Use VEC for target_desc.reg_defs

Nowadays, target_desc.reg_defs is a pointer points to a pre-generated
array, which is not flexible.  This patch changes it from an array
to a VEC so that GDBserver can create target descriptions dynamically
later.  Instead of using pre-generated array, the -generated.c calls
VEC_safe_push to add each register to vector.

Since target_desc.reg_defs is used in IPA, we need to build common/vec.c
for IPA too.

gdb/gdbserver:

2017-05-23  Yao Qi  <yao.qi@linaro.org>

	* Makefile.in (IPA_OBJS): Add vec-ipa.o
	* regcache.c (get_thread_regcache): Use VEC_length.
	(init_register_cache): Likewise.
	(regcache_cpy): Likewise.
	(registers_to_string): Iterate reg_defs via VEC_iterate.
	(find_regno): Likewise.
	(find_register_by_number): Use VEC_index.
	(register_size): Call find_register_by_number.
	(register_data): Call find_register_by_number.
	(supply_regblock): Use VEC_length.
	(regcache_raw_read_unsigned): Likewise.
	* tdesc.c (init_target_desc): Iterate reg_defs via
	VEC_iterate.
	(default_description): Update initializer.
	(copy_target_description): Don't update field num_registers.
	* tdesc.h (struct target_desc) <reg_defs>: Change it to VEC.
	<num_registers>: Remove.

gdb:

2017-05-23  Yao Qi  <yao.qi@linaro.org>

	* regformats/regdat.sh: Update generated code.

5 files changed, 37 insertions, 33 deletions

diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
index 4a031e1..6c70d29 100644
--- a/gdb/gdbserver/Makefile.in
+++ b/gdb/gdbserver/Makefile.in
@@ -390,7 +390,7 @@ gdbreplay$(EXEEXT): $(GDBREPLAY_OBS) $(LIBGNU) $(LIBIBERTY)
 IPA_OBJS = ax-ipa.o tracepoint-ipa.o format-ipa.o utils-ipa.o \
 	regcache-ipa.o remote-utils-ipa.o common-utils-ipa.o \
 	tdesc-ipa.o print-utils-ipa.o rsp-low-ipa.o errors-ipa.o \
-	${IPA_DEPFILES}
+	vec-ipa.o ${IPA_DEPFILES}
 
 IPA_LIB = libinproctrace.so
 
diff --git a/gdb/gdbserver/regcache.c b/gdb/gdbserver/regcache.c
index 0f16f60..7dbdca7 100644
--- a/gdb/gdbserver/regcache.c
+++ b/gdb/gdbserver/regcache.c
@@ -54,7 +54,7 @@ get_thread_regcache (struct thread_info *thread, int fetch)
       current_thread = thread;
       /* Invalidate all registers, to prevent stale left-overs.  */
       memset (regcache->register_status, REG_UNAVAILABLE,
-	      regcache->tdesc->num_registers);
+	      VEC_length (tdesc_reg_p, regcache->tdesc->reg_defs));
       fetch_inferior_registers (regcache, -1);
       current_thread = saved_thread;
       regcache->registers_valid = 1;
@@ -145,9 +145,9 @@ init_register_cache (struct regcache *regcache,
 	= (unsigned char *) xcalloc (1, tdesc->registers_size);
       regcache->registers_owned = 1;
       regcache->register_status
-	= (unsigned char *) xmalloc (tdesc->num_registers);
+	= (unsigned char *) xmalloc (VEC_length (tdesc_reg_p, tdesc->reg_defs));
       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
-	      tdesc->num_registers);
+	      VEC_length (tdesc_reg_p, tdesc->reg_defs));
 #else
       gdb_assert_not_reached ("can't allocate memory from the heap");
 #endif
@@ -204,7 +204,7 @@ regcache_cpy (struct regcache *dst, struct regcache *src)
 #ifndef IN_PROCESS_AGENT
   if (dst->register_status != NULL && src->register_status != NULL)
     memcpy (dst->register_status, src->register_status,
-	    src->tdesc->num_registers);
+	    VEC_length (tdesc_reg_p, src->tdesc->reg_defs));
 #endif
   dst->registers_valid = src->registers_valid;
 }
@@ -218,8 +218,9 @@ registers_to_string (struct regcache *regcache, char *buf)
   unsigned char *registers = regcache->registers;
   const struct target_desc *tdesc = regcache->tdesc;
   int i;
+  struct reg *reg;
 
-  for (i = 0; i < tdesc->num_registers; i++)
+  for (i = 0; VEC_iterate (tdesc_reg_p, tdesc->reg_defs, i, reg); i++)
     {
       if (regcache->register_status[i] == REG_VALID)
 	{
@@ -257,22 +258,23 @@ int
 find_regno (const struct target_desc *tdesc, const char *name)
 {
   int i;
+  struct reg *reg;
 
-  for (i = 0; i < tdesc->num_registers; i++)
-    if (strcmp (name, tdesc->reg_defs[i].name) == 0)
+  for (i = 0; VEC_iterate (tdesc_reg_p, tdesc->reg_defs, i, reg); i++)
+    if (strcmp (name, reg->name) == 0)
       return i;
   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 		  name);
 }
 
+#endif
+
 struct reg *
 find_register_by_number (const struct target_desc *tdesc, int n)
 {
-  return &tdesc->reg_defs[n];
+  return VEC_index (tdesc_reg_p, tdesc->reg_defs, n);
 }
 
-#endif
-
 #ifndef IN_PROCESS_AGENT
 static void
 free_register_cache_thread (struct thread_info *thread)
@@ -312,7 +314,7 @@ register_cache_size (const struct target_desc *tdesc)
 int
 register_size (const struct target_desc *tdesc, int n)
 {
-  return tdesc->reg_defs[n].size / 8;
+  return find_register_by_number (tdesc, n)->size / 8;
 }
 
 /* See common/common-regcache.h.  */
@@ -326,7 +328,8 @@ regcache_register_size (const struct regcache *regcache, int n)
 static unsigned char *
 register_data (struct regcache *regcache, int n, int fetch)
 {
-  return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
+  return (regcache->registers
+	  + find_register_by_number (regcache->tdesc, n)->offset / 8);
 }
 
 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
@@ -385,7 +388,7 @@ supply_regblock (struct regcache *regcache, const void *buf)
       {
 	int i;
 
-	for (i = 0; i < tdesc->num_registers; i++)
+	for (i = 0; i < VEC_length (tdesc_reg_p, tdesc->reg_defs); i++)
 	  regcache->register_status[i] = REG_VALID;
       }
 #endif
@@ -399,7 +402,7 @@ supply_regblock (struct regcache *regcache, const void *buf)
       {
 	int i;
 
-	for (i = 0; i < tdesc->num_registers; i++)
+	for (i = 0; i < VEC_length (tdesc_reg_p, tdesc->reg_defs); i++)
 	  regcache->register_status[i] = REG_UNAVAILABLE;
       }
 #endif
@@ -431,7 +434,8 @@ regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
   int size;
 
   gdb_assert (regcache != NULL);
-  gdb_assert (regnum >= 0 && regnum < regcache->tdesc->num_registers);
+  gdb_assert (regnum >= 0
+	      && regnum < VEC_length (tdesc_reg_p, regcache->tdesc->reg_defs));
 
   size = register_size (regcache->tdesc, regnum);
 
diff --git a/gdb/gdbserver/tdesc.c b/gdb/gdbserver/tdesc.c
index fdd35197..1b1882e 100644
--- a/gdb/gdbserver/tdesc.c
+++ b/gdb/gdbserver/tdesc.c
@@ -23,12 +23,13 @@ void
 init_target_desc (struct target_desc *tdesc)
 {
   int offset, i;
+  struct reg *reg;
 
   offset = 0;
-  for (i = 0; i < tdesc->num_registers; i++)
+  for (i = 0; VEC_iterate (tdesc_reg_p, tdesc->reg_defs, i, reg); i++)
     {
-      tdesc->reg_defs[i].offset = offset;
-      offset += tdesc->reg_defs[i].size;
+      reg->offset = offset;
+      offset += reg->size;
     }
 
   tdesc->registers_size = offset / 8;
@@ -40,14 +41,13 @@ init_target_desc (struct target_desc *tdesc)
 
 #ifndef IN_PROCESS_AGENT
 
-static const struct target_desc default_description = { 0 };
+static const struct target_desc default_description = { NULL, 0, NULL, NULL };
 
 void
 copy_target_description (struct target_desc *dest,
 			 const struct target_desc *src)
 {
   dest->reg_defs = src->reg_defs;
-  dest->num_registers = src->num_registers;
   dest->expedite_regs = src->expedite_regs;
   dest->registers_size = src->registers_size;
   dest->xmltarget = src->xmltarget;
diff --git a/gdb/gdbserver/tdesc.h b/gdb/gdbserver/tdesc.h
index 0341278..424a2fd 100644
--- a/gdb/gdbserver/tdesc.h
+++ b/gdb/gdbserver/tdesc.h
@@ -21,17 +21,16 @@
 
 struct reg;
 
+typedef struct reg *tdesc_reg_p;
+DEF_VEC_P(tdesc_reg_p);
+
 /* A target description.  */
 
 struct target_desc
 {
-  /* An array of NUM_REGISTERS elements of register definitions that
+  /* A vector of elements of register definitions that
      describe the inferior's register set.  */
-  struct reg *reg_defs;
-
-  /* The number of registers in inferior's register set (and thus in
-     the regcache).  */
-  int num_registers;
+  VEC(tdesc_reg_p) *reg_defs;
 
   /* The register cache size, in bytes.  */
   int registers_size;
diff --git a/gdb/regformats/regdat.sh b/gdb/regformats/regdat.sh
index 2c764cd..236cd93 100755
--- a/gdb/regformats/regdat.sh
+++ b/gdb/regformats/regdat.sh
@@ -131,8 +131,8 @@ do
     echo "{"
     echo "  static struct target_desc tdesc_${name}_s;"
     echo "  struct target_desc *result = &tdesc_${name}_s;"
+    echo "  memset (result, 0, sizeof (*result));"
 
-    echo "static struct reg regs_${name}[] = {"
     continue
   elif test "${type}" = "xmltarget"; then
     xmltarget="${entry}"
@@ -150,13 +150,17 @@ do
     echo "$0: $1 does not specify \`\`name''." 1>&2
     exit 1
   else
-    echo "  { \"${entry}\", ${offset}, ${type} },"
+    echo "  {struct reg *reg = XCNEW (struct reg);"
+    echo "  reg->name = \"${entry}\";"
+    echo "  reg->offset = ${offset};"
+    echo "  reg->size = ${type};"
+    echo "  VEC_safe_push (tdesc_reg_p, result->reg_defs, reg);"
+    echo "  };"
     offset=`expr ${offset} + ${type}`
     i=`expr $i + 1`
   fi
 done
 
-echo "};"
 echo
 echo "static const char *expedite_regs_${name}[] = { \"`echo ${expedite} | sed 's/,/", "/g'`\", 0 };"
 if test "${xmltarget}" = x; then
@@ -178,9 +182,6 @@ fi
 echo
 
 cat <<EOF
-  result->reg_defs = regs_${name};
-  result->num_registers = sizeof (regs_${name}) / sizeof (regs_${name}[0]);
-
 #ifndef IN_PROCESS_AGENT
   result->expedite_regs = expedite_regs_${name};
   result->xmltarget = xmltarget_${name};