--- valgrind/coregrind/m_debuginfo/readdwarf.c.jj	2009-07-13 14:09:14.478329957 +0200

+++ valgrind/coregrind/m_debuginfo/readdwarf.c	2009-07-13 15:18:35.596080042 +0200

@@ -1923,6 +1923,11 @@ static void ppRegRule ( XArray* exprs, R

 }

+/* Size of the stack of register unwind rules.  This is only

+   exceedingly rarely used, so a stack of size 1 should actually work

+   with almost all compiler-generated CFA. */

+#define N_RR_STACK 4

+

 typedef

    struct {

       /* Read-only fields (set by the CIE) */

@@ -1939,8 +1944,12 @@ typedef

       Int     cfa_reg;

       Int     cfa_off;  /* in bytes */

       Int     cfa_expr_ix; /* index into cfa_exprs */

-      /* register unwind rules */

-      RegRule reg[N_CFI_REGS];

+      /* A stack of register unwind rules.  We need a stack of them,

+         rather than just one set of rules, in order to handle

+         DW_CFA_{remember,restore}_state. */

+      RegRule reg[N_RR_STACK][N_CFI_REGS];

+      Int     reg_sp; /* 0 <= reg_sp < N_RR_STACK; points at the

+                         currently-in-use rule set. */

       /* array of CfiExpr, shared by reg[] and cfa_expr_ix */

       XArray* exprs;

    }

@@ -1948,7 +1957,7 @@ typedef

 static void ppUnwindContext ( UnwindContext* ctx )

 {

-   Int i;

+   Int j, i;

    VG_(printf)("0x%llx: ", (ULong)ctx->loc);

    if (ctx->cfa_is_regoff) {

       VG_(printf)("%d(r%d) ",  ctx->cfa_off, ctx->cfa_reg);

@@ -1958,14 +1967,19 @@ static void ppUnwindContext ( UnwindCont

       ML_(ppCfiExpr)( ctx->exprs, ctx->cfa_expr_ix );

       VG_(printf)("} ");

    }

-   for (i = 0; i < N_CFI_REGS; i++)

-      ppRegRule(ctx->exprs, &ctx->reg[i]);

+   for (j = 0; j <= ctx->reg_sp; j++) {

+      VG_(printf)("%s[%d]={ ", j > 0 ? " " : "", j);

+      for (i = 0; i < N_CFI_REGS; i++)

+         ppRegRule(ctx->exprs, &ctx->reg[j][i]);

+      VG_(printf)("}");

+   }

    VG_(printf)("\n");

 }

 static void initUnwindContext ( /*OUT*/UnwindContext* ctx )

 {

-   Int i;

+   Int j, i;

+   VG_(memset)(ctx, 0, sizeof(*ctx));

    ctx->code_a_f      = 0;

    ctx->data_a_f      = 0;

    ctx->initloc       = 0;

@@ -1976,9 +1990,12 @@ static void initUnwindContext ( /*OUT*/U

    ctx->cfa_off       = 0;

    ctx->cfa_expr_ix   = 0;

    ctx->exprs         = NULL;

-   for (i = 0; i < N_CFI_REGS; i++) {

-      ctx->reg[i].tag = RR_Undef;

-      ctx->reg[i].arg = 0;

+   ctx->reg_sp        = 0;

+   for (j = 0; j < N_RR_STACK; j++) {

+      for (i = 0; i < N_CFI_REGS; i++) {

+         ctx->reg[j][i].tag = RR_Undef;

+         ctx->reg[j][i].arg = 0;

+      }

    }

 }

@@ -2104,8 +2121,15 @@ static Bool summarise_context( /*OUT*/Di

          why = 2; goto failed; /* otherwise give up */        \

    }

-   SUMMARISE_HOW(si->ra_how, si->ra_off, ctx->reg[ctx->ra_reg] );

-   SUMMARISE_HOW(si->fp_how, si->fp_off, ctx->reg[FP_REG] );

+   /* Guard against obviously stupid settings of the reg-rule stack

+      pointer. */

+   if (ctx->reg_sp < 0)           { why = 8; goto failed; }

+   if (ctx->reg_sp >= N_RR_STACK) { why = 9; goto failed; }

+

+   SUMMARISE_HOW(si->ra_how, si->ra_off,

+                             ctx->reg[ctx->reg_sp][ctx->ra_reg] );

+   SUMMARISE_HOW(si->fp_how, si->fp_off,

+                             ctx->reg[ctx->reg_sp][FP_REG] );

 #  undef SUMMARISE_HOW

@@ -2116,7 +2140,7 @@ static Bool summarise_context( /*OUT*/Di

    /* also, gcc says "Undef" for %{e,r}bp when it is unchanged.  So

       .. */

-   if (ctx->reg[FP_REG].tag == RR_Undef)

+   if (ctx->reg[ctx->reg_sp][FP_REG].tag == RR_Undef)

       si->fp_how = CFIR_SAME;

    /* knock out some obviously stupid cases */

@@ -2215,10 +2239,10 @@ static void ppUnwindContext_summary ( Un

    }

    VG_(printf)("RA=");

-   ppRegRule( ctx->exprs, &ctx->reg[ctx->ra_reg] );

+   ppRegRule( ctx->exprs, &ctx->reg[ctx->reg_sp][ctx->ra_reg] );

    VG_(printf)("FP=");

-   ppRegRule( ctx->exprs, &ctx->reg[FP_REG] );

+   ppRegRule( ctx->exprs, &ctx->reg[ctx->reg_sp][FP_REG] );

    VG_(printf)("\n");

 }

@@ -2664,6 +2688,9 @@ static Int run_CF_instruction ( /*MOD*/U

    Addr   printing_bias = ((Addr)ctx->initloc) - ((Addr)di->text_bias);

    i++;

+   if (ctx->reg_sp < 0 || ctx->reg_sp >= N_RR_STACK)

+      return 0; /* bogus reg-rule stack pointer */

+

    if (hi2 == DW_CFA_advance_loc) {

       delta = (UInt)lo6;

       ctx->loc += delta;

@@ -2680,12 +2707,13 @@ static Int run_CF_instruction ( /*MOD*/U

       reg = (Int)lo6;

       if (reg < 0 || reg >= N_CFI_REGS) 

          return 0; /* fail */

-      ctx->reg[reg].tag = RR_CFAOff;

-      ctx->reg[reg].arg = off * ctx->data_a_f;

+      ctx->reg[ctx->reg_sp][reg].tag = RR_CFAOff;

+      ctx->reg[ctx->reg_sp][reg].arg = off * ctx->data_a_f;

       if (di->ddump_frames)

          VG_(printf)("  DW_CFA_offset: r%d at cfa%s%d\n",

-                     (Int)reg, ctx->reg[reg].arg < 0 ? "" : "+", 

-                     (Int)ctx->reg[reg].arg );

+                     (Int)reg,

+                     ctx->reg[ctx->reg_sp][reg].arg < 0 ? "" : "+", 

+                     (Int)ctx->reg[ctx->reg_sp][reg].arg );

       return i;

    }

@@ -2695,7 +2723,7 @@ static Int run_CF_instruction ( /*MOD*/U

          return 0; /* fail */

       if (restore_ctx == NULL)

          return 0; /* fail */

-      ctx->reg[reg] = restore_ctx->reg[reg];

+      ctx->reg[ctx->reg_sp][reg] = restore_ctx->reg[ctx->reg_sp][reg];

       if (di->ddump_frames)

          VG_(printf)("  DW_CFA_restore: r%d\n", (Int)reg);

       return i;

@@ -2781,8 +2809,8 @@ static Int run_CF_instruction ( /*MOD*/U

             return 0; /* fail */

          if (reg2 < 0 || reg2 >= N_CFI_REGS) 

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_Reg;

-         ctx->reg[reg].arg = reg2;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_Reg;

+         ctx->reg[ctx->reg_sp][reg].arg = reg2;

          if (di->ddump_frames)

             VG_(printf)("  DW_CFA_register: r%d in r%d\n", 

                         (Int)reg, (Int)reg2);

@@ -2795,8 +2823,8 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS)

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_CFAOff;

-         ctx->reg[reg].arg = off * ctx->data_a_f;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_CFAOff;

+         ctx->reg[ctx->reg_sp][reg].arg = off * ctx->data_a_f;

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_offset_extended\n");

          break;

@@ -2808,12 +2836,13 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS) 

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_CFAOff;

-         ctx->reg[reg].arg = off * ctx->data_a_f;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_CFAOff;

+         ctx->reg[ctx->reg_sp][reg].arg = off * ctx->data_a_f;

          if (di->ddump_frames)

             VG_(printf)("  DW_CFA_offset_extended_sf: r%d at cfa%s%d\n", 

-                        reg, ctx->reg[reg].arg < 0 ? "" : "+", 

-                        (Int)ctx->reg[reg].arg);

+                        reg,

+                        ctx->reg[ctx->reg_sp][reg].arg < 0 ? "" : "+", 

+                        (Int)ctx->reg[ctx->reg_sp][reg].arg);

          break;

       case DW_CFA_GNU_negative_offset_extended:

@@ -2823,8 +2852,8 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS)

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_CFAOff;

-         ctx->reg[reg].arg = (-off) * ctx->data_a_f;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_CFAOff;

+         ctx->reg[ctx->reg_sp][reg].arg = (-off) * ctx->data_a_f;

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_GNU_negative_offset_extended\n");

          break;

@@ -2836,7 +2865,7 @@ static Int run_CF_instruction ( /*MOD*/U

             return 0; /* fail */

 	 if (restore_ctx == NULL)

 	    return 0; /* fail */

-	 ctx->reg[reg] = restore_ctx->reg[reg];

+	 ctx->reg[ctx->reg_sp][reg] = restore_ctx->reg[ctx->reg_sp][reg];

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_restore_extended\n");

          break;

@@ -2848,8 +2877,8 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS)

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_CFAValOff;

-         ctx->reg[reg].arg = off * ctx->data_a_f;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_CFAValOff;

+         ctx->reg[ctx->reg_sp][reg].arg = off * ctx->data_a_f;

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_val_offset\n");

          break;

@@ -2861,8 +2890,8 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS)

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_CFAValOff;

-         ctx->reg[reg].arg = off * ctx->data_a_f;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_CFAValOff;

+         ctx->reg[ctx->reg_sp][reg].arg = off * ctx->data_a_f;

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_val_offset_sf\n");

          break;

@@ -2907,8 +2936,8 @@ static Int run_CF_instruction ( /*MOD*/U

          i += nleb;

          if (reg < 0 || reg >= N_CFI_REGS) 

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_Undef;

-         ctx->reg[reg].arg = 0;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_Undef;

+         ctx->reg[ctx->reg_sp][reg].arg = 0;

          if (di->ddump_frames)

             VG_(printf)("  rci:DW_CFA_undefined\n");

          break;

@@ -2952,8 +2981,8 @@ static Int run_CF_instruction ( /*MOD*/U

             return 0; /* fail */

          /* Add an extra dereference */

          j = ML_(CfiExpr_Deref)( ctx->exprs, j );

-         ctx->reg[reg].tag = RR_ValExpr;

-         ctx->reg[reg].arg = j;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_ValExpr;

+         ctx->reg[ctx->reg_sp][reg].arg = j;

          break;

       case DW_CFA_val_expression:

@@ -2981,8 +3010,8 @@ static Int run_CF_instruction ( /*MOD*/U

          }

          if (j == -1)

             return 0; /* fail */

-         ctx->reg[reg].tag = RR_ValExpr;

-         ctx->reg[reg].arg = j;

+         ctx->reg[ctx->reg_sp][reg].tag = RR_ValExpr;

+         ctx->reg[ctx->reg_sp][reg].arg = j;

          break;

       case DW_CFA_def_cfa_expression:

@@ -3008,7 +3037,39 @@ static Int run_CF_instruction ( /*MOD*/U

          /* Ignored.  This appears to be sparc-specific; quite why it

             turns up in SuSE-supplied x86 .so's beats me. */

          if (di->ddump_frames)

-            VG_(printf)("DW_CFA_GNU_window_save\n");

+            VG_(printf)("  DW_CFA_GNU_window_save\n");

+         break;

+

+      case DW_CFA_remember_state:

+         if (di->ddump_frames)

+            VG_(printf)("  DW_CFA_remember_state\n");

+         /* we just checked this at entry, so: */

+         vg_assert(ctx->reg_sp >= 0 && ctx->reg_sp < N_RR_STACK);

+         ctx->reg_sp++;

+         if (ctx->reg_sp == N_RR_STACK) {

+            /* stack overflow.  We're hosed. */

+            VG_(message)(Vg_DebugMsg, "DWARF2 CFI reader: N_RR_STACK is "

+                                      "too low; increase and recompile.");

+            i = 0; /* indicate failure */

+         } else {

+            VG_(memcpy)(/*dst*/&ctx->reg[ctx->reg_sp],

+                        /*src*/&ctx->reg[ctx->reg_sp - 1],

+                        sizeof(ctx->reg[ctx->reg_sp]) );

+         }

+         break;

+

+      case DW_CFA_restore_state:

+         if (di->ddump_frames)

+            VG_(printf)("  DW_CFA_restore_state\n");

+         /* we just checked this at entry, so: */

+         vg_assert(ctx->reg_sp >= 0 && ctx->reg_sp < N_RR_STACK);

+         if (ctx->reg_sp == 0) {

+            /* stack overflow.  Give up. */

+            i = 0; /* indicate failure */

+         } else {

+            /* simply fall back to previous entry */

+            ctx->reg_sp--;

+         }

          break;

       default: