BuildSystem: userspace has cmake target

userspace/test/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(test CXX)
+
+set(TEST_SOURCES
+	test.cpp
+)
+
+add_executable(test ${TEST_SOURCES})
+target_compile_options(test PUBLIC -O2 -g)
+add_dependencies(test libc-install)
+target_link_options(test PUBLIC -nodefaultlibs -lc)
+
+add_custom_target(test-install
+	COMMAND cp ${CMAKE_CURRENT_BINARY_DIR}/test ${BANAN_BIN}/
+	DEPENDS test
+)

userspace/test/test.cpp

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#define ERROR(msg) { perror(msg); return 1; }
+#define BUF_SIZE 1024
+
+int main()
+{
+	printf("%.2e\n", 1230.0);
+	printf("%.2e\n", 123.0);
+	printf("%.2e\n", 12.3);
+	printf("%.2e\n", 1.23);
+	printf("%.2e\n", 0.123);
+	printf("%.2e\n", 0.0123);
+	printf("%.2e\n", 0.00123);
+
+	printf("%e\n", 123.456);
+	printf("%.2e\n", 123.456);
+	printf("%.0e\n", 123.456);
+	printf("%#.0e\n", 123.456);
+
+	printf("%e\n", -123.456);
+	printf("%.2e\n", -123.456);
+	printf("%.0e\n", -123.456);
+	printf("%#.0e\n", -123.456);
+
+	printf("%e\n", 0.0);
+	printf("%e\n", -0.0);
+
+	return 0;
+
+	FILE* fp = fopen("/usr/include/stdio.h", "r");
+	if (fp == NULL)
+		ERROR("fopen");
+
+	char* buffer = (char*)malloc(BUF_SIZE);
+	if (buffer == NULL)
+		ERROR("malloc");
+
+	for (;;)
+	{
+		size_t n_read = fread(buffer, 1, BUF_SIZE - 1, fp);
+		if (n_read == 0)
+			break;
+		buffer[n_read] = '\0';
+		printf("%s", buffer);
+	}
+
+	free(buffer);
+	fclose(fp);
+
+	return 0;
+}