patch 7.4.1058

Problem:    It is not possible to test code that is only reached when memory
            allocation fails.
Solution:   Add the alloc_fail() function.  Try it out with :vimgrep.

Author: brammool

runtime/doc/eval.txt

@@ -1739,6 +1739,8 @@ USAGE				RESULT	DESCRIPTION	~
 abs( {expr})			Float or Number  absolute value of {expr}
 acos( {expr})			Float	arc cosine of {expr}
 add( {list}, {item})		List	append {item} to |List| {list}
+alloc_fail( {countdown}, {when}, {repeat})
+				nothing	make memory allocation fail
 and( {expr}, {expr})		Number  bitwise AND
 append( {lnum}, {string})	Number	append {string} below line {lnum}
 append( {lnum}, {list})		Number	append lines {list} below line {lnum}
@@ -2118,6 +2120,13 @@ add({list}, {expr})					*add()*
 		Use |insert()| to add an item at another position.
 
 
+alloc_fail({id}, {countdown}, {repeat})			*alloc_fail()*
+		This is for testing: If the memory allocation with {id} is
+		called, then decrement {countdown}, and when it reaches zero
+		let memory allocation fail {repeat} times.  When {repeat} is
+		smaller than one it fails one time.
+
+
 and({expr}, {expr})					*and()*
 		Bitwise AND on the two arguments.  The arguments are converted
 		to a number.  A List, Dict or Float argument causes an error.

src/eval.c

@@ -467,6 +467,7 @@ static void f_abs __ARGS((typval_T *argvars, typval_T *rettv));
 static void f_acos __ARGS((typval_T *argvars, typval_T *rettv));
 #endif
 static void f_add __ARGS((typval_T *argvars, typval_T *rettv));
+static void f_alloc_fail __ARGS((typval_T *argvars, typval_T *rettv));
 static void f_and __ARGS((typval_T *argvars, typval_T *rettv));
 static void f_append __ARGS((typval_T *argvars, typval_T *rettv));
 static void f_argc __ARGS((typval_T *argvars, typval_T *rettv));
@@ -8071,6 +8072,7 @@ static struct fst
     {"acos",		1, 1, f_acos},	/* WJMc */
 #endif
     {"add",		2, 2, f_add},
+    {"alloc_fail",	3, 3, f_alloc_fail},
     {"and",		2, 2, f_and},
     {"append",		2, 2, f_append},
     {"argc",		0, 0, f_argc},
@@ -8983,6 +8985,28 @@ f_add(argvars, rettv)
 	EMSG(_(e_listreq));
 }
 
+/*
+ * "alloc_fail(id, countdown, repeat)" function
+ */
+    static void
+f_alloc_fail(argvars, rettv)
+    typval_T	*argvars;
+    typval_T	*rettv UNUSED;
+{
+    if (argvars[0].v_type != VAR_NUMBER
+	    || argvars[0].vval.v_number <= 0
+	    || argvars[1].v_type != VAR_NUMBER
+	    || argvars[1].vval.v_number < 0
+	    || argvars[2].v_type != VAR_NUMBER)
+	EMSG(_(e_invarg));
+    else
+    {
+	alloc_fail_id = argvars[0].vval.v_number;
+	alloc_fail_countdown = argvars[1].vval.v_number;
+	alloc_fail_repeat = argvars[2].vval.v_number;
+    }
+}
+
 /*
  * "and(expr, expr)" function
  */

src/globals.h

@@ -1619,6 +1619,15 @@ EXTERN FILE *time_fd INIT(= NULL);  /* where to write startup timing */
 EXTERN int ignored;
 EXTERN char *ignoredp;
 
+#ifdef FEAT_EVAL
+/* set by alloc_fail(): ID */
+EXTERN int  alloc_fail_id INIT(= 0);
+/* set by alloc_fail(), when zero alloc() returns NULL */
+EXTERN int  alloc_fail_countdown INIT(= -1);
+/* set by alloc_fail(), number of times alloc() returns NULL */
+EXTERN int  alloc_fail_repeat INIT(= 0);
+#endif
+
 /*
  * Optional Farsi support.  Include it here, so EXTERN and INIT are defined.
  */

src/misc2.c

@@ -797,6 +797,21 @@ vim_mem_profile_dump()
 
 #endif /* MEM_PROFILE */
 
+#ifdef FEAT_EVAL
+    static int
+alloc_does_fail()
+{
+    if (alloc_fail_countdown == 0)
+    {
+	if (--alloc_fail_repeat <= 0)
+	    alloc_fail_id = 0;
+	return TRUE;
+    }
+    --alloc_fail_countdown;
+    return FALSE;
+}
+#endif
+
 /*
  * Some memory is reserved for error messages and for being able to
  * call mf_release_all(), which needs some memory for mf_trans_add().
@@ -820,6 +835,22 @@ alloc(size)
     return (lalloc((long_u)size, TRUE));
 }
 
+/*
+ * alloc() with an ID for alloc_fail().
+ * LAST_ID_USED: 5
+ */
+    char_u *
+alloc_id(size, id)
+    unsigned	size;
+    int		id;
+{
+#ifdef FEAT_EVAL
+    if (alloc_fail_id == id && alloc_does_fail())
+	return NULL;
+#endif
+    return (lalloc((long_u)size, TRUE));
+}
+
 /*
  * Allocate memory and set all bytes to zero.
  */
@@ -968,6 +999,23 @@ lalloc(size, message)
     return p;
 }
 
+/*
+ * lalloc() with an ID for alloc_fail().
+ * See LAST_ID_USED above.
+ */
+    char_u *
+lalloc_id(size, message, id)
+    long_u	size;
+    int		message;
+    int		id;
+{
+#ifdef FEAT_EVAL
+    if (alloc_fail_id == id && alloc_does_fail())
+	return NULL;
+#endif
+    return (lalloc((long_u)size, message));
+}
+
 #if defined(MEM_PROFILE) || defined(PROTO)
 /*
  * realloc() with memory profiling.

src/proto/misc2.pro

@@ -20,10 +20,12 @@ void adjust_cursor_col __ARGS((void));
 int leftcol_changed __ARGS((void));
 void vim_mem_profile_dump __ARGS((void));
 char_u *alloc __ARGS((unsigned size));
+char_u *alloc_id __ARGS((unsigned size, int id));
 char_u *alloc_clear __ARGS((unsigned size));
 char_u *alloc_check __ARGS((unsigned size));
 char_u *lalloc_clear __ARGS((long_u size, int message));
 char_u *lalloc __ARGS((long_u size, int message));
+char_u *lalloc_id __ARGS((long_u size, int message, int id));
 void *mem_realloc __ARGS((void *ptr, size_t size));
 void do_outofmem_msg __ARGS((long_u size));
 void free_all_mem __ARGS((void));

src/quickfix.c

@@ -253,9 +253,9 @@ qf_init_ext(qi, efile, buf, tv, errorformat, newlist, lnumfirst, lnumlast,
 			{'s', ".\\+"}
 		    };
 
-    namebuf = alloc(CMDBUFFSIZE + 1);
-    errmsg = alloc(CMDBUFFSIZE + 1);
-    pattern = alloc(CMDBUFFSIZE + 1);
+    namebuf = alloc_id(CMDBUFFSIZE + 1, 3);
+    errmsg = alloc_id(CMDBUFFSIZE + 1, 4);
+    pattern = alloc_id(CMDBUFFSIZE + 1, 5);
     if (namebuf == NULL || errmsg == NULL || pattern == NULL)
 	goto qf_init_end;
 
@@ -3465,8 +3465,8 @@ ex_vimgrep(eap)
 	goto theend;
     }
 
-    dirname_start = alloc(MAXPATHL);
-    dirname_now = alloc(MAXPATHL);
+    dirname_start = alloc_id(MAXPATHL, 1);
+    dirname_now = alloc_id(MAXPATHL, 2);
     if (dirname_start == NULL || dirname_now == NULL)
 	goto theend;
 

src/testdir/test_quickfix.vim

@@ -273,3 +273,42 @@ function Test_cbuffer()
   call XbufferTests('l')
 endfunction
 
+function Test_nomem()
+  call alloc_fail(1, 0, 0)
+  try
+    vimgrep vim runtest.vim
+  catch
+    call assert_true(v:exception =~ 'E342')
+  endtry
+
+  call alloc_fail(2, 0, 0)
+  try
+    vimgrep vim runtest.vim
+  catch
+    call assert_true(v:exception =~ 'E342')
+  endtry
+
+  call alloc_fail(3, 0, 0)
+  try
+    cfile runtest.vim
+  catch
+    call assert_true(v:exception =~ 'E342')
+  endtry
+
+  call alloc_fail(4, 0, 0)
+  try
+    cfile runtest.vim
+  catch
+    call assert_true(v:exception =~ 'E342')
+  endtry
+
+  call alloc_fail(5, 0, 0)
+  try
+    cfile runtest.vim
+  catch
+    call assert_true(v:exception =~ 'E342')
+  endtry
+
+endfunc
+
+

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1058,
 /**/
     1057,
 /**/