Re: [PATCH 4/5] add gcc/gdb interface files

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Jeff" == Jeff Law <law@redhat.com> writes:

>> One other random idea was something like:

>> GCC_METHOD7 (gcc_decl, build_decl,
>> const char *,             /* Argument NAME.  */
>> enum gcc_c_symbol_kind,   /* Argument SYM_KIND.  */

Jeff> Works for me.

I took this approach.  Other changes in this version are - a minor
change to one of the generic gcc methods to make it possible to choose
the correct compiler, and changing "GDB" in the "part of" comments to
"GCC".

Tom

2014-06-19  Phil Muldoon  <pmuldoon@redhat.com>
	    Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Tom Tromey  <tromey@redhat.com>

	* gcc-c-fe.def: New file.
	* gcc-c-interface.h: New file.
	* gcc-interface.h: New file.

---
 include/ChangeLog         |   8 ++
 include/gcc-c-fe.def      | 197 +++++++++++++++++++++++++++++++++++++++++
 include/gcc-c-interface.h | 220 ++++++++++++++++++++++++++++++++++++++++++++++
 include/gcc-interface.h   | 127 ++++++++++++++++++++++++++
 4 files changed, 552 insertions(+)
 create mode 100644 include/gcc-c-fe.def
 create mode 100644 include/gcc-c-interface.h
 create mode 100644 include/gcc-interface.h

diff --git a/include/gcc-c-fe.def b/include/gcc-c-fe.def
new file mode 100644
index 0000000..19cb867
--- /dev/null
+++ b/include/gcc-c-fe.def
@@ -0,0 +1,197 @@
+/* Interface between GCC C FE and GDB  -*- c -*-
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+
+
+/* Create a new "decl" in GCC.  A decl is a declaration, basically a
+   kind of symbol.
+
+   NAME is the name of the new symbol.  SYM_KIND is the kind of
+   symbol being requested.  SYM_TYPE is the new symbol's C type;
+   except for labels, where this is not meaningful and should be
+   zero.  If SUBSTITUTION_NAME is not NULL, then a reference to this
+   decl in the source will later be substituted with a dereference
+   of a variable of the given name.  Otherwise, for symbols having
+   an address (e.g., functions), ADDRESS is the address.  FILENAME
+   and LINE_NUMBER refer to the symbol's source location.  If this
+   is not known, FILENAME can be NULL and LINE_NUMBER can be 0.
+   This function returns the new decl.  */
+
+GCC_METHOD7 (gcc_decl, build_decl,
+	     const char *,	      /* Argument NAME.  */
+	     enum gcc_c_symbol_kind,  /* Argument SYM_KIND.  */
+	     gcc_type,		      /* Argument SYM_TYPE.  */
+	     const char *,	      /* Argument SUBSTITUTION_NAME.  */
+	     gcc_address,	      /* Argument ADDRESS.  */
+	     const char *,	      /* Argument FILENAME.  */
+	     unsigned int)	      /* Argument LINE_NUMBER.  */
+
+/* Insert a GCC decl into the symbol table.  DECL is the decl to
+   insert.  IS_GLOBAL is true if this is an outermost binding, and
+   false if it is a possibly-shadowing binding.  */
+
+GCC_METHOD2 (int /* bool */, bind,
+	     gcc_decl,		   /* Argument DECL.  */
+	     int /* bool */)       /* Argument IS_GLOBAL.  */
+
+/* Insert a tagged type into the symbol table.  NAME is the tag name
+   of the type and TAGGED_TYPE is the type itself.  TAGGED_TYPE must
+   be either a struct, union, or enum type, as these are the only
+   types that have tags.  FILENAME and LINE_NUMBER refer to the type's
+   source location.  If this is not known, FILENAME can be NULL and
+   LINE_NUMBER can be 0.  */
+
+GCC_METHOD4 (int /* bool */, tagbind,
+	     const char *,	      /* Argument NAME.  */
+	     gcc_type,		      /* Argument TAGGED_TYPE.  */
+	     const char *,	      /* Argument FILENAME.  */
+	     unsigned int)	      /* Argument LINE_NUMBER.  */
+
+/* Return the type of a pointer to a given base type.  */
+
+GCC_METHOD1 (gcc_type, build_pointer_type,
+	     gcc_type)			/* Argument BASE_TYPE.  */
+
+/* Create a new 'struct' type.  Initially it has no fields.  */
+
+GCC_METHOD0 (gcc_type, build_record_type)
+
+/* Create a new 'union' type.  Initially it has no fields.  */
+
+GCC_METHOD0 (gcc_type, build_union_type)
+
+/* Add a field to a struct or union type.  FIELD_NAME is the field's
+   name.  FIELD_TYPE is the type of the field.  BITSIZE and BITPOS
+   indicate where in the struct the field occurs.  */
+
+GCC_METHOD5 (int /* bool */, build_add_field,
+	     gcc_type,			   /* Argument RECORD_OR_UNION_TYPE. */
+	     const char *,		   /* Argument FIELD_NAME.  */
+	     gcc_type,			   /* Argument FIELD_TYPE.  */
+	     unsigned long,		   /* Argument BITSIZE.  */
+	     unsigned long)		   /* Argument BITPOS.  */
+
+/* After all the fields have been added to a struct or union, the
+   struct or union type must be "finished".  This does some final
+   cleanups in GCC.  */
+
+GCC_METHOD2 (int /* bool */, finish_record_or_union,
+	     gcc_type,			   /* Argument RECORD_OR_UNION_TYPE. */
+	     unsigned long)		   /* Argument SIZE_IN_BYTES.  */
+
+/* Create a new 'enum' type.  The new type initially has no
+   associated constants.  */
+
+GCC_METHOD1 (gcc_type, build_enum_type,
+	     gcc_type)			    /* Argument UNDERLYING_INT_TYPE. */
+
+/* Add a new constant to an enum type.  NAME is the constant's
+   name and VALUE is its value.  */
+
+GCC_METHOD3 (int /* bool */, build_add_enum_constant,
+	     gcc_type,		       /* Argument ENUM_TYPE.  */
+	     const char *,	       /* Argument NAME.  */
+	     unsigned long)	       /* Argument VALUE.  */
+
+/* After all the constants have been added to an enum, the type must
+   be "finished".  This does some final cleanups in GCC.  */
+
+GCC_METHOD1 (int /* bool */, finish_enum_type,
+	     gcc_type)		       /* Argument ENUM_TYPE.  */
+
+/* Create a new function type.  RETURN_TYPE is the type returned by
+   the function, and ARGUMENT_TYPES is a vector, of length NARGS, of
+   the argument types.  IS_VARARGS is true if the function is
+   varargs.  */
+
+GCC_METHOD3 (gcc_type, build_function_type,
+	     gcc_type,			   /* Argument RETURN_TYPE.  */
+	     const struct gcc_type_array *, /* Argument ARGUMENT_TYPES.  */
+	     int /* bool */)               /* Argument IS_VARARGS.  */
+
+/* Return an integer type with the given properties.  */
+
+GCC_METHOD2 (gcc_type, int_type,
+	     int /* bool */,               /* Argument IS_UNSIGNED.  */
+	     unsigned long)                /* Argument SIZE_IN_BYTES.  */
+
+/* Return a floating point type with the given properties.  */
+
+GCC_METHOD1 (gcc_type, float_type,
+	     unsigned long)			/* Argument SIZE_IN_BYTES.  */
+
+/* Return the 'void' type.  */
+
+GCC_METHOD0 (gcc_type, void_type)
+
+/* Return the 'bool' type.  */
+
+GCC_METHOD0 (gcc_type, bool_type)
+
+/* Create a new array type.  If NUM_ELEMENTS is -1, then the array
+   is assumed to have an unknown length.  */
+
+GCC_METHOD2 (gcc_type, build_array_type,
+	     gcc_type,			  /* Argument ELEMENT_TYPE.  */
+	     int)			  /* Argument NUM_ELEMENTS.  */
+
+/* Create a new variably-sized array type.  UPPER_BOUND_NAME is the
+   name of a local variable that holds the upper bound of the array;
+   it is one less than the array size.  */
+
+GCC_METHOD2 (gcc_type, build_vla_array_type,
+	     gcc_type,			  /* Argument ELEMENT_TYPE.  */
+	     const char *)		  /* Argument UPPER_BOUND_NAME.  */
+
+/* Return a qualified variant of a given base type.  QUALIFIERS says
+   which qualifiers to use; it is composed of or'd together
+   constants from 'enum gcc_qualifiers'.  */
+
+GCC_METHOD2 (gcc_type, build_qualified_type,
+	     gcc_type,			      /* Argument UNQUALIFIED_TYPE.  */
+	     enum gcc_qualifiers)	      /* Argument QUALIFIERS.  */
+
+/* Build a complex type given its element type.  */
+
+GCC_METHOD1 (gcc_type, build_complex_type,
+	     gcc_type)			  /* Argument ELEMENT_TYPE.  */
+
+/* Build a vector type given its element type and number of
+   elements.  */
+
+GCC_METHOD2 (gcc_type, build_vector_type,
+	     gcc_type,			  /* Argument ELEMENT_TYPE.  */
+	     int)			  /* Argument NUM_ELEMENTS.  */
+
+/* Build a constant.  NAME is the constant's name and VALUE is its
+   value.  FILENAME and LINE_NUMBER refer to the type's source
+   location.  If this is not known, FILENAME can be NULL and
+   LINE_NUMBER can be 0.  */
+
+GCC_METHOD5 (int /* bool */, build_constant,
+	     gcc_type,		  /* Argument TYPE.  */
+	     const char *,	  /* Argument NAME.  */
+	     unsigned long,	  /* Argument VALUE.  */
+	     const char *,	  /* Argument FILENAME.  */
+	     unsigned int)	  /* Argument LINE_NUMBER.  */
+
+/* Emit an error and return an error type object.  */
+
+GCC_METHOD1 (gcc_type, error,
+	     const char *)		 /* Argument MESSAGE.  */
diff --git a/include/gcc-c-interface.h b/include/gcc-c-interface.h
new file mode 100644
index 0000000..25ef62f
--- /dev/null
+++ b/include/gcc-c-interface.h
@@ -0,0 +1,220 @@
+/* Interface between GCC C FE and GDB
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_C_INTERFACE_H
+#define GCC_C_INTERFACE_H
+
+#include "gcc-interface.h"
+
+/* This header defines the interface to the GCC API.  It must be both
+   valid C and valid C++, because it is included by both programs.  */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Forward declaration.  */
+
+struct gcc_c_context;
+
+/*
+ * Definitions and declarations for the C front end.
+ */
+
+/* Defined versions of the C front-end API.  */
+
+enum gcc_c_api_version
+{
+  GCC_C_FE_VERSION_0 = 0
+};
+
+/* Qualifiers.  */
+
+enum gcc_qualifiers
+{
+  GCC_QUALIFIER_CONST = 1,
+  GCC_QUALIFIER_VOLATILE = 2,
+  GCC_QUALIFIER_RESTRICT = 4
+};
+
+/* This enumerates the kinds of decls that GDB can create.  */
+
+enum gcc_c_symbol_kind
+{
+  /* A function.  */
+
+  GCC_C_SYMBOL_FUNCTION,
+
+  /* A variable.  */
+
+  GCC_C_SYMBOL_VARIABLE,
+
+  /* A typedef.  */
+
+  GCC_C_SYMBOL_TYPEDEF,
+
+  /* A label.  */
+
+  GCC_C_SYMBOL_LABEL
+};
+
+/* This enumerates the types of symbols that GCC might request from
+   GDB.  */
+
+enum gcc_c_oracle_request
+{
+  /* An ordinary symbol -- a variable, function, typedef, or enum
+     constant.  */
+
+  GCC_C_ORACLE_SYMBOL,
+
+  /* A struct, union, or enum tag.  */
+
+  GCC_C_ORACLE_TAG,
+
+  /* A label.  */
+
+  GCC_C_ORACLE_LABEL
+};
+
+/* The type of the function called by GCC to ask GDB for a symbol's
+   definition.  DATUM is an arbitrary value supplied when the oracle
+   function is registered.  CONTEXT is the GCC context in which the
+   request is being made.  REQUEST specifies what sort of symbol is
+   being requested, and IDENTIFIER is the name of the symbol.  */
+
+typedef void gcc_c_oracle_function (void *datum,
+				    struct gcc_c_context *context,
+				    enum gcc_c_oracle_request request,
+				    const char *identifier);
+
+/* The type of the function called by GCC to ask GDB for a symbol's
+   address.  This should return 0 if the address is not known.  */
+
+typedef gcc_address gcc_c_symbol_address_function (void *datum,
+						   struct gcc_c_context *ctxt,
+						   const char *identifier);
+
+/* An array of types used for creating a function type.  */
+
+struct gcc_type_array
+{
+  /* Number of elements.  */
+
+  int n_elements;
+
+  /* The elements.  */
+
+  gcc_type *elements;
+};
+
+/* The vtable used by the C front end.  */
+
+struct gcc_c_fe_vtable
+{
+  /* The version of the C interface.  The value is one of the
+     gcc_c_api_version constants.  */
+
+  unsigned int c_version;
+
+  /* Set the callbacks for this context.
+
+     The binding oracle is called whenever the C parser needs to look
+     up a symbol.  This gives the caller a chance to lazily
+     instantiate symbols using other parts of the gcc_c_fe_interface
+     API.
+
+     The address oracle is called whenever the C parser needs to look
+     up a symbol.  This is only called for symbols not provided by the
+     symbol oracle -- that is, just built-in functions where GCC
+     provides the declaration.
+
+     DATUM is an arbitrary piece of data that is passed back verbatim
+     to the callbakcs in requests.  */
+
+  void (*set_callbacks) (struct gcc_c_context *self,
+			 gcc_c_oracle_function *binding_oracle,
+			 gcc_c_symbol_address_function *address_oracle,
+			 void *datum);
+
+#define GCC_METHOD0(R, N) \
+  R (*N) (struct gcc_c_context *);
+#define GCC_METHOD1(R, N, A) \
+  R (*N) (struct gcc_c_context *, A);
+#define GCC_METHOD2(R, N, A, B) \
+  R (*N) (struct gcc_c_context *, A, B);
+#define GCC_METHOD3(R, N, A, B, C) \
+  R (*N) (struct gcc_c_context *, A, B, C);
+#define GCC_METHOD4(R, N, A, B, C, D) \
+  R (*N) (struct gcc_c_context *, A, B, C, D);
+#define GCC_METHOD5(R, N, A, B, C, D, E) \
+  R (*N) (struct gcc_c_context *, A, B, C, D, E);
+#define GCC_METHOD7(R, N, A, B, C, D, E, F, G) \
+  R (*N) (struct gcc_c_context *, A, B, C, D, E, F, G);
+
+#include "gcc-c-fe.def"
+
+#undef GCC_METHOD0
+#undef GCC_METHOD1
+#undef GCC_METHOD2
+#undef GCC_METHOD3
+#undef GCC_METHOD4
+#undef GCC_METHOD5
+#undef GCC_METHOD7
+
+};
+
+/* The C front end object.  */
+
+struct gcc_c_context
+{
+  /* Base class.  */
+
+  struct gcc_base_context base;
+
+  /* Our vtable.  This is a separate field because this is simpler
+     than implementing a vtable inheritance scheme in C.  */
+
+  const struct gcc_c_fe_vtable *c_ops;
+};
+
+/* The name of the .so that the compiler builds.  We dlopen this
+   later.  */
+
+#define GCC_C_FE_LIBCC libcc1.so
+
+/* The compiler exports a single initialization function.  This macro
+   holds its name as a symbol.  */
+
+#define GCC_C_FE_CONTEXT gcc_c_fe_context
+
+/* The type of the initialization function.  The caller passes in the
+   desired base version and desired C-specific version.  If the
+   request can be satisfied, a compatible gcc_context object will be
+   returned.  Otherwise, the function returns NULL.  */
+
+typedef struct gcc_c_context *gcc_c_fe_context_function
+    (enum gcc_base_api_version,
+     enum gcc_c_api_version);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GCC_C_INTERFACE_H */
diff --git a/include/gcc-interface.h b/include/gcc-interface.h
new file mode 100644
index 0000000..34010f2
--- /dev/null
+++ b/include/gcc-interface.h
@@ -0,0 +1,127 @@
+/* Generic interface between GCC and GDB
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_INTERFACE_H
+#define GCC_INTERFACE_H
+
+/* This header defines the interface to the GCC API.  It must be both
+   valid C and valid C++, because it is included by both programs.  */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Opaque typedefs for objects passed through the interface.  */
+
+typedef unsigned long long gcc_type;
+typedef unsigned long long gcc_decl;
+
+/* An address in the inferior.  */
+
+typedef unsigned long long gcc_address;
+
+/* Forward declaration.  */
+
+struct gcc_base_context;
+
+/* Defined versions of the generic API.  */
+
+enum gcc_base_api_version
+{
+  GCC_FE_VERSION_0 = 0
+};
+
+/* The operations defined by the GCC base API.  This is the vtable for
+   the real context structure which is passed around.
+
+   The "base" API is concerned with basics shared by all compiler
+   front ends: setting command-line arguments, the file names, etc.
+
+   Front-end-specific interfaces inherit from this one.  */
+
+struct gcc_base_vtable
+{
+  /* The actual version implemented in this interface.  This field can
+     be relied on not to move, so users can always check it if they
+     desire.  The value is one of the gcc_base_api_version constants.
+  */
+
+  unsigned int version;
+
+  /* Set the compiler's command-line options for the next compilation.
+     TRIPLET_REGEXP is a regular expression that is used to match the
+     configury triplet prefix to the compiler.
+     The arguments are copied by GCC.  ARGV need not be
+     NULL-terminated.  The arguments must be set separately for each
+     compilation; that is, after a compile is requested, the
+     previously-set arguments cannot be reused.
+
+     This returns NULL on success.  On failure, returns a malloc()d
+     error message.  The caller is responsible for freeing it.  */
+
+  char *(*set_arguments) (struct gcc_base_context *self,
+			  const char *triplet_regexp,
+			  int argc, char **argv);
+
+  /* Set the file name of the program to compile.  The string is
+     copied by the method implementation, but the caller must
+     guarantee that the file exists through the compilation.  */
+
+  void (*set_source_file) (struct gcc_base_context *self, const char *file);
+
+  /* Set a callback to use for printing error messages.  DATUM is
+     passed through to the callback unchanged.  */
+
+  void (*set_print_callback) (struct gcc_base_context *self,
+			      void (*print_function) (void *datum,
+						      const char *message),
+			      void *datum);
+
+  /* Perform the compilation.  FILENAME is the name of the resulting
+     object file.  VERBOSE can be set to cause GCC to print some
+     information as it works.  Returns true on success, false on
+     error.  */
+
+  int /* bool */ (*compile) (struct gcc_base_context *self,
+			     const char *filename,
+			     int /* bool */ verbose);
+
+  /* Destroy this object.  */
+
+  void (*destroy) (struct gcc_base_context *self);
+};
+
+/* The GCC object.  */
+
+struct gcc_base_context
+{
+  /* The virtual table.  */
+
+  const struct gcc_base_vtable *ops;
+};
+
+/* The name of the dummy wrapper function generated by gdb.  */
+
+#define GCC_FE_WRAPPER_FUNCTION "_gdb_expr"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GCC_INTERFACE_H */
-- 
1.9.3