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parse.cxx
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// recursive descent parser for systemtap scripts
// Copyright (C) 2005-2016 Red Hat Inc.
// Copyright (C) 2006 Intel Corporation.
// Copyright (C) 2007 Bull S.A.S
// Copyright (C) 2014 Peter Kjellstrom <[email protected]>
//
// This file is part of systemtap, and is free software. You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.
#include "config.h"
#include "staptree.h"
#include "parse.h"
#include "session.h"
#include "util.h"
#include "stringtable.h"
#include <iostream>
#include <fstream>
#include <cctype>
#include <cstdlib>
#include <cassert>
#include <cerrno>
#include <climits>
#include <sstream>
#include <cstring>
#include <cctype>
#include <iterator>
#include <unordered_set>
extern "C" {
#include <fnmatch.h>
}
using namespace std;
class parser;
class lexer
{
public:
bool ate_comment; // current token follows a comment
bool ate_whitespace; // the most recent token followed whitespace
bool saw_tokens; // the lexer found tokens (before preprocessing occurred)
bool check_compatible; // whether to gate features on session.compatible
token* scan ();
lexer (istream&, const string&, systemtap_session&, bool);
void set_current_file (stapfile* f);
void set_current_token_chain (const token* tok);
inline bool has_version (const char* v) const;
unordered_set<interned_string> keywords;
static unordered_set<string> atwords;
private:
inline int input_get ();
inline int input_peek (unsigned n=0);
void input_put (const string&, const token*);
string input_name;
string input_contents; // NB: being a temporary, no need to interned_string optimize this object
const char *input_pointer; // index into input_contents; NB: recompute if input_contents changed!
const char *input_end;
unsigned cursor_suspend_count;
unsigned cursor_suspend_line;
unsigned cursor_suspend_column;
unsigned cursor_line;
unsigned cursor_column;
systemtap_session& session;
stapfile* current_file;
const token* current_token_chain;
};
class parser
{
public:
parser (systemtap_session& s, const string& n, istream& i, unsigned flags=0);
~parser ();
stapfile* parse ();
probe* parse_synthetic_probe (const token* chain);
stapfile* parse_library_macros ();
private:
typedef enum {
PP_NONE,
PP_KEEP_THEN,
PP_SKIP_THEN,
PP_KEEP_ELSE,
PP_SKIP_ELSE,
} pp_state_t;
struct pp1_activation;
struct pp_macrodecl : public macrodecl {
pp1_activation* parent_act; // used for param bindings
virtual bool is_closure() { return parent_act != 0; }
pp_macrodecl () : macrodecl(), parent_act(0) { }
};
systemtap_session& session;
string input_name;
lexer input;
bool errs_as_warnings;
bool privileged;
bool user_file;
bool auto_path;
parse_context context;
// preprocessing subordinate, first pass (macros)
struct pp1_activation {
const token* tok;
unsigned cursor; // position within macro body
map<string, pp_macrodecl*> params;
macrodecl* curr_macro;
pp1_activation (const token* tok, macrodecl* curr_macro)
: tok(tok), cursor(0), curr_macro(curr_macro) { }
~pp1_activation ();
};
map<string, macrodecl*> pp1_namespace;
vector<pp1_activation*> pp1_state;
const token* next_pp1 ();
const token* scan_pp1 (bool ignore_macros);
const token* slurp_pp1_param (vector<const token*>& param);
const token* slurp_pp1_body (vector<const token*>& body);
// preprocessing subordinate, final pass (conditionals)
vector<pair<const token*, pp_state_t> > pp_state;
const token* scan_pp ();
const token* skip_pp ();
// scanning state
const token* next ();
const token* peek ();
// Advance past and throw away current token after peek () or next ().
void swallow ();
const token* systemtap_v_seen;
const token* last_t; // the last value returned by peek() or next()
const token* next_t; // lookahead token
// expectations, these swallow the token
void expect_known (token_type tt, string const & expected);
void expect_unknown (token_type tt, interned_string & target);
void expect_unknown2 (token_type tt1, token_type tt2, interned_string & target);
// convenience forms, these also swallow the token
void expect_op (string const & expected);
interned_string expect_op_any (initializer_list<const char*> expected);
void expect_kw (string const & expected);
void expect_number (int64_t & expected);
void expect_ident_or_keyword (interned_string & target);
// convenience forms, which return true or false, these don't swallow token
bool peek_op (string const & op);
bool peek_kw (string const & kw);
// convenience forms, which return the token
const token* expect_kw_token (string const & expected);
const token* expect_ident_or_atword (interned_string & target);
void print_error (const parse_error& pe, bool errs_as_warnings = false);
unsigned num_errors;
private: // nonterminals
void parse_probe (vector<probe*>&, vector<probe_alias*>&);
void parse_private (vector<vardecl*>&, vector<probe*>&,
string const&, vector<functiondecl*>&);
void parse_global (vector<vardecl*>&, vector<probe*>&,
string const&);
void do_parse_global (vector<vardecl*>&, vector<probe*>&,
string const&, const token*, bool);
void parse_functiondecl (vector<functiondecl*>&, string const&);
void do_parse_functiondecl (vector<functiondecl*>&, const token*,
string const&, bool);
embeddedcode* parse_embeddedcode ();
vector<probe_point*> parse_probe_points ();
vector<probe_point*> parse_components ();
vector<probe_point*> parse_component ();
literal_string* consume_string_literals (const token*);
literal_string* parse_literal_string ();
literal* parse_literal ();
block* parse_stmt_block ();
try_block* parse_try_block ();
statement* parse_statement ();
if_statement* parse_if_statement ();
for_loop* parse_for_loop ();
for_loop* parse_while_loop ();
foreach_loop* parse_foreach_loop ();
expr_statement* parse_expr_statement ();
return_statement* parse_return_statement ();
delete_statement* parse_delete_statement ();
next_statement* parse_next_statement ();
break_statement* parse_break_statement ();
continue_statement* parse_continue_statement ();
indexable* parse_indexable ();
const token *parse_hist_op_or_bare_name (hist_op *&hop, interned_string &name);
target_symbol *parse_target_symbol ();
cast_op *parse_cast_op ();
atvar_op *parse_atvar_op ();
expression* parse_entry_op (const token* t);
expression* parse_defined_op (const token* t);
expression* parse_const_op (const token* t);
expression* parse_perf_op (const token* t);
expression* parse_target_register (const token* t);
expression* parse_target_deref (const token* t);
expression* parse_expression ();
expression* parse_assignment ();
expression* parse_ternary ();
expression* parse_logical_or ();
expression* parse_logical_and ();
expression* parse_boolean_or ();
expression* parse_boolean_xor ();
expression* parse_boolean_and ();
expression* parse_array_in ();
expression* parse_comparison_or_regex_query ();
expression* parse_shift ();
expression* parse_concatenation ();
expression* parse_additive ();
expression* parse_multiplicative ();
expression* parse_unary ();
expression* parse_crement ();
expression* parse_dwarf_value ();
expression* parse_value ();
expression* parse_symbol ();
bool peek_target_symbol_components ();
void parse_target_symbol_components (target_symbol* e);
};
// ------------------------------------------------------------------------
stapfile*
parse (systemtap_session& s, const string& n, istream& i, unsigned flags)
{
parser p (s, n, i, flags);
return p.parse ();
}
stapfile*
parse (systemtap_session& s, const string& name, unsigned flags)
{
ifstream i(name.c_str(), ios::in);
if (i.fail())
{
cerr << (file_exists(name)
? _F("Input file '%s' can't be opened for reading.", name.c_str())
: _F("Input file '%s' is missing.", name.c_str()))
<< endl;
return 0;
}
parser p (s, name, i, flags);
return p.parse ();
}
stapfile*
parse_library_macros (systemtap_session& s, const string& name)
{
ifstream i(name.c_str(), ios::in);
if (i.fail())
{
cerr << (file_exists(name)
? _F("Input file '%s' can't be opened for reading.", name.c_str())
: _F("Input file '%s' is missing.", name.c_str()))
<< endl;
return 0;
}
parser p (s, name, i);
return p.parse_library_macros ();
}
probe*
parse_synthetic_probe (systemtap_session &s, istream& i, const token* tok)
{
parser p (s, tok ? tok->location.file->name : "<synthetic>", i);
return p.parse_synthetic_probe (tok);
}
// ------------------------------------------------------------------------
parser::parser (systemtap_session& s, const string &n, istream& i, unsigned flags):
session (s), input_name (n), input (i, input_name, s, !(flags & pf_no_compatible)),
errs_as_warnings(flags & pf_squash_errors), privileged (flags & pf_guru),
user_file (flags & pf_user_file), auto_path (flags & pf_auto_path),
context(con_unknown), systemtap_v_seen(0), last_t (0), next_t (0), num_errors (0)
{
}
parser::~parser()
{
}
static string
tt2str(token_type tt)
{
switch (tt)
{
case tok_junk: return "junk";
case tok_identifier: return "identifier";
case tok_operator: return "operator";
case tok_string: return "string";
case tok_number: return "number";
case tok_embedded: return "embedded-code";
case tok_keyword: return "keyword";
}
return "unknown token";
}
ostream&
operator << (ostream& o, const source_loc& loc)
{
o << loc.file->name << ":"
<< loc.line << ":"
<< loc.column;
return o;
}
ostream&
operator << (ostream& o, const token& t)
{
o << tt2str(t.type);
if (t.type != tok_embedded && t.type != tok_keyword) // XXX: other types?
{
o << " '";
for (unsigned i=0; i<t.content.length(); i++)
{
char c = t.content[i];
o << (isprint (c) ? c : '?');
}
o << "'";
}
o << " at "
<< t.location;
return o;
}
void
parser::print_error (const parse_error &pe, bool errs_as_warnings)
{
const token *tok = pe.tok ? pe.tok : last_t;
session.print_error(pe, tok, input_name, errs_as_warnings);
num_errors ++;
}
template <typename OPERAND>
bool eval_comparison (const OPERAND& lhs, const token* op, const OPERAND& rhs)
{
if (op->type == tok_operator && op->content == "<=")
{ return lhs <= rhs; }
else if (op->type == tok_operator && op->content == ">=")
{ return lhs >= rhs; }
else if (op->type == tok_operator && op->content == "<")
{ return lhs < rhs; }
else if (op->type == tok_operator && op->content == ">")
{ return lhs > rhs; }
else if (op->type == tok_operator && op->content == "==")
{ return lhs == rhs; }
else if (op->type == tok_operator && op->content == "!=")
{ return lhs != rhs; }
else
throw PARSE_ERROR (_("expected comparison operator"), op);
}
// Here, we perform on-the-fly preprocessing in two passes.
// First pass - macro declaration and expansion.
//
// The basic form of a declaration is @define SIGNATURE %( BODY %)
// where SIGNATURE is of the form macro_name (a, b, c, ...)
// and BODY can obtain the parameter contents as @a, @b, @c, ....
// Note that parameterless macros can also be declared.
//
// Macro definitions may not be nested.
// A macro is available textually after it has been defined.
//
// The basic form of a macro invocation
// for a parameterless macro is @macro_name,
// for a macro with parameters is @macro_name(param_1, param_2, ...).
//
// NB: this means that a parameterless macro @foo called as @foo(a, b, c)
// leaves its 'parameters' alone, rather than consuming them to result
// in a "too many parameters error". This may be useful in the unusual
// case of wanting @foo to expand to the name of a function.
//
// Invocations of unknown macros are left unexpanded, to allow
// the continued use of constructs such as @cast, @var, etc.
macrodecl::~macrodecl ()
{
delete tok;
for (vector<const token*>::iterator it = body.begin();
it != body.end(); it++)
delete *it;
}
parser::pp1_activation::~pp1_activation ()
{
delete tok;
if (curr_macro->is_closure()) return; // body is shared with an earlier declaration
for (map<string, pp_macrodecl*>::iterator it = params.begin();
it != params.end(); it++)
delete it->second;
}
// Grab a token from the current input source (main file or macro body):
const token*
parser::next_pp1 ()
{
if (pp1_state.empty())
return input.scan ();
// otherwise, we're inside a macro
pp1_activation* act = pp1_state.back();
unsigned& cursor = act->cursor;
if (cursor < act->curr_macro->body.size())
{
token* t = new token(*act->curr_macro->body[cursor]);
t->chain = new token(*act->tok); // mark chained token
cursor++;
return t;
}
else
return 0; // reached end of macro body
}
const token*
parser::scan_pp1 (bool ignore_macros = false)
{
while (true)
{
const token* t = next_pp1 ();
if (t == 0) // EOF or end of macro body
{
if (pp1_state.empty()) // actual EOF
return 0;
// Exit macro and loop around to look for the next token.
pp1_activation* act = pp1_state.back();
pp1_state.pop_back(); delete act;
continue;
}
// macro definition
// PR18462 don't catalog preprocessor-disabled macros
if (t->type == tok_operator && t->content == "@define" && !ignore_macros)
{
if (!pp1_state.empty())
throw PARSE_ERROR (_("'@define' forbidden inside macro body"), t);
delete t;
// handle macro definition
// (1) consume macro signature
t = input.scan();
if (! (t && t->type == tok_identifier))
throw PARSE_ERROR (_("expected identifier"), t);
string name = t->content;
// check for redefinition of existing macro
if (pp1_namespace.find(name) != pp1_namespace.end())
{
parse_error er (ERR_SRC, _F("attempt to redefine macro '@%s' in the same file", name.c_str ()), t);
// Also point to pp1_namespace[name]->tok, the site of
// the original definition:
er.chain = new PARSE_ERROR (_F("macro '@%s' first defined here",
name.c_str()), pp1_namespace[name]->tok);
throw er;
}
// XXX: the above restriction was mostly necessary due to
// wanting to leave open the possibility of
// statically-scoped semantics in the future.
// XXX: this cascades into further parse errors as the
// parser tries to parse the remaining definition... (e.g.
// it can't tell that the macro body isn't a conditional,
// that the uses of parameters aren't nonexistent
// macros.....)
if (name == "define")
throw PARSE_ERROR (_("attempt to redefine '@define'"), t);
if (input.atwords.count(name))
session.print_warning (_F("macro redefines built-in operator '@%s'", name.c_str()), t);
macrodecl* decl = (pp1_namespace[name] = new macrodecl);
decl->tok = t;
// determine if the macro takes parameters
bool saw_params = false;
t = input.scan();
if (t && t->type == tok_operator && t->content == "(")
{
saw_params = true;
do
{
delete t;
t = input.scan ();
if (! (t && t->type == tok_identifier))
throw PARSE_ERROR(_("expected identifier"), t);
decl->formal_args.push_back(t->content);
delete t;
t = input.scan ();
if (t && t->type == tok_operator && t->content == ",")
{
continue;
}
else if (t && t->type == tok_operator && t->content == ")")
{
delete t;
t = input.scan();
break;
}
else
{
throw PARSE_ERROR (_("expected ',' or ')'"), t);
}
}
while (true);
}
// (2) identify & consume macro body
if (! (t && t->type == tok_operator && t->content == "%("))
{
if (saw_params)
throw PARSE_ERROR (_("expected '%('"), t);
else
throw PARSE_ERROR (_("expected '%(' or '('"), t);
}
delete t;
t = slurp_pp1_body (decl->body);
if (!t)
throw PARSE_ERROR (_("incomplete macro definition - missing '%)'"), decl->tok);
delete t;
// Now loop around to look for a real token.
continue;
}
// (potential) macro invocation
if (t->type == tok_operator && t->content[0] == '@')
{
const string& name = t->content.substr(1); // strip initial '@'
// check if name refers to a real parameter or macro
macrodecl* decl;
pp1_activation* act = pp1_state.empty() ? 0 : pp1_state.back();
if (act && act->params.find(name) != act->params.end())
decl = act->params[name];
else if (!(act && act->curr_macro->context == ctx_library)
&& pp1_namespace.find(name) != pp1_namespace.end())
decl = pp1_namespace[name];
else if (session.library_macros.find(name)
!= session.library_macros.end())
decl = session.library_macros[name];
else // this is an ordinary @operator
return t;
// handle macro invocation, taking ownership of t
pp1_activation *new_act = new pp1_activation(t, decl);
unsigned num_params = decl->formal_args.size();
// (1a) restore parameter invocation closure
if (num_params == 0 && decl->is_closure())
{
// NB: decl->parent_act is always safe since the
// parameter decl (if any) comes from an activation
// record which deeper in the stack than new_act.
// decl is a macro parameter which must be evaluated in
// the context of the original point of invocation:
new_act->params = ((pp_macrodecl*)decl)->parent_act->params;
goto expand;
}
// (1b) consume macro parameters (if any)
if (num_params == 0)
goto expand;
// for simplicity, we do not allow macro constructs here
// -- if we did, we'd have to recursively call scan_pp1()
t = next_pp1 ();
if (! (t && t->type == tok_operator && t->content == "("))
{
delete new_act;
throw PARSE_ERROR (_NF
("expected '(' in invocation of macro '@%s'"
" taking %d parameter",
"expected '(' in invocation of macro '@%s'"
" taking %d parameters",
num_params, name.c_str(), num_params), t);
}
// XXX perhaps parse/count the full number of params,
// so we can say "expected x, found y params" on error?
for (unsigned i = 0; i < num_params; i++)
{
delete t;
// create parameter closure
string param_name = decl->formal_args[i];
pp_macrodecl* p = (new_act->params[param_name]
= new pp_macrodecl);
p->tok = new token(*new_act->tok);
p->parent_act = act;
// NB: *new_act->tok points to invocation, act is NULL at top level
t = slurp_pp1_param (p->body);
// check correct usage of ',' or ')'
if (t == 0) // hit unexpected EOF or end of macro
{
// XXX could we pop the stack and continue parsing
// the invocation, allowing macros to construct new
// invocations in piecemeal fashion??
const token* orig_t = new token(*new_act->tok);
delete new_act;
throw PARSE_ERROR (_("could not find end of macro invocation"), orig_t);
}
if (t->type == tok_operator && t->content == ",")
{
if (i + 1 == num_params)
{
delete new_act;
throw PARSE_ERROR (_F("too many parameters for macro '@%s' (expected %d)", name.c_str(), num_params), t);
}
}
else if (t->type == tok_operator && t->content == ")")
{
if (i + 1 != num_params)
{
delete new_act;
throw PARSE_ERROR (_F("too few parameters for macro '@%s' (expected %d)", name.c_str(), num_params), t);
}
}
else
{
// XXX this is, incidentally, impossible
delete new_act;
throw PARSE_ERROR(_("expected ',' or ')' after macro parameter"), t);
}
}
delete t;
// (2) set up macro expansion
expand:
pp1_state.push_back (new_act);
// Now loop around to look for a real token.
continue;
}
// Otherwise, we have an ordinary token.
return t;
}
}
// Consume a single macro invocation's parameters, heeding nesting
// brackets and stopping on an unbalanced ')' or an unbracketed ','
// (and returning the final separator token).
const token*
parser::slurp_pp1_param (vector<const token*>& param)
{
const token* t = 0;
unsigned nesting = 0;
do
{
t = next_pp1 ();
if (!t)
break;
// [ needed in case macro paramater is used as prefix for array-deref operation
if (t->type == tok_operator && (t->content == "(" || t->content == "["))
++nesting;
else if (nesting && t->type == tok_operator && (t->content == ")" || t->content == "]"))
--nesting;
else if (!nesting && t->type == tok_operator
&& (t->content == ")" || t->content == ","))
break;
param.push_back(t);
}
while (true);
return t; // report ")" or "," or NULL
}
// Consume a macro declaration's body, heeding nested %( %) brackets.
const token*
parser::slurp_pp1_body (vector<const token*>& body)
{
const token* t = 0;
unsigned nesting = 0;
do
{
t = next_pp1 ();
if (!t)
break;
if (t->type == tok_operator && t->content == "%(")
++nesting;
else if (nesting && t->type == tok_operator && t->content == "%)")
--nesting;
else if (!nesting && t->type == tok_operator && t->content == "%)")
break;
body.push_back(t);
}
while (true);
return t; // report final "%)" or NULL
}
// Used for parsing .stpm files.
stapfile*
parser::parse_library_macros ()
{
stapfile* f = new stapfile;
f->privileged = this->privileged;
input.set_current_file (f);
try
{
const token* t = scan_pp ();
// Currently we only take objection to macro invocations if they
// produce a non-whitespace token after being expanded.
// XXX should we prevent macro invocations even if they expand to empty??
if (t != 0)
throw PARSE_ERROR (_F("unexpected token in library macro file '%s'", input_name.c_str()), t);
// We need to first check whether *any* of the macros are duplicates,
// then commit to including the entire file in the global namespace
// (or not). Yuck.
for (map<string, macrodecl*>::iterator it = pp1_namespace.begin();
it != pp1_namespace.end(); it++)
{
string name = it->first;
if (session.library_macros.find(name) != session.library_macros.end())
{
parse_error er(ERR_SRC, _F("duplicate definition of library macro '@%s'", name.c_str()), it->second->tok);
er.chain = new PARSE_ERROR (_F("macro '@%s' first defined here", name.c_str()), session.library_macros[name]->tok);
print_error (er);
delete er.chain;
delete f;
return 0;
}
}
}
catch (const parse_error& pe)
{
print_error (pe, errs_as_warnings);
delete f;
return 0;
}
// If no errors, include the entire file. Note how this is outside
// of the try-catch block -- no errors possible.
for (map<string, macrodecl*>::iterator it = pp1_namespace.begin();
it != pp1_namespace.end(); it++)
{
string name = it->first;
session.library_macros[name] = it->second;
session.library_macros[name]->context = ctx_library;
}
return f;
}
// Second pass - preprocessor conditional expansion.
//
// The basic form is %( CONDITION %? THEN-TOKENS %: ELSE-TOKENS %)
// where CONDITION is: kernel_v[r] COMPARISON-OP "version-string"
// or: arch COMPARISON-OP "arch-string"
// or: systemtap_v COMPARISON-OP "version-string"
// or: systemtap_privilege COMPARISON-OP "privilege-string"
// or: CONFIG_foo COMPARISON-OP "config-string"
// or: CONFIG_foo COMPARISON-OP number
// or: CONFIG_foo COMPARISON-OP CONFIG_bar
// or: "string1" COMPARISON-OP "string2"
// or: number1 COMPARISON-OP number2
// The %: ELSE-TOKENS part is optional.
//
// e.g. %( kernel_v > "2.5" %? "foo" %: "baz" %)
// e.g. %( arch != "i?86" %? "foo" %: "baz" %)
// e.g. %( CONFIG_foo %? "foo" %: "baz" %)
//
// Up to an entire %( ... %) expression is processed by a single call
// to this function. Tokens included by any nested conditions are
// enqueued in a private vector.
bool eval_pp_conditional (systemtap_session& s,
const token* l, const token* op, const token* r)
{
if (l->type == tok_identifier && (l->content == "kernel_v" ||
l->content == "kernel_vr" ||
l->content == "systemtap_v"))
{
if (! (r->type == tok_string))
throw PARSE_ERROR (_("expected string literal"), r);
string target_kernel_vr = s.kernel_release;
string target_kernel_v = s.kernel_base_release;
string target;
if (l->content == "kernel_v") target = target_kernel_v;
else if (l->content == "kernel_vr") target = target_kernel_vr;
else if (l->content == "systemtap_v") target = s.compatible;
else assert (0);
string query = r->content;
bool rhs_wildcard = (strpbrk (query.c_str(), "*?[") != 0);
// collect acceptable strverscmp results.
int rvc_ok1, rvc_ok2;
bool wc_ok = false;
if (op->type == tok_operator && op->content == "<=")
{ rvc_ok1 = -1; rvc_ok2 = 0; }
else if (op->type == tok_operator && op->content == ">=")
{ rvc_ok1 = 1; rvc_ok2 = 0; }
else if (op->type == tok_operator && op->content == "<")
{ rvc_ok1 = -1; rvc_ok2 = -1; }
else if (op->type == tok_operator && op->content == ">")
{ rvc_ok1 = 1; rvc_ok2 = 1; }
else if (op->type == tok_operator && op->content == "==")
{ rvc_ok1 = 0; rvc_ok2 = 0; wc_ok = true; }
else if (op->type == tok_operator && op->content == "!=")
{ rvc_ok1 = -1; rvc_ok2 = 1; wc_ok = true; }
else
throw PARSE_ERROR (_("expected comparison operator"), op);
if ((!wc_ok) && rhs_wildcard)
throw PARSE_ERROR (_("wildcard not allowed with order comparison operators"), op);
if (rhs_wildcard)
{
int rvc_result = fnmatch (query.c_str(), target.c_str(),
FNM_NOESCAPE); // spooky
bool badness = (rvc_result == 0) ^ (op->content == "==");
return !badness;
}
else
{
int rvc_result = strverscmp (target.c_str(), query.c_str());
// normalize rvc_result
if (rvc_result < 0) rvc_result = -1;
if (rvc_result > 0) rvc_result = 1;
return (rvc_result == rvc_ok1 || rvc_result == rvc_ok2);
}
}
else if (l->type == tok_identifier && l->content == "systemtap_privilege")
{
string target_privilege =
pr_contains(s.privilege, pr_stapdev) ? "stapdev"
: pr_contains(s.privilege, pr_stapsys) ? "stapsys"
: pr_contains(s.privilege, pr_stapusr) ? "stapusr"
: "none"; /* should be impossible -- s.privilege always one of above */
assert(target_privilege != "none");
if (! (r->type == tok_string))
throw PARSE_ERROR (_("expected string literal"), r);
string query_privilege = r->content;
bool nomatch = (target_privilege != query_privilege);
bool result;
if (op->type == tok_operator && op->content == "==")
result = !nomatch;
else if (op->type == tok_operator && op->content == "!=")
result = nomatch;
else
throw PARSE_ERROR (_("expected '==' or '!='"), op);
/* XXX perhaps allow <= >= and similar comparisons */
return result;
}
else if (l->type == tok_identifier && l->content == "guru_mode")
{
if (! (r->type == tok_number))
throw PARSE_ERROR (_("expected number"), r);
int64_t lhs = (int64_t) s.guru_mode;
int64_t rhs = lex_cast<int64_t>(r->content);
if (!((rhs == 0)||(rhs == 1)))
throw PARSE_ERROR (_("expected 0 or 1"), op);
if (!((op->type == tok_operator && op->content == "==") ||
(op->type == tok_operator && op->content == "!=")))
throw PARSE_ERROR (_("expected '==' or '!='"), op);
return eval_comparison (lhs, op, rhs);
}
else if (l->type == tok_identifier && l->content == "arch")
{
string target_architecture = s.architecture;
if (! (r->type == tok_string))
throw PARSE_ERROR (_("expected string literal"), r);
string query_architecture = r->content;
int nomatch = fnmatch (query_architecture.c_str(),
target_architecture.c_str(),
FNM_NOESCAPE); // still spooky
bool result;
if (op->type == tok_operator && op->content == "==")
result = !nomatch;
else if (op->type == tok_operator && op->content == "!=")
result = nomatch;
else
throw PARSE_ERROR (_("expected '==' or '!='"), op);
return result;
}
else if (l->type == tok_identifier && l->content == "runtime")
{
if (! (r->type == tok_string))
throw PARSE_ERROR (_("expected string literal"), r);
string query_runtime = r->content;
string target_runtime;
if (s.runtime_mode == systemtap_session::dyninst_runtime)
target_runtime = "dyninst";
else if (s.runtime_mode == systemtap_session::bpf_runtime)
target_runtime = "bpf";
else
target_runtime = "kernel";
int nomatch = fnmatch (query_runtime.c_str(),
target_runtime.c_str(),
FNM_NOESCAPE); // still spooky
bool result;
if (op->type == tok_operator && op->content == "==")
result = !nomatch;
else if (op->type == tok_operator && op->content == "!=")
result = nomatch;
else
throw PARSE_ERROR (_("expected '==' or '!='"), op);
return result;
}
else if (l->type == tok_identifier && l->content.starts_with("CONFIG_"))
{
if (r->type == tok_string)
{
string lhs = s.kernel_config[l->content]; // may be empty
string rhs = r->content;
int nomatch = fnmatch (rhs.c_str(), lhs.c_str(), FNM_NOESCAPE); // still spooky
bool result;
if (op->type == tok_operator && op->content == "==")
result = !nomatch;
else if (op->type == tok_operator && op->content == "!=")
result = nomatch;
else
throw PARSE_ERROR (_("expected '==' or '!='"), op);
return result;
}
else if (r->type == tok_number)
{
const string& lhs_string = s.kernel_config[l->content];
const char* startp = lhs_string.c_str ();
char* endp = (char*) startp;
errno = 0;
int64_t lhs = (int64_t) strtoll (startp, & endp, 0);
if (errno == ERANGE || errno == EINVAL || *endp != '\0')
throw PARSE_ERROR ("Config option value not a number", l);
int64_t rhs = lex_cast<int64_t>(r->content);
return eval_comparison (lhs, op, rhs);
}
else if (r->type == tok_identifier
&& r->content.starts_with( "CONFIG_"))
{
// First try to convert both to numbers,
// otherwise threat both as strings.