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// file : libbuild2/in/rule.hxx -*- C++ -*-
// license : MIT; see accompanying LICENSE file
#ifndef LIBBUILD2_IN_RULE_HXX
#define LIBBUILD2_IN_RULE_HXX
#include <libbuild2/types.hxx>
#include <libbuild2/forward.hxx> // depdb
#include <libbuild2/utility.hxx>
#include <libbuild2/rule.hxx>
#include <libbuild2/in/export.hxx>
namespace build2
{
namespace in
{
// Preprocess an .in file.
//
// Note that a derived rule can use the target data pad to cache data
// (e.g., in match() or apply()) to be used in substitute/lookup() calls.
//
// Note also that currently this rule ignores the dry-run mode (see
// perform_update() for the rationale).
//
class LIBBUILD2_IN_SYMEXPORT rule: public simple_rule
{
public:
// The rule id is used to form the rule name/version entry in depdb. The
// program argument is the pseudo-program name to use in the command
// line diagnostics.
//
rule (string rule_id,
string program,
char symbol = '$',
bool strict = true,
optional<string> null = nullopt)
: rule_id_ (move (rule_id)),
program_ (move (program)),
symbol_ (symbol),
strict_ (strict),
null_ (move (null)) {}
virtual bool
match (action, target&) const override;
virtual recipe
apply (action, target&) const override;
virtual target_state
perform_update (action, const target&) const;
// Customization hooks and helpers.
//
// Perform prerequisite search.
//
virtual prerequisite_target
search (action, const target&,
const prerequisite_member&,
include_type) const;
// Additional depdb entries.
//
virtual void
perform_update_depdb (action, const target&, depdb&) const;
// Pre/post update.
//
virtual void
perform_update_pre (action, const target&,
ofdstream&, const char* newline) const;
virtual void
perform_update_post (action, const target&,
ofdstream&, const char* newline) const;
// Perform variable lookup.
//
// Flags can be used by a custom implementation to alter the lookup
// semantics, for example, for special substitutions. Note, however,
// that one must make sure this semantics cannot change without changes
// to the .in file (see the depdb logic for details).
//
virtual string
lookup (const location&,
action, const target&,
const string& name,
optional<uint64_t> flags,
const optional<string>& null) const;
// Perform variable substitution. Return nullopt if it should be
// ignored.
//
virtual optional<string>
substitute (const location&,
action, const target&,
const string& name,
optional<uint64_t> flags,
bool strict,
const optional<string>& null) const;
// Call the above version and do any necessary depdb saving.
//
optional<string>
substitute (const location&,
action, const target&,
depdb& dd, size_t& dd_skip,
const string& name,
optional<uint64_t> flags,
bool strict,
const optional<string>& null) const;
// Process a line of input from the specified position performing any
// necessary substitutions.
//
virtual void
process (const location&,
action, const target&,
depdb& dd, size_t& dd_skip,
string& line, size_t pos,
const char* newline,
char sym,
bool strict,
const optional<string>& null) const;
// Replace newlines in a multi-line value with the given newline
// sequence.
//
static void
replace_newlines (string& v, const char* newline)
{
for (size_t p (0), n; (p = v.find ('\n', p)) != string::npos; p += n)
{
n = 1;
// Deal with CRLF in the value.
//
if (p != 0 && v[p - 1] == '\r')
{
--p;
++n;
}
v.replace (p, n, newline);
}
}
protected:
const string rule_id_;
const string program_;
char symbol_;
bool strict_;
optional<string> null_;
};
}
}
#endif // LIBBUILD2_IN_RULE_HXX
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