[PATCH] Avoid another non zero terminated string constant

[PATCH] Avoid another non zero terminated string constant

[Bernd Edlinger]

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Hi!

This fixes another not NUL terminated string literal that is created
in tree-ssa-forwprop.c at simplify_builtin_call.

src_buf is set up to contain a NUL at src_buf[src_len], thus use src_len + 1
as length parameter to build_string_literal.  All other uses of
build_string_literal do it right, as far as I can see.


Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
Is it OK for trunk?


Thanks
Bernd.

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2018-07-29  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* tree-ssa-forwprop.c (simplify_builtin_call): Don't create a not NUL
	terminated string literal.

Index: gcc/tree-ssa-forwprop.c
===================================================================
--- gcc/tree-ssa-forwprop.c	(revision 263045)
+++ gcc/tree-ssa-forwprop.c	(working copy)
@@ -1391,7 +1391,7 @@ simplify_builtin_call (gimple_stmt_iterator *gsi_p
 				    src_buf, ptr1_align, false))
 	    break;
 
-	  new_str_cst = build_string_literal (src_len, src_buf);
+	  new_str_cst = build_string_literal (src_len + 1, src_buf);
 	  if (callee1)
 	    {
 	      /* If STMT1 is a mem{,p}cpy call, adjust it and remove

Re: [PATCH] Avoid another non zero terminated string constant

[Richard Biener]

On Sun, 29 Jul 2018, Bernd Edlinger wrote:

> Hi!
> 
> This fixes another not NUL terminated string literal that is created
> in tree-ssa-forwprop.c at simplify_builtin_call.
> 
> src_buf is set up to contain a NUL at src_buf[src_len], thus use src_len + 1
> as length parameter to build_string_literal.  All other uses of
> build_string_literal do it right, as far as I can see.
> 
> 
> Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
> Is it OK for trunk?

OK.

Richard.

Re: [PATCH] Avoid another non zero terminated string constant (revert)

[Bernd Edlinger]

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On 07/30/18 08:52, Richard Biener wrote:
> On Sun, 29 Jul 2018, Bernd Edlinger wrote:
> 
>> Hi!
>>
>> This fixes another not NUL terminated string literal that is created
>> in tree-ssa-forwprop.c at simplify_builtin_call.
>>
>> src_buf is set up to contain a NUL at src_buf[src_len], thus use src_len + 1
>> as length parameter to build_string_literal.  All other uses of
>> build_string_literal do it right, as far as I can see.
>>
>>
>> Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
>> Is it OK for trunk?
> 
> OK.
> 
> Richard.
> 

Hi,

when I installed that patch it appeared to me that naturally all string
constants ought to be zero-terminated.

But since we have now the STRING_CST semantic changes installed,
which do equally support both zero and non-zero terminated string constants,
I want to revert this again:


r263068 | edlinger | 2018-07-30 15:26:25 +0200 (Mo, 30. Jul 2018) | 5 Zeilen
Geänderte Pfade:
    M /trunk/gcc/ChangeLog
    M /trunk/gcc/tree-ssa-forwprop.c

2018-07-30  Bernd Edlinger  <bernd.edlinger@hotmail.de>

         * tree-ssa-forwprop.c (simplify_builtin_call): Don't create a not NUL
         terminated string literal.

So unless there are reasons to keep this zero-terminated string constant,
I am going to revert this patch today evening, after another
Bootstrapped and reg-tested on x86_64-pc-linux-gnu.


Thanks
Bernd.

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Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog	(revision 263068)
+++ gcc/ChangeLog	(revision 263067)
@@ -1,8 +1,3 @@
-2018-07-30  Bernd Edlinger  <bernd.edlinger@hotmail.de>
-
-	* tree-ssa-forwprop.c (simplify_builtin_call): Don't create a not NUL
-	terminated string literal.
-
 2018-07-30  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR rtl-optimization/85160
Index: gcc/tree-ssa-forwprop.c
===================================================================
--- gcc/tree-ssa-forwprop.c	(revision 263068)
+++ gcc/tree-ssa-forwprop.c	(revision 263067)
@@ -1391,7 +1391,7 @@
 				    src_buf, ptr1_align, false))
 	    break;
 
-	  new_str_cst = build_string_literal (src_len + 1, src_buf);
+	  new_str_cst = build_string_literal (src_len, src_buf);
 	  if (callee1)
 	    {
 	      /* If STMT1 is a mem{,p}cpy call, adjust it and remove