[Bug lto/65991] maybe-unitialized - false positive

["dilyan.palauzov at aegee dot org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65991

--- Comment #5 from Дилян Палаузов <dilyan.palauzov at aegee dot org> ---
The problem does not appear anymore, since I upgraded gcc 4.9.2 -> 4.9.3 .
>From gcc-bugs-return-491631-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Jul 07 10:07:55 2015
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From: "xricht17 at stud dot fit.vutbr.cz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug pch/14940] PCH largefile test fails on various platforms
Date: Tue, 07 Jul 2015 10:07:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id\x14940

--- Comment #49 from Martin Richter <xricht17 at stud dot fit.vutbr.cz> ---
(In reply to Martin Richter from comment #47)

My apologies, that patch is incorrect - `VirtualAlloc` still uses
`pch_VA_max_size` instead of `size`.
Some discussion about this bug and the reasoning behind the patch can be found
here:
https://sourceforge.net/p/mingw-w64/bugs/382/


Now the correct patch:

diff --git a/gcc/config/i386/host-mingw32.c b/gcc/config/i386/host-mingw32.c
index aa17378..631d9c4 100644
--- a/gcc/config/i386/host-mingw32.c
+++ b/gcc/config/i386/host-mingw32.c
@@ -42,9 +42,6 @@ static size_t mingw32_gt_pch_alloc_granularity (void);

 static inline void w32_error(const char*, const char*, int, const char*);

-/* FIXME: Is this big enough?  */
-static const size_t pch_VA_max_size  = 128 * 1024 * 1024;
-
 /* Granularity for reserving address space.  */
 static size_t va_granularity = 0x10000;

@@ -86,9 +83,6 @@ static void *
 mingw32_gt_pch_get_address (size_t size, int)
 {
   void* res;
-  size = (size + va_granularity - 1) & ~(va_granularity - 1);
-  if (size > pch_VA_max_size)
-    return NULL;

   /* FIXME: We let system determine base by setting first arg to NULL.
      Allocating at top of available address space avoids unnecessary
@@ -98,7 +92,7 @@ mingw32_gt_pch_get_address (size_t size, int)
      If we allocate at bottom we need to reserve the address as early
      as possible and at the same point in each invocation. */

-  res = VirtualAlloc (NULL, pch_VA_max_size,
+  res = VirtualAlloc (NULL, size,
                      MEM_RESERVE | MEM_TOP_DOWN,
                      PAGE_NOACCESS);
   if (!res)
@@ -148,7 +142,7 @@ mingw32_gt_pch_use_address (void *addr, size_t size, int
fd,

   /* Offset must be also be a multiple of allocation granularity for
      this to work.  We can't change the offset. */
-  if ((offset & (va_granularity - 1)) != 0 || size > pch_VA_max_size)
+  if ((offset & (va_granularity - 1)) != 0)
     return -1;