Add popen(3)/pclose(3), add missing signatures to headers

Makefile

@@ -12,6 +12,8 @@ SHARED_LIBS=
 
 # Build
 CFLAGS=-I include \
+	   -ggdb \
+	   -Og \
 	   -ffreestanding \
 	   -Wall \
 	   -Wextra \

include/math.h

@@ -3,4 +3,23 @@
 #define HUGE_VAL        (__builtin_huge_val())
 
 double log10(double f);
+double log2(double f);
 double log(double f);
+double sqrt(double f);
+double floor(double f);
+double ceil(double f);
+double fmod(double x, double y);
+double atan2(double x, double y);
+double asin(double x);
+double acos(double x);
+double fabs(double x);
+double pow(double x, double y);
+double tanh(double f);
+double cosh(double f);
+double sinh(double f);
+double sin(double f);
+double cos(double f);
+double tan(double f);
+double frexp(double x, int *exp);
+double ldexp(double x, int exp);
+double exp(double f);

include/setjmp.h

@@ -4,5 +4,7 @@ typedef struct {
     unsigned long _v[8];
 } jmp_buf[1];
 
+int _setjmp(jmp_buf env);
 int setjmp(jmp_buf env);
+void _longjmp(jmp_buf env, int val);
 void longjmp(jmp_buf env, int val);

include/stdio.h

@@ -34,6 +34,12 @@ int    renameat(int olddfd, const char *oldpath, int newdfd, const char *newpath
 char  *ctermid(char *s);
 int    setvbuf(FILE *fp, char *buf, int mode, size_t size);
 void   setbuf(FILE *fp, char *buf);
+int    ungetc(int ch, FILE *fp);
+
+FILE  *tmpfile(void);
+
+FILE  *popen(const char *command, const char *type);
+int    pclose(FILE *fp);
 
 void   flockfile(FILE *fp);
 void   funlockfile(FILE *fp);

include/stdlib.h

@@ -11,12 +11,15 @@ __Malloc void *calloc(size_t size, size_t nmemb);
 __Malloc void *malloc(size_t size);
 void *realloc(void *p, size_t newsz);
 void free(void *ptr);
+_Noreturn void abort(void);
+int abs(int d);
+
+int system(const char *command);
 
 int atoi(const char *str);
 
 char *getenv(const char *name);
 int setenv(const char *name, const char *value, int overwrite);
 
-// XXX: POSIX doesn't define _Noreturn attribute on those?
-void _Exit(int status);
-void exit(int status);
+_Noreturn void _Exit(int status);
+_Noreturn void exit(int status);

include/time.h

@@ -23,4 +23,6 @@ time_t time(time_t *t);
 double difftime(time_t t1, time_t t0);
 
 struct tm *gmtime_r(const time_t *restrict timep, struct tm *restrict res);
+struct tm *localtime_r(const time_t *restrict timep, struct tm *restrict res);
+time_t mktime(struct tm *tm);
 size_t strftime(char *restrict buf, size_t lim, const char *restrict fmt, const struct tm *restrict tm);

src/malloc/calloc.c

@@ -0,0 +1,10 @@
+#include <stdlib.h>
+#include <string.h>
+
+void *calloc(size_t size, size_t nmemb) {
+    void *blk = malloc(size * nmemb);
+    if (blk) {
+        memset(blk, 0, size * nmemb);
+    }
+    return blk;
+}

src/stdio/fflush.c

@@ -2,6 +2,10 @@
 #include <stdio.h>
 
 int fflush(FILE *fp) {
+    if (!fp) {
+        // TODO: flush all open files
+        return 0;
+    }
     if (fp->buf_mode != _IONBF) {
         if (__libc_file_flush_read(fp) != 0) {
             return -1;

src/stdio/file.c

@@ -20,6 +20,7 @@ FILE *__libc_file_create(void) {
 
     res->free = file_default_free;
     res->buf = ((void *) res) + sizeof(FILE);
+    res->buf_mode = _IOLBF;
     res->ungetc = -1;
 
     return res;

src/stdio/getdelim.c

@@ -23,6 +23,7 @@ ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *fp) {
     }
 
     p = *lineptr;
+    rem = *n;
 
     while (1) {
         if (!rem) {

src/stdio/pclose.c

@@ -1,6 +1,5 @@
 #include <stdio.h>
 
 int pclose(FILE *fp) {
-    (void) fp;
-    return 0;
+    return fclose(fp);
 }

src/stdio/popen.c

@@ -1,9 +1,113 @@
+#include <_libc/stdio.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdlib.h>
 #include <errno.h>
 #include <stdio.h>
 
+// Internal pipe state
+struct pipe {
+    int fd;
+    pid_t pid;
+};
+
+static ssize_t pipe_read(void *ctx, void *buf, size_t lim) {
+    return read(((struct pipe *) ctx)->fd, buf, lim);
+}
+
+static ssize_t pipe_write(void *ctx, const void *buf, size_t lim) {
+    return write(((struct pipe *) ctx)->fd, buf, lim);
+}
+
+static off_t pipe_seek(void *ctx, off_t offset, int whence) {
+    (void) ctx;
+    (void) offset;
+    (void) whence;
+    errno = ESPIPE;
+    return -1;
+}
+
+static int pipe_close(void *_ctx) {
+    struct pipe *ctx = _ctx;
+    close(ctx->fd);
+    int r;
+    if (waitpid(ctx->pid, &r, 0) < 0) {
+        return -1;
+    }
+    free(ctx);
+    return r;
+}
+
 FILE *popen(const char *command, const char *mode) {
-    (void) command;
-    (void) mode;
-    errno = EINVAL;
+    int fds[2];
+    struct pipe *ctx;
+    FILE *fp = NULL;
+    int flags = __libc_file_mode(mode);
+    if (flags < 0) {
+        errno = EINVAL;
+        return NULL;
+    }
+    if ((flags & (FILE_MODE_WRITE | FILE_MODE_READ)) == (FILE_MODE_READ | FILE_MODE_WRITE)) {
+        errno = EINVAL;
+        return NULL;
+    }
+
+    if (!(ctx = calloc(1, sizeof(struct pipe)))) {
+        goto err;
+    }
+    if (!(fp = __libc_file_create())) {
+        goto err_ctx;
+    }
+    if (pipe(fds) != 0) {
+        goto err_file;
+    }
+    if ((ctx->pid = fork()) == -1) {
+        goto err_pipe;
+    }
+
+    if (ctx->pid == 0) {
+        // In child
+        if (flags & FILE_MODE_WRITE) {
+            if (dup2(fds[0], STDIN_FILENO) < 0) {
+                _exit(-1);
+            }
+        } else {
+            if (dup2(fds[1], STDOUT_FILENO) < 0) {
+                _exit(-1);
+            }
+        }
+        close(fds[0]);
+        close(fds[1]);
+
+        _exit(execl("/bin/sh", "sh", "-c", command, NULL));
+    }
+
+    if (flags & FILE_MODE_WRITE) {
+        close(fds[0]);
+        ctx->fd = fds[1];
+        fp->flags = FILE_MODE_WRITE;
+    } else {
+        close(fds[1]);
+        ctx->fd = fds[0];
+        fp->flags = FILE_MODE_READ;
+    }
+
+    fp->ctx = ctx;
+    fp->read = pipe_read;
+    fp->write = pipe_write;
+    fp->seek = pipe_seek;
+    fp->close = pipe_close;
+
+    return fp;
+
+    // TODO: preserve errno here
+err_pipe:
+    close(fds[0]);
+    close(fds[1]);
+err_file:
+    fclose(fp);
+err_ctx:
+    free(ctx);
+err:
     return NULL;
 }

src/time/time.c

@@ -6,5 +6,5 @@ time_t time(time_t *t) {
     if (gettimeofday(&now, NULL) != 0) {
         return -1;
     }
-    return t ? *t = now.tv_sec : now.tv_sec;
+    return t ? *t = (time_t) now.tv_sec : (time_t) now.tv_sec;
 }