Display branch destinations after PC-relative loads (#194)

Author: AetiasHax

objdiff-core/src/arch/arm.rs

@@ -347,6 +347,7 @@ impl Arch for ArchArm {
             cb(InstructionPart::reloc())?;
         } else {
             push_args(
+                ins,
                 &parsed_ins,
                 resolved.relocation,
                 resolved.ins_ref.address as u32,
@@ -478,6 +479,7 @@ impl DisasmMode {
 }
 
 fn push_args(
+    ins: unarm::Ins,
     parsed_ins: &unarm::ParsedIns,
     relocation: Option<ResolvedRelocation>,
     cur_addr: u32,
@@ -623,6 +625,14 @@ fn push_args(
             arg_cb(InstructionPart::opaque("!"))?;
         }
     }
+
+    let branch_dest = get_pc_relative_load_address(ins, cur_addr);
+    if let Some(branch_dest) = branch_dest {
+        arg_cb(InstructionPart::basic(" (->"))?;
+        arg_cb(InstructionPart::branch_dest(branch_dest))?;
+        arg_cb(InstructionPart::basic(")"))?;
+    }
+
     Ok(())
 }
 
@@ -650,3 +660,21 @@ fn find_reloc_arg(
         None
     }
 }
+
+fn get_pc_relative_load_address(ins: unarm::Ins, address: u32) -> Option<u32> {
+    match ins {
+        unarm::Ins::Arm(ins)
+            if ins.op == arm::Opcode::Ldr
+                && ins.modifier_addr_ldr_str() == arm::AddrLdrStr::Imm
+                && ins.field_rn_deref().reg == args::Register::Pc =>
+        {
+            let offset = ins.field_offset_12().value;
+            Some(address.wrapping_add_signed(offset + 8))
+        }
+        unarm::Ins::Thumb(ins) if ins.op == thumb::Opcode::LdrPc => {
+            let offset = ins.field_rel_immed_8().value;
+            Some((address & !3).wrapping_add_signed(offset + 4))
+        }
+        _ => None,
+    }
+}

objdiff-core/tests/snapshots/arch_arm__read_arm-3.snap

@@ -1,5 +1,6 @@
 ---
 source: objdiff-core/tests/arch_arm.rs
+assertion_line: 16
 expression: output
 ---
 [(Address(0), Normal, 5), (Spacing(4), Normal, 0), (Opcode("stmdb", 32895), Normal, 10), (Argument(Opaque("sp")), Normal, 0), (Argument(Opaque("!")), Normal, 0), (Basic(", "), Normal, 0), (Basic("{"), Normal, 0), (Argument(Opaque("r4")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r5")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r6")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("lr")), Normal, 0), (Basic("}"), Normal, 0), (Eol, Normal, 0)]
@@ -21,15 +22,15 @@ expression: output
 [(Address(64), Normal, 5), (Spacing(4), Normal, 0), (Opcode("b", 32773), Normal, 10), (BranchDest(152), Normal, 0), (Basic(" ~>"), Rotating(5), 0), (Eol, Normal, 0)]
 [(Address(68), Normal, 5), (Spacing(4), Normal, 0), (Opcode("b", 32773), Normal, 10), (BranchDest(164), Normal, 0), (Basic(" ~>"), Rotating(6), 0), (Eol, Normal, 0)]
 [(Address(72), Normal, 5), (Spacing(4), Normal, 0), (Opcode("b", 32773), Normal, 10), (BranchDest(164), Normal, 0), (Basic(" ~>"), Rotating(6), 0), (Eol, Normal, 0)]
-[(Address(76), Normal, 5), (Basic(" ~> "), Rotating(4), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(336)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
+[(Address(76), Normal, 5), (Basic(" ~> "), Rotating(4), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(336)), Normal, 0), (Basic("]"), Normal, 0), (Basic(" (->"), Normal, 0), (BranchDest(420), Normal, 0), (Basic(")"), Normal, 0), (Eol, Normal, 0)]
 [(Address(80), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(0)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(84), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bl", 32774), Normal, 10), (Symbol(Symbol { name: "_ZN18UnkStruct_027e103c19func_ov000_020cf01cEv", demangled_name: Some("UnkStruct_027e103c::func_ov000_020cf01c()"), address: 0, size: 0, kind: Unknown, section: None, flags: FlagSet(Global | Weak), align: None, virtual_address: None }), Bright, 0), (Addend(-8), Bright, 0), (Eol, Normal, 0)]
 [(Address(88), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldrb", 32800), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(224)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(92), Normal, 5), (Spacing(4), Normal, 0), (Opcode("cmp", 32786), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(0)), Normal, 0), (Eol, Normal, 0)]
 [(Address(96), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bne", 32773), Normal, 10), (BranchDest(108), Normal, 0), (Basic(" ~>"), Rotating(7), 0), (Eol, Normal, 0)]
 [(Address(100), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bl", 32774), Normal, 10), (Symbol(Symbol { name: "_ZN13LinkStateItem15GetEquipBombchuEv", demangled_name: Some("LinkStateItem::GetEquipBombchu()"), address: 472, size: 16, kind: Function, section: Some(0), flags: FlagSet(Global), align: None, virtual_address: None }), Bright, 0), (Addend(-8), Bright, 0), (Basic(" ~>"), Rotating(8), 0), (Eol, Normal, 0)]
 [(Address(104), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bl", 32774), Normal, 10), (Symbol(Symbol { name: "_ZN12EquipBombchu19func_ov014_0213ec64Ev", demangled_name: Some("EquipBombchu::func_ov014_0213ec64()"), address: 0, size: 0, kind: Unknown, section: None, flags: FlagSet(Global | Weak), align: None, virtual_address: None }), Bright, 0), (Addend(-8), Bright, 0), (Eol, Normal, 0)]
-[(Address(108), Normal, 5), (Basic(" ~> "), Rotating(7), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(308)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
+[(Address(108), Normal, 5), (Basic(" ~> "), Rotating(7), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(308)), Normal, 0), (Basic("]"), Normal, 0), (Basic(" (->"), Normal, 0), (BranchDest(424), Normal, 0), (Basic(")"), Normal, 0), (Eol, Normal, 0)]
 [(Address(112), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(0)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(116), Normal, 5), (Spacing(4), Normal, 0), (Opcode("blx", 32777), Normal, 10), (Symbol(Symbol { name: "_Z19func_ov014_0211fd04Pi", demangled_name: Some("func_ov014_0211fd04(int*)"), address: 0, size: 0, kind: Unknown, section: None, flags: FlagSet(Global | Weak), align: None, virtual_address: None }), Bright, 0), (Addend(-8), Bright, 0), (Eol, Normal, 0)]
 [(Address(120), Normal, 5), (Spacing(4), Normal, 0), (Opcode("b", 32773), Normal, 10), (BranchDest(200), Normal, 0), (Basic(" ~>"), Rotating(0), 0), (Eol, Normal, 0)]
@@ -43,7 +44,7 @@ expression: output
 [(Address(152), Normal, 5), (Basic(" ~> "), Rotating(5), 0), (Opcode("mov", 32818), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r5")), Normal, 0), (Eol, Normal, 0)]
 [(Address(156), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bl", 32774), Normal, 10), (Symbol(Symbol { name: "_ZN13LinkStateItem15StopUsingHammerEv", demangled_name: Some("LinkStateItem::StopUsingHammer()"), address: 0, size: 0, kind: Unknown, section: None, flags: FlagSet(Global | Weak), align: None, virtual_address: None }), Bright, 0), (Addend(-8), Bright, 0), (Eol, Normal, 0)]
 [(Address(160), Normal, 5), (Spacing(4), Normal, 0), (Opcode("b", 32773), Normal, 10), (BranchDest(200), Normal, 0), (Basic(" ~>"), Rotating(0), 0), (Eol, Normal, 0)]
-[(Address(164), Normal, 5), (Basic(" ~> "), Rotating(6), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(248)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
+[(Address(164), Normal, 5), (Basic(" ~> "), Rotating(6), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(248)), Normal, 0), (Basic("]"), Normal, 0), (Basic(" (->"), Normal, 0), (BranchDest(420), Normal, 0), (Basic(")"), Normal, 0), (Eol, Normal, 0)]
 [(Address(168), Normal, 5), (Spacing(4), Normal, 0), (Opcode("mov", 32818), Normal, 10), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(0)), Normal, 0), (Eol, Normal, 0)]
 [(Address(172), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(0)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(176), Normal, 5), (Spacing(4), Normal, 0), (Opcode("mov", 32818), Normal, 10), (Argument(Opaque("r2")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r1")), Normal, 0), (Eol, Normal, 0)]
@@ -98,7 +99,7 @@ expression: output
 [(Address(372), Normal, 5), (Spacing(4), Normal, 0), (Opcode("add", 32770), Normal, 10), (Argument(Opaque("r6")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r6")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(4)), Normal, 0), (Eol, Normal, 0)]
 [(Address(376), Normal, 5), (Spacing(4), Normal, 0), (Opcode("cmp", 32786), Normal, 10), (Argument(Opaque("r6")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r4")), Normal, 0), (Eol, Normal, 0)]
 [(Address(380), Normal, 5), (Spacing(4), Normal, 0), (Opcode("bne", 32773), Normal, 10), (BranchDest(364), Normal, 0), (Basic(" ~>"), Rotating(15), 0), (Eol, Normal, 0)]
-[(Address(384), Normal, 5), (Basic(" ~> "), Rotating(14), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(36)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
+[(Address(384), Normal, 5), (Basic(" ~> "), Rotating(14), 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(36)), Normal, 0), (Basic("]"), Normal, 0), (Basic(" (->"), Normal, 0), (BranchDest(428), Normal, 0), (Basic(")"), Normal, 0), (Eol, Normal, 0)]
 [(Address(388), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldr", 32799), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(0)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(392), Normal, 5), (Spacing(4), Normal, 0), (Opcode("ldrb", 32800), Normal, 10), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(128)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
 [(Address(396), Normal, 5), (Spacing(4), Normal, 0), (Opcode("cmp", 32786), Normal, 10), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(0)), Normal, 0), (Eol, Normal, 0)]