Re: [PATCH] gdb passes and returns incorrect values when dealing with small array on Sparc

[jose.marchesi@oracle.com (Jose E. Marchesi)]

    On 05/19/2017 10:44 AM, Jose E. Marchesi wrote:
    > 
    >     From: Vladimir Mezentsev <vladimir.mezentsev@oracle.com>
    >     
    >     gdb has a special type (TYPE_CODE_ARRAY) to support the gcc extension
    >     (https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html).
    >     TYPE_CODE_ARRAY is handled incorrectly for both (32- and 64-bit) modes on Sparc machines.
    >     
    >     Tested on sparc64-linux-gnu and sparc-solaris (32- and 64-bit mode).
    >     No regressions.
    >     
    >     gdb/ChangeLog:
    >     2017-05-12  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>
    >     
    >     	* sparc-tdep.c (sparc_structure_return_p)
    >     	(sparc_arg_on_registers_p): New functions.
    >     	(sparc32_store_arguments): Use them.
    >     	* sparc64-tdep.c (sparc64_16_byte_align_p)
    >     	(sparc64_store_floating_fields, sparc64_extract_floating_fields):
    >     	Handle TYPE_CODE_ARRAY.
    > 
    > 
    > LGTM.  Ok for master?
    > 
    
    OK with the commit log tweak mentioned at:
    
     https://sourceware.org/ml/gdb-patches/2017-04/msg00509.html


Applied as below.
Thanks.


commit 1933fd8ee01ad2e74a9c6341bc40f54962a8f889
Author: Vladimir Mezentsev <vladimir.mezentsev@oracle.com>
Date:   Fri May 19 03:06:19 2017 -0700

    gdb: fix TYPE_CODE_ARRAY handling in sparc targets
    
    gdb has a special type (TYPE_CODE_ARRAY) to support the gcc extension
    (https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html).
    TYPE_CODE_ARRAY is handled incorrectly for both (32- and 64-bit) modes
    on Sparc machines.
    
    Tested on sparc64-linux-gnu and sparc-solaris (32- and 64-bit mode).
    
    6 tests ( from gdb/testsuite/gdb.base/gnu_vector.exp) failed on
    sparc64-Linux and on sparc-Solaris in 32- and 64-bit mode.  Now all
    these tests passed.  gdb/testsuite/gdb.base/gnu_vector.exp has 117
    different cases for small (and not small) arrays and structures.
    
    No regressions.
    
    gdb/ChangeLog:
    
    2017-05-19  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>
    
    	* sparc-tdep.c (sparc_structure_return_p)
    	(sparc_arg_on_registers_p): New functions.
    	(sparc32_store_arguments): Use them.
    	* sparc64-tdep.c (sparc64_16_byte_align_p)
    	(sparc64_store_floating_fields, sparc64_extract_floating_fields):
    	Handle TYPE_CODE_ARRAY.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index fdc2a40..1273ed8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2017-05-19  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>
+
+	* sparc-tdep.c (sparc_structure_return_p)
+	(sparc_arg_on_registers_p): New functions.
+	(sparc32_store_arguments): Use them.
+	* sparc64-tdep.c (sparc64_16_byte_align_p)
+	(sparc64_store_floating_fields, sparc64_extract_floating_fields):
+	Handle TYPE_CODE_ARRAY.
+
 2017-05-17  Yao Qi  <yao.qi@linaro.org>
 
 	* cli/cli-decode.c (add_alias_cmd): New function.
diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c
index d1e64b4..fa0e04e 100644
--- a/gdb/sparc-tdep.c
+++ b/gdb/sparc-tdep.c
@@ -298,6 +298,43 @@ sparc_structure_or_union_p (const struct type *type)
   return 0;
 }
 
+/* Check whether TYPE is returned on registers.  */
+
+static bool
+sparc_structure_return_p (const struct type *type)
+{
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_LENGTH (type) <= 8)
+    {
+      struct type *t = check_typedef (TYPE_TARGET_TYPE (type));
+
+      if (sparc_floating_p (t) && TYPE_LENGTH (t) == 8)
+        return true;
+      return false;
+    }
+  if (sparc_floating_p (type) && TYPE_LENGTH (type) == 16)
+    return true;
+  return sparc_structure_or_union_p (type);
+}
+
+/* Check whether TYPE is passed on registers.  */
+
+static bool
+sparc_arg_on_registers_p (const struct type *type)
+{
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_LENGTH (type) <= 8)
+    {
+      struct type *t = check_typedef (TYPE_TARGET_TYPE (type));
+
+      if (sparc_floating_p (t) && TYPE_LENGTH (t) == 8)
+        return false;
+      return true;
+    }
+  if (sparc_structure_or_union_p (type) || sparc_complex_floating_p (type)
+      || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16))
+    return false;
+  return true;
+}
+
 /* Register information.  */
 #define SPARC32_FPU_REGISTERS                             \
   "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",         \
@@ -570,9 +607,7 @@ sparc32_store_arguments (struct regcache *regcache, int nargs,
       struct type *type = value_type (args[i]);
       int len = TYPE_LENGTH (type);
 
-      if (sparc_structure_or_union_p (type)
-	  || (sparc_floating_p (type) && len == 16)
-	  || sparc_complex_floating_p (type))
+      if (!sparc_arg_on_registers_p (type))
 	{
 	  /* Structure, Union and Quad-Precision Arguments.  */
 	  sp -= len;
@@ -594,11 +629,8 @@ sparc32_store_arguments (struct regcache *regcache, int nargs,
       else
 	{
 	  /* Integral and pointer arguments.  */
-	  gdb_assert (sparc_integral_or_pointer_p (type));
-
-	  if (len < 4)
-	    args[i] = value_cast (builtin_type (gdbarch)->builtin_int32,
-				  args[i]);
+	  gdb_assert (sparc_integral_or_pointer_p (type)
+	              || (TYPE_CODE (type) == TYPE_CODE_ARRAY && len <= 8));
 	  num_elements += ((len + 3) / 4);
 	}
     }
@@ -620,6 +652,15 @@ sparc32_store_arguments (struct regcache *regcache, int nargs,
       const bfd_byte *valbuf = value_contents (args[i]);
       struct type *type = value_type (args[i]);
       int len = TYPE_LENGTH (type);
+      gdb_byte buf[4];
+
+      if (len < 4)
+        {
+          memset (buf, 0, 4 - len);
+          memcpy (buf + 4 - len, valbuf, len);
+          valbuf = buf;
+          len = 4;
+        }
 
       gdb_assert (len == 4 || len == 8);
 
@@ -1345,10 +1386,10 @@ sparc32_extract_return_value (struct type *type, struct regcache *regcache,
   int len = TYPE_LENGTH (type);
   gdb_byte buf[32];
 
-  gdb_assert (!sparc_structure_or_union_p (type));
-  gdb_assert (!(sparc_floating_p (type) && len == 16));
+  gdb_assert (!sparc_structure_return_p (type));
 
-  if (sparc_floating_p (type) || sparc_complex_floating_p (type))
+  if (sparc_floating_p (type) || sparc_complex_floating_p (type)
+      || TYPE_CODE (type) == TYPE_CODE_ARRAY)
     {
       /* Floating return values.  */
       regcache_cooked_read (regcache, SPARC_F0_REGNUM, buf);
@@ -1397,11 +1438,9 @@ sparc32_store_return_value (struct type *type, struct regcache *regcache,
 			    const gdb_byte *valbuf)
 {
   int len = TYPE_LENGTH (type);
-  gdb_byte buf[8];
+  gdb_byte buf[32];
 
-  gdb_assert (!sparc_structure_or_union_p (type));
-  gdb_assert (!(sparc_floating_p (type) && len == 16));
-  gdb_assert (len <= 8);
+  gdb_assert (!sparc_structure_return_p (type));
 
   if (sparc_floating_p (type) || sparc_complex_floating_p (type))
     {
@@ -1457,8 +1496,7 @@ sparc32_return_value (struct gdbarch *gdbarch, struct value *function,
      guarantees that we can always find the return value, not just
      before the function returns.  */
 
-  if (sparc_structure_or_union_p (type)
-      || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16))
+  if (sparc_structure_return_p (type))
     {
       ULONGEST sp;
       CORE_ADDR addr;
diff --git a/gdb/sparc64-tdep.c b/gdb/sparc64-tdep.c
index 58f5bf0..9e0e6b5 100644
--- a/gdb/sparc64-tdep.c
+++ b/gdb/sparc64-tdep.c
@@ -669,6 +669,13 @@ static const struct frame_base sparc64_frame_base =
 static int
 sparc64_16_byte_align_p (struct type *type)
 {
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
+    {
+      struct type *t = check_typedef (TYPE_TARGET_TYPE (type));
+
+      if (sparc64_floating_p (t))
+        return 1;
+    }
   if (sparc64_floating_p (type) && TYPE_LENGTH (type) == 16)
     return 1;
 
@@ -703,7 +710,23 @@ sparc64_store_floating_fields (struct regcache *regcache, struct type *type,
 
   gdb_assert (element < 16);
 
-  if (sparc64_floating_p (type)
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
+    {
+      gdb_byte buf[8];
+      int regnum = SPARC_F0_REGNUM + element * 2 + bitpos / 32;
+
+      valbuf += bitpos / 8;
+      if (len < 8)
+        {
+          memset (buf, 0, 8 - len);
+          memcpy (buf + 8 - len, valbuf, len);
+          valbuf = buf;
+          len = 8;
+        }
+      for (int n = 0; n < (len + 3) / 4; n++)
+        regcache_cooked_write (regcache, regnum + n, valbuf + n * 4);
+    }
+  else if (sparc64_floating_p (type)
       || (sparc64_complex_floating_p (type) && len <= 16))
     {
       int regnum;
@@ -776,7 +799,23 @@ sparc64_extract_floating_fields (struct regcache *regcache, struct type *type,
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 
-  if (sparc64_floating_p (type))
+  if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
+    {
+      int len = TYPE_LENGTH (type);
+      int regnum =  SPARC_F0_REGNUM + bitpos / 32;
+
+      valbuf += bitpos / 8;
+      if (len < 4)
+        {
+          gdb_byte buf[4];
+          regcache_cooked_read (regcache, regnum, buf);
+          memcpy (valbuf, buf + 4 - len, len);
+        }
+      else
+        for (int i = 0; i < (len + 3) / 4; i++)
+          regcache_cooked_read (regcache, regnum + i, valbuf + i * 4);
+    }
+  else if (sparc64_floating_p (type))
     {
       int len = TYPE_LENGTH (type);
       int regnum;