gdb: Delay releasing target_desc_up in more cases

After commit:

  commit 51a948fdf0e14fb69ab9e0c79ae8b2415801f9a3
  Date:   Mon Jul 20 14:18:04 2020 +0100

      gdb: Have allocate_target_description return a unique_ptr

There were a few places where we could (should?) have delayed
releasing the target_desc_up until a little later.  This commit
catches these cases.

In the case of ARC, the target_desc_up is now exposed right out to
gdbserver, which means making a small change there too.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* arch/aarch32.c (aarch32_create_target_description): Release the
	target_desc_up as late as possible.
	* arch/aarch64.c (aarch64_create_target_description): Likewise.
	* arch/amd64.c (amd64_create_target_description): Likewise.
	* arch/arc.c (arc_create_target_description): Return a
	target_desc_up, don't release it.
	* arch/arc.h (arc_create_target_description): Update declaration.
	(arc_lookup_target_description): Move target_desc_up into the
	cache, and return a borrowed pointer.
	* arch/arm.c (arm_create_target_description): Release the
	target_desc_up as late as possible.
	* arch/i386.c (i386_create_target_description): Likewise.
	* arch/riscv.h (riscv_create_target_description): Update
	declaration to match definition.
	* arch/tic6x.c (tic6x_create_target_description): Release the
	target_desc_up as late as possible.

gdbserver/ChangeLog:

	* linux-arc-low.cc (arc_linux_read_description): Release the
	unique_ptr returned from arc_create_target_description.

12 files changed, 97 insertions, 69 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 75fdfeb..28fa696 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,24 @@
 2020-10-09  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* arch/aarch32.c (aarch32_create_target_description): Release the
+	target_desc_up as late as possible.
+	* arch/aarch64.c (aarch64_create_target_description): Likewise.
+	* arch/amd64.c (amd64_create_target_description): Likewise.
+	* arch/arc.c (arc_create_target_description): Return a
+	target_desc_up, don't release it.
+	* arch/arc.h (arc_create_target_description): Update declaration.
+	(arc_lookup_target_description): Move target_desc_up into the
+	cache, and return a borrowed pointer.
+	* arch/arm.c (arm_create_target_description): Release the
+	target_desc_up as late as possible.
+	* arch/i386.c (i386_create_target_description): Likewise.
+	* arch/riscv.h (riscv_create_target_description): Update
+	declaration to match definition.
+	* arch/tic6x.c (tic6x_create_target_description): Release the
+	target_desc_up as late as possible.
+
+2020-10-09  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* Makefile.in: Include Makefile.gnulib.inc.  Don't define LIBGNU
 	or INCGNU.  Make use of LIBGNU_EXTRA_LIBS when linking.
 
diff --git a/gdb/arch/aarch32.c b/gdb/arch/aarch32.c
index bf7a332..0a869ec 100644
--- a/gdb/arch/aarch32.c
+++ b/gdb/arch/aarch32.c
@@ -26,18 +26,18 @@
 target_desc *
 aarch32_create_target_description ()
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
-  set_tdesc_architecture (tdesc, "arm");
+  set_tdesc_architecture (tdesc.get (), "arm");
 #endif
 
   long regnum = 0;
 
-  regnum = create_feature_arm_arm_core (tdesc, regnum);
+  regnum = create_feature_arm_arm_core (tdesc.get (), regnum);
   /* Create a vfpv3 feature, then a blank NEON feature.  */
-  regnum = create_feature_arm_arm_vfpv3 (tdesc, regnum);
-  tdesc_create_feature (tdesc, "org.gnu.gdb.arm.neon");
+  regnum = create_feature_arm_arm_vfpv3 (tdesc.get (), regnum);
+  tdesc_create_feature (tdesc.get (), "org.gnu.gdb.arm.neon");
 
-  return tdesc;
+  return tdesc.release ();
 }
diff --git a/gdb/arch/aarch64.c b/gdb/arch/aarch64.c
index c0af7b0..f89d5e0 100644
--- a/gdb/arch/aarch64.c
+++ b/gdb/arch/aarch64.c
@@ -29,23 +29,23 @@
 target_desc *
 aarch64_create_target_description (uint64_t vq, bool pauth_p)
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
-  set_tdesc_architecture (tdesc, "aarch64");
+  set_tdesc_architecture (tdesc.get (), "aarch64");
 #endif
 
   long regnum = 0;
 
-  regnum = create_feature_aarch64_core (tdesc, regnum);
+  regnum = create_feature_aarch64_core (tdesc.get (), regnum);
 
   if (vq == 0)
-    regnum = create_feature_aarch64_fpu (tdesc, regnum);
+    regnum = create_feature_aarch64_fpu (tdesc.get (), regnum);
   else
-    regnum = create_feature_aarch64_sve (tdesc, regnum, vq);
+    regnum = create_feature_aarch64_sve (tdesc.get (), regnum, vq);
 
   if (pauth_p)
-    regnum = create_feature_aarch64_pauth (tdesc, regnum);
+    regnum = create_feature_aarch64_pauth (tdesc.get (), regnum);
 
-  return tdesc;
+  return tdesc.release ();
 }
diff --git a/gdb/arch/amd64.c b/gdb/arch/amd64.c
index b11a4fd..60d997d 100644
--- a/gdb/arch/amd64.c
+++ b/gdb/arch/amd64.c
@@ -40,39 +40,40 @@ target_desc *
 amd64_create_target_description (uint64_t xcr0, bool is_x32, bool is_linux,
 				 bool segments)
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
-  set_tdesc_architecture (tdesc, is_x32 ? "i386:x64-32" : "i386:x86-64");
+  set_tdesc_architecture (tdesc.get (),
+			  is_x32 ? "i386:x64-32" : "i386:x86-64");
 
   if (is_linux)
-    set_tdesc_osabi (tdesc, "GNU/Linux");
+    set_tdesc_osabi (tdesc.get (), "GNU/Linux");
 #endif
 
   long regnum = 0;
 
   if (is_x32)
-    regnum = create_feature_i386_x32_core (tdesc, regnum);
+    regnum = create_feature_i386_x32_core (tdesc.get (), regnum);
   else
-    regnum = create_feature_i386_64bit_core (tdesc, regnum);
+    regnum = create_feature_i386_64bit_core (tdesc.get (), regnum);
 
-  regnum = create_feature_i386_64bit_sse (tdesc, regnum);
+  regnum = create_feature_i386_64bit_sse (tdesc.get (), regnum);
   if (is_linux)
-    regnum = create_feature_i386_64bit_linux (tdesc, regnum);
+    regnum = create_feature_i386_64bit_linux (tdesc.get (), regnum);
   if (segments)
-    regnum = create_feature_i386_64bit_segments (tdesc, regnum);
+    regnum = create_feature_i386_64bit_segments (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_AVX)
-    regnum = create_feature_i386_64bit_avx (tdesc, regnum);
+    regnum = create_feature_i386_64bit_avx (tdesc.get (), regnum);
 
   if ((xcr0 & X86_XSTATE_MPX) && !is_x32)
-    regnum = create_feature_i386_64bit_mpx (tdesc, regnum);
+    regnum = create_feature_i386_64bit_mpx (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_AVX512)
-    regnum = create_feature_i386_64bit_avx512 (tdesc, regnum);
+    regnum = create_feature_i386_64bit_avx512 (tdesc.get (), regnum);
 
   if ((xcr0 & X86_XSTATE_PKRU) && !is_x32)
-    regnum = create_feature_i386_64bit_pkeys (tdesc, regnum);
+    regnum = create_feature_i386_64bit_pkeys (tdesc.get (), regnum);
 
-  return tdesc;
+  return tdesc.release ();
 }
diff --git a/gdb/arch/arc.c b/gdb/arch/arc.c
index dff4575..abed8a6 100644
--- a/gdb/arch/arc.c
+++ b/gdb/arch/arc.c
@@ -34,11 +34,11 @@
 #define STATIC_IN_GDB
 #endif
 
-STATIC_IN_GDB target_desc *
+STATIC_IN_GDB target_desc_up
 arc_create_target_description (const struct arc_arch_features &features)
 {
   /* Create a new target description.  */
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
   std::string arch_name;
@@ -57,7 +57,7 @@ arc_create_target_description (const struct arc_arch_features &features)
       gdb_assert_not_reached (msg.c_str ());
     }
 
-  set_tdesc_architecture (tdesc, arch_name.c_str ());
+  set_tdesc_architecture (tdesc.get (), arch_name.c_str ());
 #endif
 
   long regnum = 0;
@@ -65,12 +65,12 @@ arc_create_target_description (const struct arc_arch_features &features)
   switch (features.isa)
     {
     case ARC_ISA_ARCV1:
-      regnum = create_feature_arc_v1_core (tdesc, regnum);
-      regnum = create_feature_arc_v1_aux (tdesc, regnum);
+      regnum = create_feature_arc_v1_core (tdesc.get (), regnum);
+      regnum = create_feature_arc_v1_aux (tdesc.get (), regnum);
       break;
     case ARC_ISA_ARCV2:
-      regnum = create_feature_arc_v2_core (tdesc, regnum);
-      regnum = create_feature_arc_v2_aux (tdesc, regnum);
+      regnum = create_feature_arc_v2_core (tdesc.get (), regnum);
+      regnum = create_feature_arc_v2_aux (tdesc.get (), regnum);
       break;
     default:
       std::string msg = string_printf
@@ -111,12 +111,15 @@ arc_lookup_target_description (const struct arc_arch_features &features)
   if (it != arc_tdesc_cache.end ())
     return it->second.get ();
 
-  target_desc *tdesc = arc_create_target_description (features);
+  target_desc_up tdesc = arc_create_target_description (features);
 
-  /* Add the newly created target description to the repertoire.  */
-  arc_tdesc_cache.emplace (features, tdesc);
 
-  return tdesc;
+  /* Add to the cache, and return a pointer borrowed from the
+     target_desc_up.  This is safe as the cache (and the pointers
+     contained within it) are not deleted until GDB exits.  */
+  target_desc *ptr = tdesc.get ();
+  arc_tdesc_cache.emplace (features, std::move (tdesc));
+  return ptr;
 }
 
 #endif /* !GDBSERVER */
diff --git a/gdb/arch/arc.h b/gdb/arch/arc.h
index 1625759..1e0e8cd 100644
--- a/gdb/arch/arc.h
+++ b/gdb/arch/arc.h
@@ -70,7 +70,7 @@ struct arc_arch_features
    The only external client of this must be the gdbserver which manipulates
    the returned data.  */
 
-target_desc *arc_create_target_description
+target_desc_up arc_create_target_description
 	(const struct arc_arch_features &features);
 
 #else
diff --git a/gdb/arch/arm.c b/gdb/arch/arm.c
index dc67e40..406a8e7 100644
--- a/gdb/arch/arm.c
+++ b/gdb/arch/arm.c
@@ -374,18 +374,18 @@ shifted_reg_val (struct regcache *regcache, unsigned long inst,
 target_desc *
 arm_create_target_description (arm_fp_type fp_type)
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
   if (fp_type == ARM_FP_TYPE_IWMMXT)
-    set_tdesc_architecture (tdesc, "iwmmxt");
+    set_tdesc_architecture (tdesc.get (), "iwmmxt");
   else
-    set_tdesc_architecture (tdesc, "arm");
+    set_tdesc_architecture (tdesc.get (), "arm");
 #endif
 
   long regnum = 0;
 
-  regnum = create_feature_arm_arm_core (tdesc, regnum);
+  regnum = create_feature_arm_arm_core (tdesc.get (), regnum);
 
   switch (fp_type)
     {
@@ -393,22 +393,22 @@ arm_create_target_description (arm_fp_type fp_type)
       break;
 
     case ARM_FP_TYPE_VFPV2:
-      regnum = create_feature_arm_arm_vfpv2 (tdesc, regnum);
+      regnum = create_feature_arm_arm_vfpv2 (tdesc.get (), regnum);
       break;
 
     case ARM_FP_TYPE_VFPV3:
-      regnum = create_feature_arm_arm_vfpv3 (tdesc, regnum);
+      regnum = create_feature_arm_arm_vfpv3 (tdesc.get (), regnum);
       break;
 
     case ARM_FP_TYPE_IWMMXT:
-      regnum = create_feature_arm_xscale_iwmmxt (tdesc, regnum);
+      regnum = create_feature_arm_xscale_iwmmxt (tdesc.get (), regnum);
       break;
 
     default:
       error (_("Invalid Arm FP type: %d"), fp_type);
     }
 
-  return tdesc;
+  return tdesc.release ();
 }
 
 /* See arch/arm.h.  */
diff --git a/gdb/arch/i386.c b/gdb/arch/i386.c
index 13201db..d823c1a 100644
--- a/gdb/arch/i386.c
+++ b/gdb/arch/i386.c
@@ -35,39 +35,39 @@
 target_desc *
 i386_create_target_description (uint64_t xcr0, bool is_linux, bool segments)
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
 #ifndef IN_PROCESS_AGENT
-  set_tdesc_architecture (tdesc, "i386");
+  set_tdesc_architecture (tdesc.get (), "i386");
   if (is_linux)
-    set_tdesc_osabi (tdesc, "GNU/Linux");
+    set_tdesc_osabi (tdesc.get (), "GNU/Linux");
 #endif
 
   long regnum = 0;
 
   if (xcr0 & X86_XSTATE_X87)
-    regnum = create_feature_i386_32bit_core (tdesc, regnum);
+    regnum = create_feature_i386_32bit_core (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_SSE)
-    regnum = create_feature_i386_32bit_sse (tdesc, regnum);
+    regnum = create_feature_i386_32bit_sse (tdesc.get (), regnum);
 
   if (is_linux)
-    regnum = create_feature_i386_32bit_linux (tdesc, regnum);
+    regnum = create_feature_i386_32bit_linux (tdesc.get (), regnum);
 
   if (segments)
-    regnum = create_feature_i386_32bit_segments (tdesc, regnum);
+    regnum = create_feature_i386_32bit_segments (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_AVX)
-    regnum = create_feature_i386_32bit_avx (tdesc, regnum);
+    regnum = create_feature_i386_32bit_avx (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_MPX)
-    regnum = create_feature_i386_32bit_mpx (tdesc, regnum);
+    regnum = create_feature_i386_32bit_mpx (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_AVX512)
-    regnum = create_feature_i386_32bit_avx512 (tdesc, regnum);
+    regnum = create_feature_i386_32bit_avx512 (tdesc.get (), regnum);
 
   if (xcr0 & X86_XSTATE_PKRU)
-    regnum = create_feature_i386_32bit_pkeys (tdesc, regnum);
+    regnum = create_feature_i386_32bit_pkeys (tdesc.get (), regnum);
 
-  return tdesc;
+  return tdesc.release ();
 }
diff --git a/gdb/arch/riscv.h b/gdb/arch/riscv.h
index d40862c..26db0da 100644
--- a/gdb/arch/riscv.h
+++ b/gdb/arch/riscv.h
@@ -72,7 +72,7 @@ struct riscv_gdbarch_features
    This is only used directly from the gdbserver where the created target
    description is modified after it is return.  */
 
-target_desc *riscv_create_target_description
+target_desc_up riscv_create_target_description
 	(const struct riscv_gdbarch_features features);
 
 #else
diff --git a/gdb/arch/tic6x.c b/gdb/arch/tic6x.c
index dad4dd8..d52ec3a 100644
--- a/gdb/arch/tic6x.c
+++ b/gdb/arch/tic6x.c
@@ -28,20 +28,20 @@
 target_desc *
 tic6x_create_target_description (enum c6x_feature feature)
 {
-  target_desc *tdesc = allocate_target_description ().release ();
+  target_desc_up tdesc = allocate_target_description ();
 
-  set_tdesc_architecture (tdesc, "tic6x");
-  set_tdesc_osabi (tdesc, "GNU/Linux");
+  set_tdesc_architecture (tdesc.get (), "tic6x");
+  set_tdesc_osabi (tdesc.get (), "GNU/Linux");
 
   long regnum = 0;
 
-  regnum = create_feature_tic6x_core (tdesc, regnum);
+  regnum = create_feature_tic6x_core (tdesc.get (), regnum);
 
   if (feature == C6X_GP || feature == C6X_C6XP)
-    regnum = create_feature_tic6x_gp (tdesc, regnum);
+    regnum = create_feature_tic6x_gp (tdesc.get (), regnum);
 
   if (feature == C6X_C6XP)
-    regnum = create_feature_tic6x_c6xp (tdesc, regnum);
+    regnum = create_feature_tic6x_c6xp (tdesc.get (), regnum);
 
-  return tdesc;
+  return tdesc.release ();
 }
diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index 262ceff..79e6a37 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,5 +1,10 @@
 2020-10-09  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* linux-arc-low.cc (arc_linux_read_description): Release the
+	unique_ptr returned from arc_create_target_description.
+
+2020-10-09  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* Makefile.in: Include Makefile.gnulib.inc.  Don't define LIBGNU
 	or INCGNU.  Make use of LIBGNU_EXTRA_LIBS when linking.
 
diff --git a/gdbserver/linux-arc-low.cc b/gdbserver/linux-arc-low.cc
index 1f370ef..d101bd2 100644
--- a/gdbserver/linux-arc-low.cc
+++ b/gdbserver/linux-arc-low.cc
@@ -112,12 +112,12 @@ arc_linux_read_description (void)
 #else
   arc_arch_features features (4, ARC_ISA_ARCV2);
 #endif
-  struct target_desc *tdesc = arc_create_target_description (features);
+  target_desc_up tdesc = arc_create_target_description (features);
 
   static const char *expedite_regs[] = { "sp", "status32", nullptr };
-  init_target_desc (tdesc, expedite_regs);
+  init_target_desc (tdesc.get (), expedite_regs);
 
-  return tdesc;
+  return tdesc.release ();
 }
 
 void