[Libunwind-devel] [PATCH 2/8] Allow IA64 cross-compilation

[Tommi Rantala]

Change the way we generate the cursor header files, so that we do not
need to invoke IA64 binaries, which would fail when cross-compiling
libunwind.

Adopt the strategy used in the Linux kernel build system, and parse our
annotated offset information from the assembler file produced by the
compiler.
---
 src/Makefile.am         |   15 ++++----
 src/ia64/mk_Gcursor_i.c |   91 +++++++++++++----------------------------------
 src/ia64/mk_cursor_i    |    7 ++++
 3 files changed, 40 insertions(+), 73 deletions(-)
 create mode 100755 src/ia64/mk_cursor_i

diff --git a/src/Makefile.am b/src/Makefile.am
index 281f2f5..b3fd043 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -400,14 +400,15 @@ endif
  libunwind_setjmp_la_SOURCES += arm/siglongjmp.S
 else
 if ARCH_IA64
- ia64_mk_Gcursor_i_SOURCES = ia64/mk_Gcursor_i.c
- ia64_mk_Lcursor_i_SOURCES = ia64/mk_Lcursor_i.c
- noinst_PROGRAMS = ia64/mk_Gcursor_i ia64/mk_Lcursor_i
  BUILT_SOURCES = Gcursor_i.h Lcursor_i.h
-Gcursor_i.h: ia64/mk_Gcursor_i
-       ia64/mk_Gcursor_i > $@
-Lcursor_i.h: ia64/mk_Lcursor_i
-       ia64/mk_Lcursor_i > $@
+mk_Gcursor_i.s: ia64/mk_Gcursor_i.c
+       $(COMPILE) -S ia64/mk_Gcursor_i.c -o mk_Gcursor_i.s
+mk_Lcursor_i.s: ia64/mk_Lcursor_i.c
+       $(COMPILE) -S ia64/mk_Lcursor_i.c -o mk_Lcursor_i.s
+Gcursor_i.h: mk_Gcursor_i.s
+       ia64/mk_cursor_i mk_Gcursor_i.s > Gcursor_i.h
+Lcursor_i.h: mk_Lcursor_i.s
+       ia64/mk_cursor_i mk_Lcursor_i.s > Lcursor_i.h
 
  lib_LTLIBRARIES += libunwind-ia64.la
  libunwind_la_SOURCES = $(libunwind_la_SOURCES_ia64)
diff --git a/src/ia64/mk_Gcursor_i.c b/src/ia64/mk_Gcursor_i.c
index 51cb0f4..b8f3253 100644
--- a/src/ia64/mk_Gcursor_i.c
+++ b/src/ia64/mk_Gcursor_i.c
@@ -25,8 +25,6 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.  */
 
 /* Utility to generate cursor_i.h.  */
 
-#include <stdio.h>
-
 #include "libunwind_i.h"
 
 #ifdef offsetof
@@ -35,72 +33,33 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.  */
 
 #define offsetof(type,field)   ((char *) &((type *) 0)->field - (char *) 0)
 
-static struct
-  {
-    const char name[256];
-    unsigned long value;
-  }
-tab[] =
-  {
-    { "IP_OFF",                offsetof (struct cursor, ip) },
-    { "PR_OFF",                offsetof (struct cursor, pr) },
-    { "BSP_OFF",       offsetof (struct cursor, bsp) },
-    { "PSP_OFF",       offsetof (struct cursor, psp) },
-    { "PFS_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_PFS]) },
-    { "RNAT_LOC_OFF",  offsetof (struct cursor, loc[IA64_REG_RNAT]) },
-    { "UNAT_LOC_OFF",  offsetof (struct cursor, loc[IA64_REG_UNAT]) },
-    { "LC_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_LC]) },
-    { "FPSR_LOC_OFF",  offsetof (struct cursor, loc[IA64_REG_FPSR]) },
-    { "B1_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_B1]) },
-    { "B2_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_B2]) },
-    { "B3_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_B3]) },
-    { "B4_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_B4]) },
-    { "B5_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_B5]) },
-    { "F2_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_F2]) },
-    { "F3_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_F3]) },
-    { "F4_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_F4]) },
-    { "F5_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_F5]) },
-    { "FR_LOC_OFF",    offsetof (struct cursor, loc[IA64_REG_F16]) },
-    { "LOC_SIZE",
-      (offsetof (struct cursor, loc[1]) - offsetof (struct cursor, loc[0]))
-    },
-    { "SIGCONTEXT_ADDR_OFF",   offsetof (struct cursor, sigcontext_addr) },
-};
-
-static const char *tabs = "\t\t\t\t\t\t\t\t\t\t";
+#define OFFSET(sym, offset) \
+       asm volatile("\n->" #sym " %0" : : "i" (offset))
 
 int
-main (int argc, char **argv)
+main (void)
 {
-  const char *space;
-  int i, num_tabs;
-  size_t len;
-
-  printf ("#ifndef cursor_i_h\n");
-  printf ("#define cursor_i_h\n\n");
-
-  printf ("/*\n * DO NOT MODIFY\n *\n * This file was generated by "
-         "%s.\n *\n */\n\n", argv[0]);
-
-  for (i = 0; i < (int) (sizeof (tab) / sizeof (tab[0])); ++i)
-    {
-      if (tab[i].name[0] == '\0')
-       printf ("\n");
-      else
-       {
-         len = strlen (tab[i].name);
-
-         num_tabs = (40 - len) / 8;
-         if (num_tabs <= 0)
-           space = " ";
-         else
-           space = strchr(tabs, '\0') - (40 - len) / 8;
-
-         printf ("#define %s%s%lu\t/* 0x%lx */\n",
-                 tab[i].name, space, tab[i].value, tab[i].value);
-       }
-    }
-
-  printf ("\n#endif /* cursor_i_h */\n");
+  OFFSET("IP_OFF",       offsetof (struct cursor, ip));
+  OFFSET("PR_OFF",       offsetof (struct cursor, pr));
+  OFFSET("BSP_OFF",      offsetof (struct cursor, bsp));
+  OFFSET("PSP_OFF",      offsetof (struct cursor, psp));
+  OFFSET("PFS_LOC_OFF",  offsetof (struct cursor, loc[IA64_REG_PFS]));
+  OFFSET("RNAT_LOC_OFF", offsetof (struct cursor, loc[IA64_REG_RNAT]));
+  OFFSET("UNAT_LOC_OFF", offsetof (struct cursor, loc[IA64_REG_UNAT]));
+  OFFSET("LC_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_LC]));
+  OFFSET("FPSR_LOC_OFF", offsetof (struct cursor, loc[IA64_REG_FPSR]));
+  OFFSET("B1_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_B1]));
+  OFFSET("B2_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_B2]));
+  OFFSET("B3_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_B3]));
+  OFFSET("B4_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_B4]));
+  OFFSET("B5_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_B5]));
+  OFFSET("F2_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_F2]));
+  OFFSET("F3_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_F3]));
+  OFFSET("F4_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_F4]));
+  OFFSET("F5_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_F5]));
+  OFFSET("FR_LOC_OFF",   offsetof (struct cursor, loc[IA64_REG_F16]));
+  OFFSET("LOC_SIZE",
+      (offsetof (struct cursor, loc[1]) - offsetof (struct cursor, loc[0])));
+  OFFSET("SIGCONTEXT_ADDR_OFF", offsetof (struct cursor, sigcontext_addr));
   return 0;
 }
diff --git a/src/ia64/mk_cursor_i b/src/ia64/mk_cursor_i
new file mode 100755
index 0000000..9211f91
--- /dev/null
+++ b/src/ia64/mk_cursor_i
@@ -0,0 +1,7 @@
+#!/bin/sh
+test -z "$1" && exit 1
+echo "/* GENERATED */"
+echo "#ifndef cursor_i_h"
+echo "#define cursor_i_h"
+sed -ne 's/^->"\(\S*\)" \(\d*\)/#define \1 \2/p' < $1 || exit $?
+echo "#endif"
-- 
1.7.9.5