Change output_write() to writebuf(), add readbuf() helper.

* src/misc.c (writebuf, readbuf): Create helper functions that will
reliably write a buffer to a file descriptor in the face of EINTR
causing short writes, and read from a file descriptor into a buffer
in the face of EINTR causing short reads.
* src/makeint.h: Declare these functions.
* src/output.c: Remove output_write() and replace with writebuf().
(_outputs, out_of_memory): Call writebuf(), not output_write().
* src/arscan.c (ar_scan): Call readbuf() instead of read(2).
(ar_member_touch): Remove duplicate header write, call writebuf()
instead of output_write(), and readbuf() instead of read(2).

diff --git a/src/arscan.c b/src/arscan.c
index 22c5438ffda3955fd67a889afaa819490d029a61..9487917162460b56808b970d5ed029b91192526e 100644 (file)
--- a/src/arscan.c
+++ b/src/arscan.c
@@ -425,7 +425,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
   {
     char buf[SARMAG];
     int nread;
-    EINTRLOOP (nread, read (desc, buf, SARMAG));
+    nread = readbuf (desc, buf, SARMAG);
     if (nread != SARMAG || memcmp (buf, ARMAG, SARMAG))
       goto invalid;
   }
@@ -433,7 +433,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
 #ifdef AIAMAG
   {
     int nread;
-    EINTRLOOP (nread, read (desc, &fl_header, FL_HSZ));
+    nread = readbuf (desc, &fl_header, FL_HSZ);
     if (nread != FL_HSZ)
       goto invalid;
 
@@ -452,7 +452,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
           goto invalid;
 
         /* re-read the header into the "big" structure */
-        EINTRLOOP (nread, read (desc, &fl_header_big, FL_HSZ_BIG));
+        nread = readbuf (desc, &fl_header_big, FL_HSZ_BIG);
         if (nread != FL_HSZ_BIG)
           goto invalid;
       }
@@ -470,7 +470,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
     unsigned short int buf;
 #endif
     int nread;
-    EINTRLOOP (nread, read (desc, &buf, sizeof (buf)));
+    nread = readbuf (desc, &buf, sizeof (buf));
     if (nread != sizeof (buf) || buf != ARMAG)
       goto invalid;
   }
@@ -550,8 +550,8 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
 #ifdef AIAMAGBIG
         if (big_archive)
           {
-            EINTRLOOP (nread, read (desc, &member_header_big,
-                                    AR_MEMHDR_SZ(member_header_big)));
+            nread = readbuf (desc, &member_header_big,
+                             AR_MEMHDR_SZ(member_header_big));
 
             if (nread != AR_MEMHDR_SZ(member_header_big))
               goto invalid;
@@ -560,7 +560,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
             if (name_len < 1 || name_len > ARNAME_MAX)
               goto invalid;
 
-            EINTRLOOP (nread, read (desc, name, name_len));
+            nread = readbuf (desc, name, name_len);
             if (nread != name_len)
               goto invalid;
 
@@ -578,8 +578,8 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
         else
 #endif
           {
-            EINTRLOOP (nread, read (desc, &member_header,
-                                    AR_MEMHDR_SZ(member_header)));
+            nread = readbuf (desc, &member_header,
+                             AR_MEMHDR_SZ(member_header));
 
             if (nread != AR_MEMHDR_SZ(member_header))
               goto invalid;
@@ -588,7 +588,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
             if (name_len < 1 || name_len > ARNAME_MAX)
               goto invalid;
 
-            EINTRLOOP (nread, read (desc, name, name_len));
+            nread = readbuf (desc, name, name_len);
             if (nread != name_len)
               goto invalid;
 
@@ -612,7 +612,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
                        eltmode, arg);
 
 #else   /* Not AIAMAG.  */
-        EINTRLOOP (nread, read (desc, &member_header, AR_HDR_SIZE));
+        nread = readbuf (desc, &member_header, AR_HDR_SIZE);
         if (nread == 0)
           /* No data left means end of file; that is OK.  */
           break;
@@ -691,7 +691,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
                 goto invalid;
 
               name = alloca (name_len + 1);
-              EINTRLOOP (nread, read (desc, name, name_len));
+              nread = readbuf (desc, name, name_len);
               if (nread != name_len)
                 goto invalid;
 
@@ -759,7 +759,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *arg)
             if (eltsize > INT_MAX)
               goto invalid;
             namemap = alloca (eltsize + 1);
-            EINTRLOOP (nread, read (desc, namemap, eltsize));
+            nread = readbuf (desc, namemap, eltsize);
             if (nread != eltsize)
               goto invalid;
             namemap_size = eltsize;
@@ -897,14 +897,7 @@ ar_member_touch (const char *arname, const char *memname)
   EINTRLOOP (o, lseek (fd, pos, 0));
   if (o < 0)
     goto lose;
-  EINTRLOOP (r, read (fd, &ar_hdr, AR_HDR_SIZE));
-  if (r != AR_HDR_SIZE)
-    goto lose;
-  /* Write back the header, thus touching the archive file.  */
-  EINTRLOOP (o, lseek (fd, pos, 0));
-  if (o < 0)
-    goto lose;
-  r = output_write (fd, &ar_hdr, AR_HDR_SIZE);
+  r = readbuf (fd, &ar_hdr, AR_HDR_SIZE);
   if (r != AR_HDR_SIZE)
     goto lose;
   /* The file's mtime is the time we we want.  */
@@ -926,7 +919,7 @@ ar_member_touch (const char *arname, const char *memname)
   EINTRLOOP (o, lseek (fd, pos, 0));
   if (o < 0)
     goto lose;
-  r = output_write (fd, &ar_hdr, AR_HDR_SIZE);
+  r = writebuf (fd, &ar_hdr, AR_HDR_SIZE);
   if (r != AR_HDR_SIZE)
     goto lose;
   close (fd);

diff --git a/src/makeint.h b/src/makeint.h
index 79b286cca2fe2254c78675f453a52d6189970d06..315500fce31242bdaf2d797c51ae8418c8a89048 100644 (file)
--- a/src/makeint.h
+++ b/src/makeint.h
@@ -529,6 +529,8 @@ void print_spaces (unsigned int);
 char *find_percent (char *);
 const char *find_percent_cached (const char **);
 FILE *get_tmpfile (char **, const char *);
+ssize_t writebuf (int, const void*, size_t);
+ssize_t readbuf (int, void*, size_t);
 
 #ifndef NO_ARCHIVES
 int ar_name (const char *);

diff --git a/src/misc.c b/src/misc.c
index f3594ad344113fe24fdf5d446be841787b3cdd92..307ff2b0509a936f44a674e11a64a830891086c3 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -335,6 +335,52 @@ find_next_token (const char **ptr, size_t *lengthptr)
   return (char *)p;
 }
 \f
+/* Write a BUFFER of size LEN to file descriptor FD.
+   Retry short writes from EINTR.  Return LEN, or -1 on error.  */
+ssize_t
+writebuf (int fd, const void *buffer, size_t len)
+{
+  const char *msg = buffer;
+  size_t l = len;
+  while (l)
+    {
+      ssize_t r;
+
+      EINTRLOOP (r, write (fd, msg, l));
+      if (r < 0)
+        return r;
+
+      l -= r;
+      msg += r;
+    }
+
+  return (ssize_t)len;
+}
+
+/* Read until we get LEN bytes from file descriptor FD, into BUFFER.
+   Retry short reads on EINTR.  If we get an error, return it.
+   Return 0 at EOF.  */
+ssize_t
+readbuf (int fd, void *buffer, size_t len)
+{
+  char *msg = buffer;
+  while (len)
+    {
+      ssize_t r;
+
+      EINTRLOOP (r, read (fd, msg, len));
+      if (r < 0)
+        return r;
+      if (r == 0)
+        break;
+
+      len -= r;
+      msg += r;
+    }
+
+  return (ssize_t)(msg - (char*)buffer);
+}
+\f
 
 /* Copy a chain of 'struct dep'.  For 2nd expansion deps, dup the name.  */
 

diff --git a/src/output.c b/src/output.c
index 8557de27e44cf49e42bebe3f4a626a96f218532b..9a58b9f1c2417ded796cc53d78714110201dea00 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -53,26 +53,6 @@ unsigned int stdio_traced = 0;
 # define STREAM_OK(_s) 1
 #endif
 
-/* Write a BUFFER of size LEN to file descriptor FD.
-   Handle EINTR and other short writes.  If we get an error, ignore it.  */
-int
-output_write (int fd, const void *buffer, size_t len)
-{
-  const char *msg = buffer;
-  while (1)
-    {
-      ssize_t r;
-
-      EINTRLOOP (r, write (fd, msg, len));
-
-      if (r < 0 || (size_t)r == len)
-        return r;
-
-      len -= r;
-      msg += r;
-    }
-}
-
 /* Write a string to the current STDOUT or STDERR.  */
 static void
 _outputs (struct output *out, int is_err, const char *msg)
@@ -89,7 +69,7 @@ _outputs (struct output *out, int is_err, const char *msg)
       size_t len = strlen (msg);
       int r;
       EINTRLOOP (r, lseek (fd, 0, SEEK_END));
-      output_write (fd, msg, len);
+      writebuf (fd, msg, len);
     }
 }
 \f
@@ -696,7 +676,7 @@ pfatal_with_name (const char *name)
 void
 out_of_memory ()
 {
-  output_write (FD_STDOUT, program, strlen (program));
-  output_write (FD_STDOUT, STRING_SIZE_TUPLE (": *** virtual memory exhausted\n"));
+  writebuf (FD_STDOUT, program, strlen (program));
+  writebuf (FD_STDOUT, STRING_SIZE_TUPLE (": *** virtual memory exhausted\n"));
   exit (MAKE_FAILURE);
 }