shared: clean up printf, %u support (amongst other things)

8 files changed, 158 insertions, 72 deletions

diff --git a/src/kernel/arch/amd64/boot.c b/src/kernel/arch/amd64/boot.c
index 301df52..570cebb 100644
--- a/src/kernel/arch/amd64/boot.c
+++ b/src/kernel/arch/amd64/boot.c
@@ -53,8 +53,7 @@ void kmain_early(struct multiboot_info *multiboot) {
 	vid.height = multiboot->framebuffer_height;
 	vid.bpp    = multiboot->framebuffer_bpp;
 
-	// TODO printf decimal
-	kprintf("framebuffer at 0x%x, %xx%x bpp 0x%x\n", vid.b, vid.width, vid.height, vid.bpp);
+	kprintf("framebuffer at 0x%x, %ux%u bpp %u\n", vid.b, vid.width, vid.height, vid.bpp);
 	video_init(vid);
 
 
diff --git a/src/shared/printf.c b/src/shared/printf.c
index b50d4ef..47d56f8 100644
--- a/src/shared/printf.c
+++ b/src/shared/printf.c
@@ -1,71 +1,133 @@
+#include <stdbool.h>
 #include <shared/mem.h>
 #include <shared/printf.h>
 
+struct out_state {
+	void (*back)(void *, const char *, size_t);
+	void *backarg;
+	int written;
+};
+
+static int output(struct out_state *os, const char *buf, size_t len) {
+	if (len) os->back(os->backarg, buf, len);
+	os->written += len;
+	return os->written;
+}
+
+static void output_c(struct out_state *os, char c) {
+	output(os, &c, 1);
+}
+
+
+struct mods {
+	char fill_char;
+	size_t field_width;
+};
+
+static void pad(struct out_state *os, struct mods *m, size_t len) {
+	for (size_t i = 0; len + i < m->field_width; i++)
+		output(os, &m->fill_char, 1);
+}
+
+static void output_uint(struct out_state *os, struct mods *m, unsigned long long n) {
+	// TODO static assert sizeof(unsigned long long) <= 8
+	char buf[20];
+	size_t pos = sizeof(buf);
+
+	if (!n) {
+		buf[--pos] = '0';
+	} else while (n) {
+		unsigned long long q = n / 10, r = n % 10;
+		buf[--pos] = r + '0';
+		n = q;
+	}
+	pad(os, m, sizeof(buf) - pos);
+	output(os, buf + pos, sizeof(buf) - pos);
+}
+
+
 int __printf_internal(const char *fmt, va_list argp,
-		void (*back)(void*, const char*, size_t), void *back_arg)
+		void (*back)(void*, const char*, size_t), void *backarg)
 {
-	const char *seg = fmt; // beginning of the current segment
-	int total = 0;
+	const char *seg = fmt; /* beginning of the current non-modifier streak */
+	struct out_state os = {
+		.back = back,
+		.backarg = backarg,
+	};
 
 	for (;;) {
 		char c = *fmt++;
+		if (c == '\0') {
+			return output(&os, seg, fmt - seg - 1);
+		}
+		if (c != '%') continue;
+		output(&os, seg, fmt - seg - 1);
+
+		struct mods m = {
+			.fill_char = ' ',
+			.field_width = 0,
+		};
+
+		for (bool modifier = true; modifier;) {
+			c = *fmt++;
+			switch (c) {
+				case '0':
+					m.fill_char = '0';
+					break;
+				default:
+					modifier = false;
+					break;
+			}
+		}
+
+		while ('0' <= c && c <= '9') {
+			m.field_width *= 10;
+			m.field_width += c - '0';
+			c = *fmt++;
+		}
+
+		// TODO length modifiers
+
 		switch (c) {
-			case '\0':
-				back(back_arg, seg, fmt - seg - 1);
-				return total + (fmt - seg - 1);
+			unsigned long n, len;
 
-			case '%':
-				back(back_arg, seg, fmt - seg - 1);
-				total += fmt - seg - 1;
-				size_t pad_len = 0;
-
-				c = *fmt++;
-				while (1) {
-					switch (c) {
-						case '0':
-							pad_len = *fmt++ - '0'; // can skip over the null byte, idc
-							break;
-						default:
-							goto modifier_break;
-					}
-					c = *fmt++;
+			case 'c':
+				output_c(&os, va_arg(argp, int));
+				break;
+
+			case 's':
+				const char *s = va_arg(argp, char*);
+				if (s) {
+					len = strlen(s);
+					pad(&os, &m, len);
+					output(&os, s, len);
+				} else {
+					pad(&os, &m, 0);
 				}
-modifier_break:
-				switch (c) {
-					case 'c':
-						char c = va_arg(argp, int);
-						back(back_arg, &c, 1);
-						total += 1;
-						break;
-
-					case 's':
-						const char *s = va_arg(argp, char*);
-						if (s) {
-							back(back_arg, s, strlen(s));
-							total += strlen(s);
-						}
-						break;
-
-					case 'x':
-						unsigned long n = va_arg(argp, long);
-						size_t i = 4; // nibbles * 4
-						while (n >> i && i < (sizeof(n) * 8))
-							i += 4;
-
-						if (i < pad_len * 4)
-							i = pad_len * 4;
-
-						while (i > 0) {
-							i -= 4;
-							char h = '0' + ((n >> i) & 0xf);
-							if (h > '9') h += 'a' - '9' - 1;
-							back(back_arg, &h, 1);
-							total++;
-						}
-						break;
+				break;
+
+			case 'x':
+				n = va_arg(argp, unsigned long);
+				len = 1;
+				while (n >> (len * 4) && (len * 4) < (sizeof(n) * 8))
+					len++;
+				pad(&os, &m, len);
+				while (len-- > 0) {
+					char h = '0' + ((n >> (len * 4)) & 0xf);
+					if (h > '9') h += 'a' - '9' - 1;
+					output_c(&os, h);
 				}
-				seg = fmt;
+				break;
+
+			case 'u':
+				n = va_arg(argp, unsigned long);
+				output_uint(&os, &m, n);
+				break;
+
+			case '%':
+				output(&os, "%", 1);
 				break;
 		}
+		seg = fmt;
 	}
 }
diff --git a/src/user/app/iostress/iostress.c b/src/user/app/iostress/iostress.c
index 843a19a..27e9d33 100644
--- a/src/user/app/iostress/iostress.c
+++ b/src/user/app/iostress/iostress.c
@@ -18,7 +18,7 @@ int main(void) {
 	}
 
 	for (int i = 0; i < NUM_RUNS; i++) {
-		printf("run %x: %x\n", i, results[i] / 3000);
+		printf("run %u: %u\n", i, results[i] / 3000);
 	}
 
 	return 0;
diff --git a/src/user/app/shell/shell.c b/src/user/app/shell/shell.c
index 6eb328f..66725a1 100644
--- a/src/user/app/shell/shell.c
+++ b/src/user/app/shell/shell.c
@@ -51,7 +51,7 @@ static void run_args(int argc, char **argv, struct redir *redir) {
 		uint64_t div = 3000;
 		run_args(argc - 1, argv + 1, redir);
 		time = __rdtsc() - time;
-		printf("0x%x ns (assuming 3GHz)\n", time / div);
+		printf("%u ns (assuming 3GHz)\n", time / div);
 		return;
 	} else if (!strcmp(argv[0], "exit")) {
 		exit(0);
diff --git a/src/user/app/testelf/main.c b/src/user/app/testelf/main.c
index 5111791..aa1f596 100644
--- a/src/user/app/testelf/main.c
+++ b/src/user/app/testelf/main.c
@@ -5,8 +5,8 @@ const char *str = "Hello!", *str2 = "World.";
 int main(int argc, char **argv, char **envp) {
 	printf("elftest's &main == 0x%x\n", &main);
 	printf("%s %s\n", str, str2);
-	printf("argc == 0x%x\n", argc);
+	printf("argc == %u\n", argc);
 	for (int i = 0; i < argc; i++)
-		printf("argv[0x%x] == 0x%x == \"%s\"\n", i, argv[i], argv[i]);
+		printf("argv[%u] == 0x%x == \"%s\"\n", i, argv[i], argv[i]);
 	return 0;
 }
diff --git a/src/user/app/tests/printf.c b/src/user/app/tests/printf.c
new file mode 100644
index 0000000..6c6c609
--- /dev/null
+++ b/src/user/app/tests/printf.c
@@ -0,0 +1,32 @@
+#define TEST_MACROS
+#include "tests.h"
+#include <stdio.h>
+#include <string.h>
+
+void test_printf(void) {
+	char buf[64];
+	memset(buf, '?', 64);
+
+	/* test proper overflow handling in snprintf */
+	assert(13 == snprintf(buf, 15, "That's 0x%x", 0x1337));
+	assert(!memcmp(buf, "That's 0x1337\0??", 16));
+	assert(17 == snprintf(buf, 15, "%05x %05x %05x", 0, 0, 0));
+	assert(!memcmp(buf, "00000 00000 00\0?", 16));
+
+	/* all the other stuff */
+	snprintf(buf, sizeof buf, "%010x", 0x1BABE);
+	assert(!strcmp(buf, "000001babe"));
+	snprintf(buf, sizeof buf, "%10x", 0x1BABE);
+	assert(!strcmp(buf, "     1babe"));
+	snprintf(buf, sizeof buf, "%10s", "hello");
+	assert(!strcmp(buf, "     hello"));
+
+	snprintf(buf, sizeof buf, "%s%%%s", "ab", "cd");
+	assert(!strcmp(buf, "ab%cd"));
+
+	snprintf(buf, sizeof buf, "%05u %05u", 1234, 56789);
+	assert(!strcmp(buf, "01234 56789"));
+
+	snprintf(buf, sizeof buf, "%u %x", 0, 0);
+	assert(!strcmp(buf, "0 0"));
+}
diff --git a/src/user/app/tests/tests.c b/src/user/app/tests/tests.c
index 4390747..f8abc49 100644
--- a/src/user/app/tests/tests.c
+++ b/src/user/app/tests/tests.c
@@ -237,15 +237,6 @@ static void test_execbuf(void) {
 	test_fail();
 }
 
-static void test_snprintf(void) {
-	char buf[16];
-	memset(buf, '?', 16);
-	assert(13 == snprintf(buf, 15, "That's 0x%x", 0x1337));
-	assert(!memcmp(buf, "That's 0x1337\0??", 16));
-	assert(17 == snprintf(buf, 15, "%05x %05x %05x", 0, 0, 0));
-	assert(!memcmp(buf, "00000 00000 00\0?", 16));
-}
-
 static void test_misc(void) {
 	assert(_syscall(~0, 0, 0, 0, 0, 0) < 0); /* try making an invalid syscall */
 }
@@ -263,7 +254,7 @@ int main(void) {
 	run_forked(test_semaphore);
 	run_forked(test_efault);
 	run_forked(test_execbuf);
-	run_forked(test_snprintf);
+	run_forked(test_printf);
 	run_forked(test_misc);
 	return 1;
 }
diff --git a/src/user/app/tests/tests.h b/src/user/app/tests/tests.h
index 39294eb..5f36fe0 100644
--- a/src/user/app/tests/tests.h
+++ b/src/user/app/tests/tests.h
@@ -1,18 +1,20 @@
 #pragma once
 #include <camellia/syscalls.h>
 #include <stdio.h>
+#include <unistd.h>
 
 void stress_all(void);
 void test_all(void);
 
 void test_pipe(void);
+void test_printf(void);
 void test_semaphore(void);
 
 #ifdef TEST_MACROS
 
 #define argify(str) str, sizeof(str) - 1
 #define test_fail() do { \
-	printf("\033[31m" "TEST FAILED: %s:%xh\n" "\033[0m", __func__, __LINE__); \
+	printf("\033[31m" "TEST FAILED: %s():%u\n" "\033[0m", __func__, __LINE__); \
 	exit(0); \
 } while (0)
 #define assert(cond) if (!(cond)) test_fail();