Remove simpler cases of OOM error handling (after *alloc calls)

By simpler cases I mean cases where the OOM error is not expected to be handled
by the caller of the function that calls `alloc`, `lalloc`, `xrealloc`,
`xmalloc`, `alloc_clear`, and `lalloc_clear`.

These are the functions that:

 - Do not return an allocated buffer
 - Have OOM as the only error condition

I took note of the functions that expect the caller to handle the OOM error and
will go through them to check all the callers that may be handling OOM error in
future commits.

I'm ignoring eval.c and ex_.c in this series of commits. eval.c will soon be
obsolete and I will deal with ex_.c in later PRs.

1 files changed, 34 insertions, 118 deletions

diff --git a/src/if_cscope.c b/src/if_cscope.c
index d1f709010c..e257e4e84b 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -461,12 +461,9 @@ static void cs_stat_emsg(char *fname)
   char *stat_emsg = _("E563: stat(%s) error: %d");
   char *buf = (char *)alloc((unsigned)strlen(stat_emsg) + MAXPATHL + 10);
 
-  if (buf != NULL) {
-    (void)sprintf(buf, stat_emsg, fname, errno);
-    (void)EMSG(buf);
-    vim_free(buf);
-  } else
-    (void)EMSG(_("E563: stat error"));
+  (void)sprintf(buf, stat_emsg, fname, errno);
+  (void)EMSG(buf);
+  vim_free(buf);
 }
 
 
@@ -495,8 +492,7 @@ cs_add_common (
   char_u      *fbuf = NULL;
 
   /* get the filename (arg1), expand it, and try to stat it */
-  if ((fname = (char *)alloc(MAXPATHL + 1)) == NULL)
-    goto add_err;
+  fname = (char *)alloc(MAXPATHL + 1);
 
   expand_env((char_u *)arg1, (char_u *)fname, MAXPATHL);
   len = (int)STRLEN(fname);
@@ -519,8 +515,7 @@ staterr:
   if (arg2 != NULL) {
     struct stat statbuf2;
 
-    if ((ppath = (char *)alloc(MAXPATHL + 1)) == NULL)
-      goto add_err;
+    ppath = (char *)alloc(MAXPATHL + 1);
 
     expand_env((char_u *)arg2, (char_u *)ppath, MAXPATHL);
     ret = stat(ppath, &statbuf2);
@@ -531,8 +526,6 @@ staterr:
   /* if filename is a directory, append the cscope database name to it */
   if ((statbuf.st_mode & S_IFMT) == S_IFDIR) {
     fname2 = (char *)alloc((unsigned)(strlen(CSCOPE_DBFILE) + strlen(fname) + 2));
-    if (fname2 == NULL)
-      goto add_err;
 
     while (fname[strlen(fname)-1] == '/'
            ) {
@@ -646,8 +639,6 @@ static int cs_cnt_matches(int idx)
   int nlines;
 
   buf = (char *)alloc(CSREAD_BUFSIZE);
-  if (buf == NULL)
-    return 0;
   for (;; ) {
     if (!fgets(buf, CSREAD_BUFSIZE, csinfo[idx].fr_fp)) {
       if (feof(csinfo[idx].fr_fp))
@@ -740,8 +731,7 @@ static char *cs_create_cmd(char *csoption, char *pattern)
     while (vim_iswhite(*pat))
       ++pat;
 
-  if ((cmd = (char *)alloc((unsigned)(strlen(pat) + 2))) == NULL)
-    return NULL;
+  cmd = (char *)alloc((unsigned)(strlen(pat) + 2));
 
   (void)sprintf(cmd, "%d%s", search, pat);
 
@@ -821,29 +811,14 @@ err_closing:
   }
 #endif
     /* expand the cscope exec for env var's */
-    if ((prog = (char *)alloc(MAXPATHL + 1)) == NULL) {
-#ifdef UNIX
-      return CSCOPE_FAILURE;
-#else
-      /* WIN32 */
-      goto err_closing;
-#endif
-    }
+    prog = (char *)alloc(MAXPATHL + 1);
     expand_env((char_u *)p_csprg, (char_u *)prog, MAXPATHL);
 
     /* alloc space to hold the cscope command */
     len = (int)(strlen(prog) + strlen(csinfo[i].fname) + 32);
     if (csinfo[i].ppath) {
       /* expand the prepend path for env var's */
-      if ((ppath = (char *)alloc(MAXPATHL + 1)) == NULL) {
-        vim_free(prog);
-#ifdef UNIX
-        return CSCOPE_FAILURE;
-#else
-        /* WIN32 */
-        goto err_closing;
-#endif
-      }
+      ppath = (char *)alloc(MAXPATHL + 1);
       expand_env((char_u *)csinfo[i].ppath, (char_u *)ppath, MAXPATHL);
 
       len += (int)strlen(ppath);
@@ -852,16 +827,7 @@ err_closing:
     if (csinfo[i].flags)
       len += (int)strlen(csinfo[i].flags);
 
-    if ((cmd = (char *)alloc(len)) == NULL) {
-      vim_free(prog);
-      vim_free(ppath);
-#ifdef UNIX
-      return CSCOPE_FAILURE;
-#else
-      /* WIN32 */
-      goto err_closing;
-#endif
-    }
+    cmd = (char *)alloc(len);
 
     /* run the cscope command; is there execl for non-unix systems? */
 #if defined(UNIX)
@@ -1052,14 +1018,12 @@ static int cs_find_common(char *opt, char *pat, int forceit, int verbose, int us
     /* next symbol must be + or - */
     if (strchr(CSQF_FLAGS, *qfpos) == NULL) {
       char *nf = _("E469: invalid cscopequickfix flag %c for %c");
+      /* strlen will be enough because we use chars */
       char *buf = (char *)alloc((unsigned)strlen(nf));
 
-      /* strlen will be enough because we use chars */
-      if (buf != NULL) {
-        sprintf(buf, nf, *qfpos, *(qfpos-1));
-        (void)EMSG(buf);
-        vim_free(buf);
-      }
+      sprintf(buf, nf, *qfpos, *(qfpos-1));
+      (void)EMSG(buf);
+      vim_free(buf);
       return FALSE;
     }
 
@@ -1077,8 +1041,6 @@ static int cs_find_common(char *opt, char *pat, int forceit, int verbose, int us
     return FALSE;
 
   nummatches = (int *)alloc(sizeof(int)*csinfo_size);
-  if (nummatches == NULL)
-    return FALSE;
 
   /* Send query to all open connections, then count the total number
    * of matches so we can alloc all in one swell foop. */
@@ -1113,13 +1075,9 @@ static int cs_find_common(char *opt, char *pat, int forceit, int verbose, int us
     }
 
     buf = (char *)alloc((unsigned)(strlen(opt) + strlen(pat) + strlen(nf)));
-    if (buf == NULL)
-      (void)EMSG(nf);
-    else {
-      sprintf(buf, nf, opt, pat);
-      (void)EMSG(buf);
-      vim_free(buf);
-    }
+    sprintf(buf, nf, opt, pat);
+    (void)EMSG(buf);
+    vim_free(buf);
     vim_free(nummatches);
     return FALSE;
   }
@@ -1334,37 +1292,22 @@ static int cs_insert_filelist(char *fname, char *ppath, char *flags, struct stat
       csinfo_size *= 2;
       csinfo = xrealloc(csinfo, sizeof(csinfo_T)*csinfo_size);
     }
-    if (csinfo == NULL)
-      return -1;
     for (j = csinfo_size/2; j < csinfo_size; j++)
       clear_csinfo(j);
   }
 
-  if ((csinfo[i].fname = (char *)alloc((unsigned)strlen(fname)+1)) == NULL)
-    return -1;
+  csinfo[i].fname = (char *)alloc((unsigned)strlen(fname)+1);
 
   (void)strcpy(csinfo[i].fname, (const char *)fname);
 
   if (ppath != NULL) {
-    if ((csinfo[i].ppath = (char *)alloc((unsigned)strlen(ppath) + 1)) ==
-        NULL) {
-      vim_free(csinfo[i].fname);
-      csinfo[i].fname = NULL;
-      return -1;
-    }
+    csinfo[i].ppath = (char *)alloc((unsigned)strlen(ppath) + 1);
     (void)strcpy(csinfo[i].ppath, (const char *)ppath);
   } else
     csinfo[i].ppath = NULL;
 
   if (flags != NULL) {
-    if ((csinfo[i].flags = (char *)alloc((unsigned)strlen(flags) + 1)) ==
-        NULL) {
-      vim_free(csinfo[i].fname);
-      vim_free(csinfo[i].ppath);
-      csinfo[i].fname = NULL;
-      csinfo[i].ppath = NULL;
-      return -1;
-    }
+    csinfo[i].flags = (char *)alloc((unsigned)strlen(flags) + 1);
     (void)strcpy(csinfo[i].flags, (const char *)flags);
   } else
     csinfo[i].flags = NULL;
@@ -1674,8 +1617,6 @@ static void cs_file_results(FILE *f, int *nummatches_a)
   char *context;
 
   buf = (char *)alloc(CSREAD_BUFSIZE);
-  if (buf == NULL)
-    return;
 
   for (i = 0; i < csinfo_size; i++) {
     if (nummatches_a[i] < 1)
@@ -1687,8 +1628,6 @@ static void cs_file_results(FILE *f, int *nummatches_a)
         continue;
 
       context = (char *)alloc((unsigned)strlen(cntx)+5);
-      if (context == NULL)
-        continue;
 
       if (strcmp(cntx, "<global>")==0)
         strcpy(context, "<<global>>");
@@ -1731,13 +1670,9 @@ static void cs_fill_results(char *tagstr, int totmatches, int *nummatches_a, cha
   assert(totmatches > 0);
 
   buf = (char *)alloc(CSREAD_BUFSIZE);
-  if (buf == NULL)
-    return;
 
-  if ((matches = (char **)alloc(sizeof(char *) * totmatches)) == NULL)
-    goto parse_out;
-  if ((cntxts = (char **)alloc(sizeof(char *) * totmatches)) == NULL)
-    goto parse_out;
+  matches = (char **)alloc(sizeof(char *) * totmatches);
+  cntxts = (char **)alloc(sizeof(char *) * totmatches);
 
   for (i = 0; i < csinfo_size; i++) {
     if (nummatches_a[i] < 1)
@@ -1770,7 +1705,6 @@ static void cs_fill_results(char *tagstr, int totmatches, int *nummatches_a, cha
 
   }   /* for all cscope connections */
 
-parse_out:
   if (totsofar == 0) {
     /* No matches, free the arrays and return NULL in "*matches_p". */
     vim_free(matches);
@@ -1827,19 +1761,16 @@ static void cs_print_tags_priv(char **matches, char **cntxts, int num_matches)
 
   assert (num_matches > 0);
 
-  if ((tbuf = (char *)alloc((unsigned)strlen(matches[0]) + 1)) == NULL)
-    return;
+  tbuf = (char *)alloc((unsigned)strlen(matches[0]) + 1);
 
   strcpy(tbuf, matches[0]);
   ptag = strtok(tbuf, "\t");
 
   newsize = (int)(strlen(cstag_msg) + strlen(ptag));
   buf = (char *)alloc(newsize);
-  if (buf != NULL) {
-    bufsize = newsize;
-    (void)sprintf(buf, cstag_msg, ptag);
-    MSG_PUTS_ATTR(buf, hl_attr(HLF_T));
-  }
+  bufsize = newsize;
+  (void)sprintf(buf, cstag_msg, ptag);
+  MSG_PUTS_ATTR(buf, hl_attr(HLF_T));
 
   vim_free(tbuf);
 
@@ -1855,8 +1786,7 @@ static void cs_print_tags_priv(char **matches, char **cntxts, int num_matches)
      * by parsing matches[i] on the fly and placing stuff into buf
      * directly, but that's too much of a hassle
      */
-    if ((tbuf = (char *)alloc((unsigned)strlen(matches[idx]) + 1)) == NULL)
-      continue;
+    tbuf = (char *)alloc((unsigned)strlen(matches[idx]) + 1);
     (void)strcpy(tbuf, matches[idx]);
 
     if (strtok(tbuf, (const char *)"\t") == NULL)
@@ -1873,10 +1803,7 @@ static void cs_print_tags_priv(char **matches, char **cntxts, int num_matches)
     newsize = (int)(strlen(csfmt_str) + 16 + strlen(lno));
     if (bufsize < newsize) {
       buf = (char *)xrealloc(buf, newsize);
-      if (buf == NULL)
-        bufsize = 0;
-      else
-        bufsize = newsize;
+      bufsize = newsize;
     }
     if (buf != NULL) {
       /* csfmt_str = "%4d %6s  "; */
@@ -1894,10 +1821,7 @@ static void cs_print_tags_priv(char **matches, char **cntxts, int num_matches)
 
     if (bufsize < newsize) {
       buf = (char *)xrealloc(buf, newsize);
-      if (buf == NULL)
-        bufsize = 0;
-      else
-        bufsize = newsize;
+      bufsize = newsize;
     }
     if (buf != NULL) {
       (void)sprintf(buf, cntxformat, context);
@@ -2159,12 +2083,6 @@ static int cs_reset(exarg_T *eap)
   dblist = (char **)alloc(csinfo_size * sizeof(char *));
   pplist = (char **)alloc(csinfo_size * sizeof(char *));
   fllist = (char **)alloc(csinfo_size * sizeof(char *));
-  if (dblist == NULL || pplist == NULL || fllist == NULL) {
-    vim_free(dblist);
-    vim_free(pplist);
-    vim_free(fllist);
-    return CSCOPE_FAILURE;
-  }
 
   for (i = 0; i < csinfo_size; i++) {
     dblist[i] = csinfo[i].fname;
@@ -2230,12 +2148,10 @@ static char *cs_resolve_file(int i, char *name)
     /* If 'cscoperelative' is set and ppath is not set, use cscope.out
      * path in path resolution. */
     csdir = alloc(MAXPATHL);
-    if (csdir != NULL) {
-      vim_strncpy(csdir, (char_u *)csinfo[i].fname,
-          path_tail((char_u *)csinfo[i].fname)
-          - (char_u *)csinfo[i].fname);
-      len += (int)STRLEN(csdir);
-    }
+    vim_strncpy(csdir, (char_u *)csinfo[i].fname,
+        path_tail((char_u *)csinfo[i].fname)
+        - (char_u *)csinfo[i].fname);
+    len += (int)STRLEN(csdir);
   }
 
   /* Note/example: this won't work if the cscope output already starts
@@ -2245,8 +2161,8 @@ static char *cs_resolve_file(int i, char *name)
       && (strncmp(name, csinfo[i].ppath, strlen(csinfo[i].ppath)) != 0)
       && (name[0] != '/')
       ) {
-    if ((fullname = (char *)alloc(len)) != NULL)
-      (void)sprintf(fullname, "%s/%s", csinfo[i].ppath, name);
+    fullname = (char *)alloc(len);
+    (void)sprintf(fullname, "%s/%s", csinfo[i].ppath, name);
   } else if (csdir != NULL && csinfo[i].fname != NULL && *csdir != NUL) {
     /* Check for csdir to be non empty to avoid empty path concatenated to
      * cscope output. */