Lazily and dynamically create i386-linux target descriptions

Instead of using pre-generated target descriptions, this patch
changes GDB to lazily and dynamically create target descriptions
according to the target hardware capability (xcr0 in i386).
This support any combination of target features.

This patch also adds a unit test to make sure dynamically generated
tdesc are identical to these generated from xml files.

gdb:

2017-04-27  Yao Qi  <yao.qi@linaro.org>

	* i386-linux-tdep.c (i386_linux_read_description): Generate
	target description if it doesn't exist.
        [GDB_SELF_TEST] (i386_linux_read_description_test): New unit test.
        (_initialize_i386_linux_tdep) [GDB_SELF_TEST]: Register unit test.

diff --git a/gdb/features/i386/32bit-linux.c b/gdb/features/i386/32bit-linux.c
index 3f7bfe7598be5e102e6a64afa27a3206d5cf315f..ff90d40605a88617b453dcf7a5971954d19366b0 100644 (file)
--- a/gdb/features/i386/32bit-linux.c
+++ b/gdb/features/i386/32bit-linux.c
@@ -11,6 +11,7 @@ create_feature_i386_32bit_linux (struct target_desc *result, long regnum)
   struct tdesc_feature *feature;
 
   feature = tdesc_create_feature (result, "org.gnu.gdb.i386.linux");
+  regnum = 41;
   tdesc_create_reg (feature, "orig_eax", regnum++, 1, NULL, 32, "int");
   return regnum;
 }

diff --git a/gdb/features/i386/32bit-sse.c b/gdb/features/i386/32bit-sse.c
index 9aa7d3eb2ad45ec004f20f73f9200a8561358ad1..08c3948beb15d5a4bf6650213009b6d889684751 100644 (file)
--- a/gdb/features/i386/32bit-sse.c
+++ b/gdb/features/i386/32bit-sse.c
@@ -63,6 +63,7 @@ create_feature_i386_32bit_sse (struct target_desc *result, long regnum)
   tdesc_add_flag (type, 12, "PM");
   tdesc_add_flag (type, 15, "FZ");
 
+  regnum = 32;
   tdesc_create_reg (feature, "xmm0", regnum++, 1, NULL, 128, "vec128");
   tdesc_create_reg (feature, "xmm1", regnum++, 1, NULL, 128, "vec128");
   tdesc_create_reg (feature, "xmm2", regnum++, 1, NULL, 128, "vec128");

diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index d0ecb1a879004c0c7aec428c58f79444fe3ea58e..26bc577ab71d1156f1656d72e01e732a49a359de 100644 (file)
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -45,13 +45,14 @@
 
 #include "record-full.h"
 #include "linux-record.h"
-#include "features/i386/i386-linux.c"
-#include "features/i386/i386-mmx-linux.c"
-#include "features/i386/i386-mpx-linux.c"
-#include "features/i386/i386-avx-mpx-linux.c"
-#include "features/i386/i386-avx-linux.c"
-#include "features/i386/i386-avx-avx512-linux.c"
-#include "features/i386/i386-avx-mpx-avx512-pku-linux.c"
+
+#include "features/i386/32bit-core.c"
+#include "features/i386/32bit-sse.c"
+#include "features/i386/32bit-linux.c"
+#include "features/i386/32bit-avx.c"
+#include "features/i386/32bit-mpx.c"
+#include "features/i386/32bit-avx512.c"
+#include "features/i386/32bit-pkeys.c"
 
 /* Return non-zero, when the register is in the corresponding register
    group.  Put the LINUX_ORIG_EAX register in the system group.  */
@@ -681,27 +682,50 @@ i386_linux_core_read_xcr0 (bfd *abfd)
 const struct target_desc *
 i386_linux_read_description (uint64_t xcr0)
 {
-  switch ((xcr0 & X86_XSTATE_ALL_MASK))
+  if (xcr0 == 0)
+    return NULL;
+
+  static struct target_desc *i386_linux_tdescs \
+    [2/*X87*/][2/*SSE*/][2/*AVX*/][2/*MPX*/][2/*AVX512*/][2/*PKRU*/] = {};
+  struct target_desc **tdesc;
+
+  tdesc = &i386_linux_tdescs[(xcr0 & X86_XSTATE_X87) ? 1 : 0]
+    [(xcr0 & X86_XSTATE_SSE) ? 1 : 0]
+    [(xcr0 & X86_XSTATE_AVX) ? 1 : 0]
+    [(xcr0 & X86_XSTATE_MPX) ? 1 : 0]
+    [(xcr0 & X86_XSTATE_AVX512) ? 1 : 0]
+    [(xcr0 & X86_XSTATE_PKRU) ? 1 : 0];
+
+  if (*tdesc == NULL)
     {
-    case X86_XSTATE_AVX_MPX_AVX512_PKU_MASK:
-      return tdesc_i386_avx_mpx_avx512_pku_linux;
-    case X86_XSTATE_AVX_AVX512_MASK:
-      return tdesc_i386_avx_avx512_linux;
-    case X86_XSTATE_MPX_MASK:
-      return tdesc_i386_mpx_linux;
-    case X86_XSTATE_AVX_MPX_MASK:
-      return tdesc_i386_avx_mpx_linux;
-    case X86_XSTATE_AVX_MASK:
-      return tdesc_i386_avx_linux;
-    case X86_XSTATE_SSE_MASK:
-      return tdesc_i386_linux;
-    case X86_XSTATE_X87_MASK:
-      return tdesc_i386_mmx_linux;
-    default:
-      break;
+      *tdesc = allocate_target_description ();
+      set_tdesc_architecture (*tdesc, bfd_scan_arch ("i386"));
+      set_tdesc_osabi (*tdesc, osabi_from_tdesc_string ("GNU/Linux"));
+
+      long regnum = 0;
+
+      if (xcr0 & X86_XSTATE_X87)
+       regnum = create_feature_i386_32bit_core (*tdesc, regnum);
+
+      if (xcr0 & X86_XSTATE_SSE)
+       regnum = create_feature_i386_32bit_sse (*tdesc, regnum);
+
+      regnum = create_feature_i386_32bit_linux (*tdesc, regnum);
+
+      if (xcr0 & X86_XSTATE_AVX)
+       regnum = create_feature_i386_32bit_avx (*tdesc, regnum);
+
+      if (xcr0 & X86_XSTATE_MPX)
+       regnum = create_feature_i386_32bit_mpx (*tdesc, regnum);
+
+      if (xcr0 & X86_XSTATE_AVX512)
+       regnum = create_feature_i386_32bit_avx512 (*tdesc, regnum);
+
+      if (xcr0 & X86_XSTATE_PKRU)
+       regnum = create_feature_i386_32bit_pkeys (*tdesc, regnum);
     }
 
-  return NULL;
+  return *tdesc;
 }
 
 /* Get Linux/x86 target description from core dump.  */
@@ -1090,13 +1114,4 @@ _initialize_i386_linux_tdep (void)
 {
   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX,
                          i386_linux_init_abi);
-
-  /* Initialize the Linux target description.  */
-  initialize_tdesc_i386_linux ();
-  initialize_tdesc_i386_mmx_linux ();
-  initialize_tdesc_i386_avx_linux ();
-  initialize_tdesc_i386_mpx_linux ();
-  initialize_tdesc_i386_avx_mpx_linux ();
-  initialize_tdesc_i386_avx_avx512_linux ();
-  initialize_tdesc_i386_avx_mpx_avx512_pku_linux ();
 }

diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c
index 10f3be13eba672d8af4ab72a9056d1cf10fb0858..13468e544afaa885cdb3e96521a0a7fe0b09608f 100644 (file)
--- a/gdb/target-descriptions.c
+++ b/gdb/target-descriptions.c
@@ -2097,6 +2097,12 @@ public:
 
   void visit (const tdesc_reg *reg) override
   {
+    if (reg->target_regnum > next_regnum)
+      {
+       printf_unfiltered ("  regnum = %ld;\n", reg->target_regnum);
+       next_regnum = reg->target_regnum;
+      }
+
     printf_unfiltered ("  tdesc_create_reg (feature, \"%s\", regnum++, %d, ",
                       reg->name, reg->save_restore);
     if (reg->group)
@@ -2104,8 +2110,13 @@ public:
     else
       printf_unfiltered ("NULL, ");
     printf_unfiltered ("%d, \"%s\");\n", reg->bitsize, reg->type);
+
+    next_regnum++;
   }
 
+private:
+  /* The register number to use for the next register we see.  */
+  int next_regnum = 0;
 };
 
 static void