFONTS_H
 #define LIBFONTS_H
 
+#include <stdarg.h>
 #include <stdint.h>
 #include <unistd.h>
 
@@ -1622,6 +1623,27 @@ struct libfonts_context {
 	 * Only used if `.use_context_uid` is non-zero
 	 */
 	uid_t uid;
+
+	/**
+	 * Application data used in as the last argument
+	 * in callback functions
+	 */
+	void *user;
+
+	/**
+	 * If non-`NULL` some function may call thing
+	 * function to let the application print a
+	 * warning
+	 * 
+	 * @param  err       `errno` value for the warning, 0 if none
+	 * @param  function  The name of the function the warning is emitted from (closest public function)
+	 * @param  fmt       Formattable description of the warning, will start in lower case,
+	 *                   and will end with a colon if and only if a description of `err`
+	 *                   shall be appended to the message (with a preceding space)
+	 * @param  args      Argument used into the description via formatting
+	 * @param  user      `.user` as is
+	 */
+	void (*warning)(int err, const char *function, const char *fmt, va_list args, void *user);
 };
 
 
diff --git a/libfonts_get_default_font.c b/libfonts_get_default_font.c
index 69d2729..e0ad9ab 100644
--- a/libfonts_get_default_font.c
+++ b/libfonts_get_default_font.c
@@ -25,6 +25,7 @@ getn(char **outp, const char *file_part1, size_t file_part1_len, const char *fil
 	char *line, *buf = NULL;
 	size_t size = 0, off = 0, avail = 0;
 	char *value;
+	size_t lineno = 0;
 
 	*outp = NULL;
 
@@ -60,7 +61,7 @@ open_again:
 		case ENODEV:
 		case ENOTDIR:
 		case ENXIO:
-			/* TODO print warning using `ctx` */
+			warning(ctx, errno, "libfonts_get_default_font", "failed to open %s:", path);
 			goto out;
 		default:
 			goto out;
@@ -83,6 +84,7 @@ open_again:
 		if (!len)
 			break;
 		line[len -= 1] = '\0';
+		lineno++;
 
 		while (isblank(*line)) {
 			line++;
@@ -96,13 +98,13 @@ open_again:
 
 		value = libfonts_confsplit__(line);
 		if (!value) {
-			/* TODO warning */
+			warning(ctx, 0, "libfonts_get_default_font", "bad line in %s at line %zu", path, lineno);
 			continue;
 		}
 
 		if (!strcmp(line, name)) {
 			if (*outp) {
-				/* TODO warning */
+				warning(ctx, 0, "libfonts_get_default_font", "duplicate definition in %s at line %zu", path, lineno);
 				free(*outp);
 				*outp = NULL;
 			}
@@ -110,7 +112,7 @@ open_again:
 			if (!*outp)
 				goto fail;
 		} else if (strcmp(line, "sans-serif") && strcmp(line, "serif") && strcmp(line, "monospace")) {
-			/* TODO warning */
+			warning(ctx, 0, "libfonts_get_default_font", "bad font class in %s at line %zu: %s", path, lineno, line);
 		}
 	}
 
diff --git a/libfonts_get_default_rendering_settings.c b/libfonts_get_default_rendering_settings.c
index ebdc51c..f40b1d1 100644
--- a/libfonts_get_default_rendering_settings.c
+++ b/libfonts_get_default_rendering_settings.c
@@ -15,6 +15,7 @@ getn(const char *file_part1, size_t file_part1_len, const char *file_part2,
 	size_t size = 0, off = 0, avail = 0;
 	char *value;
 	unsigned int found_fields = 0;
+	size_t lineno = 0;
 
 	if (file_part1_len > SIZE_MAX - file_part2_len - 1)
 		goto enomem;
@@ -48,7 +49,7 @@ open_again:
 		case ENODEV:
 		case ENOTDIR:
 		case ENXIO:
-			/* TODO print warning using `ctx` */
+			warning(ctx, errno, "libfonts_get_default_rendering_settings", "failed to open %s:", path);
 			goto out;
 		default:
 			goto out;
@@ -68,6 +69,7 @@ open_again:
 		if (!len)
 			break;
 		line[len -= 1] = '\0';
+		lineno++;
 
 		while (isblank(*line))
 			line++;
@@ -79,22 +81,25 @@ open_again:
 
 		value = libfonts_confsplit__(line);
 		if (!value) {
-			/* TODO warning */
+			warning(ctx, 0, "libfonts_get_default_rendering_settings", "bad line in %s at line %zu", path, lineno);
 			continue;
 		}
 
 #define X(INDEX, CONFNAME, CNAME, DEFVAL, PARSER)\
 		if (!strcmp(line, CONFNAME)) {\
 			if (found_fields & (1U << INDEX)) {\
-				/* TODO warning */\
+				warning(ctx, 0, "libfonts_get_default_rendering_settings",\
+				        "duplicate definition in %s at line %zu", path, lineno); \
 			}\
 			found_fields |= (1U << INDEX);\
 			if (!PARSER(&settings->CNAME, value)) {\
-				/* TODO warning */\
+				warning(ctx, 0, "libfonts_get_default_rendering_settings",\
+				        "invalid value in %s at line %zu: %s", path, lineno, value);\
 			}\
 		} else
 		LIST_RENDERING_SETTINGS(X,) {
-			/* TODO warning */
+			warning(ctx, 0, "libfonts_get_default_rendering_settings",\
+			        "bad definition in %s at line %zu: %s", path, lineno, line);\
 		}
 #undef X
 	}
diff --git a/libfonts_get_output_rendering_settings.c b/libfonts_get_output_rendering_settings.c
index 2cecf3c..b9c1efd 100644
--- a/libfonts_get_output_rendering_settings.c
+++ b/libfonts_get_output_rendering_settings.c
@@ -18,6 +18,7 @@ getn(const char *file_part1, size_t file_part1_len, const char *file_part2,
 	int in_a_section = 0;
 	char *value;
 	unsigned int found_fields = 0;
+	size_t lineno = 0;
 
 	if (file_part1_len > SIZE_MAX - file_part2_len - 1)
 		goto enomem;
@@ -51,7 +52,7 @@ open_again:
 		case ENODEV:
 		case ENOTDIR:
 		case ENXIO:
-			/* TODO print warning using `ctx` */
+			warning(ctx, errno, "libfonts_get_default_rendering_settings", "failed to open %s:", path);
 			goto out;
 		default:
 			goto out;
@@ -71,6 +72,7 @@ open_again:
 		if (!len)
 			break;
 		line[len -= 1] = '\0';
+		lineno++;
 
 		while (isblank(*line)) {
 			line++;
@@ -93,7 +95,7 @@ open_again:
 		} else if (!in_a_section) {
 			value = libfonts_confsplit__(line);
 			if (!value) {
-				/* TODO warning */
+				warning(ctx, 0, "libfonts_get_output_rendering_settings", "bad line in %s at line %zu", path, lineno);
 				continue;
 			}
 			/* TODO aliases should be declarable above the first "[%s]" */
@@ -101,21 +103,24 @@ open_again:
 		} else if (in_the_section) {
 			value = libfonts_confsplit__(line);
 			if (!value) {
-				/* TODO warning */
+				warning(ctx, 0, "libfonts_get_output_rendering_settings", "bad line in %s at line %zu", path, lineno);
 				continue;
 			}
 #define X(INDEX, CONFNAME, CNAME, DEFVAL, PARSER)\
 			if (!strcmp(line, CONFNAME)) {\
 				if (found_fields & (1U << INDEX)) {\
-					/* TODO warning */\
+					warning(ctx, 0, "libfonts_get_output_rendering_settings",\
+					        "duplicate definition in %s at line %zu", path, lineno); \
 				}\
 				found_fields |= (1U << INDEX);\
 				if (!PARSER(&settings->CNAME, value)) {\
-					/* TODO warning */\
+					warning(ctx, 0, "libfonts_get_output_rendering_settings",\
+					        "invalid value in %s at line %zu: %s", path, lineno, value);\
 				}\
 			} else
 			LIST_RENDERING_SETTINGS(X,) {
-				/* TODO warning */
+				warning(ctx, 0, "libfonts_get_output_rendering_settings",\
+				        "bad definition in %s at line %zu: %s", path, lineno, line);\
 			}
 #undef X
 		}
diff --git a/libfonts_parse_aa__.c b/libfonts_parse_aa__.c
index 0ed9a3d..8394a56 100644
--- a/libfonts_parse_aa__.c
+++ b/libfonts_parse_aa__.c
@@ -36,7 +36,7 @@ main(void)
 			ASSERT(res == C);\
 			strcpy(buf, S);\
 			for (i = 0; buf[i]; i++)\
-				buf[i] = toupper(buf[i]);\
+				buf[i] = (char)toupper(buf[i]);\
 			res = 999;\
 			ASSERT(libfonts_parse_aa__(&res, buf) == 1);\
 			ASSERT(res == C);\
diff --git a/libfonts_parse_order__.c b/libfonts_parse_order__.c
index 349347e..906c4a9 100644
--- a/libfonts_parse_order__.c
+++ b/libfonts_parse_order__.c
@@ -37,7 +37,7 @@ main(void)
 			ASSERT(res == C);\
 			strcpy(buf, S);\
 			for (i = 0; buf[i]; i++)\
-				buf[i] = toupper(buf[i]);\
+				buf[i] = (char)toupper(buf[i]);\
 			res = 999;\
 			ASSERT(libfonts_parse_order__(&res, buf) == 1);\
 			ASSERT(res == C);\