Use policies for code generation

This patch changes code generation procedures add_code_header,
add_code_footer, and several other language-specific code generation
functions into policies.

gdb/ChangeLog:
        * compile/compile-c-support.c (add_code_header, add_code_footer):
        Move into policy class.
        (c_push_user_expression, pop_user_expression_nop)
        (c_add_code_header, c_add_code_footer, c_add_input): New policy class.
        (compile_program): New host class.
        (c_compile_program): New typedef.
        (c_compute_porgram): Use c_compile_program.
This commit is contained in:
Keith Seitz 2018-08-10 11:01:24 -07:00
parent 0cfbf43085
commit ad3a68e9b9
2 changed files with 274 additions and 165 deletions

View File

@ -1,3 +1,13 @@
2018-08-10 Keith Seitz <keiths@redhat.com>
* compile/compile-c-support.c (add_code_header, add_code_footer):
Move into policy class.
(c_push_user_expression, pop_user_expression_nop)
(c_add_code_header, c_add_code_footer, c_add_input): New policy class.
(compile_program): New host class.
(c_compile_program): New typedef.
(c_compute_porgram): Use c_compile_program.
2018-08-10 Keith Seitz <keiths@redhat.com>
* compile/compile-internal.h (compile_instance::~compile_instance):

View File

@ -180,71 +180,6 @@ write_macro_definitions (const struct block *block, CORE_ADDR pc,
}
}
/* Helper function to construct a header scope for a block of code.
Takes a scope argument which selects the correct header to
insert into BUF. */
static void
add_code_header (enum compile_i_scope_types type, struct ui_file *buf)
{
switch (type)
{
case COMPILE_I_SIMPLE_SCOPE:
fputs_unfiltered ("void "
GCC_FE_WRAPPER_FUNCTION
" (struct "
COMPILE_I_SIMPLE_REGISTER_STRUCT_TAG
" *"
COMPILE_I_SIMPLE_REGISTER_ARG_NAME
") {\n",
buf);
break;
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
/* <string.h> is needed for a memcpy call below. */
fputs_unfiltered ("#include <string.h>\n"
"void "
GCC_FE_WRAPPER_FUNCTION
" (struct "
COMPILE_I_SIMPLE_REGISTER_STRUCT_TAG
" *"
COMPILE_I_SIMPLE_REGISTER_ARG_NAME
", "
COMPILE_I_PRINT_OUT_ARG_TYPE
" "
COMPILE_I_PRINT_OUT_ARG
") {\n",
buf);
break;
case COMPILE_I_RAW_SCOPE:
break;
default:
gdb_assert_not_reached (_("Unknown compiler scope reached."));
}
}
/* Helper function to construct a footer scope for a block of code.
Takes a scope argument which selects the correct footer to
insert into BUF. */
static void
add_code_footer (enum compile_i_scope_types type, struct ui_file *buf)
{
switch (type)
{
case COMPILE_I_SIMPLE_SCOPE:
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
fputs_unfiltered ("}\n", buf);
break;
case COMPILE_I_RAW_SCOPE:
break;
default:
gdb_assert_not_reached (_("Unknown compiler scope reached."));
}
}
/* Generate a structure holding all the registers used by the function
we're generating. */
@ -325,13 +260,267 @@ generate_register_struct (struct ui_file *stream, struct gdbarch *gdbarch,
fputs_unfiltered ("};\n\n", stream);
}
/* Take the source code provided by the user with the 'compile'
command, and compute the additional wrapping, macro, variable and
register operations needed. INPUT is the source code derived from
the 'compile' command, GDBARCH is the architecture to use when
computing above, EXPR_BLOCK denotes the block relevant contextually
to the inferior when the expression was created, and EXPR_PC
indicates the value of $PC. */
/* C-language policy to emit a push user expression pragma into BUF. */
struct c_push_user_expression
{
void push_user_expression (struct ui_file *buf)
{
fputs_unfiltered ("#pragma GCC user_expression\n", buf);
}
};
/* C-language policy to emit a pop user expression pragma into BUF.
For C, this is a nop. */
struct pop_user_expression_nop
{
void pop_user_expression (struct ui_file *buf)
{
/* Nothing to do. */
}
};
/* C-language policy to construct a code header for a block of code.
Takes a scope TYPE argument which selects the correct header to
insert into BUF. */
struct c_add_code_header
{
void add_code_header (enum compile_i_scope_types type, struct ui_file *buf)
{
switch (type)
{
case COMPILE_I_SIMPLE_SCOPE:
fputs_unfiltered ("void "
GCC_FE_WRAPPER_FUNCTION
" (struct "
COMPILE_I_SIMPLE_REGISTER_STRUCT_TAG
" *"
COMPILE_I_SIMPLE_REGISTER_ARG_NAME
") {\n",
buf);
break;
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
/* <string.h> is needed for a memcpy call below. */
fputs_unfiltered ("#include <string.h>\n"
"void "
GCC_FE_WRAPPER_FUNCTION
" (struct "
COMPILE_I_SIMPLE_REGISTER_STRUCT_TAG
" *"
COMPILE_I_SIMPLE_REGISTER_ARG_NAME
", "
COMPILE_I_PRINT_OUT_ARG_TYPE
" "
COMPILE_I_PRINT_OUT_ARG
") {\n",
buf);
break;
case COMPILE_I_RAW_SCOPE:
break;
default:
gdb_assert_not_reached (_("Unknown compiler scope reached."));
}
}
};
/* C-language policy to construct a code footer for a block of code.
Takes a scope TYPE which selects the correct footer to insert into BUF. */
struct c_add_code_footer
{
void add_code_footer (enum compile_i_scope_types type, struct ui_file *buf)
{
switch (type)
{
case COMPILE_I_SIMPLE_SCOPE:
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
fputs_unfiltered ("}\n", buf);
break;
case COMPILE_I_RAW_SCOPE:
break;
default:
gdb_assert_not_reached (_("Unknown compiler scope reached."));
}
}
};
/* C-language policy to emit the user code snippet INPUT into BUF based on the
scope TYPE. */
struct c_add_input
{
void add_input (enum compile_i_scope_types type, const char *input,
struct ui_file *buf)
{
switch (type)
{
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
fprintf_unfiltered (buf,
"__auto_type " COMPILE_I_EXPR_VAL " = %s;\n"
"typeof (%s) *" COMPILE_I_EXPR_PTR_TYPE ";\n"
"memcpy (" COMPILE_I_PRINT_OUT_ARG ", %s"
COMPILE_I_EXPR_VAL ",\n"
"sizeof (*" COMPILE_I_EXPR_PTR_TYPE "));\n"
, input, input,
(type == COMPILE_I_PRINT_ADDRESS_SCOPE
? "&" : ""));
break;
default:
fputs_unfiltered (input, buf);
break;
}
fputs_unfiltered ("\n", buf);
}
};
/* A host class representing a compile program.
CompileInstanceType is the type of the compile_instance for the
language.
PushUserExpressionPolicy and PopUserExpressionPolicy are used to
push and pop user expression pragmas to the compile plug-in.
AddCodeHeaderPolicy and AddCodeFooterPolicy are used to add the appropriate
code header and footer, respectively.
AddInputPolicy adds the actual user code. */
template <class CompileInstanceType, class PushUserExpressionPolicy,
class PopUserExpressionPolicy, class AddCodeHeaderPolicy,
class AddCodeFooterPolicy, class AddInputPolicy>
class compile_program
: private PushUserExpressionPolicy, private PopUserExpressionPolicy,
private AddCodeHeaderPolicy, private AddCodeFooterPolicy,
private AddInputPolicy
{
public:
/* Construct a compile_program using the compiler instance INST
using the architecture given by GDBARCH. */
compile_program (CompileInstanceType *inst, struct gdbarch *gdbarch)
: m_instance (inst), m_arch (gdbarch)
{
}
/* Take the source code provided by the user with the 'compile'
command and compute the additional wrapping, macro, variable and
register operations needed. INPUT is the source code derived from
the 'compile' command, EXPR_BLOCK denotes the block relevant contextually
to the inferior when the expression was created, and EXPR_PC
indicates the value of $PC.
Returns the text of the program to compile. */
std::string compute (const char *input, const struct block *expr_block,
CORE_ADDR expr_pc)
{
string_file var_stream;
string_file buf;
/* Do not generate local variable information for "raw"
compilations. In this case we aren't emitting our own function
and the user's code may only refer to globals. */
if (m_instance->scope () != COMPILE_I_RAW_SCOPE)
{
/* Generate the code to compute variable locations, but do it
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
= generate_c_for_variable_locations (m_instance, var_stream, m_arch,
expr_block, expr_pc);
buf.puts ("typedef unsigned int"
" __attribute__ ((__mode__(__pointer__)))"
" __gdb_uintptr;\n");
buf.puts ("typedef int"
" __attribute__ ((__mode__(__pointer__)))"
" __gdb_intptr;\n");
/* Iterate all log2 sizes in bytes supported by c_get_mode_for_size. */
for (int i = 0; i < 4; ++i)
{
const char *mode = c_get_mode_for_size (1 << i);
gdb_assert (mode != NULL);
buf.printf ("typedef int"
" __attribute__ ((__mode__(__%s__)))"
" __gdb_int_%s;\n",
mode, mode);
}
generate_register_struct (&buf, m_arch, registers_used.get ());
}
AddCodeHeaderPolicy::add_code_header (m_instance->scope (), &buf);
if (m_instance->scope () == COMPILE_I_SIMPLE_SCOPE
|| m_instance->scope () == COMPILE_I_PRINT_ADDRESS_SCOPE
|| m_instance->scope () == COMPILE_I_PRINT_VALUE_SCOPE)
{
buf.write (var_stream.c_str (), var_stream.size ());
PushUserExpressionPolicy::push_user_expression (&buf);
}
write_macro_definitions (expr_block, expr_pc, &buf);
/* The user expression has to be in its own scope, so that "extern"
works properly. Otherwise gcc thinks that the "extern"
declaration is in the same scope as the declaration provided by
gdb. */
if (m_instance->scope () != COMPILE_I_RAW_SCOPE)
buf.puts ("{\n");
buf.puts ("#line 1 \"gdb command line\"\n");
AddInputPolicy::add_input (m_instance->scope (), input, &buf);
/* For larger user expressions the automatic semicolons may be
confusing. */
if (strchr (input, '\n') == NULL)
buf.puts (";\n");
if (m_instance->scope () != COMPILE_I_RAW_SCOPE)
buf.puts ("}\n");
if (m_instance->scope () == COMPILE_I_SIMPLE_SCOPE
|| m_instance->scope () == COMPILE_I_PRINT_ADDRESS_SCOPE
|| m_instance->scope () == COMPILE_I_PRINT_VALUE_SCOPE)
PopUserExpressionPolicy::pop_user_expression (&buf);
AddCodeFooterPolicy::add_code_footer (m_instance->scope (), &buf);
return buf.string ();
}
private:
/* The compile instance to be used for compilation and
type-conversion. */
CompileInstanceType *m_instance;
/* The architecture to be used. */
struct gdbarch *m_arch;
};
/* Type used for C program computations. */
typedef compile_program<compile_c_instance,
c_push_user_expression, pop_user_expression_nop,
c_add_code_header, c_add_code_footer,
c_add_input> c_compile_program;
/* The la_compute_program method for C. */
std::string
c_compute_program (compile_instance *inst,
@ -340,98 +529,8 @@ c_compute_program (compile_instance *inst,
const struct block *expr_block,
CORE_ADDR expr_pc)
{
compile_c_instance *context
= static_cast<compile_c_instance *> (inst);
compile_c_instance *c_inst = static_cast<compile_c_instance *> (inst);
c_compile_program program (c_inst, gdbarch);
string_file buf;
string_file var_stream;
write_macro_definitions (expr_block, expr_pc, &buf);
/* Do not generate local variable information for "raw"
compilations. In this case we aren't emitting our own function
and the user's code may only refer to globals. */
if (inst->scope () != COMPILE_I_RAW_SCOPE)
{
int i;
/* Generate the code to compute variable locations, but do it
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
= generate_c_for_variable_locations (context, var_stream, gdbarch,
expr_block, expr_pc);
buf.puts ("typedef unsigned int"
" __attribute__ ((__mode__(__pointer__)))"
" __gdb_uintptr;\n");
buf.puts ("typedef int"
" __attribute__ ((__mode__(__pointer__)))"
" __gdb_intptr;\n");
/* Iterate all log2 sizes in bytes supported by c_get_mode_for_size. */
for (i = 0; i < 4; ++i)
{
const char *mode = c_get_mode_for_size (1 << i);
gdb_assert (mode != NULL);
buf.printf ("typedef int"
" __attribute__ ((__mode__(__%s__)))"
" __gdb_int_%s;\n",
mode, mode);
}
generate_register_struct (&buf, gdbarch, registers_used.get ());
}
add_code_header (inst->scope (), &buf);
if (inst->scope () == COMPILE_I_SIMPLE_SCOPE
|| inst->scope () == COMPILE_I_PRINT_ADDRESS_SCOPE
|| inst->scope () == COMPILE_I_PRINT_VALUE_SCOPE)
{
buf.write (var_stream.c_str (), var_stream.size ());
buf.puts ("#pragma GCC user_expression\n");
}
/* The user expression has to be in its own scope, so that "extern"
works properly. Otherwise gcc thinks that the "extern"
declaration is in the same scope as the declaration provided by
gdb. */
if (inst->scope () != COMPILE_I_RAW_SCOPE)
buf.puts ("{\n");
buf.puts ("#line 1 \"gdb command line\"\n");
switch (inst->scope ())
{
case COMPILE_I_PRINT_ADDRESS_SCOPE:
case COMPILE_I_PRINT_VALUE_SCOPE:
buf.printf (
"__auto_type " COMPILE_I_EXPR_VAL " = %s;\n"
"typeof (%s) *" COMPILE_I_EXPR_PTR_TYPE ";\n"
"memcpy (" COMPILE_I_PRINT_OUT_ARG ", %s" COMPILE_I_EXPR_VAL ",\n"
"sizeof (*" COMPILE_I_EXPR_PTR_TYPE "));\n"
, input, input,
(inst->scope () == COMPILE_I_PRINT_ADDRESS_SCOPE
? "&" : ""));
break;
default:
buf.puts (input);
break;
}
buf.puts ("\n");
/* For larger user expressions the automatic semicolons may be
confusing. */
if (strchr (input, '\n') == NULL)
buf.puts (";\n");
if (inst->scope () != COMPILE_I_RAW_SCOPE)
buf.puts ("}\n");
add_code_footer (inst->scope (), &buf);
return std::move (buf.string ());
return program.compute (input, expr_block, expr_pc);
}