import gdb-1999-11-01 snapshot

1 files changed, 316 insertions, 36 deletions

diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c
index 12fbe3e..6573153 100644
--- a/gdb/i386-linux-nat.c
+++ b/gdb/i386-linux-nat.c
@@ -45,6 +45,35 @@ static int regmap[] =
 };
 
 
+/* Which ptrace request retrieves which registers?
+   These apply to the corresponding SET requests as well.  */
+#define GETREGS_SUPPLIES(regno) \
+  (0 <= (regno) && (regno) <= 15)
+#define GETFPREGS_SUPPLIES(regno) \
+  (FP0_REGNUM <= (regno) && (regno) <= LAST_FPU_CTRL_REGNUM)
+#define GETXFPREGS_SUPPLIES(regno) \
+  (FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)
+
+/* Does the current host support the GETXFPREGS request?  The header
+   file may or may not define it, and even if it is defined, the
+   kernel will return EIO if it's running on a pre-SSE processor.
+
+   My instinct is to attach this to some architecture- or
+   target-specific data structure, but really, a particular GDB
+   process can only run on top of one kernel at a time.  So it's okay
+   for this to be a simple variable.  */
+int have_ptrace_getxfpregs =
+#ifdef HAVE_PTRACE_GETXFPREGS
+  1
+#else
+  0
+#endif
+;
+
+
+
+/* Transfering the general registers between GDB, inferiors and core files.  */
+
 /* Given a pointer to a general register set in struct user format
    (gregset_t *), unpack the register contents and supply them as
    gdb's idea of the current register values. */
@@ -61,6 +90,7 @@ supply_gregset (gregsetp)
     }
 }
 
+
 /* Fill in a gregset_t object with selected data from a gdb-format
    register file.
    - GREGSETP points to the gregset_t object to be filled.
@@ -82,6 +112,9 @@ convert_to_gregset (gregset_t *gregsetp,
       *(regp + regmap[regi]) = * (int *) &registers[REGISTER_BYTE (regi)];
 }
 
+
+/* Store GDB's value for REGNO in *GREGSETP.  If REGNO is -1, do all
+   of them.  */
 void
 fill_gregset (gregset_t *gregsetp,
 	      int regno)
@@ -98,8 +131,56 @@ fill_gregset (gregset_t *gregsetp,
 }
 
 
-/* Where does st(N) start in the fpregset_t structure F?  */
-#define FPREGSET_T_FPREG_OFFSET(f, n) \
+/* Read the general registers from the process, and store them
+   in registers[].  */
+static void
+fetch_regs ()
+{
+  int ret, regno;
+  gregset_t buf;
+
+  ret = ptrace (PTRACE_GETREGS, inferior_pid, 0, (int) &buf);
+  if (ret < 0)
+    {
+      warning ("Couldn't get registers");
+      return;
+    }
+
+  supply_gregset (&buf);
+}
+
+
+/* Set the inferior's general registers to the values in registers[]
+   --- but only those registers marked as valid.  */
+static void
+store_regs ()
+{
+  int ret, regno;
+  gregset_t buf;
+
+  ret = ptrace (PTRACE_GETREGS, inferior_pid, 0, (int) &buf);
+  if (ret < 0)
+    {
+      warning ("Couldn't get registers");
+      return;
+    }
+
+  convert_to_gregset (&buf, registers, register_valid);
+
+  ret = ptrace (PTRACE_SETREGS, inferior_pid, 0, (int)buf);
+  if (ret < 0)
+    {
+      warning ("Couldn't write registers");
+      return;
+    }
+}
+
+
+
+/* Transfering floating-point registers between GDB, inferiors and cores.  */
+
+/* What is the address of st(N) within the fpregset_t structure F?  */
+#define FPREGSET_T_FPREG_ADDR(f, n) \
   ((char *) &(f)->st_space + (n) * 10)
 
 /* Fill GDB's register file with the floating-point register values in
@@ -111,7 +192,7 @@ supply_fpregset (fpregset_t *fpregsetp)
 
   /* Supply the floating-point registers.  */
   for (i = 0; i < 8; i++)
-    supply_register (FP0_REGNUM + i, FPREGSET_T_FPREG_OFFSET (fpregsetp, i));
+    supply_register (FP0_REGNUM + i, FPREGSET_T_FPREG_ADDR (fpregsetp, i));
 
   supply_register (FCTRL_REGNUM, (char *) &fpregsetp->cwd);
   supply_register (FSTAT_REGNUM, (char *) &fpregsetp->swd);
@@ -151,7 +232,7 @@ convert_to_fpregset (fpregset_t *fpregsetp,
   /* Fill in the floating-point registers.  */
   for (i = 0; i < 8; i++)
     if (!valid || valid[i])
-      memcpy (FPREGSET_T_FPREG_OFFSET (fpregsetp, i),
+      memcpy (FPREGSET_T_FPREG_ADDR (fpregsetp, i),
 	      &registers[REGISTER_BYTE (FP0_REGNUM + i)],
 	      REGISTER_RAW_SIZE(FP0_REGNUM + i));
 
@@ -240,51 +321,190 @@ store_fpregs ()
     }
 }
 
+
+/* Transfering floating-point and SSE registers to and from GDB.  */
 
-/* Read the general registers from the process, and store them
-   in registers[].  */
+
+#ifdef HAVE_PTRACE_GETXFPREGS
 static void
-fetch_regs ()
+supply_xfpregset (struct user_xfpregs_struct *xfpregs)
 {
-  int ret, regno;
-  gregset_t buf;
+  int reg;
 
-  ret = ptrace (PTRACE_GETREGS, inferior_pid, 0, (int) &buf);
-  if (ret < 0)
+  /* Supply the floating-point registers.  */
+  for (reg = 0; reg < 8; reg++)
+    supply_register (FP0_REGNUM + reg, (char *) &xfpregs->st_space[reg]);
+
+  {
+    supply_register (FCTRL_REGNUM, (char *) &xfpregs->cwd);
+    supply_register (FSTAT_REGNUM, (char *) &xfpregs->swd);
+    supply_register (FTAG_REGNUM,  (char *) &xfpregs->twd);
+    supply_register (FCOFF_REGNUM, (char *) &xfpregs->fip);
+    supply_register (FDS_REGNUM,   (char *) &xfpregs->fos);
+    supply_register (FDOFF_REGNUM, (char *) &xfpregs->foo);
+  
+    /* Extract the code segment and opcode from the  "fcs" member.  */
     {
-      warning ("Couldn't get registers");
-      return;
+      long l;
+      
+      l = xfpregs->fcs & 0xffff;
+      supply_register (FCS_REGNUM, (char *) &l);
+
+      l = (xfpregs->fcs >> 16) & ((1 << 11) - 1);
+      supply_register (FOP_REGNUM, (char *) &l);
     }
+  }
 
-  supply_gregset (&buf);
+  /* Supply the SSE registers.  */
+  for (reg = 0; reg < 8; reg++)
+    supply_register (XMM0_REGNUM + reg, (char *) &xfpregs->xmm_space[reg]);
+  supply_register (MXCSR_REGNUM, (char *) &xfpregs->mxcsr);
 }
 
 
-/* Set the inferior's general registers to the values in registers[]
-   --- but only those registers marked as valid.  */
 static void
-store_regs ()
+convert_to_xfpregset (struct user_xfpregs_struct *xfpregs,
+		      char *gdb_regs,
+		      signed char *valid)
 {
-  int ret, regno;
-  gregset_t buf;
+  int reg;
 
-  ret = ptrace (PTRACE_GETREGS, inferior_pid, 0, (int) &buf);
-  if (ret < 0)
+  /* Fill in the floating-point registers.  */
+  for (reg = 0; reg < 8; reg++)
+    if (!valid || valid[reg])
+      memcpy (&xfpregs->st_space[reg],
+	      &registers[REGISTER_BYTE (FP0_REGNUM + reg)],
+	      REGISTER_RAW_SIZE(FP0_REGNUM + reg));
+
+#define fill(MEMBER, REGNO)						\
+  if (! valid || valid[(REGNO)])					\
+    memcpy (&xfpregs->MEMBER, &registers[REGISTER_BYTE (REGNO)],	\
+	    sizeof (xfpregs->MEMBER))
+
+  fill (cwd, FCTRL_REGNUM);
+  fill (swd, FSTAT_REGNUM);
+  fill (twd, FTAG_REGNUM);
+  fill (fip, FCOFF_REGNUM);
+  fill (foo, FDOFF_REGNUM);
+  fill (fos, FDS_REGNUM);
+
+#undef fill
+
+  if (! valid || valid[FCS_REGNUM])
+    xfpregs->fcs
+      = ((xfpregs->fcs & ~0xffff)
+	 | (* (int *) &registers[REGISTER_BYTE (FCS_REGNUM)] & 0xffff));
+
+  if (! valid || valid[FOP_REGNUM])
+    xfpregs->fcs
+      = ((xfpregs->fcs & 0xffff)
+	 | ((*(int *) &registers[REGISTER_BYTE (FOP_REGNUM)] & ((1 << 11) - 1))
+	    << 16));
+
+  /* Fill in the XMM registers.  */
+  for (reg = 0; reg < 8; reg++)
+    if (! valid || valid[reg])
+      memcpy (&xfpregs->xmm_space[reg],
+	      &registers[REGISTER_BYTE (XMM0_REGNUM + reg)],
+	      REGISTER_RAW_SIZE (XMM0_REGNUM + reg));
+}
+
+
+/* Make a PTRACE_GETXFPREGS request, and supply all the register
+   values that yields to GDB.  */
+static int
+fetch_xfpregs ()
+{
+  int ret;
+  struct user_xfpregs_struct xfpregs;
+
+  if (! have_ptrace_getxfpregs) 
+    return 0;
+
+  ret = ptrace (PTRACE_GETXFPREGS, inferior_pid, 0, &xfpregs);
+  if (ret == -1)
     {
-      warning ("Couldn't get registers");
-      return;
+      if (errno == EIO)
+	{
+	  have_ptrace_getxfpregs = 0;
+	  return 0;
+	}
+
+      warning ("couldn't read floating-point and SSE registers.");
+      return 0;
     }
 
-  convert_to_gregset (&buf, registers, register_valid);
+  supply_xfpregset (&xfpregs);
+  return 1;
+}
 
-  ret = ptrace (PTRACE_SETREGS, inferior_pid, 0, (int)buf);
-  if (ret < 0)
+
+/* Send all the valid register values in GDB's register file covered
+   by the PTRACE_SETXFPREGS request to the inferior.  */
+static int
+store_xfpregs ()
+{
+  int ret;
+  struct user_xfpregs_struct xfpregs;
+
+  if (! have_ptrace_getxfpregs)
+    return 0;
+
+  ret = ptrace (PTRACE_GETXFPREGS, inferior_pid, 0, &xfpregs);
+  if (ret == -1)
     {
-      warning ("Couldn't write registers");
-      return;
+      if (errno == EIO)
+	{
+	  have_ptrace_getxfpregs = 0;
+	  return 0;
+	}
+
+      warning ("couldn't read floating-point and SSE registers.");
+      return 0;
     }
+
+  convert_to_xfpregset (&xfpregs, registers, register_valid);
+
+  if (ptrace (PTRACE_SETXFPREGS, inferior_pid, 0, &xfpregs) < 0)
+    {
+      warning ("Couldn't write floating-point and SSE registers.");
+      return 0;
+    }
+
+  return 1;
+}
+
+
+/* Fill the XMM registers in the register file with dummy values.  For
+   cases where we don't have access to the XMM registers.  I think
+   this is cleaner than printing a warning.  For a cleaner solution,
+   we should gdbarchify the i386 family.  */
+static void
+dummy_sse_values ()
+{
+  /* C doesn't have a syntax for NaN's, so write it out as an array of
+     longs.  */
+  static long dummy[4] = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff };
+  static long mxcsr = 0x1f80;
+  int reg;
+
+  for (reg = 0; reg < 8; reg++)
+    supply_register (XMM0_REGNUM + reg, (char *) dummy);
+  supply_register (MXCSR_REGNUM, (char *) &mxcsr);
 }
 
+#else
+
+/* Stub versions of the above routines, for systems that don't have
+   PTRACE_GETXFPREGS.  */
+static int store_xfpregs () { return 0; }
+static int fetch_xfpregs () { return 0; }
+static void dummy_sse_values () {}
+
+#endif
+
+
+/* Transferring arbitrary registers between GDB and inferior.  */
 
 /* Fetch registers from the child process.
    Fetch all if regno == -1, otherwise fetch all ordinary
@@ -294,11 +514,42 @@ store_regs ()
 void
 fetch_inferior_registers (int regno)
 {
-  if (regno < NUM_GREGS || regno == -1)
-    fetch_regs ();
+  /* Use the xfpregs requests whenever possible, since they transfer
+     more registers in one system call, and we'll cache the results.
+     But remember that fetch_xfpregs can fail, and return zero.  */
+  if (regno == -1)
+    {
+      fetch_regs ();
+      if (fetch_xfpregs ())
+	return;
+      fetch_fpregs ();
+      return;
+    }
+
+  if (GETREGS_SUPPLIES (regno))
+    {
+      fetch_regs ();
+      return;
+    }
+
+  if (GETXFPREGS_SUPPLIES (regno))
+    {
+      if (fetch_xfpregs ())
+	return;
+
+      /* Either our processor or our kernel doesn't support the SSE
+	 registers, so read the FP registers in the traditional way,
+	 and fill the SSE registers with dummy values.  It would be
+	 more graceful to handle differences in the register set using
+	 gdbarch.  Until then, this will at least make things work
+	 plausibly.  */
+      fetch_fpregs ();
+      dummy_sse_values ();
+      return;
+    }
 
-  if (regno >= NUM_GREGS || regno == -1)
-    fetch_fpregs ();
+  internal_error ("i386-linux-nat.c (fetch_inferior_registers): "
+		  "got request for bad register number %d", regno);
 }
 
 
@@ -312,14 +563,43 @@ void
 store_inferior_registers (regno)
      int regno;
 {
-  if (regno < NUM_GREGS || regno == -1)
-    store_regs ();
+  /* Use the xfpregs requests whenever possible, since they transfer
+     more registers in one system call.  But remember that
+     fetch_xfpregs can fail, and return zero.  */
+  if (regno == -1)
+    {
+      store_regs ();
+      if (store_xfpregs ())
+	return;
+      store_fpregs ();
+      return;
+    }
 
-  if (regno >= NUM_GREGS || regno == -1)
-    store_fpregs ();
+  if (GETREGS_SUPPLIES (regno))
+    {
+      store_regs ();
+      return;
+    }
+
+  if (GETXFPREGS_SUPPLIES (regno))
+    {
+      if (store_xfpregs ())
+	return;
+
+      /* Either our processor or our kernel doesn't support the SSE
+	 registers, so just write the FP registers in the traditional way.  */
+      store_fpregs ();
+      return;
+    }
+
+  internal_error ("i386-linux-nat.c (store_inferior_registers): "
+		  "got request to store bad register number %d", regno);
 }
 
 
+
+/* Calling functions in shared libraries.  */
+
 /* Find the minimal symbol named NAME, and return both the minsym
    struct and its objfile.  This probably ought to be in minsym.c, but
    everything there is trying to deal with things like C++ and