Miscellaneous compat work while seeing if GNU coreutils would build.

LibC/Makefile

@@ -25,6 +25,7 @@ LIBC_OBJS = \
        termcap.o \
        setjmp.o \
        stat.o \
+       mntent.o \
        entry.o
 
 OBJS = $(AK_OBJS) $(LIBC_OBJS)

LibC/errno_numbers.h

@@ -37,6 +37,8 @@
     __ERROR(ENAMETOOLONG,   "Name too long") \
     __ERROR(ELOOP,          "Too many symlinks") \
     __ERROR(EOVERFLOW,      "Overflow") \
+    __ERROR(EOPNOTSUPP,     "Operation not supported") \
+    __ERROR(ENOSYS,         "No such syscall") \
     __ERROR(ENOTIMPL,       "Not implemented") \
 
 enum __errno_values {

LibC/limits.h

@@ -1,3 +1,8 @@
 #pragma once
 
+#include <stdint.h>
+
 #define PATH_MAX 4096
+
+#define INT_MAX INT32_MAX
+#define INT_MIN INT32_MIN

LibC/mntent.cpp

@@ -0,0 +1,13 @@
+#include <mntent.h>
+#include <assert.h>
+
+extern "C" {
+
+struct mntent* getmntent(FILE* stream)
+{
+    assert(false);
+    return nullptr;
+}
+
+}
+

LibC/mntent.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <sys/cdefs.h>
+#include <stdio.h>
+
+__BEGIN_DECLS
+
+#define MOUNTED "/etc/mtab"
+#define MNTTAB "/etc/fstab"
+
+struct mntent {
+    char* mnt_fsname;
+    char* mnt_dir;
+    char* mnt_type;
+    char* mnt_opts;
+    int mnt_freq;
+    int mnt_passno;
+};
+
+struct mntent* getmntent(FILE* stream);
+
+__END_DECLS
+

LibC/stddef.h

@@ -0,0 +1,4 @@
+#pragma once
+
+#include <sys/cdefs.h>
+#include <sys/types.h>

LibC/stdint.h

@@ -12,5 +12,15 @@ typedef signed int int32_t;
 typedef signed short int16_t;
 typedef signed char int8_t;
 
+#define INT8_MIN (-128)
+#define INT16_MIN (-32767-1)
+#define INT32_MIN (-2147483647-1)
+#define INT8_MAX (127)
+#define INT16_MAX (32767)
+#define INT32_MAX (2147483647)
+#define UINT8_MAX (255)
+#define UINT16_MAX (65535)
+#define UINT32_MAX (4294967295U)
+
 __END_DECLS
 

LibC/stdio.cpp

@@ -72,6 +72,8 @@ int fputc(int ch, FILE* stream)
 {
     assert(stream);
     write(stream->fd, &ch, 1);
+    if (stream->eof)
+        return EOF;
     return (byte)ch;
 }
 
@@ -85,10 +87,31 @@ int putchar(int ch)
     return putc(ch, stdout);
 }
 
+int fputs(const char* s, FILE* stream)
+{
+    for (; *s; ++s) {
+        int rc = putc(*s, stream);
+        if (rc == EOF)
+            return EOF;
+    }
+    return putc('\n', stream);
+}
+
+int puts(const char* s)
+{
+    fputs(s, stdout);
+}
+
 void clearerr(FILE* stream)
 {
     assert(stream);
     stream->eof = false;
+    stream->error = false;
+}
+
+int ferror(FILE* stream)
+{
+    return stream->error;
 }
 
 size_t fread(void* ptr, size_t size, size_t nmemb, FILE* stream)
@@ -190,6 +213,7 @@ FILE* fopen(const char* pathname, const char* mode)
     auto* fp = (FILE*)malloc(sizeof(FILE));
     fp->fd = fd;
     fp->eof = false;
+    fp->error = 0;
     return fp;
 }
 
@@ -201,6 +225,7 @@ FILE* fdopen(int fd, const char* mode)
     auto* fp = (FILE*)malloc(sizeof(FILE));
     fp->fd = fd;
     fp->eof = false;
+    fp->error = 0;
     return fp;
 }
 

LibC/stdio.h

@@ -16,6 +16,7 @@ __BEGIN_DECLS
 struct __STDIO_FILE {
     int fd;
     int eof;
+    int error;
 };
 
 typedef struct __STDIO_FILE FILE;
@@ -34,6 +35,7 @@ FILE* fopen(const char* pathname, const char* mode);
 int fclose(FILE*);
 void rewind(FILE*);
 void clearerr(FILE*);
+int ferror(FILE*);
 int feof(FILE*);
 int fflush(FILE*);
 size_t fread(void* ptr, size_t size, size_t nmemb, FILE*);
@@ -42,6 +44,9 @@ int fprintf(FILE*, const char* fmt, ...);
 int printf(const char* fmt, ...);
 int sprintf(char* buffer, const char* fmt, ...);
 int putchar(int ch);
+int putc(int ch, FILE*);
+int puts(const char*);
+int fputs(const char*, FILE*);
 void perror(const char*);
 int sscanf (const char* buf, const char* fmt, ...);
 int fscanf(FILE*, const char* fmt, ...);

LibC/sys/stat.h

@@ -6,5 +6,6 @@
 __BEGIN_DECLS
 
 mode_t umask(mode_t);
+int chmod(const char* pathname, mode_t);
 
 __END_DECLS

LibC/sys/types.h

@@ -22,8 +22,8 @@ typedef uint32_t blksize_t;
 typedef uint32_t blkcnt_t;
 typedef uint32_t time_t;
 typedef uint32_t suseconds_t;
-
 typedef uint32_t clock_t;
+typedef uint32_t socklen_t;
 
 struct timeval {
     time_t tv_sec;