[Qemu-devel] [RCF PATCH 1/2] tcg: add tcg_abort_dbg() for additional debug info

2014-03-12 Thread alex . bennee 
From: Alex Bennée alex.ben...@linaro.org

There are times the tcg aborts with a fatal but terse error which isn't
overly helpful. This adds an alternative macro that can be used to show
a little more helper information when an abort occurs.

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index f832282..1a6c565 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -1342,7 +1342,7 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, 
TCGLabelQemuLdst *l)
 }
 break;
 default:
-tcg_abort();
+tcg_abort_dbg(bad opc:%x, opc);
 }
 
 /* Jump to the code corresponding to next IR of qemu_st */
@@ -1519,7 +1519,7 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg 
datalo, TCGReg datahi,
 }
 break;
 default:
-tcg_abort();
+tcg_abort_dbg(bad memop=%x, memop);
 }
 }
 
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 743..ae1a3f8 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -407,7 +407,7 @@ static bool do_constant_folding_cond_eq(TCGCond c)
 case TCG_COND_EQ:
 return 1;
 default:
-tcg_abort();
+tcg_abort_dbg(bad condition:%d, c);
 }
 }
 
diff --git a/tcg/tcg.h b/tcg/tcg.h
index f7efcb4..bfde09f 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -657,12 +657,15 @@ typedef struct TCGTargetOpDef {
 const char *args_ct_str[TCG_MAX_OP_ARGS];
 } TCGTargetOpDef;
 
-#define tcg_abort() \
+#define tcg_abort_dbg(fmt, ...)\
 do {\
-fprintf(stderr, %s:%d: tcg fatal error\n, __FILE__, __LINE__);\
+fprintf(stderr, %s:%d: tcg fatal error  fmt \n,\
+__FILE__, __LINE__, ## __VA_ARGS__);\
 abort();\
 } while (0)
 
+#define tcg_abort() tcg_abort_dbg()
+
 #ifdef CONFIG_DEBUG_TCG
 # define tcg_debug_assert(X) do { assert(X); } while (0)
 #elif QEMU_GNUC_PREREQ(4, 5)
-- 
1.9.0

[Qemu-devel] [RCF PATCH 1/2] tcg: add tcg_abort_dbg() for additional debug info

2014-03-12 Thread alex . bennee 
From: Alex Bennée alex.ben...@linaro.org

There are times the tcg aborts with a fatal but terse error which isn't
overly helpful. This adds an alternative macro that can be used to show
a little more helper information when an abort occurs.

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index f832282..1a6c565 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -1342,7 +1342,7 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, 
TCGLabelQemuLdst *l)
 }
 break;
 default:
-tcg_abort();
+tcg_abort_dbg(bad opc:%x, opc);
 }
 
 /* Jump to the code corresponding to next IR of qemu_st */
@@ -1519,7 +1519,7 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg 
datalo, TCGReg datahi,
 }
 break;
 default:
-tcg_abort();
+tcg_abort_dbg(bad memop=%x, memop);
 }
 }
 
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 743..ae1a3f8 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -407,7 +407,7 @@ static bool do_constant_folding_cond_eq(TCGCond c)
 case TCG_COND_EQ:
 return 1;
 default:
-tcg_abort();
+tcg_abort_dbg(bad condition:%d, c);
 }
 }
 
diff --git a/tcg/tcg.h b/tcg/tcg.h
index f7efcb4..bfde09f 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -657,12 +657,15 @@ typedef struct TCGTargetOpDef {
 const char *args_ct_str[TCG_MAX_OP_ARGS];
 } TCGTargetOpDef;
 
-#define tcg_abort() \
+#define tcg_abort_dbg(fmt, ...)\
 do {\
-fprintf(stderr, %s:%d: tcg fatal error\n, __FILE__, __LINE__);\
+fprintf(stderr, %s:%d: tcg fatal error  fmt \n,\
+__FILE__, __LINE__, ## __VA_ARGS__);\
 abort();\
 } while (0)
 
+#define tcg_abort() tcg_abort_dbg()
+
 #ifdef CONFIG_DEBUG_TCG
 # define tcg_debug_assert(X) do { assert(X); } while (0)
 #elif QEMU_GNUC_PREREQ(4, 5)
-- 
1.9.0

Re: [Qemu-devel] [RCF PATCH 1/2] tcg: add tcg_abort_dbg() for additional debug info

2014-03-12 Thread Peter Maydell 
On 12 March 2014 14:12,  alex.ben...@linaro.org wrote:
 From: Alex Bennée alex.ben...@linaro.org

 There are times the tcg aborts with a fatal but terse error which isn't
 overly helpful. This adds an alternative macro that can be used to show
 a little more helper information when an abort occurs.

 diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
 index f832282..1a6c565 100644
 --- a/tcg/i386/tcg-target.c
 +++ b/tcg/i386/tcg-target.c
 @@ -1342,7 +1342,7 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, 
 TCGLabelQemuLdst *l)
  }
  break;
  default:
 -tcg_abort();
 +tcg_abort_dbg(bad opc:%x, opc);
  }

  /* Jump to the code corresponding to next IR of qemu_st */
 @@ -1519,7 +1519,7 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, 
 TCGReg datalo, TCGReg datahi,
  }
  break;
  default:
 -tcg_abort();
 +tcg_abort_dbg(bad memop=%x, memop);
  }
  }

 diff --git a/tcg/optimize.c b/tcg/optimize.c
 index 743..ae1a3f8 100644
 --- a/tcg/optimize.c
 +++ b/tcg/optimize.c
 @@ -407,7 +407,7 @@ static bool do_constant_folding_cond_eq(TCGCond c)
  case TCG_COND_EQ:
  return 1;
  default:
 -tcg_abort();
 +tcg_abort_dbg(bad condition:%d, c);

This is the wrong place to be diagnosing this. We should be (when
TCG debug is enabled) checking the condition when the tcg_gen_setcond
or tcg_set_brcond function is called, so that you get a useful backtrace
that points directly at the buggy frontend code. I suspect the other
two cases are similar.

thanks
-- PMM

Re: [Qemu-devel] [RCF PATCH 1/2] tcg: add tcg_abort_dbg() for additional debug info

2014-03-12 Thread Richard Henderson 
On 03/12/2014 08:02 AM, Peter Maydell wrote:
 This is the wrong place to be diagnosing this. We should be (when
 TCG debug is enabled) checking the condition when the tcg_gen_setcond
 or tcg_set_brcond function is called, so that you get a useful backtrace
 that points directly at the buggy frontend code. I suspect the other
 two cases are similar.

Indeed.  See the asserts in tcg_gen_deposit_i32 for example.


r~