[RFA][PATCH v4 5/5] PowerPC: Exploit dynamic core regset sections

Andreas Arnez
2013-07-03T17:21:21Z

Use a dynamic iterator function for enumerating the supported core
regset sections on a PowerPC target. Compared to the previous approach
of selecting one out of six static lists, this simplifies the code.

2013-07-03 Andreas Arnez <arnez@linux.vnet.ibm.com>

* ppc-linux-tdep.c (ppc_linux_vsx_regset_sections): Remove array.
(ppc_linux_vmx_regset_sections): Likewise.
(ppc_linux_fp_regset_sections): Likewise.
(ppc64_linux_vsx_regset_sections): Likewise.
(ppc64_linux_vmx_regset_sections): Likewise.
(ppc64_linux_fp_regset_sections): Likewise.
(ppc_linux_iterate_over_regset_sections): New function.
(ppc_linux_init_abi): Remove all invocations of
set_gdbarch_core_regset_sections; instead, call
set_gdbarch_iterate_over_regset_sections.

Index: gdb/gdb/ppc-linux-tdep.c
===================================================================
--- gdb.orig/gdb/ppc-linux-tdep.c
+++ gdb/gdb/ppc-linux-tdep.c
@@ -256,53 +256,28 @@ ppc_linux_return_value (struct gdbarch *
readbuf, writebuf);
}

-static struct core_regset_section ppc_linux_vsx_regset_sections[] =
-{
- { ".reg", 48 * 4, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { ".reg-ppc-vmx", 544, "ppc Altivec" },
- { ".reg-ppc-vsx", 256, "POWER7 VSX" },
- { NULL, 0}
-};
-
-static struct core_regset_section ppc_linux_vmx_regset_sections[] =
-{
- { ".reg", 48 * 4, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { ".reg-ppc-vmx", 544, "ppc Altivec" },
- { NULL, 0}
-};
-
-static struct core_regset_section ppc_linux_fp_regset_sections[] =
-{
- { ".reg", 48 * 4, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { NULL, 0}
-};
-
-static struct core_regset_section ppc64_linux_vsx_regset_sections[] =
-{
- { ".reg", 48 * 8, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { ".reg-ppc-vmx", 544, "ppc Altivec" },
- { ".reg-ppc-vsx", 256, "POWER7 VSX" },
- { NULL, 0}
-};
+/* Iterate over supported core file register note sections. */

-static struct core_regset_section ppc64_linux_vmx_regset_sections[] =
+static void
+ppc_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
+ iterate_over_regset_sections_cb *cb,
+ void *cb_data,
+ const struct regcache *regcache)
{
- { ".reg", 48 * 8, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { ".reg-ppc-vmx", 544, "ppc Altivec" },
- { NULL, 0}
-};
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ int have_vsx = tdep->ppc_vr0_regnum != -1;
+ int have_altivec = tdep->ppc_vsr0_upper_regnum != -1;

-static struct core_regset_section ppc64_linux_fp_regset_sections[] =
-{
- { ".reg", 48 * 8, "general-purpose" },
- { ".reg2", 264, "floating-point" },
- { NULL, 0}
-};
+ if (cb (".reg", 48 * tdep->wordsize, "general-purpose", cb_data))
+ return;
+ if (cb (".reg2", 264, "floating-point", cb_data))
+ return;
+ if (have_altivec)
+ if (cb (".reg-ppc-vmx", 544, "ppc Altivec", cb_data))
+ return;
+ if (have_vsx)
+ cb (".reg-ppc-vsx", 256, "POWER7 VSX", cb_data);
+}

/* PLT stub in executable. */
static struct ppc_insn_pattern powerpc32_plt_stub[] =
@@ -1305,19 +1280,6 @@ ppc_linux_init_abi (struct gdbarch_info
else
set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc");

- /* Supported register sections. */
- if (tdesc_find_feature (info.target_desc,
- "org.gnu.gdb.power.vsx"))
- set_gdbarch_core_regset_sections (gdbarch,
- ppc_linux_vsx_regset_sections);
- else if (tdesc_find_feature (info.target_desc,
- "org.gnu.gdb.power.altivec"))
- set_gdbarch_core_regset_sections (gdbarch,
- ppc_linux_vmx_regset_sections);
- else
- set_gdbarch_core_regset_sections (gdbarch,
- ppc_linux_fp_regset_sections);
-
if (powerpc_so_ops.in_dynsym_resolve_code == NULL)
{
powerpc_so_ops = svr4_so_ops;
@@ -1359,19 +1321,6 @@ ppc_linux_init_abi (struct gdbarch_info
set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpcle");
else
set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc");
-
- /* Supported register sections. */
- if (tdesc_find_feature (info.target_desc,
- "org.gnu.gdb.power.vsx"))
- set_gdbarch_core_regset_sections (gdbarch,
- ppc64_linux_vsx_regset_sections);
- else if (tdesc_find_feature (info.target_desc,
- "org.gnu.gdb.power.altivec"))
- set_gdbarch_core_regset_sections (gdbarch,
- ppc64_linux_vmx_regset_sections);
- else
- set_gdbarch_core_regset_sections (gdbarch,
- ppc64_linux_fp_regset_sections);
}

/* PPC32 uses a different prpsinfo32 compared to most other Linux
@@ -1383,6 +1332,8 @@ ppc_linux_init_abi (struct gdbarch_info
set_gdbarch_regset_from_core_section (gdbarch,
ppc_linux_regset_from_core_section);
set_gdbarch_core_read_description (gdbarch, ppc_linux_core_read_description);
+ set_gdbarch_iterate_over_regset_sections (gdbarch,
+ ppc_linux_iterate_over_regset_sections);

/* Enable TLS support. */
set_gdbarch_fetch_tls_load_module_address (gdbarch,