DefreprCheck.cxx File Reference

Requirements checking pass for DEFREPR declarations. More...

#include <stdint.h>
#include <stdlib.h>
#include <dirent.h>
#include <fstream>
#include <iostream>
#include <string>
#include <map>
#include <sstream>
#include <errno.h>
#include "Version.hxx"
#include "UocInfo.hxx"
#include "AST.hxx"
#include "Environment.hxx"
#include "inter-pass.hxx"
#include "backend.hxx"

Go to the source code of this file.

Functions
static shared_ptr< AST >	getTypeAst (shared_ptr< AST > fld)
	Given a sub-form describing a field, return the AST describing its type.
static size_t	bitOffset (shared_ptr< AST > leg, size_t n)
	Compute the bit offset of a field within its containing union.
static bool	TypesAgree (shared_ptr< AST > fld1, shared_ptr< AST > fld2)
	Compare types of two fields.
bool	reprCheck (std::ostream &errStream, shared_ptr< AST > ast)
	Enforce the sanity requirements on REPR declarations.

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Detailed Description

Requirements checking pass for DEFREPR declarations.

Consider the defrepr:

    (defrepr name
      (Ctr1 f11:type f21:type ... fn1:type
        (where fp1=val11 fq1=val21 ... fm1=valm1))
      (Ctr2 f12:type f22:type ... fn2:type
        (where fp2=val12 fq2=val22 ... fm2=valm2))
     ... )
    </ped>

    The following restrictions apply:

    For all constructors Ctrx, Ctry, Ctrz ...:

All fields fpx, fqx...fmx appearing in the `when' clause of a
      constructor form Ctrx must be described within the body of
      Ctrx. That is, {fpx, fqx...fmx} <= {f1x ... fnx}

If the same field name appears in multiple legs of a DEFREPR, that
      field must appear at the same bit offset in all legs where it
      appears.  That is, fpx = fpy implies
      bitOffset(fpx) = bitOffset(fpy).

The fields within the when clauses of all constructor forms must
      uniquely distinguish all constructible values of the union. The
      compiler will not introduce any more tag bits for any defrepr
      value.

The defrepr form will not accept type arguments over
      which it can be instantiated.

    This pass tests that all of these requirements are satisfied.

Definition in file DefreprCheck.cxx.

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Function Documentation

static size_t bitOffset	(	shared_ptr< AST >	leg,
		size_t	n
	)			[static]

Compute the bit offset of a field within its containing union.

Note that this computation is target dependent if the Word type is being used.

Definition at line 122 of file DefreprCheck.cxx.

References at_bitfieldType, and getTypeAst().

Referenced by reprCheck().

static shared_ptr<AST> getTypeAst

(

shared_ptr< AST >

fld

)

[static]

Given a sub-form describing a field, return the AST describing its type.

Definition at line 101 of file DefreprCheck.cxx.

References assert(), at_field, at_fill, at_methdecl, and boost::GC_NULL.

Referenced by bitOffset(), and TypesAgree().

bool reprCheck	(	std::ostream &	errStream,
		shared_ptr< AST >	ast
	)

Enforce the sanity requirements on REPR declarations.

Definition at line 157 of file DefreprCheck.cxx.

References assert(), at_declrepr, at_defrepr, at_defunion, at_field, at_reprctr, at_reprctrs, bitOffset(), CHKERR, FLD_IS_DISCM, TypesAgree(), and UNION_IS_REPR.

static bool TypesAgree	(	shared_ptr< AST >	fld1,
		shared_ptr< AST >	fld2
	)			[static]

Compare types of two fields.

If a field appears in multiple legs of a DEFREPR, it must have the same type in all legs. If it is of bitfield type, it must also have the same number of bits in all occurrences.

Definition at line 143 of file DefreprCheck.cxx.

References getTypeAst().

Referenced by reprCheck().

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