[pushed] Darwin : Avoid a C++ ODR violation seen with LTO.

[Iain Sandoe]

Hi

We have a similar code pattern in darwin-c.c to one in c-pragmas
(most likely a cut & paste) with a struct type used locally to the
TU.  With C++ we need to rename the type to avoid an ODR violation.

tested on x86_64-darwin19 ‘—with-build-config=bootstrap-lto-noplugin’
pushed to master,
thanks
Iain

gcc/ChangeLog:

        * config/darwin-c.c (struct f_align_stack): Rename
        to type from align_stack to f_align_stack.
        (push_field_alignment): Likewise.
        (pop_field_alignment): Likewise.
---
 gcc/config/darwin-c.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/gcc/config/darwin-c.c b/gcc/config/darwin-c.c
index 9034f49908e..96172305711 100644
--- a/gcc/config/darwin-c.c
+++ b/gcc/config/darwin-c.c
@@ -44,13 +44,12 @@ static bool using_frameworks = false;
 static const char *find_subframework_header (cpp_reader *pfile, const char 
*header,
                                             cpp_dir **dirp);

-typedef struct align_stack
-{
-  int alignment;
-  struct align_stack * prev;
-} align_stack;
+struct fld_align_stack {
+  int  alignment;
+  struct fld_align_stack * prev;
+};

-static struct align_stack * field_align_stack = NULL;
+static struct fld_align_stack * field_align_stack;

 /* Maintain a small stack of alignments.  This is similar to pragma
    pack's stack, but simpler.  */
@@ -58,7 +57,7 @@ static struct align_stack * field_align_stack = NULL;
 static void
 push_field_alignment (int bit_alignment)
 {
-  align_stack *entry = XNEW (align_stack);
+  fld_align_stack *entry = XNEW (fld_align_stack);

   entry->alignment = maximum_field_alignment;
   entry->prev = field_align_stack;
@@ -72,7 +71,7 @@ pop_field_alignment (void)
 {
   if (field_align_stack)
     {
-      align_stack *entry = field_align_stack;
+      fld_align_stack *entry = field_align_stack;

       maximum_field_alignment = entry->alignment;
       field_align_stack = entry->prev;
--
2.24.1