llvm-project/lldb/source/Core/RegularExpression.cpp

262 lines
7.3 KiB
C++

//===-- RegularExpression.cpp -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Core/RegularExpression.h"
// C Includes
// C++ Includes
#include <cstring>
// Other libraries and framework includes
#include "llvm/ADT/StringRef.h"
// Project includes
#include "lldb/Core/Error.h"
//----------------------------------------------------------------------
// Enable enhanced mode if it is available. This allows for things like
// \d for digit, \s for space, and many more, but it isn't available
// everywhere.
//----------------------------------------------------------------------
#if defined(REG_ENHANCED)
#define DEFAULT_COMPILE_FLAGS (REG_ENHANCED|REG_EXTENDED)
#else
#define DEFAULT_COMPILE_FLAGS (REG_EXTENDED)
#endif
using namespace lldb_private;
RegularExpression::RegularExpression() :
m_re(),
m_comp_err (1),
m_preg()
{
memset(&m_preg, 0, sizeof(m_preg));
}
//----------------------------------------------------------------------
// Constructor that compiles "re" using "flags" and stores the
// resulting compiled regular expression into this object.
//----------------------------------------------------------------------
RegularExpression::RegularExpression(const char* re) :
m_re(),
m_comp_err (1),
m_preg()
{
memset(&m_preg,0,sizeof(m_preg));
Compile(re);
}
RegularExpression::RegularExpression(const RegularExpression &rhs)
{
memset(&m_preg,0,sizeof(m_preg));
Compile(rhs.GetText());
}
const RegularExpression &
RegularExpression::operator= (const RegularExpression &rhs)
{
if (&rhs != this)
Compile (rhs.GetText());
return *this;
}
//----------------------------------------------------------------------
// Destructor
//
// Any previously compiled regular expression contained in this
// object will be freed.
//----------------------------------------------------------------------
RegularExpression::~RegularExpression()
{
Free();
}
//----------------------------------------------------------------------
// Compile a regular expression using the supplied regular
// expression text and flags. The compiled regular expression lives
// in this object so that it can be readily used for regular
// expression matches. Execute() can be called after the regular
// expression is compiled. Any previously compiled regular
// expression contained in this object will be freed.
//
// RETURNS
// True if the regular expression compiles successfully, false
// otherwise.
//----------------------------------------------------------------------
bool
RegularExpression::Compile(const char* re)
{
Free();
if (re && re[0])
{
m_re = re;
m_comp_err = ::regcomp (&m_preg, re, DEFAULT_COMPILE_FLAGS);
}
else
{
// No valid regular expression
m_comp_err = 1;
}
return m_comp_err == 0;
}
//----------------------------------------------------------------------
// Execute a regular expression match using the compiled regular
// expression that is already in this object against the match
// string "s". If any parens are used for regular expression
// matches "match_count" should indicate the number of regmatch_t
// values that are present in "match_ptr". The regular expression
// will be executed using the "execute_flags".
//---------------------------------------------------------------------
bool
RegularExpression::Execute (const char* s, Match *match) const
{
int err = 1;
if (s != nullptr && m_comp_err == 0)
{
if (match)
{
err = ::regexec (&m_preg,
s,
match->GetSize(),
match->GetData(),
0);
}
else
{
err = ::regexec(&m_preg,
s,
0,
nullptr,
0);
}
}
if (err != 0)
{
// The regular expression didn't compile, so clear the matches
if (match)
match->Clear();
return false;
}
return true;
}
bool
RegularExpression::Match::GetMatchAtIndex (const char* s, uint32_t idx, std::string& match_str) const
{
llvm::StringRef match_str_ref;
if (GetMatchAtIndex(s, idx, match_str_ref))
{
match_str = match_str_ref.str();
return true;
}
return false;
}
bool
RegularExpression::Match::GetMatchAtIndex (const char* s, uint32_t idx, llvm::StringRef& match_str) const
{
if (idx < m_matches.size())
{
if (m_matches[idx].rm_eo == -1 && m_matches[idx].rm_so == -1)
return false;
if (m_matches[idx].rm_eo == m_matches[idx].rm_so)
{
// Matched the empty string...
match_str = llvm::StringRef();
return true;
}
else if (m_matches[idx].rm_eo > m_matches[idx].rm_so)
{
match_str = llvm::StringRef (s + m_matches[idx].rm_so, m_matches[idx].rm_eo - m_matches[idx].rm_so);
return true;
}
}
return false;
}
bool
RegularExpression::Match::GetMatchSpanningIndices (const char* s, uint32_t idx1, uint32_t idx2, llvm::StringRef& match_str) const
{
if (idx1 < m_matches.size() && idx2 < m_matches.size())
{
if (m_matches[idx1].rm_so == m_matches[idx2].rm_eo)
{
// Matched the empty string...
match_str = llvm::StringRef();
return true;
}
else if (m_matches[idx1].rm_so < m_matches[idx2].rm_eo)
{
match_str = llvm::StringRef (s + m_matches[idx1].rm_so, m_matches[idx2].rm_eo - m_matches[idx1].rm_so);
return true;
}
}
return false;
}
//----------------------------------------------------------------------
// Returns true if the regular expression compiled and is ready
// for execution.
//----------------------------------------------------------------------
bool
RegularExpression::IsValid () const
{
return m_comp_err == 0;
}
//----------------------------------------------------------------------
// Returns the text that was used to compile the current regular
// expression.
//----------------------------------------------------------------------
const char*
RegularExpression::GetText () const
{
return (m_re.empty() ? nullptr : m_re.c_str());
}
//----------------------------------------------------------------------
// Free any contained compiled regular expressions.
//----------------------------------------------------------------------
void
RegularExpression::Free()
{
if (m_comp_err == 0)
{
m_re.clear();
regfree(&m_preg);
// Set a compile error since we no longer have a valid regex
m_comp_err = 1;
}
}
size_t
RegularExpression::GetErrorAsCString (char *err_str, size_t err_str_max_len) const
{
if (m_comp_err == 0)
{
if (err_str && err_str_max_len)
*err_str = '\0';
return 0;
}
return ::regerror (m_comp_err, &m_preg, err_str, err_str_max_len);
}
bool
RegularExpression::operator < (const RegularExpression& rhs) const
{
return (m_re < rhs.m_re);
}