initial import of the C runtime

src/runtime/c/gu/log.c

@@ -0,0 +1,79 @@
+#include <gu/defs.h>
+#include <gu/log.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+static int gu_log_depth = 0;
+
+static bool
+gu_log_match(const char* pat, size_t patlen, const char* str)
+{
+	if (patlen > 0 && pat[patlen-1] == '*') {
+		return strncmp(pat, str, patlen-1) == 0;
+	} else if (strlen(str) == patlen) {
+		return strncmp(pat, str, patlen) == 0;
+	} 
+	return false;
+}
+
+static bool
+gu_log_enabled(const char* func, const char* file)
+{
+	const char* cfg = getenv("GU_LOG");
+	if (cfg == NULL) {
+		return false;
+	}
+	const char* p = cfg;
+	while (true) {
+		size_t len = strcspn(p, ",");
+		if (gu_log_match(p, len, func)) {
+			return true;
+		}
+		if (gu_log_match(p, len, file)) {
+			return true;
+		}
+		if (p[len] == '\0') {
+			break;
+		}
+		p = &p[len + 1];
+	} 
+	return false;
+}
+
+
+void
+gu_log_full_v(GuLogKind kind, const char* func, const char* file, int line,
+	      const char* fmt, va_list args)
+{
+	(void) (kind && line);
+	if (!gu_log_enabled(func, file)) {
+		return;
+	}
+	if (kind == GU_LOG_KIND_EXIT) {
+		gu_log_depth--;
+	}
+	if (fmt) {
+		int indent = gu_min(32 + gu_log_depth, 48);
+		fprintf(stderr, "%-*s: ", indent, func);
+		vfprintf(stderr, fmt, args);
+		fputc('\n', stderr);
+		fflush(stderr);
+	}
+	if (kind == GU_LOG_KIND_ENTER) {
+		gu_log_depth++;
+	}
+}
+
+void
+gu_log_full(GuLogKind kind, const char* func, const char* file, int line,
+	    const char* fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	gu_log_full_v(kind, func, file, line, fmt, args);
+	va_end(args);
+}
+