Hi!

The nvptx backend defines ASM_OUTPUT_DEF along with
ASM_OUTPUT_DEF_FROM_DECLS.  Much like the rs6000 coff target, nvptx
triggers an unused variable warning:

/usr/lib/gcc-snapshot/bin/g++  -fno-PIE -c   -g -O2   -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE   -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common  -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/. -I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include -I../../gcc/gcc/../libcody  -I../../gcc/gcc/../libdecnumber -I../../gcc/gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc/gcc/../libbacktrace   -o varasm.o -MT varasm.o -MMD -MP -MF ./.deps/varasm.TPo ../../gcc/gcc/varasm.cc
../../gcc/gcc/varasm.cc: In function 'void output_constant_pool_contents(rtx_constant_pool*)':
../../gcc/gcc/varasm.cc:4318:21: error: unused variable 'name' [-Werror=unused-variable]
 4318 |         const char *name = XSTR (desc->sym, 0);
      |                     ^~~~
cc1plus: all warnings being treated as errors
make[1]: *** [Makefile:1145: varasm.o] Error 1


Fixed the same way:

diff --git a/gcc/config/nvptx/nvptx.h b/gcc/config/nvptx/nvptx.h
index ed72c253191..71297440566 100644
--- a/gcc/config/nvptx/nvptx.h
+++ b/gcc/config/nvptx/nvptx.h
@@ -321,6 +321,9 @@ struct GTY(()) machine_function
 #define ASM_OUTPUT_DEF(FILE,LABEL1,LABEL2)	\
   do						\
     {						\
+      (void) (FILE);				\
+      (void) (LABEL1);				\
+      (void) (LABEL2);				\
       gcc_unreachable ();			\
     }						\
   while (0)


Ok for HEAD?

Thanks,
  Jan-Benedict

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