X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/e92ef179a31b2357ec1dcec634767d7d1eed97e3..247d234f2e263700e0a7ce7f6c9219d010c182ca:/src/error.c

diff --git a/src/error.c b/src/error.c
index fe0695c..36e6366 100644
--- a/src/error.c
+++ b/src/error.c
@@ -1,6 +1,6 @@
 /*
  *  Error handling for libcdecl.
- *  Copyright © 2011-2012, 2021 Nick Bowler
+ *  Copyright © 2011-2012, 2021, 2023 Nick Bowler
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -19,9 +19,7 @@
 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <assert.h>
-#include <stdarg.h>
 
 #include "cdecl.h"
 #include "cdecl-internal.h"
@@ -29,7 +27,9 @@
 #include <glthread/lock.h>
 #include <glthread/tls.h>
 
-gl_once_define(static, tls_initialized);
+#include "errmsg.h"
+
+gl_once_define(static, tls_initialized)
 static gl_tls_key_t tls_key;
 
 struct err_state {
@@ -38,13 +38,8 @@ struct err_state {
 	char str[FLEXIBLE_ARRAY_MEMBER];
 };
 
-/* This error is reserved for extremely dire out-of-memory conditions. */
-static struct err_state err_no_mem = {
-	.err = {
-		.code = CDECL_ENOMEM,
-		.str  = NULL,
-	},
-};
+/* This pre-initialized error is reserved for dire out-of-memory conditions. */
+static struct cdecl_error err_no_mem;
 
 static void free_err(void *err)
 {
@@ -54,71 +49,100 @@ static void free_err(void *err)
 	free(err);
 }
 
+static void set_err(unsigned code, struct cdecl_error *err)
+{
+	static const char errmsgs[] = STRTAB_INITIALIZER;
+
+	switch (code) {
+	case CDECL__ENOMEM:
+		err->code = CDECL_ENOMEM;
+		break;
+	default:
+		err->code = CDECL_ENOPARSE;
+		break;
+	}
+
+	err->str = _(&errmsgs[code]);
+}
+
 static void initialize(void)
 {
 	cdecl__init_i18n();
-	err_no_mem.err.str = _("failed to allocate memory");
-
+	set_err(CDECL__ENOMEM, &err_no_mem);
 	gl_tls_key_init(tls_key, free_err);
 }
 
-/*
- * cdecl__err(CDECL_ENOMEM);
- * cdecl__err(code, fmt, ...);
- *
- * Sets the library error to code, with a printf-style error string.
- */
-void cdecl__err(unsigned code, ...)
+static void *alloc_err_state(void *old, size_t buf_size)
 {
-	const char *fmt;
 	struct err_state *state;
-	int rc, try = 0;
-	va_list ap;
+	void *p;
+
+	state = p = realloc(old, offsetof(struct err_state, str) + buf_size);
+	if (state) {
+		state->nstr = buf_size;
+	} else if (old) {
+		/* Failed allocation, but existing state is still good */
+		p = old;
+	} else {
+		/* Failed allocation, no existing state */
+		p = &err_no_mem;
+	}
+
+	gl_tls_set(tls_key, p);
+	return state;
+}
+
+static struct err_state *get_err_state(void)
+{
+	void *state;
 
 	gl_once(tls_initialized, initialize);
 
 	state = gl_tls_get(tls_key);
-	if (!state || state == &err_no_mem) {
-		void *tmp = malloc(sizeof *state + 100);
-
-		if (!tmp) {
-			state = &err_no_mem;
-			return;
-		}
+	if (state == &err_no_mem)
+		state = NULL;
+	if (!state)
+		return alloc_err_state(state, 100);
+	return state;
+}
 
-		gl_tls_set(tls_key, (state = tmp));
-		state->nstr = 100;
-	}
+/*
+ * Set the library error to one of the preset messages defined in errmsg.h
+ * (CDECL__Exxx).
+ */
+void cdecl__errmsg(unsigned msg)
+{
+	struct err_state *state;
 
-	if (code == CDECL_ENOMEM) {
-		if (state != &err_no_mem)
-			state->err = err_no_mem.err;
+	state = get_err_state();
+	if (!state)
 		return;
-	}
-retry:
-	va_start(ap, code);
-	fmt = va_arg(ap, const char *);
-	rc = vsnprintf(state->str, state->nstr, fmt, ap);
-	va_end(ap);
 
-	if (rc > 0 && rc >= state->nstr) {
-		void *tmp;
-		size_t n;
+	set_err(msg, &state->err);
+}
 
-		assert(try == 0 && rc < SIZE_MAX / 4);
+/*
+ * Sets the library error to code; fmt is a printf-style string that may use
+ * up to one %s directive, to refer to arg.
+ */
+void cdecl__err(unsigned code, const char *fmt, const char *arg)
+{
+	struct err_state *state;
+	int rc, try = 0;
 
-		n = ((size_t)rc + 1) * 2;
-		tmp = realloc(state, sizeof *state + n);
-		if (tmp) {
-			state = tmp;
-			state->nstr = n;
-			try++;
+	state = get_err_state();
+	if (!state)
+		return;
 
-			goto retry;
-		}
+retry:
+	rc = snprintf(state->str, state->nstr, fmt, arg);
+	if (rc > 0 && rc >= state->nstr) {
+		assert(try++ == 0 && rc < SIZE_MAX / 4);
+		state = alloc_err_state(state, (size_t)(rc+1u) * 3 / 2);
+		if (!state)
+			return;
 
-		state->err = err_no_mem.err;
-		return;
+		goto retry;
 	}
 
 	state->err.str = state->str;
@@ -127,10 +151,7 @@ retry:
 
 const struct cdecl_error *cdecl_get_error(void)
 {
-	struct err_state *state;
+	struct err_state *state = get_err_state();
 
-	gl_once(tls_initialized, initialize);
-
-	state = gl_tls_get(tls_key);
 	return state ? &state->err : NULL;
 }