[PATCH] RISC-V: Don't report an error until the link phase if suitable multilib isn't found.

[Jin Ma <jinma@linux.alibaba.com>]

When suitable multilib isn't found, an error is not reported until the
link period, which is inconsistent with the result of compiling option
`-print-multi-directory`. For example, when suitable multilib isn't
found, the return result of `-print-multi-directory` is the default
value '.', while the actual execution result is an error during the
link phase. This is not very reasonable.

I think the error should be reported in advance, so that the compilation
option `-print-multi-directory` will also report an error. The two
should be consistent, either reporting errors or using default values.

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc
	(riscv_compute_multilib): report an error if suitable multilib isn't found.
	(struct riscv_multi_lib_info_t): Delet.
	(riscv_multi_lib_check): Likewise.
	* config/riscv/elf.h (LIB_SPEC): Likewise.
	* config/riscv/riscv.h (riscv_multi_lib_check): Likewise.
	(EXTRA_SPEC_FUNCTIONS): Likewise.
---
 gcc/common/config/riscv/riscv-common.cc | 25 +++++--------------------
 gcc/config/riscv/elf.h                  |  3 +--
 gcc/config/riscv/riscv.h                |  4 +---
 3 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index ebc1ed7d7e4..3f27ecf4b3c 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -274,9 +274,6 @@ struct riscv_multi_lib_info_t {
 		     const std::vector<std::string> &);
 };
 
-/* Flag for checking if there is no suitable multi-lib found.  */
-static bool riscv_no_matched_multi_lib;
-
 /* Used for record value of -march and -mabi.  */
 static std::string riscv_current_arch_str;
 static std::string riscv_current_abi_str;
@@ -1396,21 +1393,6 @@ riscv_expand_arch_from_cpu (int argc ATTRIBUTE_UNUSED,
   return xasprintf ("-march=%s", arch.c_str());
 }
 
-/* Report error if not found suitable multilib.  */
-const char *
-riscv_multi_lib_check (int argc ATTRIBUTE_UNUSED,
-		       const char **argv ATTRIBUTE_UNUSED)
-{
-  if (riscv_no_matched_multi_lib)
-    fatal_error (
-      input_location,
-      "Cannot find suitable multilib set for %<-march=%s%>/%<-mabi=%s%>",
-      riscv_current_arch_str.c_str (),
-      riscv_current_abi_str.c_str ());
-
-  return "";
-}
-
 /* We only override this in bare-metal toolchain.  */
 #ifdef RISCV_USE_CUSTOMISED_MULTI_LIB
 
@@ -1583,7 +1565,6 @@ riscv_compute_multilib (
   const char *this_path;
   size_t this_path_len;
   bool result;
-  riscv_no_matched_multi_lib = false;
   riscv_subset_list *subset_list = NULL;
 
   std::vector<riscv_multi_lib_info_t> multilib_infos;
@@ -1709,7 +1690,11 @@ riscv_compute_multilib (
 
   if (best_match_multi_lib == -1)
     {
-      riscv_no_matched_multi_lib = true;
+      fatal_error (
+	input_location,
+	"Cannot find suitable multilib set for %<-march=%s%>/%<-mabi=%s%>",
+	riscv_current_arch_str.c_str (),
+	riscv_current_abi_str.c_str ());
       return multilib_dir;
     }
   else
diff --git a/gcc/config/riscv/elf.h b/gcc/config/riscv/elf.h
index a725c00b637..7b8dc29d4cb 100644
--- a/gcc/config/riscv/elf.h
+++ b/gcc/config/riscv/elf.h
@@ -28,8 +28,7 @@ along with GCC; see the file COPYING3.  If not see
    Handle the circular dependence between libc and libgloss. */
 #undef  LIB_SPEC
 #define LIB_SPEC \
-  "--start-group -lc %{!specs=nosys.specs:-lgloss} --end-group " \
-  "%{!nostartfiles:%{!nodefaultlibs:%{!nolibc:%{!nostdlib:%:riscv_multi_lib_check()}}}}"
+  "--start-group -lc %{!specs=nosys.specs:-lgloss} --end-group"
 
 #undef  STARTFILE_SPEC
 #define STARTFILE_SPEC "crt0%O%s crtbegin%O%s"
diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index 5bc7f2f467d..b8fa5f022db 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -46,13 +46,11 @@ along with GCC; see the file COPYING3.  If not see
 extern const char *riscv_expand_arch (int argc, const char **argv);
 extern const char *riscv_expand_arch_from_cpu (int argc, const char **argv);
 extern const char *riscv_default_mtune (int argc, const char **argv);
-extern const char *riscv_multi_lib_check (int argc, const char **argv);
 
 # define EXTRA_SPEC_FUNCTIONS						\
   { "riscv_expand_arch", riscv_expand_arch },				\
   { "riscv_expand_arch_from_cpu", riscv_expand_arch_from_cpu },		\
-  { "riscv_default_mtune", riscv_default_mtune },			\
-  { "riscv_multi_lib_check", riscv_multi_lib_check },
+  { "riscv_default_mtune", riscv_default_mtune },
 
 /* Support for a compile-time default CPU, et cetera.  The rules are:
    --with-arch is ignored if -march or -mcpu is specified.
-- 
2.17.1