>From 98710a202b7bbd1c3eb4f7479969cf9e37f886a2 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sat, 27 Feb 2021 22:50:56 +0100
Subject: [PATCH] Fix compilation errors with GCC < 4.6.

* libpoke/pkl-env.h (pkl_env): Add double-definition guard.
* libpoke/pkl.h (pkl_compiler, pkl_env): Likewise.
* libpoke/pvm.h (pvm_program, pkl_compiler): Likewise.
* libpoke/pvm-val.h (pvm_program, pvm_program_program_point): Likewise.
* libpoke/pvm-program.h (pvm_program_program_point): Likewise.
* libpoke/pkl-env.c (HASH_TABLE_SIZE, pkl_hash): Comment out definitions.
---
 libpoke/pkl-env.c     | 2 ++
 libpoke/pkl-env.h     | 3 +++
 libpoke/pkl.h         | 6 ++++++
 libpoke/pvm-program.h | 3 +++
 libpoke/pvm-val.h     | 6 ++++++
 libpoke/pvm.h         | 6 ++++++
 6 files changed, 26 insertions(+)

diff --git a/libpoke/pkl-env.c b/libpoke/pkl-env.c
index 782f022..98ccc74 100644
--- a/libpoke/pkl-env.c
+++ b/libpoke/pkl-env.c
@@ -43,8 +43,10 @@
    UP is a link to the immediately enclosing frame.  This is NULL for
    the top-level frame.  */
 
+#if 0 /* defined in pkl-ast.h */
 #define HASH_TABLE_SIZE 1008
 typedef pkl_ast_node pkl_hash[HASH_TABLE_SIZE];
+#endif
 
 struct pkl_env
 {
diff --git a/libpoke/pkl-env.h b/libpoke/pkl-env.h
index ef162d2..f403013 100644
--- a/libpoke/pkl-env.h
+++ b/libpoke/pkl-env.h
@@ -55,7 +55,10 @@
    are not generally available at compile-time.  However, the type
    information is always available at compile-time.  */
 
+#ifndef PKL_ENV_DEFINED
+#define PKL_ENV_DEFINED
 typedef struct pkl_env *pkl_env;  /* Struct defined in pkl-env.c */
+#endif
 
 /* Get an empty environment.  */
 
diff --git a/libpoke/pkl.h b/libpoke/pkl.h
index d016eac..ef9f33c 100644
--- a/libpoke/pkl.h
+++ b/libpoke/pkl.h
@@ -60,8 +60,11 @@
    longer needed, in order to do some finalization tasks and free
    resources.  */
 
+#ifndef PKL_COMPILER_DEFINED
+#define PKL_COMPILER_DEFINED
 typedef struct pkl_compiler *pkl_compiler; /* This data structure is
                                               defined in pkl.c */
+#endif
 
 /* Initialization and finalization functions.  */
 
@@ -140,7 +143,10 @@ pvm pkl_get_vm (pkl_compiler compiler);
 
 /* Return the current compile-time environment in COMPILER.  */
 
+#ifndef PKL_ENV_DEFINED
+#define PKL_ENV_DEFINED
 typedef struct pkl_env *pkl_env;  /* Struct defined in pkl-env.c */
+#endif
 
 pkl_env pkl_get_env (pkl_compiler compiler);
 
diff --git a/libpoke/pvm-program.h b/libpoke/pvm-program.h
index d878ef7..ba06f7e 100644
--- a/libpoke/pvm-program.h
+++ b/libpoke/pvm-program.h
@@ -21,7 +21,10 @@
 
 #include "pvm-vm.h"
 
+#ifndef PVM_PROGRAM_PROGRAM_POINT_DEFINED
+#define PVM_PROGRAM_PROGRAM_POINT_DEFINED
 typedef void *pvm_program_program_point; /* XXX better name */
+#endif
 
 /* Initialize and finalize the pvm-program subsystem.  */
 
diff --git a/libpoke/pvm-val.h b/libpoke/pvm-val.h
index 0c45f7d..dca133a 100644
--- a/libpoke/pvm-val.h
+++ b/libpoke/pvm-val.h
@@ -500,8 +500,14 @@ typedef struct pvm_type *pvm_type;
 #define PVM_VAL_CLS_ENTRY_POINT(V) (PVM_VAL_CLS((V))->entry_point)
 #define PVM_VAL_CLS_ENV(V) (PVM_VAL_CLS((V))->env)
 
+#ifndef PKL_PROGRAM_DEFINED
+#define PKL_PROGRAM_DEFINED
 typedef struct pvm_program *pvm_program;
+#endif
+#ifndef PVM_PROGRAM_PROGRAM_POINT_DEFINED
+#define PVM_PROGRAM_PROGRAM_POINT_DEFINED
 typedef void *pvm_program_program_point;
+#endif
 
 struct pvm_cls
 {
diff --git a/libpoke/pvm.h b/libpoke/pvm.h
index 30e9b7b..573264e 100644
--- a/libpoke/pvm.h
+++ b/libpoke/pvm.h
@@ -58,7 +58,10 @@ typedef uint64_t pvm_val;
 /* PVM programs are sequences of instructions, labels and directives,
    that can be run in the virtual machine.  */
 
+#ifndef PKL_PROGRAM_DEFINED
+#define PKL_PROGRAM_DEFINED
 typedef struct pvm_program *pvm_program;
+#endif
 
 /* Each PVM program can contain zero or more labels.  Labels are used
    as targets of branch instructions.  */
@@ -673,7 +676,10 @@ void pvm_set_oacutoff (pvm vm, unsigned int cutoff);
    It there is no compiler associated with VM, pvm_compiler returns
    NULL.  */
 
+#ifndef PKL_COMPILER_DEFINED
+#define PKL_COMPILER_DEFINED
 typedef struct pkl_compiler *pkl_compiler;
+#endif
 
 pkl_compiler pvm_compiler (pvm vm);
 
-- 
2.7.4