Replace unchecked fwrite() calls

Instead of having unchecked fwrite() calls, introduce nasm_write()
which does error checking (and fatal errors if the write fails).

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

13 files changed, 63 insertions, 64 deletions

diff --git a/nasmlib.c b/nasmlib.c
index 4588ff38..b16d1f36 100644
--- a/nasmlib.c
+++ b/nasmlib.c
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *   
- *   Copyright 1996-2013 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2014 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -41,6 +41,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <errno.h>
 #include <inttypes.h>
 
 #include "nasm.h"
@@ -143,6 +144,13 @@ no_return nasm_assert_failed(const char *file, int line, const char *msg)
     exit(1);
 }
 
+void nasm_write(const void *ptr, size_t size, FILE *f)
+{
+    size_t n = fwrite(ptr, 1, size, f);
+    if (n != size)
+        nasm_error(ERR_FATAL, "unable to write output: %s", strerror(errno));
+}
+
 #ifndef nasm_stricmp
 int nasm_stricmp(const char *s1, const char *s2)
 {
@@ -385,22 +393,22 @@ int32_t seg_alloc(void)
 
 void fwriteint16_t(uint16_t data, FILE * fp)
 {
-    fwrite(&data, 1, 2, fp);
+    nasm_write(&data, 2, fp);
 }
 
 void fwriteint32_t(uint32_t data, FILE * fp)
 {
-    fwrite(&data, 1, 4, fp);
+    nasm_write(&data, 4, fp);
 }
 
 void fwriteint64_t(uint64_t data, FILE * fp)
 {
-    fwrite(&data, 1, 8, fp);
+    nasm_write(&data, 8, fp);
 }
 
 void fwriteaddr(uint64_t data, int size, FILE * fp)
 {
-    fwrite(&data, 1, size, fp);
+    nasm_write(&data, size, fp);
 }
 
 #else /* not WORDS_LITTLEENDIAN */
@@ -409,50 +417,42 @@ void fwriteint16_t(uint16_t data, FILE * fp)
 {
     char buffer[2], *p = buffer;
     WRITESHORT(p, data);
-    fwrite(buffer, 1, 2, fp);
+    nasm_write(buffer, 2, fp);
 }
 
 void fwriteint32_t(uint32_t data, FILE * fp)
 {
     char buffer[4], *p = buffer;
     WRITELONG(p, data);
-    fwrite(buffer, 1, 4, fp);
+    nasm_write(buffer, 1, 4, fp);
 }
 
 void fwriteint64_t(uint64_t data, FILE * fp)
 {
     char buffer[8], *p = buffer;
     WRITEDLONG(p, data);
-    fwrite(buffer, 1, 8, fp);
+    nasm_write(buffer, 8, fp);
 }
 
 void fwriteaddr(uint64_t data, int size, FILE * fp)
 {
     char buffer[8], *p = buffer;
     WRITEADDR(p, data, size);
-    fwrite(buffer, 1, size, fp);
+    nasm_write(buffer, size, fp);
 }
 
 #endif
 
-size_t fwritezero(size_t bytes, FILE *fp)
+void fwritezero(size_t bytes, FILE *fp)
 {
-    size_t count = 0;
     size_t blksize;
-    size_t rv;
 
     while (bytes) {
 	blksize = (bytes < ZERO_BUF_SIZE) ? bytes : ZERO_BUF_SIZE;
 
-	rv = fwrite(zero_buffer, 1, blksize, fp);
-	if (!rv)
-	    break;
-
-	count += rv;
-	bytes -= rv;
+	nasm_write(zero_buffer, blksize, fp);
+	bytes -= blksize;
     }
-
-    return count;
 }
 
 void standard_extension(char *inname, char *outname, char *extension)
diff --git a/nasmlib.h b/nasmlib.h
index 8f6c8852..fb2bb084 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -143,6 +143,11 @@ char *nasm_strdup(const char *);
 char *nasm_strndup(const char *, size_t);
 
 /*
+ * Wrapper around fwrite() which fatal-errors on output failure.
+ */
+void nasm_write(const void *, size_t, FILE *);
+
+/*
  * NASM assert failure
  */
 no_return nasm_assert_failed(const char *, int, const char *);
@@ -399,7 +404,7 @@ const char *prefix_name(int);
 
 #define ZERO_BUF_SIZE 4096
 extern const uint8_t zero_buffer[ZERO_BUF_SIZE];
-size_t fwritezero(size_t bytes, FILE *fp);
+void fwritezero(size_t bytes, FILE *fp);
 
 static inline bool overflow_general(int64_t value, int bytes)
 {
diff --git a/output/outas86.c b/output/outas86.c
index 7af8d785..95675ef8 100644
--- a/output/outas86.c
+++ b/output/outas86.c
@@ -545,7 +545,7 @@ static void as86_write_section(struct Section *sect, int index)
                 int32_t tmplen = (length > 64 ? 64 : length);
                 fputc(0x40 | (tmplen & 0x3F), ofile);
                 saa_rnbytes(sect->data, buf, tmplen);
-                fwrite(buf, 1, tmplen, ofile);
+                nasm_write(buf, tmplen, ofile);
                 length -= tmplen;
             } while (length > 0);
             break;
diff --git a/output/outbin.c b/output/outbin.c
index c600e557..01eae1cf 100644
--- a/output/outbin.c
+++ b/output/outbin.c
@@ -1468,8 +1468,8 @@ static void do_output_bin(void)
 }
 
 /* Generate Intel hex file output */
-static int write_ith_record(unsigned int len, uint16_t addr,
-			    uint8_t type, void *data)
+static void write_ith_record(unsigned int len, uint16_t addr,
+                             uint8_t type, void *data)
 {
     char buf[1+2+4+2+255*2+2+2];
     char *p = buf;
@@ -1488,10 +1488,7 @@ static int write_ith_record(unsigned int len, uint16_t addr,
 	p += sprintf(p, "%02X", dptr[i]);
     p += sprintf(p, "%02X\n", csum);
 
-    if (fwrite(buf, 1, p-buf, ofile) != (size_t)(p-buf))
-	return -1;
-
-    return 0;
+    nasm_write(buf, p-buf, ofile);
 }
 
 static void do_output_ith(void)
@@ -1542,8 +1539,8 @@ static void do_output_ith(void)
 }
 
 /* Generate Motorola S-records */
-static int write_srecord(unsigned int len,  unsigned int alen,
-			 uint32_t addr, uint8_t type, void *data)
+static void write_srecord(unsigned int len,  unsigned int alen,
+                          uint32_t addr, uint8_t type, void *data)
 {
     char buf[2+2+8+255*2+2+2];
     char *p = buf;
@@ -1576,10 +1573,7 @@ static int write_srecord(unsigned int len,  unsigned int alen,
 	p += sprintf(p, "%02X", dptr[i]);
     p += sprintf(p, "%02X\n", csum);
 
-    if (fwrite(buf, 1, p-buf, ofile) != (size_t)(p-buf))
-	return -1;
-
-    return 0;
+    nasm_write(buf, p-buf, ofile);
 }
 
 static void do_output_srec(void)
diff --git a/output/outcoff.c b/output/outcoff.c
index 3949028b..5af063b5 100644
--- a/output/outcoff.c
+++ b/output/outcoff.c
@@ -998,7 +998,7 @@ static void coff_section_header(char *name, int32_t namepos, int32_t vsize,
 
     if (namepos == -1) {
         strncpy(padname, name, 8);
-        fwrite(padname, 8, 1, ofile);
+        nasm_write(padname, 8, ofile);
     } else {
         /*
          * If name is longer than 8 bytes, write '/' followed
@@ -1020,7 +1020,7 @@ static void coff_section_header(char *name, int32_t namepos, int32_t vsize,
         padname[6] = '0' + (namepos / 10);
         namepos = namepos % 10;
         padname[7] = '0' + (namepos);
-        fwrite(padname, 8, 1, ofile);
+        nasm_write(padname, 8, ofile);
     }
 
     fwriteint32_t(0,            ofile); /* Virtual size field - set to 0 or vsize */
@@ -1073,7 +1073,7 @@ static void coff_symbol(char *name, int32_t strpos, int32_t value,
 
     if (name) {
         strncpy(padname, name, 8);
-        fwrite(padname, 8, 1, ofile);
+        nasm_write(padname, 8, ofile);
     } else {
         fwriteint32_t(0, ofile);
         fwriteint32_t(strpos, ofile);
@@ -1097,7 +1097,7 @@ static void coff_write_symbols(void)
      */
     coff_symbol(".file", 0L, 0L, -2, 0, 0x67, 1);
     strncpy(filename, coff_infile, 18);
-    fwrite(filename, 18, 1, ofile);
+    nasm_write(filename, 18, ofile);
 
     /*
      * The section records, with their auxiliaries.
@@ -1108,7 +1108,7 @@ static void coff_write_symbols(void)
         coff_symbol(sects[i]->name, 0L, 0L, i + 1, 0, 3, 1);
         fwriteint32_t(sects[i]->len,    ofile);
         fwriteint16_t(sects[i]->nrelocs,ofile);
-        fwrite(filename, 12, 1, ofile);
+        nasm_write(filename, 12, ofile);
     }
 
     /*
diff --git a/output/outelf32.c b/output/outelf32.c
index af0547af..b55853ce 100644
--- a/output/outelf32.c
+++ b/output/outelf32.c
@@ -935,7 +935,7 @@ static void elf_write(void)
     /*
      * Output the ELF header.
      */
-    fwrite("\177ELF\1\1\1", 7, 1, ofile);
+    nasm_write("\177ELF\1\1\1", 7, ofile);
     fputc(elf_osabi, ofile);
     fputc(elf_abiver, ofile);
     fwritezero(7, ofile);
@@ -1286,7 +1286,7 @@ static void elf_write_sections(void)
             if (elf_sects[i].is_saa)
                 saa_fpwrite(elf_sects[i].data, ofile);
             else
-                fwrite(elf_sects[i].data, len, 1, ofile);
+                nasm_write(elf_sects[i].data, len, ofile);
             fwritezero(align, ofile);
         }
 }
diff --git a/output/outelf64.c b/output/outelf64.c
index 0e6b6bc3..241e345f 100644
--- a/output/outelf64.c
+++ b/output/outelf64.c
@@ -1025,7 +1025,7 @@ static void elf_write(void)
     /*
      * Output the ELF header.
      */
-    fwrite("\177ELF\2\1\1", 7, 1, ofile);
+    nasm_write("\177ELF\2\1\1", 7, ofile);
     fputc(elf_osabi, ofile);
     fputc(elf_abiver, ofile);
     fwritezero(7, ofile);
@@ -1374,7 +1374,7 @@ static void elf_write_sections(void)
             if (elf_sects[i].is_saa)
                 saa_fpwrite(elf_sects[i].data, ofile);
             else
-                fwrite(elf_sects[i].data, len, 1, ofile);
+                nasm_write(elf_sects[i].data, len, ofile);
             fwritezero(align, ofile);
         }
 }
diff --git a/output/outelfx32.c b/output/outelfx32.c
index 6b352a22..a9b6957a 100644
--- a/output/outelfx32.c
+++ b/output/outelfx32.c
@@ -983,7 +983,7 @@ static void elf_write(void)
     /*
      * Output the ELF header.
      */
-    fwrite("\177ELF\1\1\1", 7, 1, ofile);
+    nasm_write("\177ELF\1\1\1", 7, ofile);
     fputc(elf_osabi, ofile);
     fputc(elf_abiver, ofile);
     fwritezero(7, ofile);
@@ -1334,7 +1334,7 @@ static void elf_write_sections(void)
             if (elf_sects[i].is_saa)
                 saa_fpwrite(elf_sects[i].data, ofile);
             else
-                fwrite(elf_sects[i].data, len, 1, ofile);
+                nasm_write(elf_sects[i].data, len, ofile);
             fwritezero(align, ofile);
         }
 }
diff --git a/output/outmac32.c b/output/outmac32.c
index c2c91b48..616211eb 100644
--- a/output/outmac32.c
+++ b/output/outmac32.c
@@ -883,8 +883,8 @@ static uint32_t macho_write_segment (uint32_t offset)
 
     /* emit section headers */
     for (s = sects; s != NULL; s = s->next) {
-	fwrite(s->sectname, sizeof(s->sectname), 1, ofile);
-	fwrite(s->segname, sizeof(s->segname), 1, ofile);
+	nasm_write(s->sectname, sizeof(s->sectname), ofile);
+	nasm_write(s->segname, sizeof(s->segname), ofile);
 	fwriteint32_t(s->addr, ofile);
 	fwriteint32_t(s->size, ofile);
 
@@ -1050,8 +1050,8 @@ static void macho_write_symtab (void)
     for (i = 0; i < nextdefsym; i++) {
 	sym = extdefsyms[i];
 	fwriteint32_t(sym->strx, ofile);
-	fwrite(&sym->type, 1, 1, ofile);	/* symbol type */
-	fwrite(&sym->sect, 1, 1, ofile);	/* section */
+	nasm_write(&sym->type, 1, ofile);	/* symbol type */
+	nasm_write(&sym->sect, 1, ofile);	/* section */
 	fwriteint16_t(sym->desc, ofile);	/* description */
 
 	/* Fix up the symbol value now that we know the final section
@@ -1068,8 +1068,8 @@ static void macho_write_symtab (void)
      for (i = 0; i < nundefsym; i++) {
 	 sym = undefsyms[i];
 	 fwriteint32_t(sym->strx, ofile);
-	 fwrite(&sym->type, 1, 1, ofile);	/* symbol type */
-	 fwrite(&sym->sect, 1, 1, ofile);	/* section */
+	 nasm_write(&sym->type, 1, ofile);	/* symbol type */
+	 nasm_write(&sym->sect, 1, ofile);	/* section */
 	 fwriteint16_t(sym->desc, ofile);	/* description */
 
 	 /* Fix up the symbol value now that we know the final section
diff --git a/output/outmac64.c b/output/outmac64.c
index abad84aa..44dcf0c7 100644
--- a/output/outmac64.c
+++ b/output/outmac64.c
@@ -1005,7 +1005,7 @@ static void macho_write_header (void)
     fwriteint32_t(head_ncmds64, ofile);	/* number of load commands */
     fwriteint32_t(head_sizeofcmds64, ofile);	/* size of load commands */
     fwriteint32_t(0, ofile);	/* no flags */
-	fwriteint32_t(0, ofile); /* reserved for future use */
+    fwriteint32_t(0, ofile);	/* reserved for future use */
 }
 
 /* Write out the segment load command at offset.  */
@@ -1036,8 +1036,8 @@ static uint32_t macho_write_segment (uint64_t offset)
 
     /* emit section headers */
     for (s = sects; s != NULL; s = s->next) {
-        fwrite(s->sectname, sizeof(s->sectname), 1, ofile);
-        fwrite(s->segname, sizeof(s->segname), 1, ofile);
+        nasm_write(s->sectname, sizeof(s->sectname), ofile);
+        nasm_write(s->segname, sizeof(s->segname), ofile);
         fwriteint64_t(s->addr, ofile);
         fwriteint64_t(s->size, ofile);
 
@@ -1202,9 +1202,9 @@ static void macho_write_symtab (void)
     for (sym = syms; sym != NULL; sym = sym->next) {
 	if ((sym->type & N_EXT) == 0) {
 	    fwriteint32_t(sym->strx, ofile);		/* string table entry number */
-	    fwrite(&sym->type, 1, 1, ofile);	/* symbol type */
-	    fwrite(&sym->sect, 1, 1, ofile);	/* section */
-	    fwriteint16_t(sym->desc, ofile);	/* description */
+	    nasm_write(&sym->type, 1, ofile);		/* symbol type */
+	    nasm_write(&sym->sect, 1, ofile);		/* section */
+	    fwriteint16_t(sym->desc, ofile);		/* description */
 
 	    /* Fix up the symbol value now that we know the final section
 	       sizes.  */
@@ -1224,8 +1224,8 @@ static void macho_write_symtab (void)
     for (i = 0; i < nextdefsym; i++) {
 	sym = extdefsyms[i];
 	fwriteint32_t(sym->strx, ofile);
-	fwrite(&sym->type, 1, 1, ofile);	/* symbol type */
-	fwrite(&sym->sect, 1, 1, ofile);	/* section */
+	nasm_write(&sym->type, 1, ofile);	/* symbol type */
+	nasm_write(&sym->sect, 1, ofile);	/* section */
 	fwriteint16_t(sym->desc, ofile);	/* description */
 
 	/* Fix up the symbol value now that we know the final section
@@ -1242,8 +1242,8 @@ static void macho_write_symtab (void)
      for (i = 0; i < nundefsym; i++) {
 	 sym = undefsyms[i];
 	 fwriteint32_t(sym->strx, ofile);
-	 fwrite(&sym->type, 1, 1, ofile);	/* symbol type */
-	 fwrite(&sym->sect, 1, 1, ofile);	/* section */
+	 nasm_write(&sym->type, 1, ofile);	/* symbol type */
+	 nasm_write(&sym->sect, 1, ofile);	/* section */
 	 fwriteint16_t(sym->desc, ofile);	/* description */
 
 	 // Fix up the symbol value now that we know the final section sizes.
diff --git a/output/outobj.c b/output/outobj.c
index 7fa29b27..225ea4fe 100644
--- a/output/outobj.c
+++ b/output/outobj.c
@@ -2396,7 +2396,7 @@ static void obj_fwrite(ObjRecord * orp)
     len = orp->committed + 1;
     cksum += (len & 0xFF) + ((len >> 8) & 0xFF);
     fwriteint16_t(len, ofile);
-    fwrite(orp->buf, 1, len - 1, ofile);
+    nasm_write(orp->buf, len-1, ofile);
     for (ptr = orp->buf; --len; ptr++)
         cksum += *ptr;
     fputc((-cksum) & 0xFF, ofile);
diff --git a/output/outrdf2.c b/output/outrdf2.c
index c7aeb28b..fdac5ee3 100644
--- a/output/outrdf2.c
+++ b/output/outrdf2.c
@@ -670,7 +670,7 @@ static void rdf2_cleanup(int debuginfo)
     /* should write imported & exported symbol declarations to header here */
 
     /* generate the output file... */
-    fwrite(RDOFF2Id, 6, 1, ofile);      /* file type magic number */
+    nasm_write(RDOFF2Id, 6, ofile); /* file type magic number */
 
     if (bsslength != 0) {       /* reserve BSS */
         bs.type = RDFREC_BSS;
diff --git a/saa.c b/saa.c
index 6719584a..a0350c10 100644
--- a/saa.c
+++ b/saa.c
@@ -278,7 +278,7 @@ void saa_fpwrite(struct SAA *s, FILE * fp)
 
     saa_rewind(s);
     while (len = s->datalen, (data = saa_rbytes(s, &len)) != NULL)
-        fwrite(data, 1, len, fp);
+        nasm_write(data, len, fp);
 }
 
 void saa_write8(struct SAA *s, uint8_t v)