From d4473757f18e0c7a56cde8c53256e87d5134ad06 Mon Sep 17 00:00:00 2001 From: Kevin Buettner Date: Thu, 20 Dec 2001 21:56:56 +0000 Subject: [PATCH] * arm-tdep.c (arm_scan_prologue): Don't require "mov ip, sp" to be the first instruction in the prologue. Also, revise the way the frame offset is computed for frameless functions. --- gdb/ChangeLog | 4 ++ gdb/arm-tdep.c | 144 +++++++++++++++++++++++++------------------------ 2 files changed, 79 insertions(+), 69 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 634024abe81..34cf3fdcda0 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -8,6 +8,10 @@ is no longer needed now that the frame info is being properly initialized. + * arm-tdep.c (arm_scan_prologue): Don't require "mov ip, sp" + to be the first instruction in the prologue. Also, revise + the way the frame offset is computed for frameless functions. + 2001-12-20 Michael Snyder * maint.c (maintenance_info_sections): Pass string argument to diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 4e88dd6a4b4..b78a53a03ce 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -812,98 +812,104 @@ arm_scan_prologue (struct frame_info *fi) traceback. In the APCS, the prologue should start with "mov ip, sp" so - if we don't see this as the first insn, we will stop. */ + if we don't see this as the first insn, we will stop. [Note: + This doesn't seem to be true any longer, so it's now an optional + part of the prologue. - Kevin Buettner, 2001-11-20] */ sp_offset = fp_offset = 0; if (read_memory_unsigned_integer (prologue_start, 4) == 0xe1a0c00d) /* mov ip, sp */ + current_pc = prologue_start + 4; + else + current_pc = prologue_start; + + for (; current_pc < prologue_end; current_pc += 4) { - for (current_pc = prologue_start + 4; current_pc < prologue_end; - current_pc += 4) + unsigned int insn = read_memory_unsigned_integer (current_pc, 4); + + if ((insn & 0xffff0000) == 0xe92d0000) + /* stmfd sp!, {..., fp, ip, lr, pc} + or + stmfd sp!, {a1, a2, a3, a4} */ { - unsigned int insn = read_memory_unsigned_integer (current_pc, 4); + int mask = insn & 0xffff; - if ((insn & 0xffff0000) == 0xe92d0000) - /* stmfd sp!, {..., fp, ip, lr, pc} - or - stmfd sp!, {a1, a2, a3, a4} */ - { - int mask = insn & 0xffff; + /* Calculate offsets of saved registers. */ + for (regno = PC_REGNUM; regno >= 0; regno--) + if (mask & (1 << regno)) + { + sp_offset -= 4; + fi->fsr.regs[regno] = sp_offset; + } + } + else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */ + { + unsigned imm = insn & 0xff; /* immediate value */ + unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ + imm = (imm >> rot) | (imm << (32 - rot)); + fp_offset = -imm; + fi->framereg = FP_REGNUM; + } + else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */ + { + unsigned imm = insn & 0xff; /* immediate value */ + unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ + imm = (imm >> rot) | (imm << (32 - rot)); + sp_offset -= imm; + } + else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */ + { + sp_offset -= 12; + regno = F0_REGNUM + ((insn >> 12) & 0x07); + fi->fsr.regs[regno] = sp_offset; + } + else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */ + { + int n_saved_fp_regs; + unsigned int fp_start_reg, fp_bound_reg; - /* Calculate offsets of saved registers. */ - for (regno = PC_REGNUM; regno >= 0; regno--) - if (mask & (1 << regno)) - { - sp_offset -= 4; - fi->fsr.regs[regno] = sp_offset; - } - } - else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */ + if ((insn & 0x800) == 0x800) /* N0 is set */ { - unsigned imm = insn & 0xff; /* immediate value */ - unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ - imm = (imm >> rot) | (imm << (32 - rot)); - fp_offset = -imm; - fi->framereg = FP_REGNUM; + if ((insn & 0x40000) == 0x40000) /* N1 is set */ + n_saved_fp_regs = 3; + else + n_saved_fp_regs = 1; } - else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */ + else { - unsigned imm = insn & 0xff; /* immediate value */ - unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ - imm = (imm >> rot) | (imm << (32 - rot)); - sp_offset -= imm; + if ((insn & 0x40000) == 0x40000) /* N1 is set */ + n_saved_fp_regs = 2; + else + n_saved_fp_regs = 4; } - else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */ + + fp_start_reg = F0_REGNUM + ((insn >> 12) & 0x7); + fp_bound_reg = fp_start_reg + n_saved_fp_regs; + for (; fp_start_reg < fp_bound_reg; fp_start_reg++) { sp_offset -= 12; - regno = F0_REGNUM + ((insn >> 12) & 0x07); - fi->fsr.regs[regno] = sp_offset; - } - else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */ - { - int n_saved_fp_regs; - unsigned int fp_start_reg, fp_bound_reg; - - if ((insn & 0x800) == 0x800) /* N0 is set */ - { - if ((insn & 0x40000) == 0x40000) /* N1 is set */ - n_saved_fp_regs = 3; - else - n_saved_fp_regs = 1; - } - else - { - if ((insn & 0x40000) == 0x40000) /* N1 is set */ - n_saved_fp_regs = 2; - else - n_saved_fp_regs = 4; - } - - fp_start_reg = F0_REGNUM + ((insn >> 12) & 0x7); - fp_bound_reg = fp_start_reg + n_saved_fp_regs; - for (; fp_start_reg < fp_bound_reg; fp_start_reg++) - { - sp_offset -= 12; - fi->fsr.regs[fp_start_reg++] = sp_offset; - } + fi->fsr.regs[fp_start_reg++] = sp_offset; } - else if ((insn & 0xf0000000) != 0xe0000000) - break; /* Condition not true, exit early */ - else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */ - break; /* Don't scan past a block load */ - else - /* The optimizer might shove anything into the prologue, - so we just skip what we don't recognize. */ - continue; } + else if ((insn & 0xf0000000) != 0xe0000000) + break; /* Condition not true, exit early */ + else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */ + break; /* Don't scan past a block load */ + else + /* The optimizer might shove anything into the prologue, + so we just skip what we don't recognize. */ + continue; } /* The frame size is just the negative of the offset (from the original SP) of the last thing thing we pushed on the stack. The frame offset is [new FP] - [new SP]. */ fi->framesize = -sp_offset; - fi->frameoffset = fp_offset - sp_offset; + if (fi->framereg == FP_REGNUM) + fi->frameoffset = fp_offset - sp_offset; + else + fi->frameoffset = 0; save_prologue_cache (fi); } -- 2.30.2