llvm/lib/Support/SourceMgr.cpp
Chris Lattner 1d96ccc69a add a trivial line # cache to SourceMgr to make repeated queries to
FindLineNumber much faster when in sequence.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78693 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-11 17:49:14 +00:00

216 lines
6.8 KiB
C++

//===- SourceMgr.cpp - Manager for Simple Source Buffers & Diagnostics ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SourceMgr class. This class is used as a simple
// substrate for diagnostics, #include handling, and other low level things for
// simple parsers.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
struct LineNoCacheTy {
int LastQueryBufferID;
const char *LastQuery;
unsigned LineNoOfQuery;
};
}
static LineNoCacheTy *getCache(void *Ptr) {
return (LineNoCacheTy*)Ptr;
}
SourceMgr::~SourceMgr() {
// Delete the line # cache if allocated.
if (LineNoCacheTy *Cache = getCache(LineNoCache))
delete Cache;
while (!Buffers.empty()) {
delete Buffers.back().Buffer;
Buffers.pop_back();
}
}
/// AddIncludeFile - Search for a file with the specified name in the current
/// directory or in one of the IncludeDirs. If no file is found, this returns
/// ~0, otherwise it returns the buffer ID of the stacked file.
unsigned SourceMgr::AddIncludeFile(const std::string &Filename,
SMLoc IncludeLoc) {
MemoryBuffer *NewBuf = MemoryBuffer::getFile(Filename.c_str());
// If the file didn't exist directly, see if it's in an include path.
for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
std::string IncFile = IncludeDirectories[i] + "/" + Filename;
NewBuf = MemoryBuffer::getFile(IncFile.c_str());
}
if (NewBuf == 0) return ~0U;
return AddNewSourceBuffer(NewBuf, IncludeLoc);
}
/// FindBufferContainingLoc - Return the ID of the buffer containing the
/// specified location, returning -1 if not found.
int SourceMgr::FindBufferContainingLoc(SMLoc Loc) const {
for (unsigned i = 0, e = Buffers.size(); i != e; ++i)
if (Loc.getPointer() >= Buffers[i].Buffer->getBufferStart() &&
// Use <= here so that a pointer to the null at the end of the buffer
// is included as part of the buffer.
Loc.getPointer() <= Buffers[i].Buffer->getBufferEnd())
return i;
return -1;
}
/// FindLineNumber - Find the line number for the specified location in the
/// specified file. This is not a fast method.
unsigned SourceMgr::FindLineNumber(SMLoc Loc, int BufferID) const {
if (BufferID == -1) BufferID = FindBufferContainingLoc(Loc);
assert(BufferID != -1 && "Invalid Location!");
MemoryBuffer *Buff = getBufferInfo(BufferID).Buffer;
// Count the number of \n's between the start of the file and the specified
// location.
unsigned LineNo = 1;
const char *Ptr = Buff->getBufferStart();
// If we have a line number cache, and if the query is to a later point in the
// same file, start searching from the last query location. This optimizes
// for the case when multiple diagnostics come out of one file in order.
if (LineNoCacheTy *Cache = getCache(LineNoCache))
if (Cache->LastQueryBufferID == BufferID &&
Cache->LastQuery <= Loc.getPointer()) {
Ptr = Cache->LastQuery;
LineNo = Cache->LineNoOfQuery;
}
// Scan for the location being queried, keeping track of the number of lines
// we see.
for (; SMLoc::getFromPointer(Ptr) != Loc; ++Ptr)
if (*Ptr == '\n') ++LineNo;
// Allocate the line number cache if it doesn't exist.
if (LineNoCache == 0)
LineNoCache = new LineNoCacheTy();
// Update the line # cache.
LineNoCacheTy &Cache = *getCache(LineNoCache);
Cache.LastQueryBufferID = BufferID;
Cache.LastQuery = Ptr;
Cache.LineNoOfQuery = LineNo;
return LineNo;
}
void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const {
if (IncludeLoc == SMLoc()) return; // Top of stack.
int CurBuf = FindBufferContainingLoc(IncludeLoc);
assert(CurBuf != -1 && "Invalid or unspecified location!");
PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
OS << "Included from "
<< getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
<< ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
}
/// GetMessage - Return an SMDiagnostic at the specified location with the
/// specified string.
///
/// @param Type - If non-null, the kind of message (e.g., "error") which is
/// prefixed to the message.
SMDiagnostic SourceMgr::GetMessage(SMLoc Loc, const std::string &Msg,
const char *Type) const {
// First thing to do: find the current buffer containing the specified
// location.
int CurBuf = FindBufferContainingLoc(Loc);
assert(CurBuf != -1 && "Invalid or unspecified location!");
MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
// Scan backward to find the start of the line.
const char *LineStart = Loc.getPointer();
while (LineStart != CurMB->getBufferStart() &&
LineStart[-1] != '\n' && LineStart[-1] != '\r')
--LineStart;
// Get the end of the line.
const char *LineEnd = Loc.getPointer();
while (LineEnd != CurMB->getBufferEnd() &&
LineEnd[0] != '\n' && LineEnd[0] != '\r')
++LineEnd;
std::string PrintedMsg;
if (Type) {
PrintedMsg = Type;
PrintedMsg += ": ";
}
PrintedMsg += Msg;
// Print out the line.
return SMDiagnostic(CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
Loc.getPointer()-LineStart, PrintedMsg,
std::string(LineStart, LineEnd));
}
void SourceMgr::PrintMessage(SMLoc Loc, const std::string &Msg,
const char *Type) const {
raw_ostream &OS = errs();
int CurBuf = FindBufferContainingLoc(Loc);
assert(CurBuf != -1 && "Invalid or unspecified location!");
PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
GetMessage(Loc, Msg, Type).Print(0, OS);
}
//===----------------------------------------------------------------------===//
// SMDiagnostic Implementation
//===----------------------------------------------------------------------===//
void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) {
if (ProgName && ProgName[0])
S << ProgName << ": ";
if (Filename == "-")
S << "<stdin>";
else
S << Filename;
if (LineNo != -1) {
S << ':' << LineNo;
if (ColumnNo != -1)
S << ':' << (ColumnNo+1);
}
S << ": " << Message << '\n';
if (LineNo != -1 && ColumnNo != -1) {
S << LineContents << '\n';
// Print out spaces/tabs before the caret.
for (unsigned i = 0; i != unsigned(ColumnNo); ++i)
S << (LineContents[i] == '\t' ? '\t' : ' ');
S << "^\n";
}
}