IT, BX LR - untested

6 files changed, 46 insertions, 20 deletions

diff --git a/lib/dis-arm.inc.h b/lib/dis-arm.inc.h
index c95e450..0779205 100644
--- a/lib/dis-arm.inc.h
+++ b/lib/dis-arm.inc.h
@@ -193,6 +193,9 @@ static INLINE void P(addr_offset_none_addr_postidx_reg_Rm_unk_Rt_3_LDRHTr)(tdis_
 static INLINE void P(GPR_Rt_addr_offset_none_addr_postidx_reg_Rm_S_1_STRHTr)(tdis_ctx ctx, struct bitslice Rm, struct bitslice Rt, struct bitslice addr) {
     data(r(addr), r(Rt), r(Rm));
 }
+static INLINE void P(GPR_dst_B_2_BX)(tdis_ctx ctx, UNUSED struct bitslice dst) {
+    return P(ret)(ctx);
+}
 
 static INLINE void P(dis_arm)(tdis_ctx ctx) {
     uint32_t op = ctx->op = *(uint32_t *) ctx->ptr;
diff --git a/lib/dis-thumb.inc.h b/lib/dis-thumb.inc.h
index a0434bc..6d9683e 100644
--- a/lib/dis-thumb.inc.h
+++ b/lib/dis-thumb.inc.h
@@ -53,14 +53,26 @@ static INLINE void P(t_bcctarget_target_B_1_tBcc)(tdis_ctx ctx, struct bitslice
     return P(branch)(ctx, ctx->pc + 4 + 2 * sext(bs_get(target, ctx->op), 8), /*cond*/ true);
 }
 static INLINE void P(t_brtarget_target_B_1_tB)(tdis_ctx ctx, struct bitslice target) {
-    return P(branch)(ctx, ctx->pc + 4 + 2 * sext(bs_get(target, ctx->op), 11), /*cond*/ false);
+    bool cond = ctx->arch.thumb_it_length > 0;
+    return P(branch)(ctx, ctx->pc + 4 + 2 * sext(bs_get(target, ctx->op), 11), cond);
 }
 static INLINE void P(t_cbtarget_target_B_2_tCBNZ)(tdis_ctx ctx, struct bitslice target) {
     return P(branch)(ctx, ctx->pc + 4 + 2 * bs_get(target, ctx->op), /*cond*/ true);
 }
+static INLINE void P(it_pred_cc_it_mask_mask_1_t2IT)(tdis_ctx ctx, struct bitslice mask, UNUSED struct bitslice cc) {
+    /* why */
+    unsigned mask_val = bs_get(mask, ctx->op);
+    unsigned length = __builtin_ctz(mask_val);
+    if (length >= 3)
+        return P(unidentified)(ctx); /* nop */
+    ctx->arch.thumb_it_length = length;
+    return P(unidentified)(ctx);
+}
 
 static INLINE void P(dis_thumb)(tdis_ctx ctx) {
     uint16_t op = ctx->op = *(uint16_t *) ctx->ptr;
+    if (ctx->arch.thumb_it_length)
+        ctx->arch.thumb_it_length--;
     ctx->op_size = 2;
     #include "../generated/generic-dis-thumb.inc.h"
     __builtin_abort();
diff --git a/lib/dis-thumb2.inc.h b/lib/dis-thumb2.inc.h
index 36d341e..632e2a2 100644
--- a/lib/dis-thumb2.inc.h
+++ b/lib/dis-thumb2.inc.h
@@ -148,7 +148,8 @@ static INLINE void P(t2ldrlabel_addr_unk_Rt_5_t2LDRBpci)(tdis_ctx ctx, struct bi
     return P(pcrel)(ctx, ((ctx->pc + 4) & ~2) + (bs_get(addr, ctx->op) & ((1 << 12) - 1)), bs_get(Rt, ctx->op), get_thumb2_load_mode(ctx->op));
 }
 static INLINE void P(uncondbrtarget_target_B_1_t2B)(tdis_ctx ctx, struct bitslice target) {
-    return P(branch)(ctx, ctx->pc + 4 + 2 * sext(bs_get(target, ctx->op), 24), /*cond*/ false);
+    bool cond = ctx->arch.thumb_it_length > 0;
+    return P(branch)(ctx, ctx->pc + 4 + 2 * sext(bs_get(target, ctx->op), 24), cond);
 }
 static INLINE void P(unk_Rd_3_t2MOVTi16)(tdis_ctx ctx, struct bitslice Rd) {
     data(rout(Rd));
@@ -163,6 +164,8 @@ static INLINE void P(unk_Rt_13_VMOVRRD)(tdis_ctx ctx, UNUSED struct bitslice Rt)
 
 static INLINE void P(dis_thumb2)(tdis_ctx ctx) {
     uint32_t op = ctx->op = *(uint32_t *) ctx->ptr;
+    if (ctx->arch.thumb_it_length)
+        ctx->arch.thumb_it_length--;
     ctx->op_size = 4;
     #include "../generated/generic-dis-thumb2.inc.h"
     __builtin_abort();
diff --git a/lib/dis.h b/lib/dis.h
index 5a49723..37c0889 100644
--- a/lib/dis.h
+++ b/lib/dis.h
@@ -107,14 +107,18 @@ static const unsigned null_op = -0x100;
 #if defined(TARGET_x86_64)
     #define MIN_INSN_SIZE 1
     #error "no x86 dis yet"
+    struct arch_dis_ctx {};
 #elif defined(TARGET_i386)
     #define MIN_INSN_SIZE 1
     #error "no x86 dis yet"
+    struct arch_dis_ctx {};
 #elif defined(TARGET_arm)
     #define MIN_INSN_SIZE 2
     #define TARGET_DIS_HEADER "dis-arm-multi.inc.h"
+    struct arch_dis_ctx { unsigned thumb_it_length; };
 #elif defined(TARGET_arm64)
     #define MIN_INSN_SIZE 4
     #define TARGET_DIS_HEADER "dis-arm64.inc.h"
+    struct arch_dis_ctx {};
 #endif
 
diff --git a/lib/jump-dis.c b/lib/jump-dis.c
index aa3b5f3..b6ddd13 100644
--- a/lib/jump-dis.c
+++ b/lib/jump-dis.c
@@ -18,24 +18,26 @@ enum {
 };
 
 struct jump_dis_ctx {
-   /* outputs */
-   bool bad_insn;
-   bool continue_after_this_insn;
-
-   uintptr_t pc;
-   uintptr_t pc_patch_start;
-   uintptr_t pc_patch_end;
-   bool pc_low_bit;
-   unsigned op;
-   const void *ptr;
-   int op_size;
-   uint8_t seen_mask[JUMP_ANALYSIS_MAX_INSNS / 8];
-   /* queue of instructions to visit */
-   uintptr_t *queue;
-   size_t queue_write_off;
-   size_t queue_read_off;
-   size_t queue_size;
-   size_t queue_count;
+    /* outputs */
+    bool bad_insn;
+    bool continue_after_this_insn;
+
+    uintptr_t pc;
+    uintptr_t pc_patch_start;
+    uintptr_t pc_patch_end;
+    bool pc_low_bit;
+    unsigned op;
+    const void *ptr;
+    int op_size;
+    uint8_t seen_mask[JUMP_ANALYSIS_MAX_INSNS / 8];
+    /* queue of instructions to visit */
+    uintptr_t *queue;
+    size_t queue_write_off;
+    size_t queue_read_off;
+    size_t queue_size;
+    size_t queue_count;
+
+    struct arch_dis_ctx arch;
 };
 
 #undef P
diff --git a/lib/transform-dis.inc.h b/lib/transform-dis.inc.h
index b20012a..04cd7f2 100644
--- a/lib/transform-dis.inc.h
+++ b/lib/transform-dis.inc.h
@@ -22,6 +22,8 @@ struct transform_dis_ctx {
     const void *ptr;
     void **rewritten_ptr_ptr;
     void *write_newop_here;
+
+    struct arch_dis_ctx arch;
 };
 
 #define tdis_ctx struct transform_dis_ctx *