Use std::vector for "registers_used" in compile feature

This changes the GDB compile code to use std::vector<bool> when
computing which registers are used.  This is a bit more idiomatic, but
the main benefit is that it also adds some checking when the libstd++
debug mode is enabled.

2021-01-23  Tom Tromey  <tom@tromey.com>

	* symtab.h (struct symbol_computed_ops) <generate_c_location>:
	Change type of "registers_used".
	* dwarf2/loc.h (dwarf2_compile_property_to_c): Update.
	* dwarf2/loc.c (dwarf2_compile_property_to_c)
	(locexpr_generate_c_location, loclist_generate_c_location): Change
	type of "registers_used".
	* compile/compile.h (compile_dwarf_expr_to_c)
	(compile_dwarf_bounds_to_c): Update.
	* compile/compile-loc2c.c (pushf_register_address)
	(pushf_register, do_compile_dwarf_expr_to_c)
	(compile_dwarf_expr_to_c, compile_dwarf_bounds_to_c): Change type
	of "registers_used".
	* compile/compile-c.h (generate_c_for_variable_locations):
	Update.
	* compile/compile-c-symbols.c (generate_vla_size)
	(generate_c_for_for_one_variable): Change type of
	"registers_used".
	(generate_c_for_variable_locations): Return std::vector.
	* compile/compile-c-support.c (generate_register_struct): Change
	type of "registers_used".
	(compute): Update.

9 files changed, 51 insertions, 26 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a45957b..8fa20fa 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,29 @@
 2021-01-23  Tom Tromey  <tom@tromey.com>
 
+	* symtab.h (struct symbol_computed_ops) <generate_c_location>:
+	Change type of "registers_used".
+	* dwarf2/loc.h (dwarf2_compile_property_to_c): Update.
+	* dwarf2/loc.c (dwarf2_compile_property_to_c)
+	(locexpr_generate_c_location, loclist_generate_c_location): Change
+	type of "registers_used".
+	* compile/compile.h (compile_dwarf_expr_to_c)
+	(compile_dwarf_bounds_to_c): Update.
+	* compile/compile-loc2c.c (pushf_register_address)
+	(pushf_register, do_compile_dwarf_expr_to_c)
+	(compile_dwarf_expr_to_c, compile_dwarf_bounds_to_c): Change type
+	of "registers_used".
+	* compile/compile-c.h (generate_c_for_variable_locations):
+	Update.
+	* compile/compile-c-symbols.c (generate_vla_size)
+	(generate_c_for_for_one_variable): Change type of
+	"registers_used".
+	(generate_c_for_variable_locations): Return std::vector.
+	* compile/compile-c-support.c (generate_register_struct): Change
+	type of "registers_used".
+	(compute): Update.
+
+2021-01-23  Tom Tromey  <tom@tromey.com>
+
 	* compile/compile-internal.h (class compile_instance)
 	<set_arguments>: Change return type.
 	* compile/compile.c (compile_to_object): Remove call to reset.
diff --git a/gdb/compile/compile-c-support.c b/gdb/compile/compile-c-support.c
index 7ce58c2..5f49a0a 100644
--- a/gdb/compile/compile-c-support.c
+++ b/gdb/compile/compile-c-support.c
@@ -213,7 +213,7 @@ write_macro_definitions (const struct block *block, CORE_ADDR pc,
 
 static void
 generate_register_struct (struct ui_file *stream, struct gdbarch *gdbarch,
-			  const unsigned char *registers_used)
+			  const std::vector<bool> &registers_used)
 {
   int i;
   int seen = 0;
@@ -221,7 +221,7 @@ generate_register_struct (struct ui_file *stream, struct gdbarch *gdbarch,
   fputs_unfiltered ("struct " COMPILE_I_SIMPLE_REGISTER_STRUCT_TAG " {\n",
 		    stream);
 
-  if (registers_used != NULL)
+  if (!registers_used.empty ())
     for (i = 0; i < gdbarch_num_regs (gdbarch); ++i)
       {
 	if (registers_used[i])
@@ -572,7 +572,7 @@ public:
 	   before generating the function header, so we can define the
 	   register struct before the function body.  This requires a
 	   temporary stream.  */
-	gdb::unique_xmalloc_ptr<unsigned char> registers_used
+	std::vector<bool> registers_used
 	  = generate_c_for_variable_locations (m_instance, &var_stream, m_arch,
 					       expr_block, expr_pc);
 
@@ -595,7 +595,7 @@ public:
 			mode, mode);
 	  }
 
-	generate_register_struct (&buf, m_arch, registers_used.get ());
+	generate_register_struct (&buf, m_arch, registers_used);
       }
 
     AddCodeHeaderPolicy::add_code_header (m_instance->scope (), &buf);
diff --git a/gdb/compile/compile-c-symbols.c b/gdb/compile/compile-c-symbols.c
index 6ae3b42..08ebe0f 100644
--- a/gdb/compile/compile-c-symbols.c
+++ b/gdb/compile/compile-c-symbols.c
@@ -487,7 +487,7 @@ static void
 generate_vla_size (compile_instance *compiler,
 		   string_file *stream,
 		   struct gdbarch *gdbarch,
-		   unsigned char *registers_used,
+		   std::vector<bool> &registers_used,
 		   CORE_ADDR pc,
 		   struct type *type,
 		   struct symbol *sym)
@@ -541,7 +541,7 @@ static void
 generate_c_for_for_one_variable (compile_instance *compiler,
 				 string_file *stream,
 				 struct gdbarch *gdbarch,
-				 unsigned char *registers_used,
+				 std::vector<bool> &registers_used,
 				 CORE_ADDR pc,
 				 struct symbol *sym)
 {
@@ -606,7 +606,7 @@ generate_c_for_for_one_variable (compile_instance *compiler,
 
 /* See compile-c.h.  */
 
-gdb::unique_xmalloc_ptr<unsigned char>
+std::vector<bool>
 generate_c_for_variable_locations (compile_instance *compiler,
 				   string_file *stream,
 				   struct gdbarch *gdbarch,
@@ -618,10 +618,9 @@ generate_c_for_variable_locations (compile_instance *compiler,
   /* If we're already in the static or global block, there is nothing
      to write.  */
   if (static_block == NULL || block == static_block)
-    return NULL;
+    return {};
 
-  gdb::unique_xmalloc_ptr<unsigned char> registers_used
-    (XCNEWVEC (unsigned char, gdbarch_num_regs (gdbarch)));
+  std::vector<bool> registers_used (gdbarch_num_regs (gdbarch));
 
   /* Ensure that a given name is only entered once.  This reflects the
      reality of shadowing.  */
@@ -641,7 +640,7 @@ generate_c_for_variable_locations (compile_instance *compiler,
 	{
 	  if (!symbol_seen (symhash.get (), sym))
 	    generate_c_for_for_one_variable (compiler, stream, gdbarch,
-					     registers_used.get (), pc, sym);
+					     registers_used, pc, sym);
 	}
 
       /* If we just finished the outermost block of a function, we're
diff --git a/gdb/compile/compile-c.h b/gdb/compile/compile-c.h
index 526cc98..e8082d8 100644
--- a/gdb/compile/compile-c.h
+++ b/gdb/compile/compile-c.h
@@ -66,7 +66,7 @@ private:
    register number, where each element indicates if the corresponding
    register is needed to compute a local variable.  */
 
-extern gdb::unique_xmalloc_ptr<unsigned char>
+extern std::vector<bool>
   generate_c_for_variable_locations
      (compile_instance *compiler,
       string_file *stream,
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index 8ce4a23..ee9595c 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -511,12 +511,12 @@ print_label (string_file *stream, unsigned int scope, int target)
 
 static void
 pushf_register_address (int indent, string_file *stream,
-			unsigned char *registers_used,
+			std::vector<bool> &registers_used,
 			struct gdbarch *gdbarch, int regnum)
 {
   std::string regname = compile_register_name_mangled (gdbarch, regnum);
 
-  registers_used[regnum] = 1;
+  registers_used[regnum] = true;
   pushf (indent, stream,
 	 "(" GCC_UINTPTR ") &" COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
 	 regname.c_str ());
@@ -529,12 +529,12 @@ pushf_register_address (int indent, string_file *stream,
 
 static void
 pushf_register (int indent, string_file *stream,
-		unsigned char *registers_used,
+		std::vector<bool> &registers_used,
 		struct gdbarch *gdbarch, int regnum, uint64_t offset)
 {
   std::string regname = compile_register_name_mangled (gdbarch, regnum);
 
-  registers_used[regnum] = 1;
+  registers_used[regnum] = true;
   if (offset == 0)
     pushf (indent, stream, COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
 	   regname.c_str ());
@@ -579,7 +579,7 @@ do_compile_dwarf_expr_to_c (int indent, string_file *stream,
 			    const char *result_name,
 			    struct symbol *sym, CORE_ADDR pc,
 			    struct gdbarch *arch,
-			    unsigned char *registers_used,
+			    std::vector<bool> &registers_used,
 			    unsigned int addr_size,
 			    const gdb_byte *op_ptr, const gdb_byte *op_end,
 			    CORE_ADDR *initial,
@@ -1129,7 +1129,8 @@ do_compile_dwarf_expr_to_c (int indent, string_file *stream,
 void
 compile_dwarf_expr_to_c (string_file *stream, const char *result_name,
 			 struct symbol *sym, CORE_ADDR pc,
-			 struct gdbarch *arch, unsigned char *registers_used,
+			 struct gdbarch *arch,
+			 std::vector<bool> &registers_used,
 			 unsigned int addr_size,
 			 const gdb_byte *op_ptr, const gdb_byte *op_end,
 			 dwarf2_per_cu_data *per_cu,
@@ -1147,7 +1148,8 @@ compile_dwarf_bounds_to_c (string_file *stream,
 			   const char *result_name,
 			   const struct dynamic_prop *prop,
 			   struct symbol *sym, CORE_ADDR pc,
-			   struct gdbarch *arch, unsigned char *registers_used,
+			   struct gdbarch *arch,
+			   std::vector<bool> &registers_used,
 			   unsigned int addr_size,
 			   const gdb_byte *op_ptr, const gdb_byte *op_end,
 			   dwarf2_per_cu_data *per_cu,
diff --git a/gdb/compile/compile.h b/gdb/compile/compile.h
index 9dd7f38..5e733f3 100644
--- a/gdb/compile/compile.h
+++ b/gdb/compile/compile.h
@@ -64,7 +64,7 @@ extern void compile_dwarf_expr_to_c (string_file *stream,
 				     struct symbol *sym,
 				     CORE_ADDR pc,
 				     struct gdbarch *arch,
-				     unsigned char *registers_used,
+				     std::vector<bool> &registers_used,
 				     unsigned int addr_size,
 				     const gdb_byte *op_ptr,
 				     const gdb_byte *op_end,
@@ -103,7 +103,7 @@ extern void compile_dwarf_bounds_to_c (string_file *stream,
 				       const struct dynamic_prop *prop,
 				       struct symbol *sym, CORE_ADDR pc,
 				       struct gdbarch *arch,
-				       unsigned char *registers_used,
+				       std::vector<bool> &registers_used,
 				       unsigned int addr_size,
 				       const gdb_byte *op_ptr,
 				       const gdb_byte *op_end,
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index 580e5b0..aec50da 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -2699,7 +2699,7 @@ void
 dwarf2_compile_property_to_c (string_file *stream,
 			      const char *result_name,
 			      struct gdbarch *gdbarch,
-			      unsigned char *registers_used,
+			      std::vector<bool> &registers_used,
 			      const struct dynamic_prop *prop,
 			      CORE_ADDR pc,
 			      struct symbol *sym)
@@ -4475,7 +4475,7 @@ locexpr_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
 static void
 locexpr_generate_c_location (struct symbol *sym, string_file *stream,
 			     struct gdbarch *gdbarch,
-			     unsigned char *registers_used,
+			     std::vector<bool> &registers_used,
 			     CORE_ADDR pc, const char *result_name)
 {
   struct dwarf2_locexpr_baton *dlbaton
@@ -4707,7 +4707,7 @@ loclist_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
 static void
 loclist_generate_c_location (struct symbol *sym, string_file *stream,
 			     struct gdbarch *gdbarch,
-			     unsigned char *registers_used,
+			     std::vector<bool> &registers_used,
 			     CORE_ADDR pc, const char *result_name)
 {
   struct dwarf2_loclist_baton *dlbaton
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
index 694300f..2943baf 100644
--- a/gdb/dwarf2/loc.h
+++ b/gdb/dwarf2/loc.h
@@ -120,7 +120,7 @@ bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
 void dwarf2_compile_property_to_c (string_file *stream,
 				   const char *result_name,
 				   struct gdbarch *gdbarch,
-				   unsigned char *registers_used,
+				   std::vector<bool> &registers_used,
 				   const struct dynamic_prop *prop,
 				   CORE_ADDR address,
 				   struct symbol *sym);
diff --git a/gdb/symtab.h b/gdb/symtab.h
index 3c3483e..f060e0e 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1022,7 +1022,7 @@ struct symbol_computed_ops
 
   void (*generate_c_location) (struct symbol *symbol, string_file *stream,
 			       struct gdbarch *gdbarch,
-			       unsigned char *registers_used,
+			       std::vector<bool> &registers_used,
 			       CORE_ADDR pc, const char *result_name);
 
 };