--- /dev/null
+From 88ac930a725b8aac8284a2738f03b843f4343dd0 Mon Sep 17 00:00:00 2001
+From: Victor Do Nascimento <Victor.DoNascimento@arm.com>
+Date: Thu, 17 Nov 2022 14:48:37 +0000
+Subject: [PATCH 116/160] arm: Use DWARF numbering convention for
+ pseudo-register representation
+
+The patch, initially submitted to trunk in
+https://sourceware.org/pipermail/binutils/2022-July/122092.html ensures correct
+support for handling .save directives for mixed-register type lists involving
+the ra_auth_code pseudo-register, whereby the support first introduced in 2.39
+(https://sourceware.org/pipermail/binutils/2022-May/120672.html) led to the
+generation of unwinder code popping registers in reversed order.
+
+gas/Changelog:
+
+ * config/tc-arm.c (REG_RA_AUTH_CODE): New.
+ (parse_dot_save): Likewise.
+ (parse_reg_list): Remove obsolete code.
+ (reg_names): Set ra_auth_code to 143.
+ (s_arm_unwind_save): Handle core and pseudo-register lists via
+ parse_dot_save.
+ (s_arm_unwind_save_mixed): Deleted.
+ (s_arm_unwind_save_pseudo): Handle one register at a time.
+ * testsuite/gas/arm/unwind-pacbti-m-readelf.d: Fix test.
+ * testsuite/gas/arm/unwind-pacbti-m.d: Likewise.
+
+(cherry picked from commit 3a368c4c248f6e9f4bda3a5369befa17a4560293)
+---
+ gas/config/tc-arm.c | 159 ++++++++++--------
+ .../gas/arm/unwind-pacbti-m-readelf.d | 4 +-
+ gas/testsuite/gas/arm/unwind-pacbti-m.d | 2 +-
+ 3 files changed, 95 insertions(+), 70 deletions(-)
+
+--- a/gas/config/tc-arm.c
++++ b/gas/config/tc-arm.c
+@@ -742,6 +742,7 @@ const char * const reg_expected_msgs[] =
+ #define REG_SP 13
+ #define REG_LR 14
+ #define REG_PC 15
++#define REG_RA_AUTH_CODE 143
+
+ /* ARM instructions take 4bytes in the object file, Thumb instructions
+ take 2: */
+@@ -1943,21 +1944,6 @@ parse_reg_list (char ** strp, enum reg_l
+
+ reg = arm_reg_parse (&str, rt);
+
+- /* Skip over allowed registers of alternative types in mixed-type
+- register lists. */
+- if (reg == FAIL && rt == REG_TYPE_PSEUDO
+- && ((reg = arm_reg_parse (&str, REG_TYPE_RN)) != FAIL))
+- {
+- cur_reg = reg;
+- continue;
+- }
+- else if (reg == FAIL && rt == REG_TYPE_RN
+- && ((reg = arm_reg_parse (&str, REG_TYPE_PSEUDO)) != FAIL))
+- {
+- cur_reg = reg;
+- continue;
+- }
+-
+ if (etype == REGLIST_CLRM)
+ {
+ if (reg == REG_SP || reg == REG_PC)
+@@ -4139,7 +4125,6 @@ s_arm_unwind_fnstart (int ignored ATTRIB
+ unwind.sp_restored = 0;
+ }
+
+-
+ /* Parse a handlerdata directive. Creates the exception handling table entry
+ for the function. */
+
+@@ -4297,15 +4282,19 @@ s_arm_unwind_personality (int ignored AT
+ /* Parse a directive saving pseudo registers. */
+
+ static void
+-s_arm_unwind_save_pseudo (long range)
++s_arm_unwind_save_pseudo (int regno)
+ {
+ valueT op;
+
+- if (range & (1 << 12))
++ switch (regno)
+ {
++ case REG_RA_AUTH_CODE:
+ /* Opcode for restoring RA_AUTH_CODE. */
+ op = 0xb4;
+ add_unwind_opcode (op, 1);
++ break;
++ default:
++ as_bad (_("Unknown register %d encountered\n"), regno);
+ }
+ }
+
+@@ -4375,6 +4364,80 @@ s_arm_unwind_save_core (long range)
+ }
+ }
+
++/* Implement correct handling of .save lists enabling the split into
++sublists where necessary, while preserving correct sublist ordering. */
++
++static void
++parse_dot_save (char **str_p, int prev_reg)
++{
++ long core_regs = 0;
++ int reg;
++ int in_range = 0;
++
++ if (**str_p == ',')
++ *str_p += 1;
++ if (**str_p == '}')
++ {
++ *str_p += 1;
++ return;
++ }
++
++ while ((reg = arm_reg_parse (str_p, REG_TYPE_RN)) != FAIL)
++ {
++ if (!in_range)
++ {
++ if (core_regs & (1 << reg))
++ as_tsktsk (_("Warning: duplicated register (r%d) in register list"),
++ reg);
++ else if (reg <= prev_reg)
++ as_tsktsk (_("Warning: register list not in ascending order"));
++
++ core_regs |= (1 << reg);
++ prev_reg = reg;
++ if (skip_past_char(str_p, '-') != FAIL)
++ in_range = 1;
++ else if (skip_past_comma(str_p) == FAIL)
++ first_error (_("bad register list"));
++ }
++ else
++ {
++ int i;
++ if (reg <= prev_reg)
++ first_error (_("bad range in register list"));
++ for (i = prev_reg + 1; i <= reg; i++)
++ {
++ if (core_regs & (1 << i))
++ as_tsktsk (_("Warning: duplicated register (r%d) in register list"),
++ i);
++ else
++ core_regs |= 1 << i;
++ }
++ in_range = 0;
++ }
++ }
++ if (core_regs)
++ {
++ /* Higher register numbers go in higher memory addresses. When splitting a list,
++ right-most sublist should therefore be .saved first. Use recursion for this. */
++ parse_dot_save (str_p, reg);
++ /* We're back from recursion, so emit .save insn for sublist. */
++ s_arm_unwind_save_core (core_regs);
++ return;
++ }
++ /* Handle pseudo-regs, under assumption these are emitted singly. */
++ else if ((reg = arm_reg_parse (str_p, REG_TYPE_PSEUDO)) != FAIL)
++ {
++ /* Recurse for remainder of input. Note: No assumption is made regarding which
++ register in core register set holds pseudo-register. It's not considered in
++ ordering check beyond ensuring it's not sandwiched between 2 consecutive
++ registers. */
++ parse_dot_save (str_p, prev_reg + 1);
++ s_arm_unwind_save_pseudo (reg);
++ return;
++ }
++ else
++ as_bad (BAD_SYNTAX);
++}
+
+ /* Parse a directive saving FPA registers. */
+
+@@ -4716,39 +4779,13 @@ s_arm_unwind_save_mmxwcg (void)
+ ignore_rest_of_line ();
+ }
+
+-/* Convert range and mask_range into a sequence of s_arm_unwind_core
+- and s_arm_unwind_pseudo operations. We assume that mask_range will
+- not have consecutive bits set, or that one operation per bit is
+- acceptable. */
+-
+-static void
+-s_arm_unwind_save_mixed (long range, long mask_range)
+-{
+- while (mask_range)
+- {
+- long mask_bit = mask_range & -mask_range;
+- long subrange = range & (mask_bit - 1);
+-
+- if (subrange)
+- s_arm_unwind_save_core (subrange);
+-
+- s_arm_unwind_save_pseudo (mask_bit);
+- range &= ~subrange;
+- mask_range &= ~mask_bit;
+- }
+-
+- if (range)
+- s_arm_unwind_save_core (range);
+-}
+-
+ /* Parse an unwind_save directive.
+ If the argument is non-zero, this is a .vsave directive. */
+
+ static void
+ s_arm_unwind_save (int arch_v6)
+ {
+- char *peek, *mask_peek;
+- long range, mask_range;
++ char *peek;
+ struct reg_entry *reg;
+ bool had_brace = false;
+
+@@ -4756,7 +4793,7 @@ s_arm_unwind_save (int arch_v6)
+ as_bad (MISSING_FNSTART);
+
+ /* Figure out what sort of save we have. */
+- peek = mask_peek = input_line_pointer;
++ peek = input_line_pointer;
+
+ if (*peek == '{')
+ {
+@@ -4788,20 +4825,13 @@ s_arm_unwind_save (int arch_v6)
+
+ case REG_TYPE_PSEUDO:
+ case REG_TYPE_RN:
+- mask_range = parse_reg_list (&mask_peek, REGLIST_PSEUDO);
+- range = parse_reg_list (&input_line_pointer, REGLIST_RN);
+-
+- if (range == FAIL || mask_range == FAIL)
+- {
+- as_bad (_("expected register list"));
+- ignore_rest_of_line ();
+- return;
+- }
+-
+- demand_empty_rest_of_line ();
+-
+- s_arm_unwind_save_mixed (range, mask_range);
+- return;
++ {
++ if (had_brace)
++ input_line_pointer++;
++ parse_dot_save (&input_line_pointer, -1);
++ demand_empty_rest_of_line ();
++ return;
++ }
+
+ case REG_TYPE_VFD:
+ if (arch_v6)
+@@ -23993,12 +24023,8 @@ static const struct reg_entry reg_names[
+ /* XScale accumulator registers. */
+ REGNUM(acc,0,XSCALE), REGNUM(ACC,0,XSCALE),
+
+- /* DWARF ABI defines RA_AUTH_CODE to 143. It also reserves 134-142 for future
+- expansion. RA_AUTH_CODE here is given the value 143 % 134 to make it easy
+- for tc_arm_regname_to_dw2regnum to translate to DWARF reg number using
+- 134 + reg_number should the range 134 to 142 be used for more pseudo regs
+- in the future. This also helps fit RA_AUTH_CODE into a bitmask. */
+- REGDEF(ra_auth_code,12,PSEUDO),
++ /* AADWARF32 defines RA_AUTH_CODE to 143. */
++ REGDEF(ra_auth_code,143,PSEUDO),
+ };
+ #undef REGDEF
+ #undef REGNUM
+@@ -27905,7 +27931,6 @@ create_unwind_entry (int have_data)
+ return 0;
+ }
+
+-
+ /* Initialize the DWARF-2 unwind information for this procedure. */
+
+ void
+--- a/gas/testsuite/gas/arm/unwind-pacbti-m-readelf.d
++++ b/gas/testsuite/gas/arm/unwind-pacbti-m-readelf.d
+@@ -10,11 +10,11 @@ Unwind section '.ARM.exidx' at offset 0x
+
+ 0x0 <foo>: @0x0
+ Compact model index: 1
+- 0x84 0x00 pop {r14}
+ 0xb4 pop {ra_auth_code}
+ 0x84 0x00 pop {r14}
+- 0xb4 pop {ra_auth_code}
+ 0xa3 pop {r4, r5, r6, r7}
+ 0xb4 pop {ra_auth_code}
++ 0x84 0x00 pop {r14}
++ 0xb4 pop {ra_auth_code}
+ 0xa8 pop {r4, r14}
+ 0xb0 finish
+--- a/gas/testsuite/gas/arm/unwind-pacbti-m.d
++++ b/gas/testsuite/gas/arm/unwind-pacbti-m.d
+@@ -8,4 +8,4 @@
+ .*: file format.*
+
+ Contents of section .ARM.extab:
+- 0000 (00840281 b40084b4 b0a8b4a3|81028400 b48400b4 a3b4a8b0) 00000000 .*
++ 0000 (84b40281 84b4a300 b0a8b400|8102b484 00a3b484 00b4a8b0) 00000000 .*
projects / openwrt / staging / dedeckeh.git / blobdiff