configurator: Inline err.h functions

On systems where err.h is not provided (e.g. MSVC) configurator must
provide its own definition.  The err module can not be used by
configurator due to its dependency on config.h, so the relevant source
is copied into configurator with the minimum changes necessary.

Changes since v2:
- Use the CCAN err module sources instead of musl libc sources to avoid
  introducing another implementation of these functions.
- Prefix err.h functions with "c12r_" to avoid name conflicts and
  "static declaration follows non-static" errors.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tools/configurator/configurator.c

@@ -3,6 +3,9 @@
  *
  * Copyright 2011 Rusty Russell <rusty@rustcorp.com.au>.  MIT license.
  *
+ * c12r_err, c12r_errx functions copied from ccan/err/err.c
+ * Copyright Rusty Russell <rusty@rustcorp.com.au>. CC0 (Public domain) License.
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -23,10 +26,11 @@
  */
 #define _POSIX_C_SOURCE 200809L                /* For pclose, popen, strdup */
 
+#include <errno.h>
 #include <stdio.h>
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdlib.h>
-#include <err.h>
 #include <string.h>
 
 #ifdef _MSC_VER
@@ -46,6 +50,7 @@
 #define DIR_SEP   "/"
 #endif
 
+static const char *progname = "";
 static int verbose;
 
 enum test_style {
@@ -377,6 +382,31 @@ static struct test tests[] = {
 	},
 };
 
+static void c12r_err(int eval, const char *fmt, ...)
+{
+	int err_errno = errno;
+	va_list ap;
+
+	fprintf(stderr, "%s: ", progname);
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, ": %s\n", strerror(err_errno));
+	exit(eval);
+}
+
+static void c12r_errx(int eval, const char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "%s: ", progname);
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+	exit(eval);
+}
+
 static char *grab_stream(FILE *file)
 {
 	size_t max, ret, size = 0;
@@ -390,7 +420,7 @@ static char *grab_stream(FILE *file)
 	}
 	size += ret;
 	if (ferror(file))
-		err(1, "reading from command");
+		c12r_err(1, "reading from command");
 	buffer[size] = '\0';
 	return buffer;
 }
@@ -410,7 +440,7 @@ static char *run(const char *cmd, int *exitstatus)
 
 	cmdout = popen(cmdredir, "r");
 	if (!cmdout)
-		err(1, "popen \"%s\"", cmdredir);
+		c12r_err(1, "popen \"%s\"", cmdredir);
 
 	free(cmdredir);
 
@@ -502,7 +532,7 @@ static bool run_test(const char *cmd, struct test *test)
 
 	outf = fopen(INPUT_FILE, "w");
 	if (!outf)
-		err(1, "creating %s", INPUT_FILE);
+		c12r_err(1, "creating %s", INPUT_FILE);
 
 	fprintf(outf, "%s", PRE_BOILERPLATE);
 	switch (test->style & ~(EXECUTE|MAY_NOT_COMPILE)) {
@@ -567,8 +597,8 @@ static bool run_test(const char *cmd, struct test *test)
 			       status ? "fail" : "warning",
 			       test->name, status, output);
 		if ((test->style & EXECUTE) && !(test->style & MAY_NOT_COMPILE))
-			errx(1, "Test for %s did not compile:\n%s",
-			     test->name, output);
+			c12r_errx(1, "Test for %s did not compile:\n%s",
+				  test->name, output);
 		test->answer = false;
 		free(output);
 	} else {
@@ -578,8 +608,8 @@ static bool run_test(const char *cmd, struct test *test)
 		if ((test->style & EXECUTE) || (test->style & INSIDE_MAIN)) {
 			output = run("." DIR_SEP OUTPUT_FILE, &status);
 			if (!(test->style & EXECUTE) && status != 0)
-				errx(1, "Test for %s failed with %i:\n%s",
-				     test->name, status, output);
+				c12r_errx(1, "Test for %s failed with %i:\n%s",
+					  test->name, status, output);
 			if (verbose && status)
 				printf("%s exited %i\n", test->name, status);
 			free(output);
@@ -603,6 +633,9 @@ int main(int argc, const char *argv[])
 	const char *default_args[]
 		= { "", DEFAULT_COMPILER, DEFAULT_FLAGS, NULL };
 
+	if (argc > 0)
+		progname = argv[0];
+
 	if (argc > 1) {
 		if (strcmp(argv[1], "--help") == 0) {
 			printf("Usage: configurator [-v] [<compiler> <flags>...]\n"