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//===- DependencyDirectivesSourceMinimizer.cpp - -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This is the implementation for minimizing header and source files to the
/// minimum necessary preprocessor directives for evaluating includes. It
/// reduces the source down to #define, #include, #import, @import, and any
/// conditional preprocessor logic that contains one of those.
///
//===----------------------------------------------------------------------===//
#include "clang/Lex/DependencyDirectivesSourceMinimizer.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Lex/LexDiagnostic.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/MemoryBuffer.h"
using namespace llvm;
using namespace clang;
using namespace clang::minimize_source_to_dependency_directives;
namespace {
struct Minimizer {
/// Minimized output.
SmallVectorImpl<char> &Out;
/// The known tokens encountered during the minimization.
SmallVectorImpl<Token> &Tokens;
Minimizer(SmallVectorImpl<char> &Out, SmallVectorImpl<Token> &Tokens,
StringRef Input, DiagnosticsEngine *Diags,
SourceLocation InputSourceLoc)
: Out(Out), Tokens(Tokens), Input(Input), Diags(Diags),
InputSourceLoc(InputSourceLoc) {}
/// Lex the provided source and emit the minimized output.
///
/// \returns True on error.
bool minimize();
private:
struct IdInfo {
const char *Last;
StringRef Name;
};
/// Lex an identifier.
///
/// \pre First points at a valid identifier head.
LLVM_NODISCARD IdInfo lexIdentifier(const char *First, const char *const End);
LLVM_NODISCARD bool isNextIdentifier(StringRef Id, const char *&First,
const char *const End);
LLVM_NODISCARD bool minimizeImpl(const char *First, const char *const End);
LLVM_NODISCARD bool lexPPLine(const char *&First, const char *const End);
LLVM_NODISCARD bool lexAt(const char *&First, const char *const End);
LLVM_NODISCARD bool lexModule(const char *&First, const char *const End);
LLVM_NODISCARD bool lexDefine(const char *&First, const char *const End);
LLVM_NODISCARD bool lexPragma(const char *&First, const char *const End);
LLVM_NODISCARD bool lexEndif(const char *&First, const char *const End);
LLVM_NODISCARD bool lexDefault(TokenKind Kind, StringRef Directive,
const char *&First, const char *const End);
Token &makeToken(TokenKind K) {
Tokens.emplace_back(K, Out.size());
return Tokens.back();
}
void popToken() {
Out.resize(Tokens.back().Offset);
Tokens.pop_back();
}
TokenKind top() const { return Tokens.empty() ? pp_none : Tokens.back().K; }
Minimizer &put(char Byte) {
Out.push_back(Byte);
return *this;
}
Minimizer &append(StringRef S) { return append(S.begin(), S.end()); }
Minimizer &append(const char *First, const char *Last) {
Out.append(First, Last);
return *this;
}
void printToNewline(const char *&First, const char *const End);
void printAdjacentModuleNameParts(const char *&First, const char *const End);
LLVM_NODISCARD bool printAtImportBody(const char *&First,
const char *const End);
void printDirectiveBody(const char *&First, const char *const End);
void printAdjacentMacroArgs(const char *&First, const char *const End);
LLVM_NODISCARD bool printMacroArgs(const char *&First, const char *const End);
/// Reports a diagnostic if the diagnostic engine is provided. Always returns
/// true at the end.
bool reportError(const char *CurPtr, unsigned Err);
StringMap<char> SplitIds;
StringRef Input;
DiagnosticsEngine *Diags;
SourceLocation InputSourceLoc;
};
} // end anonymous namespace
bool Minimizer::reportError(const char *CurPtr, unsigned Err) {
if (!Diags)
return true;
assert(CurPtr >= Input.data() && "invalid buffer ptr");
Diags->Report(InputSourceLoc.getLocWithOffset(CurPtr - Input.data()), Err);
return true;
}
static void skipOverSpaces(const char *&First, const char *const End) {
while (First != End && isHorizontalWhitespace(*First))
++First;
}
LLVM_NODISCARD static bool isRawStringLiteral(const char *First,
const char *Current) {
assert(First <= Current);
// Check if we can even back up.
if (*Current != '"' || First == Current)
return false;
// Check for an "R".
--Current;
if (*Current != 'R')
return false;
if (First == Current || !isAsciiIdentifierContinue(*--Current))
return true;
// Check for a prefix of "u", "U", or "L".
if (*Current == 'u' || *Current == 'U' || *Current == 'L')
return First == Current || !isAsciiIdentifierContinue(*--Current);
// Check for a prefix of "u8".
if (*Current != '8' || First == Current || *Current-- != 'u')
return false;
return First == Current || !isAsciiIdentifierContinue(*--Current);
}
static void skipRawString(const char *&First, const char *const End) {
assert(First[0] == '"');
assert(First[-1] == 'R');
const char *Last = ++First;
while (Last != End && *Last != '(')
++Last;
if (Last == End) {
First = Last; // Hit the end... just give up.
return;
}
StringRef Terminator(First, Last - First);
for (;;) {
// Move First to just past the next ")".
First = Last;
while (First != End && *First != ')')
++First;
if (First == End)
return;
++First;
// Look ahead for the terminator sequence.
Last = First;
while (Last != End && size_t(Last - First) < Terminator.size() &&
Terminator[Last - First] == *Last)
++Last;
// Check if we hit it (or the end of the file).
if (Last == End) {
First = Last;
return;
}
if (size_t(Last - First) < Terminator.size())
continue;
if (*Last != '"')
continue;
First = Last + 1;
return;
}
}
// Returns the length of EOL, either 0 (no end-of-line), 1 (\n) or 2 (\r\n)
static unsigned isEOL(const char *First, const char *const End) {
if (First == End)
return 0;
if (End - First > 1 && isVerticalWhitespace(First[0]) &&
isVerticalWhitespace(First[1]) && First[0] != First[1])
return 2;
return !!isVerticalWhitespace(First[0]);
}
static void skipString(const char *&First, const char *const End) {
assert(*First == '\'' || *First == '"' || *First == '<');
const char Terminator = *First == '<' ? '>' : *First;
for (++First; First != End && *First != Terminator; ++First) {
// String and character literals don't extend past the end of the line.
if (isVerticalWhitespace(*First))
return;
if (*First != '\\')
continue;
// Skip past backslash to the next character. This ensures that the
// character right after it is skipped as well, which matters if it's
// the terminator.
if (++First == End)
return;
if (!isWhitespace(*First))
continue;
// Whitespace after the backslash might indicate a line continuation.
const char *FirstAfterBackslashPastSpace = First;
skipOverSpaces(FirstAfterBackslashPastSpace, End);
if (unsigned NLSize = isEOL(FirstAfterBackslashPastSpace, End)) {
// Advance the character pointer to the next line for the next
// iteration.
First = FirstAfterBackslashPastSpace + NLSize - 1;
}
}
if (First != End)
++First; // Finish off the string.
}
// Returns the length of the skipped newline
static unsigned skipNewline(const char *&First, const char *End) {
if (First == End)
return 0;
assert(isVerticalWhitespace(*First));
unsigned Len = isEOL(First, End);
assert(Len && "expected newline");
First += Len;
return Len;
}
static bool wasLineContinuation(const char *First, unsigned EOLLen) {
return *(First - (int)EOLLen - 1) == '\\';
}
static void skipToNewlineRaw(const char *&First, const char *const End) {
for (;;) {
if (First == End)
return;
unsigned Len = isEOL(First, End);
if (Len)
return;
do {
if (++First == End)
return;
Len = isEOL(First, End);
} while (!Len);
if (First[-1] != '\\')
return;
First += Len;
// Keep skipping lines...
}
}
static const char *findLastNonSpace(const char *First, const char *Last) {
assert(First <= Last);
while (First != Last && isHorizontalWhitespace(Last[-1]))
--Last;
return Last;
}
static const char *findFirstTrailingSpace(const char *First,
const char *Last) {
const char *LastNonSpace = findLastNonSpace(First, Last);
if (Last == LastNonSpace)
return Last;
assert(isHorizontalWhitespace(LastNonSpace[0]));
return LastNonSpace + 1;
}
static void skipLineComment(const char *&First, const char *const End) {
assert(First[0] == '/' && First[1] == '/');
First += 2;
skipToNewlineRaw(First, End);
}
static void skipBlockComment(const char *&First, const char *const End) {
assert(First[0] == '/' && First[1] == '*');
if (End - First < 4) {
First = End;
return;
}
for (First += 3; First != End; ++First)
if (First[-1] == '*' && First[0] == '/') {
++First;
return;
}
}
/// \returns True if the current single quotation mark character is a C++ 14
/// digit separator.
static bool isQuoteCppDigitSeparator(const char *const Start,
const char *const Cur,
const char *const End) {
assert(*Cur == '\'' && "expected quotation character");
// skipLine called in places where we don't expect a valid number
// body before `start` on the same line, so always return false at the start.
if (Start == Cur)
return false;
// The previous character must be a valid PP number character.
// Make sure that the L, u, U, u8 prefixes don't get marked as a
// separator though.
char Prev = *(Cur - 1);
if (Prev == 'L' || Prev == 'U' || Prev == 'u')
return false;
if (Prev == '8' && (Cur - 1 != Start) && *(Cur - 2) == 'u')
return false;
if (!isPreprocessingNumberBody(Prev))
return false;
// The next character should be a valid identifier body character.
return (Cur + 1) < End && isAsciiIdentifierContinue(*(Cur + 1));
}
static void skipLine(const char *&First, const char *const End) {
for (;;) {
assert(First <= End);
if (First == End)
return;
if (isVerticalWhitespace(*First)) {
skipNewline(First, End);
return;
}
const char *Start = First;
while (First != End && !isVerticalWhitespace(*First)) {
// Iterate over strings correctly to avoid comments and newlines.
if (*First == '"' ||
(*First == '\'' && !isQuoteCppDigitSeparator(Start, First, End))) {
if (isRawStringLiteral(Start, First))
skipRawString(First, End);
else
skipString(First, End);
continue;
}
// Iterate over comments correctly.
if (*First != '/' || End - First < 2) {
++First;
continue;
}
if (First[1] == '/') {
// "//...".
skipLineComment(First, End);
continue;
}
if (First[1] != '*') {
++First;
continue;
}
// "/*...*/".
skipBlockComment(First, End);
}
if (First == End)
return;
// Skip over the newline.
unsigned Len = skipNewline(First, End);
if (!wasLineContinuation(First, Len)) // Continue past line-continuations.
break;
}
}
static void skipDirective(StringRef Name, const char *&First,
const char *const End) {
if (llvm::StringSwitch<bool>(Name)
.Case("warning", true)
.Case("error", true)
.Default(false))
// Do not process quotes or comments.
skipToNewlineRaw(First, End);
else
skipLine(First, End);
}
void Minimizer::printToNewline(const char *&First, const char *const End) {
while (First != End && !isVerticalWhitespace(*First)) {
const char *Last = First;
do {
// Iterate over strings correctly to avoid comments and newlines.
if (*Last == '"' || *Last == '\'' ||
(*Last == '<' && top() == pp_include)) {
if (LLVM_UNLIKELY(isRawStringLiteral(First, Last)))
skipRawString(Last, End);
else
skipString(Last, End);
continue;
}
if (*Last != '/' || End - Last < 2) {
++Last;
continue; // Gather the rest up to print verbatim.
}
if (Last[1] != '/' && Last[1] != '*') {
++Last;
continue;
}
// Deal with "//..." and "/*...*/".
append(First, findFirstTrailingSpace(First, Last));
First = Last;
if (Last[1] == '/') {
skipLineComment(First, End);
return;
}
put(' ');
skipBlockComment(First, End);
skipOverSpaces(First, End);
Last = First;
} while (Last != End && !isVerticalWhitespace(*Last));
// Print out the string.
const char *LastBeforeTrailingSpace = findLastNonSpace(First, Last);
if (Last == End || LastBeforeTrailingSpace == First ||
LastBeforeTrailingSpace[-1] != '\\') {
append(First, LastBeforeTrailingSpace);
First = Last;
skipNewline(First, End);
return;
}
// Print up to the backslash, backing up over spaces. Preserve at least one
// space, as the space matters when tokens are separated by a line
// continuation.
append(First, findFirstTrailingSpace(
First, LastBeforeTrailingSpace - 1));
First = Last;
skipNewline(First, End);
skipOverSpaces(First, End);
}
}
static void skipWhitespace(const char *&First, const char *const End) {
for (;;) {
assert(First <= End);
skipOverSpaces(First, End);
if (End - First < 2)
return;
if (First[0] == '\\' && isVerticalWhitespace(First[1])) {
skipNewline(++First, End);
continue;
}
// Check for a non-comment character.
if (First[0] != '/')
return;
// "// ...".
if (First[1] == '/') {
skipLineComment(First, End);
return;
}
// Cannot be a comment.
if (First[1] != '*')
return;
// "/*...*/".
skipBlockComment(First, End);
}
}
void Minimizer::printAdjacentModuleNameParts(const char *&First,
const char *const End) {
// Skip over parts of the body.
const char *Last = First;
do
++Last;
while (Last != End && (isAsciiIdentifierContinue(*Last) || *Last == '.'));
append(First, Last);
First = Last;
}
bool Minimizer::printAtImportBody(const char *&First, const char *const End) {
for (;;) {
skipWhitespace(First, End);
if (First == End)
return true;
if (isVerticalWhitespace(*First)) {
skipNewline(First, End);
continue;
}
// Found a semicolon.
if (*First == ';') {
put(*First++).put('\n');
return false;
}
// Don't handle macro expansions inside @import for now.
if (!isAsciiIdentifierContinue(*First) && *First != '.')
return true;
printAdjacentModuleNameParts(First, End);
}
}
void Minimizer::printDirectiveBody(const char *&First, const char *const End) {
skipWhitespace(First, End); // Skip initial whitespace.
printToNewline(First, End);
while (Out.back() == ' ')
Out.pop_back();
put('\n');
}
LLVM_NODISCARD static const char *lexRawIdentifier(const char *First,
const char *const End) {
assert(isAsciiIdentifierContinue(*First) && "invalid identifer");
const char *Last = First + 1;
while (Last != End && isAsciiIdentifierContinue(*Last))
++Last;
return Last;
}
LLVM_NODISCARD static const char *
getIdentifierContinuation(const char *First, const char *const End) {
if (End - First < 3 || First[0] != '\\' || !isVerticalWhitespace(First[1]))
return nullptr;
++First;
skipNewline(First, End);
if (First == End)
return nullptr;
return isAsciiIdentifierContinue(First[0]) ? First : nullptr;
}
Minimizer::IdInfo Minimizer::lexIdentifier(const char *First,
const char *const End) {
const char *Last = lexRawIdentifier(First, End);
const char *Next = getIdentifierContinuation(Last, End);
if (LLVM_LIKELY(!Next))
return IdInfo{Last, StringRef(First, Last - First)};
// Slow path, where identifiers are split over lines.
SmallVector<char, 64> Id(First, Last);
while (Next) {
Last = lexRawIdentifier(Next, End);
Id.append(Next, Last);
Next = getIdentifierContinuation(Last, End);
}
return IdInfo{
Last,
SplitIds.try_emplace(StringRef(Id.begin(), Id.size()), 0).first->first()};
}
void Minimizer::printAdjacentMacroArgs(const char *&First,
const char *const End) {
// Skip over parts of the body.
const char *Last = First;
do
++Last;
while (Last != End &&
(isAsciiIdentifierContinue(*Last) || *Last == '.' || *Last == ','));
append(First, Last);
First = Last;
}
bool Minimizer::printMacroArgs(const char *&First, const char *const End) {
assert(*First == '(');
put(*First++);
for (;;) {
skipWhitespace(First, End);
if (First == End)
return true;
if (*First == ')') {
put(*First++);
return false;
}
// This is intentionally fairly liberal.
if (!(isAsciiIdentifierContinue(*First) || *First == '.' || *First == ','))
return true;
printAdjacentMacroArgs(First, End);
}
}
/// Looks for an identifier starting from Last.
///
/// Updates "First" to just past the next identifier, if any. Returns true iff
/// the identifier matches "Id".
bool Minimizer::isNextIdentifier(StringRef Id, const char *&First,
const char *const End) {
skipWhitespace(First, End);
if (First == End || !isAsciiIdentifierStart(*First))
return false;
IdInfo FoundId = lexIdentifier(First, End);
First = FoundId.Last;
return FoundId.Name == Id;
}
bool Minimizer::lexAt(const char *&First, const char *const End) {
// Handle "@import".
const char *ImportLoc = First++;
if (!isNextIdentifier("import", First, End)) {
skipLine(First, End);
return false;
}
makeToken(decl_at_import);
append("@import ");
if (printAtImportBody(First, End))
return reportError(
ImportLoc, diag::err_dep_source_minimizer_missing_sema_after_at_import);
skipWhitespace(First, End);
if (First == End)
return false;
if (!isVerticalWhitespace(*First))
return reportError(
ImportLoc, diag::err_dep_source_minimizer_unexpected_tokens_at_import);
skipNewline(First, End);
return false;
}
bool Minimizer::lexModule(const char *&First, const char *const End) {
IdInfo Id = lexIdentifier(First, End);
First = Id.Last;
bool Export = false;
if (Id.Name == "export") {
Export = true;
skipWhitespace(First, End);
if (!isAsciiIdentifierContinue(*First)) {
skipLine(First, End);
return false;
}
Id = lexIdentifier(First, End);
First = Id.Last;
}
if (Id.Name != "module" && Id.Name != "import") {
skipLine(First, End);
return false;
}
skipWhitespace(First, End);
// Ignore this as a module directive if the next character can't be part of
// an import.
switch (*First) {
case ':':
case '<':
case '"':
break;
default:
if (!isAsciiIdentifierContinue(*First)) {
skipLine(First, End);
return false;
}
}
if (Export) {
makeToken(cxx_export_decl);
append("export ");
}
if (Id.Name == "module")
makeToken(cxx_module_decl);
else
makeToken(cxx_import_decl);
append(Id.Name);
append(" ");
printToNewline(First, End);
append("\n");
return false;
}
bool Minimizer::lexDefine(const char *&First, const char *const End) {
makeToken(pp_define);
append("#define ");
skipWhitespace(First, End);
if (!isAsciiIdentifierStart(*First))
return reportError(First, diag::err_pp_macro_not_identifier);
IdInfo Id = lexIdentifier(First, End);
const char *Last = Id.Last;
append(Id.Name);
if (Last == End)
return false;
if (*Last == '(') {
size_t Size = Out.size();
if (printMacroArgs(Last, End)) {
// Be robust to bad macro arguments, since they can show up in disabled
// code.
Out.resize(Size);
append("(/* invalid */\n");
skipLine(Last, End);
return false;
}
}
skipWhitespace(Last, End);
if (Last == End)
return false;
if (!isVerticalWhitespace(*Last))
put(' ');
printDirectiveBody(Last, End);
First = Last;
return false;
}
bool Minimizer::lexPragma(const char *&First, const char *const End) {
// #pragma.
skipWhitespace(First, End);
if (First == End || !isAsciiIdentifierStart(*First))
return false;
IdInfo FoundId = lexIdentifier(First, End);
First = FoundId.Last;
if (FoundId.Name == "once") {
// #pragma once
skipLine(First, End);
makeToken(pp_pragma_once);
append("#pragma once\n");
return false;
}
if (FoundId.Name == "push_macro") {
// #pragma push_macro
makeToken(pp_pragma_push_macro);
append("#pragma push_macro");
printDirectiveBody(First, End);
return false;
}
if (FoundId.Name == "pop_macro") {
// #pragma pop_macro
makeToken(pp_pragma_pop_macro);
append("#pragma pop_macro");
printDirectiveBody(First, End);
return false;
}
if (FoundId.Name == "include_alias") {
// #pragma include_alias
makeToken(pp_pragma_include_alias);
append("#pragma include_alias");
printDirectiveBody(First, End);
return false;
}
if (FoundId.Name != "clang") {
skipLine(First, End);
return false;
}
// #pragma clang.
if (!isNextIdentifier("module", First, End)) {
skipLine(First, End);
return false;
}
// #pragma clang module.
if (!isNextIdentifier("import", First, End)) {
skipLine(First, End);
return false;
}
// #pragma clang module import.
makeToken(pp_pragma_import);
append("#pragma clang module import ");
printDirectiveBody(First, End);
return false;
}
bool Minimizer::lexEndif(const char *&First, const char *const End) {
// Strip out "#else" if it's empty.
if (top() == pp_else)
popToken();
// If "#ifdef" is empty, strip it and skip the "#endif".
//
// FIXME: Once/if Clang starts disallowing __has_include in macro expansions,
// we can skip empty `#if` and `#elif` blocks as well after scanning for a
// literal __has_include in the condition. Even without that rule we could
// drop the tokens if we scan for identifiers in the condition and find none.
if (top() == pp_ifdef || top() == pp_ifndef) {
popToken();
skipLine(First, End);
return false;
}
return lexDefault(pp_endif, "endif", First, End);
}
bool Minimizer::lexDefault(TokenKind Kind, StringRef Directive,
const char *&First, const char *const End) {
makeToken(Kind);
put('#').append(Directive).put(' ');
printDirectiveBody(First, End);
return false;
}
static bool isStartOfRelevantLine(char First) {
switch (First) {
case '#':
case '@':
case 'i':
case 'e':
case 'm':
return true;
}
return false;
}
bool Minimizer::lexPPLine(const char *&First, const char *const End) {
assert(First != End);
skipWhitespace(First, End);
assert(First <= End);
if (First == End)
return false;
if (!isStartOfRelevantLine(*First)) {
skipLine(First, End);
assert(First <= End);
return false;
}
// Handle "@import".
if (*First == '@')
return lexAt(First, End);
if (*First == 'i' || *First == 'e' || *First == 'm')
return lexModule(First, End);
// Handle preprocessing directives.
++First; // Skip over '#'.
skipWhitespace(First, End);
if (First == End)
return reportError(First, diag::err_pp_expected_eol);
if (!isAsciiIdentifierStart(*First)) {
skipLine(First, End);
return false;
}
// Figure out the token.
IdInfo Id = lexIdentifier(First, End);
First = Id.Last;
if (Id.Name == "pragma")
return lexPragma(First, End);
auto Kind = llvm::StringSwitch<TokenKind>(Id.Name)
.Case("include", pp_include)
.Case("__include_macros", pp___include_macros)
.Case("define", pp_define)
.Case("undef", pp_undef)
.Case("import", pp_import)
.Case("include_next", pp_include_next)
.Case("if", pp_if)
.Case("ifdef", pp_ifdef)
.Case("ifndef", pp_ifndef)
.Case("elif", pp_elif)
.Case("elifdef", pp_elifdef)
.Case("elifndef", pp_elifndef)
.Case("else", pp_else)
.Case("endif", pp_endif)
.Default(pp_none);
if (Kind == pp_none) {
skipDirective(Id.Name, First, End);
return false;
}
if (Kind == pp_endif)
return lexEndif(First, End);
if (Kind == pp_define)
return lexDefine(First, End);
// Everything else.
return lexDefault(Kind, Id.Name, First, End);
}
static void skipUTF8ByteOrderMark(const char *&First, const char *const End) {
if ((End - First) >= 3 && First[0] == '\xef' && First[1] == '\xbb' &&
First[2] == '\xbf')
First += 3;
}
bool Minimizer::minimizeImpl(const char *First, const char *const End) {
skipUTF8ByteOrderMark(First, End);
while (First != End)
if (lexPPLine(First, End))
return true;
return false;
}
bool Minimizer::minimize() {
bool Error = minimizeImpl(Input.begin(), Input.end());
if (!Error) {
// Add a trailing newline and an EOF on success.
if (!Out.empty() && Out.back() != '\n')
Out.push_back('\n');
makeToken(pp_eof);
}
// Null-terminate the output. This way the memory buffer that's passed to
// Clang will not have to worry about the terminating '\0'.
Out.push_back(0);
Out.pop_back();
return Error;
}
bool clang::minimize_source_to_dependency_directives::computeSkippedRanges(
ArrayRef<Token> Input, llvm::SmallVectorImpl<SkippedRange> &Range) {
struct Directive {
enum DirectiveKind {
If, // if/ifdef/ifndef
Else // elif/elifdef/elifndef, else
};
int Offset;
DirectiveKind Kind;
};
llvm::SmallVector<Directive, 32> Offsets;
for (const Token &T : Input) {
switch (T.K) {
case pp_if:
case pp_ifdef:
case pp_ifndef:
Offsets.push_back({T.Offset, Directive::If});
break;
case pp_elif:
case pp_elifdef:
case pp_elifndef:
case pp_else: {
if (Offsets.empty())
return true;
int PreviousOffset = Offsets.back().Offset;
Range.push_back({PreviousOffset, T.Offset - PreviousOffset});
Offsets.push_back({T.Offset, Directive::Else});
break;
}
case pp_endif: {
if (Offsets.empty())
return true;
int PreviousOffset = Offsets.back().Offset;
Range.push_back({PreviousOffset, T.Offset - PreviousOffset});
do {
Directive::DirectiveKind Kind = Offsets.pop_back_val().Kind;
if (Kind == Directive::If)
break;
} while (!Offsets.empty());
break;
}
default:
break;
}
}
return false;
}
bool clang::minimizeSourceToDependencyDirectives(
StringRef Input, SmallVectorImpl<char> &Output,
SmallVectorImpl<Token> &Tokens, DiagnosticsEngine *Diags,
SourceLocation InputSourceLoc) {
Output.clear();
Tokens.clear();
return Minimizer(Output, Tokens, Input, Diags, InputSourceLoc).minimize();
}