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//===--- DiagnosticRenderer.cpp - Diagnostic Pretty-Printing --------------===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
#include "clang/Frontend/DiagnosticRenderer.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Frontend/DiagnosticOptions.h"
#include "clang/Lex/Lexer.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/ADT/SmallString.h"
#include <algorithm>
using namespace clang;
/// Look through spelling locations for a macro argument expansion, and
/// if found skip to it so that we can trace the argument rather than the macros
/// in which that argument is used. If no macro argument expansion is found,
/// don't skip anything and return the starting location.
static SourceLocation skipToMacroArgExpansion(const SourceManager &SM,
SourceLocation StartLoc) {
for (SourceLocation L = StartLoc; L.isMacroID();
L = SM.getImmediateSpellingLoc(L)) {
if (SM.isMacroArgExpansion(L))
return L;
// Otherwise just return initial location, there's nothing to skip.
return StartLoc;
/// Gets the location of the immediate macro caller, one level up the stack
/// toward the initial macro typed into the source.
static SourceLocation getImmediateMacroCallerLoc(const SourceManager &SM,
SourceLocation Loc) {
if (!Loc.isMacroID()) return Loc;
// When we have the location of (part of) an expanded parameter, its spelling
// location points to the argument as typed into the macro call, and
// therefore is used to locate the macro caller.
if (SM.isMacroArgExpansion(Loc))
return SM.getImmediateSpellingLoc(Loc);
// Otherwise, the caller of the macro is located where this macro is
// expanded (while the spelling is part of the macro definition).
return SM.getImmediateExpansionRange(Loc).first;
/// Gets the location of the immediate macro callee, one level down the stack
/// toward the leaf macro.
static SourceLocation getImmediateMacroCalleeLoc(const SourceManager &SM,
SourceLocation Loc) {
if (!Loc.isMacroID()) return Loc;
// When we have the location of (part of) an expanded parameter, its
// expansion location points to the unexpanded paramater reference within
// the macro definition (or callee).
if (SM.isMacroArgExpansion(Loc))
return SM.getImmediateExpansionRange(Loc).first;
// Otherwise, the callee of the macro is located where this location was
// spelled inside the macro definition.
return SM.getImmediateSpellingLoc(Loc);
/// \brief Retrieve the name of the immediate macro expansion.
/// This routine starts from a source location, and finds the name of the macro
/// responsible for its immediate expansion. It looks through any intervening
/// macro argument expansions to compute this. It returns a StringRef which
/// refers to the SourceManager-owned buffer of the source where that macro
/// name is spelled. Thus, the result shouldn't out-live that SourceManager.
/// This differs from Lexer::getImmediateMacroName in that any macro argument
/// location will result in the topmost function macro that accepted it.
/// e.g.
/// \code
/// MAC1( MAC2(foo) )
/// \endcode
/// for location of 'foo' token, this function will return "MAC1" while
/// Lexer::getImmediateMacroName will return "MAC2".
static StringRef getImmediateMacroName(SourceLocation Loc,
const SourceManager &SM,
const LangOptions &LangOpts) {
assert(Loc.isMacroID() && "Only reasonble to call this on macros");
// Walk past macro argument expanions.
while (SM.isMacroArgExpansion(Loc))
Loc = SM.getImmediateExpansionRange(Loc).first;
// Find the spelling location of the start of the non-argument expansion
// range. This is where the macro name was spelled in order to begin
// expanding this macro.
Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
// Dig out the buffer where the macro name was spelled and the extents of the
// name so that we can render it into the expansion note.
std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
/// Get the presumed location of a diagnostic message. This computes the
/// presumed location for the top of any macro backtrace when present.
static PresumedLoc getDiagnosticPresumedLoc(const SourceManager &SM,
SourceLocation Loc) {
// This is a condensed form of the algorithm used by emitCaretDiagnostic to
// walk to the top of the macro call stack.
while (Loc.isMacroID()) {
Loc = skipToMacroArgExpansion(SM, Loc);
Loc = getImmediateMacroCallerLoc(SM, Loc);
return SM.getPresumedLoc(Loc);
DiagnosticRenderer::DiagnosticRenderer(const SourceManager &SM,
const LangOptions &LangOpts,
const DiagnosticOptions &DiagOpts)
: SM(SM), LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
DiagnosticRenderer::~DiagnosticRenderer() {}
void DiagnosticRenderer::emitDiagnostic(SourceLocation Loc,
DiagnosticsEngine::Level Level,
StringRef Message,
ArrayRef<CharSourceRange> Ranges,
ArrayRef<FixItHint> FixItHints,
DiagOrStoredDiag D) {
beginDiagnostic(D, Level);
PresumedLoc PLoc = getDiagnosticPresumedLoc(SM, Loc);
// First, if this diagnostic is not in the main file, print out the
// "included from" lines.
emitIncludeStack(PLoc.getIncludeLoc(), Level);
// Next, emit the actual diagnostic message.
emitDiagnosticMessage(Loc, PLoc, Level, Message, Ranges, D);
// Only recurse if we have a valid location.
if (Loc.isValid()) {
// Get the ranges into a local array we can hack on.
SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
for (ArrayRef<FixItHint>::const_iterator I = FixItHints.begin(),
E = FixItHints.end();
I != E; ++I)
if (I->RemoveRange.isValid())
unsigned MacroDepth = 0;
emitMacroExpansionsAndCarets(Loc, Level, MutableRanges, FixItHints,
LastLoc = Loc;
LastLevel = Level;
endDiagnostic(D, Level);
void DiagnosticRenderer::emitStoredDiagnostic(StoredDiagnostic &Diag) {
emitDiagnostic(Diag.getLocation(), Diag.getLevel(), Diag.getMessage(),
Diag.getRanges(), Diag.getFixIts(),
/// \brief Prints an include stack when appropriate for a particular
/// diagnostic level and location.
/// This routine handles all the logic of suppressing particular include
/// stacks (such as those for notes) and duplicate include stacks when
/// repeated warnings occur within the same file. It also handles the logic
/// of customizing the formatting and display of the include stack.
/// \param Level The diagnostic level of the message this stack pertains to.
/// \param Loc The include location of the current file (not the diagnostic
/// location).
void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
DiagnosticsEngine::Level Level) {
// Skip redundant include stacks altogether.
if (LastIncludeLoc == Loc)
LastIncludeLoc = Loc;
if (!DiagOpts.ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
/// \brief Helper to recursivly walk up the include stack and print each layer
/// on the way back down.
void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc) {
if (Loc.isInvalid())
PresumedLoc PLoc = SM.getPresumedLoc(Loc);
if (PLoc.isInvalid())
// Emit the other include frames first.
// Emit the inclusion text/note.
emitIncludeLocation(Loc, PLoc);
/// \brief Recursively emit notes for each macro expansion and caret
/// diagnostics where appropriate.
/// Walks up the macro expansion stack printing expansion notes, the code
/// snippet, caret, underlines and FixItHint display as appropriate at each
/// level.
/// \param Loc The location for this caret.
/// \param Level The diagnostic level currently being emitted.
/// \param Ranges The underlined ranges for this code snippet.
/// \param Hints The FixIt hints active for this diagnostic.
/// \param MacroSkipEnd The depth to stop skipping macro expansions.
/// \param OnMacroInst The current depth of the macro expansion stack.
void DiagnosticRenderer::emitMacroExpansionsAndCarets(
SourceLocation Loc,
DiagnosticsEngine::Level Level,
SmallVectorImpl<CharSourceRange>& Ranges,
ArrayRef<FixItHint> Hints,
unsigned &MacroDepth,
unsigned OnMacroInst)
assert(!Loc.isInvalid() && "must have a valid source location here");
// If this is a file source location, directly emit the source snippet and
// caret line. Also record the macro depth reached.
if (Loc.isFileID()) {
assert(MacroDepth == 0 && "We shouldn't hit a leaf node twice!");
MacroDepth = OnMacroInst;
emitCodeContext(Loc, Level, Ranges, Hints);
// Otherwise recurse through each macro expansion layer.
// When processing macros, skip over the expansions leading up to
// a macro argument, and trace the argument's expansion stack instead.
Loc = skipToMacroArgExpansion(SM, Loc);
SourceLocation OneLevelUp = getImmediateMacroCallerLoc(SM, Loc);
// FIXME: Map ranges?
emitMacroExpansionsAndCarets(OneLevelUp, Level, Ranges, Hints, MacroDepth,
OnMacroInst + 1);
// Save the original location so we can find the spelling of the macro call.
SourceLocation MacroLoc = Loc;
// Map the location.
Loc = getImmediateMacroCalleeLoc(SM, Loc);
unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
if (MacroDepth > DiagOpts.MacroBacktraceLimit &&
DiagOpts.MacroBacktraceLimit != 0) {
MacroSkipStart = DiagOpts.MacroBacktraceLimit / 2 +
DiagOpts.MacroBacktraceLimit % 2;
MacroSkipEnd = MacroDepth - DiagOpts.MacroBacktraceLimit / 2;
// Whether to suppress printing this macro expansion.
bool Suppressed = (OnMacroInst >= MacroSkipStart &&
OnMacroInst < MacroSkipEnd);
// Map the ranges.
for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
E = Ranges.end();
I != E; ++I) {
SourceLocation Start = I->getBegin(), End = I->getEnd();
if (Start.isMacroID())
I->setBegin(getImmediateMacroCalleeLoc(SM, Start));
if (End.isMacroID())
I->setEnd(getImmediateMacroCalleeLoc(SM, End));
if (Suppressed) {
// Tell the user that we've skipped contexts.
if (OnMacroInst == MacroSkipStart) {
SmallString<200> MessageStorage;
llvm::raw_svector_ostream Message(MessageStorage);
Message << "(skipping " << (MacroSkipEnd - MacroSkipStart)
<< " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
"see all)";
SmallString<100> MessageStorage;
llvm::raw_svector_ostream Message(MessageStorage);
Message << "expanded from macro '"
<< getImmediateMacroName(MacroLoc, SM, LangOpts) << "'";
emitDiagnostic(SM.getSpellingLoc(Loc), DiagnosticsEngine::Note,
Ranges, ArrayRef<FixItHint>());
DiagnosticNoteRenderer::~DiagnosticNoteRenderer() {}
void DiagnosticNoteRenderer::emitIncludeLocation(SourceLocation Loc,
PresumedLoc PLoc) {
// Generate a note indicating the include location.
SmallString<200> MessageStorage;
llvm::raw_svector_ostream Message(MessageStorage);
Message << "in file included from " << PLoc.getFilename() << ':'
<< PLoc.getLine() << ":";
emitNote(Loc, Message.str());
void DiagnosticNoteRenderer::emitBasicNote(StringRef Message) {
emitNote(SourceLocation(), Message);