Re: [PATCH] Fix -Wshadow=local warnings in dumpfile.h

[Bernd Edlinger <bernd.edlinger@hotmail.de>]

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On 10/4/19 2:16 PM, Richard Sandiford wrote:
> Bernd Edlinger <bernd.edlinger@hotmail.de> writes:
>> Hi,
>>
>> this fixes a -Wshadow=local warning when using AUTO_DUMP_SCOPE in
>> nested blocks.  Since NAME i a string I cannot use it to create
>> a unique name for the auto_dump_scope object.
>>
>> So I used XCONCAT2 from good old symcat.h, to mangle the __LINE__
>> macro into the scope object name.
> 
> Seems a pity to reintroduce uses of symcat.h again now when it was
> originally only a bridge from pre-ISO C.  How about just importing
> XCONCAT2 into system.h instead?  I guess it's a bit of an abuse of
> system.h, but not really much worse than CEIL, ROUND_UP, etc., and
> that's where symcat.h was originally included.
> 

Done.

Is it OK for trunk?


Thanks
Bernd.

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2019-10-04  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* system.h (CONCAT2, XCONCAT2): Imported from symcat.h
	* dumpfile.h (AUTO_DUMP_SCOPE): Use XCONCAT2 and __LINE__
	to form a unique name for the scope variable.

Index: gcc/system.h
===================================================================
--- gcc/system.h	(revision 276589)
+++ gcc/system.h	(working copy)
@@ -392,6 +392,12 @@ extern int errno;
 /* This macro rounds x down to the y boundary.  */
 #define ROUND_DOWN(x,y) ((x) & ~((y) - 1))
  	
+/* This concatenates two symbols before macro expansion. */
+#define CONCAT2(a,b)	a##b
+
+/* This concatenates two symbols after macro expansion. */
+#define XCONCAT2(a,b)	CONCAT2(a,b)
+
 #ifdef HAVE_SYS_WAIT_H
 #include <sys/wait.h>
 #endif
Index: gcc/dumpfile.h
===================================================================
--- gcc/dumpfile.h	(revision 276589)
+++ gcc/dumpfile.h	(working copy)
@@ -634,7 +634,7 @@ class auto_dump_scope
    in a nested scope implicitly default to MSG_PRIORITY_INTERNALS.  */
 
 #define AUTO_DUMP_SCOPE(NAME, USER_LOC) \
-  auto_dump_scope scope (NAME, USER_LOC)
+  auto_dump_scope XCONCAT2 (scope, __LINE__) (NAME, USER_LOC)
 
 extern void dump_function (int phase, tree fn);
 extern void print_combine_total_stats (void);