[PATCH v2] sim/igen: Fix linker error with -fno-common

[Sebastian Huber]

GCC 10 enables -fno-common by default.  This resulted in multiple
definition linker errors since a global variable was declared and
defined in a header file:

  ld: libsim.a(idecode.o):sim/v850/idecode.h:71: multiple definition of
  `idecode_issue'; libsim.a(irun.o):sim/v850/idecode.h:71: first defined
  here

  ld: libsim.a(engine.o):sim/v850/idecode.h:71: multiple definition of
  `idecode_issue'; libsim.a(irun.o):sim/v850/idecode.h:71: first defined
  here

  ld: libsim.a(support.o):sim/v850/idecode.h:71: multiple definition of
  `idecode_issue'; libsim.a(irun.o):sim/v850/idecode.h:71: first defined
  here

  ld: libsim.a(semantics.o):sim/v850/idecode.h:71: multiple definition
  of `idecode_issue'; libsim.a(irun.o):sim/v850/idecode.h:71: first
  defined here

sim/igen

	PR sim/26194

	* lf.h (lf_get_file_type): Declare.
	* lf.c (lf_get_file_type): Define.
	* gen-idecode.c (print_idecode_issue_function_header): Use
	lf_get_file_type() to issue an extern variable declaration in
	case of header files.
---

v2: Improve commit message.

 sim/igen/gen-idecode.c | 2 ++
 sim/igen/lf.c          | 7 +++++++
 sim/igen/lf.h          | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/sim/igen/gen-idecode.c b/sim/igen/gen-idecode.c
index b8f8ca15061..741498a1be9 100644
--- a/sim/igen/gen-idecode.c
+++ b/sim/igen/gen-idecode.c
@@ -930,6 +930,8 @@ print_idecode_issue_function_header (lf *file,
 					"INLINE_IDECODE", "\n");
       break;
     case is_function_variable:
+      if (lf_get_file_type (file) == lf_is_h)
+	lf_printf (file, "extern ");
       print_semantic_function_type (file);
       lf_printf (file, " (*");
       break;
diff --git a/sim/igen/lf.c b/sim/igen/lf.c
index 0f377d48d88..937e3d939ff 100644
--- a/sim/igen/lf.c
+++ b/sim/igen/lf.c
@@ -86,6 +86,13 @@ lf_open (char *name,
 }
 
 
+lf_file_type
+lf_get_file_type (const lf *file)
+{
+  return file->type;
+}
+
+
 void
 lf_close (lf *file)
 {
diff --git a/sim/igen/lf.h b/sim/igen/lf.h
index 54b4dcd0de1..6d86fac8d3f 100644
--- a/sim/igen/lf.h
+++ b/sim/igen/lf.h
@@ -54,6 +54,8 @@ extern lf *lf_open
    lf_file_references file_references,
    lf_file_type type, const char *program);
 
+extern lf_file_type lf_get_file_type (const lf *file);
+
 extern void lf_close (lf *file);
 
 
-- 
2.26.2