[v2,for-2.6] tci: Fix build regression

Commit d38ea87ac54af64ef611de434d07c12dc0399216 cleaned the include
statements which resulted in a wrong order of assert.h and the definition
of NDEBUG in tci.c. Normally NDEBUG modifies the definition of the assert
macro, but here this definition comes too late which results in a failing
build.

To fix this, a new macro tci_assert which depends on CONFIG_DEBUG_TCG
is introduced. Only builds with CONFIG_DEBUG_TCG will use assertions.
Even in this case, it is still possible to disable assertions by
defining NDEBUG via compiler settings.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---

v2:
Use parentheses around (void)0 as suggested by Sergey Fedorov
and Peter Maydell and required for assert by the POSIX standard.


 tci.c | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

Quoting Stefan Weil (2016-04-05 15:29:37)
> Commit d38ea87ac54af64ef611de434d07c12dc0399216 cleaned the include
> statements which resulted in a wrong order of assert.h and the definition
> of NDEBUG in tci.c. Normally NDEBUG modifies the definition of the assert
> macro, but here this definition comes too late which results in a failing
> build.
> 
> To fix this, a new macro tci_assert which depends on CONFIG_DEBUG_TCG
> is introduced. Only builds with CONFIG_DEBUG_TCG will use assertions.
> Even in this case, it is still possible to disable assertions by
> defining NDEBUG via compiler settings.
> 
> Signed-off-by: Stefan Weil <sw@weilnetz.de>

Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>

> ---
> 
> v2:
> Use parentheses around (void)0 as suggested by Sergey Fedorov
> and Peter Maydell and required for assert by the POSIX standard.
> 
> 
>  tci.c | 41 ++++++++++++++++++++++-------------------
>  1 file changed, 22 insertions(+), 19 deletions(-)
> 
> diff --git a/tci.c b/tci.c
> index 7cbb39e..82705fe 100644
> --- a/tci.c
> +++ b/tci.c
> @@ -1,7 +1,7 @@
>  /*
>   * Tiny Code Interpreter for QEMU
>   *
> - * Copyright (c) 2009, 2011 Stefan Weil
> + * Copyright (c) 2009, 2011, 2016 Stefan Weil
>   *
>   * This program is free software: you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License as published by
> @@ -19,9 +19,12 @@
> 
>  #include "qemu/osdep.h"
> 
> -/* Defining NDEBUG disables assertions (which makes the code faster). */
> -#if !defined(CONFIG_DEBUG_TCG) && !defined(NDEBUG)
> -# define NDEBUG
> +/* Enable TCI assertions only when debugging TCG (and without NDEBUG defined).
> + * Without assertions, the interpreter runs much faster. */
> +#if defined(CONFIG_DEBUG_TCG)
> +# define tci_assert(cond) assert(cond)
> +#else
> +# define tci_assert(cond) ((void)0)
>  #endif
> 
>  #include "qemu-common.h"
> @@ -56,7 +59,7 @@ static tcg_target_ulong tci_reg[TCG_TARGET_NB_REGS];
> 
>  static tcg_target_ulong tci_read_reg(TCGReg index)
>  {
> -    assert(index < ARRAY_SIZE(tci_reg));
> +    tci_assert(index < ARRAY_SIZE(tci_reg));
>      return tci_reg[index];
>  }
> 
> @@ -105,9 +108,9 @@ static uint64_t tci_read_reg64(TCGReg index)
> 
>  static void tci_write_reg(TCGReg index, tcg_target_ulong value)
>  {
> -    assert(index < ARRAY_SIZE(tci_reg));
> -    assert(index != TCG_AREG0);
> -    assert(index != TCG_REG_CALL_STACK);
> +    tci_assert(index < ARRAY_SIZE(tci_reg));
> +    tci_assert(index != TCG_AREG0);
> +    tci_assert(index != TCG_REG_CALL_STACK);
>      tci_reg[index] = value;
>  }
> 
> @@ -325,7 +328,7 @@ static uint64_t tci_read_ri64(uint8_t **tb_ptr)
>  static tcg_target_ulong tci_read_label(uint8_t **tb_ptr)
>  {
>      tcg_target_ulong label = tci_read_i(tb_ptr);
> -    assert(label != 0);
> +    tci_assert(label != 0);
>      return label;
>  }
> 
> @@ -468,11 +471,11 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
> 
>      tci_reg[TCG_AREG0] = (tcg_target_ulong)env;
>      tci_reg[TCG_REG_CALL_STACK] = sp_value;
> -    assert(tb_ptr);
> +    tci_assert(tb_ptr);
> 
>      for (;;) {
>          TCGOpcode opc = tb_ptr[0];
> -#if !defined(NDEBUG)
> +#if defined(CONFIG_DEBUG_TCG) && !defined(NDEBUG)
>          uint8_t op_size = tb_ptr[1];
>          uint8_t *old_code_ptr = tb_ptr;
>  #endif
> @@ -525,7 +528,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              break;
>          case INDEX_op_br:
>              label = tci_read_label(&tb_ptr);
> -            assert(tb_ptr == old_code_ptr + op_size);
> +            tci_assert(tb_ptr == old_code_ptr + op_size);
>              tb_ptr = (uint8_t *)label;
>              continue;
>          case INDEX_op_setcond_i32:
> @@ -600,7 +603,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              t0 = tci_read_r32(&tb_ptr);
>              t1 = tci_read_r(&tb_ptr);
>              t2 = tci_read_s32(&tb_ptr);
> -            assert(t1 != sp_value || (int32_t)t2 < 0);
> +            tci_assert(t1 != sp_value || (int32_t)t2 < 0);
>              *(uint32_t *)(t1 + t2) = t0;
>              break;
> 
> @@ -725,7 +728,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              condition = *tb_ptr++;
>              label = tci_read_label(&tb_ptr);
>              if (tci_compare32(t0, t1, condition)) {
> -                assert(tb_ptr == old_code_ptr + op_size);
> +                tci_assert(tb_ptr == old_code_ptr + op_size);
>                  tb_ptr = (uint8_t *)label;
>                  continue;
>              }
> @@ -751,7 +754,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              condition = *tb_ptr++;
>              label = tci_read_label(&tb_ptr);
>              if (tci_compare64(tmp64, v64, condition)) {
> -                assert(tb_ptr == old_code_ptr + op_size);
> +                tci_assert(tb_ptr == old_code_ptr + op_size);
>                  tb_ptr = (uint8_t *)label;
>                  continue;
>              }
> @@ -885,7 +888,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              t0 = tci_read_r64(&tb_ptr);
>              t1 = tci_read_r(&tb_ptr);
>              t2 = tci_read_s32(&tb_ptr);
> -            assert(t1 != sp_value || (int32_t)t2 < 0);
> +            tci_assert(t1 != sp_value || (int32_t)t2 < 0);
>              *(uint64_t *)(t1 + t2) = t0;
>              break;
> 
> @@ -992,7 +995,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              condition = *tb_ptr++;
>              label = tci_read_label(&tb_ptr);
>              if (tci_compare64(t0, t1, condition)) {
> -                assert(tb_ptr == old_code_ptr + op_size);
> +                tci_assert(tb_ptr == old_code_ptr + op_size);
>                  tb_ptr = (uint8_t *)label;
>                  continue;
>              }
> @@ -1087,7 +1090,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              break;
>          case INDEX_op_goto_tb:
>              t0 = tci_read_i32(&tb_ptr);
> -            assert(tb_ptr == old_code_ptr + op_size);
> +            tci_assert(tb_ptr == old_code_ptr + op_size);
>              tb_ptr += (int32_t)t0;
>              continue;
>          case INDEX_op_qemu_ld_i32:
> @@ -1234,7 +1237,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr)
>              TODO();
>              break;
>          }
> -        assert(tb_ptr == old_code_ptr + op_size);
> +        tci_assert(tb_ptr == old_code_ptr + op_size);
>      }
>  exit:
>      return next_tb;
> -- 
> 2.1.4
> 
>