Remove where-is-mcontext.c

That's pretty old. Using the same code for ppc32/ppc64 appears to
work.

.gitignore

@@ -32,7 +32,6 @@ src/runtime/target-arch-os.h
 src/runtime/target-arch.h
 src/runtime/target-lispregs.h
 src/runtime/target-os.h
-src/runtime/ppc-linux-mcontext.h
 tests/test-status.lisp-expr
 tests/test.log
 tests/*.so

clean.sh

@@ -110,7 +110,6 @@ find . \( \
         -name 'test.log' -o \
         -name 'a.out' -o \
         -name 'sbcl' -o \
-        -name 'ppc-linux-mcontext.h' -o \
         -name 'depend' -o \
         -name 'TAGS' -o \
         -name 'tags' -o \

make-config.sh

@@ -724,15 +724,7 @@ case "$sbcl_arch" in
     esac
     ;;
   ppc)
-    if [ "$sbcl_os" = "linux" ]; then
-        # Use a C program to detect which kind of glibc we're building on,
-        # to bandage across the break in source compatibility between
-        # versions 2.3.1 and 2.3.2
-        #
-        # FIXME: integrate to grovel-features, mayhaps
-	$GNUMAKE -C tools-for-build where-is-mcontext -I ../src/runtime
-	tools-for-build/where-is-mcontext > src/runtime/ppc-linux-mcontext.h || (echo "error running where-is-mcontext"; exit 1)
-    elif [ "$sbcl_os" = "darwin" ]; then
+    if [ "$sbcl_os" = "darwin" ]; then
         # We provide a dlopen shim, so a little lie won't hurt
  	printf ' :os-provides-dlopen' >> $ltf
         # The default stack ulimit under darwin is too small to run PURIFY.
@@ -745,10 +737,6 @@ case "$sbcl_arch" in
     fi
     ;;
   ppc64)
-    # there is no glibc bug that requires the 'where-is-mcontext' hack.
-    # (Sufficiently new glibc uses the correct definition, which is the same as
-    # 2.3.1, so define our constant for that)
-    echo '#define GLIBC231_STYLE_UCONTEXT 1' > src/runtime/ppc-linux-mcontext.h
    ;;
   riscv)
     if [ "$xlen" = "64" ]; then

src/runtime/ppc-linux-os.c

@@ -34,7 +34,6 @@
 #include <sys/prctl.h>
 
 #include "validate.h"
-#include "ppc-linux-mcontext.h"
 
 int arch_os_thread_init(struct thread *thread) {
     /* For some reason, PPC Linux appears to default to not generating
@@ -62,74 +61,37 @@ int arch_os_thread_cleanup(struct thread *thread) {
 os_context_register_t   *
 os_context_register_addr(os_context_t *context, int offset)
 {
-#if defined(GLIBC231_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.regs)->gpr[offset]);
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.uc_regs->gregs)[offset]);
-#endif
+    return &context->uc_mcontext.regs->gpr[offset];
 }
 
 os_context_register_t *
 os_context_lr_addr(os_context_t *context)
 {
-#if defined(GLIBC231_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.regs)->link);
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.uc_regs->gregs)[PT_LNK]);
-#endif
+    return &context->uc_mcontext.regs->link;
 }
 
 os_context_register_t *
 os_context_ctr_addr(os_context_t *context)
 {
-    /* Like os_context_fp_control() and os_context_lr_addr(), this
-     * uses an index beyond the declared end of the array in order to
-     * find the correct register value in the context. */
-#if defined(GLIBC231_STYLE_UCONTEXT)
-    /* FIXME: This probably should be ->ctr instead of ->gpr[PT_CTR]. */
-    return &((context->uc_mcontext.regs)->gpr[PT_CTR]);
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.uc_regs)->gregs[PT_CTR]);
-#endif
+    return &context->uc_mcontext.regs->ctr;
 }
 
 os_context_register_t *
 os_context_cr_addr(os_context_t *context)
 {
-    /* Like os_context_fp_control() and os_context_lr_addr(), this
-     * uses an index beyond the declared end of the array in order to
-     * find the correct register value in the context. */
-#if defined(GLIBC231_STYLE_UCONTEXT)
-    /* FIXME: This probably should be ->ccr instead of ->gpr[PT_CCR]. */
-    return &((context->uc_mcontext.regs)->gpr[PT_CCR]);
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return &((context->uc_mcontext.uc_regs)->gregs[PT_CCR]);
-#endif
+    return &context->uc_mcontext.regs->ccr;
 }
 
 sigset_t *
 os_context_sigmask_addr(os_context_t *context)
 {
-#if defined(GLIBC231_STYLE_UCONTEXT)
     return &context->uc_sigmask;
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return &context->uc_sigmask;
-#endif
 }
 
 unsigned long
 os_context_fp_control(os_context_t *context)
 {
-    /* So this may look like nice, well behaved code. However, closer
-       inspection reveals that gpr is simply the general purpose
-       registers, and PT_FPSCR is an offset that is larger than 32
-       (the number of ppc registers), but that happens to get the
-       right answer. -- CSR, 2002-07-11 */
-#if defined(GLIBC231_STYLE_UCONTEXT)
-    return context->uc_mcontext.regs->gpr[PT_FPSCR];
-#elif defined(GLIBC232_STYLE_UCONTEXT)
-    return context->uc_mcontext.uc_regs->gregs[PT_FPSCR];
-#endif
+    return ((unsigned long*)context->uc_mcontext.regs)[PT_FPSCR];
 }
 
 void

src/runtime/ppc-linux-os.h

@@ -8,13 +8,6 @@ unsigned long os_context_fp_control(os_context_t *context);
 #define RESTORE_FP_CONTROL_FROM_CONTEXT
 void os_restore_fp_control(os_context_t *context);
 
-#include "ppc-linux-mcontext.h" // Selects one of these two definitions
-#ifdef GLIBC231_STYLE_UCONTEXT
-#  define OS_CONTEXT_PC(context) (context->uc_mcontext.regs)->nip
-#elif defined GLIBC232_STYLE_UCONTEXT
-#  define OS_CONTEXT_PC(context) (context->uc_mcontext.uc_regs->gregs)[PT_NIP]
-#else
-#  error "Need a definition of OS_CONTEXT_PC"
-#endif
+#define OS_CONTEXT_PC(context) (context->uc_mcontext.regs)->nip
 
 #endif /* _PPC_LINUX_OS_H */

tools-for-build/where-is-mcontext.c

@@ -1,51 +0,0 @@
-/*
- * Find the offset of uc_mcontext in a ucontext structure, to enable
- * building on both (glibc-2.3.1 and earlier) and (glibc-2.3.2 and
- * later), after the glibc developers broke source code compatibility.
- * (see also Debian bugs #207806 and #209074)
- */
-
-/*
- * This software is part of the SBCL system. See the README file for
- * more information.
- *
- * While most of SBCL is derived from the CMU CL system, many
- * utilities for the build process (like this one) were written from
- * scratch after the fork from CMU CL.
- *
- * This software is in the public domain and is provided with
- * absolutely no warranty. See the COPYING and CREDITS files for
- * more information.
- */
-
-#include <stdio.h>
-#include <stddef.h>
-#include <stdlib.h>
-#include <sys/ucontext.h>
-
-int main (int argc, char *argv[]) {
-
-    if(argc != 1) {
-        fprintf(stderr,"%s: command line arguments provided.  Don't do that.\n", argv[0]);
-        exit(1);
-    }
-
-    printf("\
-/* This is an automatically-generated file; please do not edit it.\n\
-   See the program tools-for-build/where-is-mcontext.c.\n\
- */\n\n");
-
-    printf("\
-#ifndef PPC_LINUX_MCONTEXT_H\n\
-#define PPC_LINUX_MCONTEXT_H\n\n");
-
-    if (offsetof(ucontext_t,uc_mcontext) > 40) {
-        printf("#define GLIBC232_STYLE_UCONTEXT\n\n");
-    } else {
-        printf("#define GLIBC231_STYLE_UCONTEXT\n\n");
-    }
-    printf("\
-#endif /* PPC_LINUX_MCONTEXT_H */\n");
-    exit(0);
-}
-