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chromium / external / github.com / include-what-you-use / include-what-you-use / refs/heads/upstream/clang_3.2 / . / iwyu_output.cc
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//===--- iwyu_output.cc - output-emitting code for include-what-you-use ---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "iwyu_output.h"
#include <stdio.h> // for snprintf
#include <algorithm> // for sort, find
// TODO(wan): make sure IWYU doesn't suggest <iterator>.
#include <iterator> // for find
#include <map> // for _Rb_tree_const_iterator, etc
#include <utility> // for pair, make_pair, operator>
#include <vector> // for vector, vector<>::iterator, etc
#include "iwyu_ast_util.h"
#include "iwyu_globals.h"
#include "iwyu_include_picker.h"
#include "iwyu_location_util.h"
#include "iwyu_path_util.h"
#include "iwyu_preprocessor.h" // IWYU pragma: keep
#include "iwyu_stl_util.h"
#include "iwyu_string_util.h"
#include "iwyu_verrs.h"
// TODO(wan): remove this once the IWYU bug is fixed.
// IWYU pragma: no_include "foo/bar/baz.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/raw_ostream.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/Basic/SourceLocation.h"
namespace include_what_you_use {
using clang::ClassTemplateDecl;
using clang::ClassTemplateSpecializationDecl;
using clang::CXXMethodDecl;
using clang::CXXRecordDecl;
using clang::Decl;
using clang::DeclContext;
using clang::FileEntry;
using clang::FullSourceLoc;
using clang::FunctionDecl;
using clang::NamedDecl;
using clang::NamespaceDecl;
using clang::RecordDecl;
using clang::SourceRange;
using clang::TemplateDecl;
using clang::SourceLocation;
using llvm::cast;
using llvm::errs;
using llvm::isa;
using llvm::raw_string_ostream;
using std::find;
using std::map;
using std::multimap;
using std::pair;
using std::sort;
using std::vector;
namespace internal {
namespace {
// A map that effectively allows us to dynamic cast from a NamedDecl
// to a FakeNamedDecl. When a FakeNamedDecl is created, it will be
// inserted into the map with itself as the key (implicitly casted to
// a NamedDecl).
std::map<const clang::NamedDecl*, const FakeNamedDecl*>
g_fake_named_decl_map;
// Since dynamic casting is not an option, this method is provided to
// determine if a decl is actually a FakeNamedDecl.
const FakeNamedDecl* FakeNamedDeclIfItIsOne(const clang::NamedDecl* decl) {
return GetOrDefault(g_fake_named_decl_map, decl, NULL);
}
} // namespace
FakeNamedDecl::FakeNamedDecl(const string& kind_name, const string& qual_name,
const string& decl_filepath, int decl_linenum)
: clang::NamedDecl(clang::Decl::Record, NULL, clang::SourceLocation(),
clang::DeclarationName()),
kind_name_(kind_name),
qual_name_(qual_name),
decl_filepath_(decl_filepath), decl_linenum_(decl_linenum) {
g_fake_named_decl_map[this] = this;
}
// When testing IWYU, we provide a fake object (FakeNamedDecl) that
// needs to provide its own version of NamedDecl::getKindName() and
// NamedDecl::getQualifiedNameAsString(). Unfortunately they aren't
// virtual. Hence we define the following helpers to dispatch the
// call ourselves.
string GetKindName(const clang::TagDecl* tag_decl) {
const clang::NamedDecl* const named_decl = tag_decl;
if (const FakeNamedDecl* fake = FakeNamedDeclIfItIsOne(named_decl)) {
return fake->kind_name();
}
return tag_decl->getKindName();
}
string GetQualifiedNameAsString(const clang::NamedDecl* named_decl) {
if (const FakeNamedDecl* fake = FakeNamedDeclIfItIsOne(named_decl)) {
return fake->qual_name();
}
return named_decl->getQualifiedNameAsString();
}
// Name we put in the comments next to an #include.
string GetShortNameAsString(const clang::NamedDecl* named_decl) {
if (const FakeNamedDecl* fake = FakeNamedDeclIfItIsOne(named_decl)) {
return fake->qual_name();
}
// This is modified from NamedDecl::getQualifiedNameAsString:
// http://clang.llvm.org/doxygen/Decl_8cpp_source.html#l00742
const DeclContext *decl_context = named_decl->getDeclContext();
if (decl_context->isFunctionOrMethod())
return named_decl->getNameAsString();
vector<const DeclContext*> contexts;
while (decl_context && isa<NamedDecl>(decl_context)) {
contexts.push_back(decl_context);
decl_context = decl_context->getParent();
};
std::string retval;
raw_string_ostream ostream(retval);
for (vector<const DeclContext*>::reverse_iterator it = contexts.rbegin();
it != contexts.rend(); ++it) {
if (const ClassTemplateSpecializationDecl* tpl_decl = DynCastFrom(*it)) {
ostream << tpl_decl->getName() << "<>::";
} else if (isa<NamespaceDecl>(*it)) {
// We don't want to include namespaces in our shortname.
} else if (const RecordDecl *record_decl = DynCastFrom(*it)) {
if (!record_decl->getIdentifier())
ostream << "<anonymous " << record_decl->getKindName() << ">::";
else
ostream << *record_decl << "::";
} else if (const FunctionDecl *function_decl = DynCastFrom(*it)) {
ostream << *function_decl << "::"; // could also add in '<< "()"'
} else {
ostream << *(cast<NamedDecl>(*it)) << "::";
}
}
// Due to the way DeclarationNameInfo::printName() is written, this
// will show template arguments for templated constructors and
// destructors. Since iwyu only shows these when they're defined in
// a -inl.h file, I'm not going to worry about it.
if (named_decl->getDeclName())
ostream << *named_decl;
else
ostream << "<anonymous>";
return ostream.str();
}
} // namespace internal
// Holds information about a single full or fwd-decl use of a symbol.
OneUse::OneUse(const NamedDecl* decl, SourceLocation use_loc,
OneUse::UseKind use_kind, bool in_cxx_method_body,
const char* comment)
: symbol_name_(internal::GetQualifiedNameAsString(decl)),
short_symbol_name_(internal::GetShortNameAsString(decl)),
decl_(decl),
decl_filepath_(GetFilePath(decl)),
use_loc_(use_loc),
use_kind_(use_kind), // full use or fwd-declare use
in_cxx_method_body_(in_cxx_method_body),
comment_(comment ? comment : ""),
public_headers_(),
suggested_header_(), // figure that out later
ignore_use_(false),
is_iwyu_violation_(false) {
}
// This constructor always creates a full use.
OneUse::OneUse(const string& symbol_name, const string& dfn_filepath,
SourceLocation use_loc)
: symbol_name_(symbol_name),
short_symbol_name_(symbol_name),
decl_(NULL),
decl_filepath_(dfn_filepath),
use_loc_(use_loc),
use_kind_(kFullUse),
in_cxx_method_body_(false),
comment_(),
public_headers_(),
suggested_header_(),
ignore_use_(false),
is_iwyu_violation_(false) {
// Sometimes dfn_filepath is actually a fully quoted include. In
// that case, we take that as an unchangable mapping that we
// should never remove, so we make it the suggested header.
CHECK_(!decl_filepath_.empty() && "Must pass a real filepath to OneUse");
if (decl_filepath_[0] == '"' || decl_filepath_[0] == '<')
suggested_header_ = decl_filepath_;
}
int OneUse::UseLinenum() const {
return GetLineNumber(use_loc_);
}
string OneUse::PrintableUseLoc() const {
return PrintableLoc(use_loc());
}
void OneUse::SetPublicHeaders() {
// We should never need to deal with public headers if we already know
// who we map to.
CHECK_(suggested_header_.empty() && "Should not need a public header here");
const IncludePicker& picker = GlobalIncludePicker(); // short alias
// If the symbol has a special mapping, use it, otherwise map its file.
public_headers_ = picker.GetCandidateHeadersForSymbol(symbol_name_);
if (public_headers_.empty())
public_headers_ = picker.GetCandidateHeadersForFilepathIncludedFrom(
decl_filepath_, GetFilePath(use_loc_));
if (public_headers_.empty())
public_headers_.push_back(ConvertToQuotedInclude(decl_filepath_));
}
const vector<string>& OneUse::public_headers() {
if (public_headers_.empty()) {
SetPublicHeaders();
CHECK_(!public_headers_.empty() && "Should always have at least one hdr");
}
return public_headers_;
}
bool OneUse::PublicHeadersContain(const string& elt) {
// TODO(csilvers): get rid of this method.
return ContainsValue(public_headers(), elt);
}
bool OneUse::NeedsSuggestedHeader() const {
return (!ignore_use() && is_full_use() && suggested_header_.empty());;
}
namespace internal {
// At verbose level 7 and above, returns a printable version of
// the pointer, suitable for being emitted after AnnotatedName.
// At lower verbose levels, returns the empty string.
string PrintablePtr(const void* ptr) {
if (ShouldPrint(7)) {
char buffer[32];
snprintf(buffer, sizeof(buffer), "%p ", ptr);
return buffer;
}
return "";
}
// Helpers for printing a forward declaration of a record type or
// record type template that can be put in source code. The hierarchy
// of the Decl classes used in these helpers looks like:
//
// NamedDecl
// |-- NamespaceDecl
// |-- TemplateDecl
// `-- TypeDecl
// `-- TagDecl (class, struct, union, enum)
// `-- RecordDecl (class, struct, union)
// Given a NamedDecl that presents a (possibly template) record
// (i.e. class, struct, or union) type declaration, and the print-out
// of its (possible) template parameters and kind (e.g. "template
// <typename T> struct"), returns its forward declaration line.
string PrintForwardDeclare(const NamedDecl* decl,
const string& tpl_params_and_kind) {
// We need to short-circuit the logic for testing.
if (const FakeNamedDecl* fake = FakeNamedDeclIfItIsOne(decl)) {
return tpl_params_and_kind + " " + fake->qual_name() + ";";
}
CHECK_((isa<RecordDecl>(decl) || isa<TemplateDecl>(decl)) &&
"IWYU only allows forward declaring (possibly template) record types");
std::string fwd_decl = std::string(decl->getName()) + ";";
bool seen_namespace = false;
for (const DeclContext* ctx = decl->getDeclContext();
ctx && isa<NamedDecl>(ctx); ctx = ctx->getParent()) {
if (const RecordDecl* rec = DynCastFrom(ctx)) {
fwd_decl = std::string(rec->getName()) + "::" + fwd_decl;
} else if (const NamespaceDecl* ns = DynCastFrom(ctx)) {
if (!seen_namespace) {
seen_namespace = true;
fwd_decl = tpl_params_and_kind + " " + fwd_decl;
}
const std::string ns_name = ns->isAnonymousNamespace() ?
"" : (std::string(ns->getName()) + " ");
fwd_decl = "namespace " + ns_name + "{ " + fwd_decl + " }";
} else if (const FunctionDecl* fn = DynCastFrom(ctx)) {
// A local class (class defined inside a function).
fwd_decl = std::string(fn->getName()) + "::" + fwd_decl;
} else {
CHECK_(false && "Unexpected decoration for type");
}
}
if (!seen_namespace) {
fwd_decl = tpl_params_and_kind + " " + fwd_decl;
}
return fwd_decl;
}
// Given a RecordDecl, return the line that could be put in source
// code to forward-declare the record type, e.g. "namespace ns { class Foo; }".
string MungedForwardDeclareLineForNontemplates(const RecordDecl* decl) {
return PrintForwardDeclare(decl, GetKindName(decl));
}
// Given a TemplateDecl representing a class|struct|union template
// declaration, return the line that could be put in source code to
// forward-declare the template, e.g.
// "namespace ns { template <typename T> class Foo; }".
string MungedForwardDeclareLineForTemplates(const TemplateDecl* decl) {
// DeclPrinter prints the class name just as we like it (with
// default args and everything) -- with logic that doesn't exist
// elsewhere in clang that I can see. Unfortunately, it also prints
// the full class body. So, as a hack, we use PrintableDecl to get
// the full declaration, and then hack off everything after the
// template name. We also have to replace the name with the fully
// qualified name. TODO(csilvers): prepend namespaces instead.
std::string line; // llvm wants regular string, not our versa-string
raw_string_ostream ostream(line);
decl->print(ostream); // calls DeclPrinter
line = ostream.str();
string::size_type endpos = line.length();
// Get rid of the superclasses, if any (this will nix the body too).
line = Split(line, " :", 2)[0];
// Get rid of the template body, if any (true if no superclasses).
line = Split(line, " {", 2)[0];
// The template name is now the last word on the line. Replace it
// by its fully-qualified form. Apparently rfind's endpos
// argument is inclusive, so substract one to get past the end-space.
const string::size_type name = line.rfind(' ', endpos - 1);
CHECK_(name != string::npos && "Unexpected printable template-type");
return PrintForwardDeclare(decl, line.substr(0, name));
}
string MungedForwardDeclareLine(const NamedDecl* decl) {
if (const RecordDecl* rec_decl = DynCastFrom(decl))
return MungedForwardDeclareLineForNontemplates(rec_decl);
else if (const TemplateDecl* template_decl = DynCastFrom(decl))
return MungedForwardDeclareLineForTemplates(template_decl);
CHECK_(false && "Unexpected decl type for MungedForwardDeclareLine");
return "<error>";
}
} // namespace internal
OneIncludeOrForwardDeclareLine::OneIncludeOrForwardDeclareLine(
const NamedDecl* fwd_decl)
: line_(internal::MungedForwardDeclareLine(fwd_decl)),
start_linenum_(-1), end_linenum_(-1), // set 'for real' below
is_desired_(false), is_present_(false), symbol_counts_(),
quoted_include_(), fwd_decl_(fwd_decl) {
const SourceRange decl_lines = GetSourceRangeOfClassDecl(fwd_decl);
// We always want to use the instantiation line numbers: for code like
// FORWARD_DECLARE_CLASS(MyClass);
// we care about where this macro is called, not where it's defined.
start_linenum_ = GetLineNumber(GetInstantiationLoc(decl_lines.getBegin()));
end_linenum_ = GetLineNumber(GetInstantiationLoc(decl_lines.getEnd()));
}
OneIncludeOrForwardDeclareLine::OneIncludeOrForwardDeclareLine(
const string& quoted_include, int linenum)
: line_("#include " + quoted_include),
start_linenum_(linenum), end_linenum_(linenum),
is_desired_(false), is_present_(false), symbol_counts_(),
quoted_include_(quoted_include), fwd_decl_(NULL) {
}
bool OneIncludeOrForwardDeclareLine::HasSymbolUse(const string& symbol_name)
const {
return ContainsKey(symbol_counts_, symbol_name);
}
void OneIncludeOrForwardDeclareLine::AddSymbolUse(const string& symbol_name) {
++symbol_counts_[symbol_name];
}
bool OneIncludeOrForwardDeclareLine::IsIncludeLine() const {
// Since we construct line_, we know it's in canonical form, and
// can't look like ' # include <foo.h>' or some such.
return StartsWith(line_, "#include");
}
string OneIncludeOrForwardDeclareLine::LineNumberString() const {
char buf[64]; // big enough for any two numbers
snprintf(buf, sizeof(buf), "%d-%d", start_linenum_, end_linenum_);
return buf;
}
IwyuFileInfo::IwyuFileInfo(const clang::FileEntry* this_file,
const IwyuPreprocessorInfo* preprocessor_info,
const string& quoted_include_name)
: file_(this_file),
preprocessor_info_(preprocessor_info),
quoted_file_(quoted_include_name),
internal_headers_(),
symbol_uses_(),
lines_(),
direct_includes_(),
direct_includes_as_fileentries_(),
direct_forward_declares_(),
desired_includes_(),
desired_includes_have_been_calculated_(false)
{}
void IwyuFileInfo::AddInternalHeader(const IwyuFileInfo* other) {
VERRS(6) << "Adding " << GetFilePath(other->file_)
<< " as internal header for " << GetFilePath(file_) << "\n";
internal_headers_.insert(other);
}
void IwyuFileInfo::AddInclude(const clang::FileEntry* includee,
const string& quoted_includee, int linenumber) {
OneIncludeOrForwardDeclareLine new_include(quoted_includee, linenumber);
new_include.set_present();
// It's possible for the same #include to be seen multiple times
// (for instance, if we include a .h file twice, and that .h file
// does not have a header guard). Ignore all but the first.
// TODO(csilvers): could rewrite this so it's constant-time.
for (Each<OneIncludeOrForwardDeclareLine> line(&lines_); !line.AtEnd();
++line) {
if (line->LineNumbersMatch(new_include)) {
VERRS(6) << "Ignoring repeated include: "
<< GetFilePath(file_) << ":" << linenumber
<< " -> " << GetFilePath(includee) << "\n";
return;
}
}
lines_.push_back(new_include);
// Store in a few other ways as well.
direct_includes_as_fileentries_.insert(includee);
direct_includes_.insert(quoted_includee);
VERRS(6) << "Found include: "
<< GetFilePath(file_) << ":" << linenumber
<< " -> " << GetFilePath(includee) << "\n";
}
void IwyuFileInfo::AddForwardDeclare(const clang::NamedDecl* fwd_decl,
bool definitely_keep_fwd_decl) {
CHECK_(fwd_decl && "forward_declare_decl unexpectedly NULL");
CHECK_((isa<ClassTemplateDecl>(fwd_decl) || isa<RecordDecl>(fwd_decl))
&& "Can only forward declare classes and class templates");
lines_.push_back(OneIncludeOrForwardDeclareLine(fwd_decl));
lines_.back().set_present();
if (definitely_keep_fwd_decl)
lines_.back().set_desired();
direct_forward_declares_.insert(fwd_decl); // store in another way as well
VERRS(6) << "Found forward-declare: "
<< GetFilePath(file_) << ":" << lines_.back().LineNumberString()
<< ": " << internal::PrintablePtr(fwd_decl)
<< internal::GetQualifiedNameAsString(fwd_decl) << "\n";
}
static void LogSymbolUse(const string& prefix, const OneUse& use) {
string decl_loc;
string printable_ptr;
if (use.decl()) {
decl_loc = PrintableLoc(GetLocation(use.decl()));
printable_ptr = internal::PrintablePtr(use.decl());
} else {
decl_loc = use.decl_filepath();
}
VERRS(6) << prefix << " " << printable_ptr << use.symbol_name()
<< " (from " << decl_loc << ")"
<< " at " << use.PrintableUseLoc() << "\n";
}
void IwyuFileInfo::ReportFullSymbolUse(SourceLocation use_loc,
const NamedDecl* decl,
bool in_cxx_method_body,
const char* comment) {
if (decl) {
// Since we need the full symbol, we need the decl's definition-site.
decl = GetDefinitionAsWritten(decl);
symbol_uses_.push_back(OneUse(decl, use_loc, OneUse::kFullUse,
in_cxx_method_body, comment));
LogSymbolUse("Marked full-info use of decl", symbol_uses_.back());
}
}
void IwyuFileInfo::ReportFullSymbolUse(SourceLocation use_loc,
const string& dfn_filepath,
const string& symbol) {
symbol_uses_.push_back(OneUse(symbol, dfn_filepath, use_loc));
LogSymbolUse("Marked full-info use of symbol", symbol_uses_.back());
}
void IwyuFileInfo::ReportIncludeFileUse(const string& quoted_include) {
symbol_uses_.push_back(OneUse("", quoted_include, SourceLocation()));
LogSymbolUse("Marked use of include-file", symbol_uses_.back());
}
void IwyuFileInfo::ReportForwardDeclareUse(SourceLocation use_loc,
const NamedDecl* decl,
bool in_cxx_method_body,
const char* comment) {
if (!decl)
return;
// Sometimes, a bug in clang (http://llvm.org/bugs/show_bug.cgi?id=8669)
// combines friend decls with true forward-declare decls. If that
// happened here, replace the friend with a real fwd decl.
decl = GetNonfriendClassRedecl(decl);
symbol_uses_.push_back(OneUse(decl, use_loc, OneUse::kForwardDeclareUse,
in_cxx_method_body, comment));
LogSymbolUse("Marked fwd-decl use of decl", symbol_uses_.back());
}
// Given a collection of symbol-uses for symbols defined in various
// files, figures out the minimal set of #includes needed to get those
// definitions. Typically this is a trivial task: if we need the full
// information from a decl, we just have to #include the header file
// with the decl's definition. But if that header file is a private
// decl -- e.g. <bits/stl_vector.h> -- we need to map that to a public
// decl first. And if more than one public decl fits the bill, we
// want to pick the one that minimizes the number of new #includes
// added. Stores its results by updating the input vector of
// OneUse's. For convenience, returns the set of "desired" includes:
// all includes that were added to suggested_header.
static void LogIncludeMapping(const string& reason, const OneUse& use) {
VERRS(6) << "Mapped " << use.decl_filepath() << " to "
<< use.suggested_header() << " for " << use.symbol_name()
<< " (" << reason << ")\n";
}
namespace internal {
bool DeclCanBeForwardDeclared(const Decl* decl) {
// Only uses of classes or template classes can be forward-declared.
return isa<RecordDecl>(decl) || isa<ClassTemplateDecl>(decl);
}
// Helper to tell whether a forward-declare use is 'preceded' by a
// declaration inside the same file. 'Preceded' is in quotes, because
// it's actually ok if the declaration follows the use, inside a
// class. (You can write a method using a Foo* before defining the
// nested class Foo later in the class.)
bool DeclIsVisibleToUseInSameFile(const Decl* decl, const OneUse& use) {
if (GetFileEntry(decl) != GetFileEntry(use.use_loc()))
return false;
// If the decl comes before the use, it's visible to it. (The
// decl can also be at the same location as the use, e.g. for
// struct Foo { int x, y; } myvar
// ) It can even be visible if the decl comes after, if the decl
// is inside the class definition and the use is in the body of a
// method.
return (IsBeforeInSameFile(decl, use.use_loc()) ||
GetLocation(decl) == use.use_loc() ||
(DeclsAreInSameClass(decl, use.decl()) && !decl->isOutOfLine()
&& use.in_cxx_method_body()));
}
// This makes a best-effort attempt to find the smallest set of
// #include files that satisfy all uses. A more accurate name
// might be "calculate minimal-ish includes". :-) It populates
// each OneUse in uses with the best #include for that use.
// direct_includes: this file's direct includes only.
// associated_direct_includes: direct includes for 'associated'
// files. For everything but foo.cc, this is empty; for foo.cc it's
// foo.h's includes and foo-inl.h's includes.
set<string> CalculateMinimalIncludes(
const set<string>& direct_includes,
const set<string>& associated_direct_includes,
vector<OneUse>* uses) {
set<string> desired_headers;
// TODO(csilvers): if a use's decl supports equivalent redecls
// (such as a FunctionDecl or TypedefDecl), pick the redecl
// that yields the "best" #include.
// Step (1) The easy case: decls that map to just one file. This
// captures both decls that aren't in private header files, and
// those in private header files that only map to one public file.
// For every other decl, we store the (decl, public-headers) pair.
// Note we can't use Each<> because it only gives const iterators.
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
// We don't need to add any #includes for non-full-use.
if (it->ignore_use() || !it->is_full_use())
continue;
// Special case #1: Some uses come with a suggested header already picked.
if (it->has_suggested_header()) {
desired_headers.insert(it->suggested_header());
continue;
}
// Special case #2: if the dfn-file maps to the use-file, then
// this is a file that the use-file is re-exporting symbols for,
// and we should keep the #include as-is.
const string use_file = ConvertToQuotedInclude(GetFilePath(it->use_loc()));
if (it->PublicHeadersContain(use_file)) {
it->set_suggested_header(ConvertToQuotedInclude(it->decl_filepath()));
desired_headers.insert(it->suggested_header());
LogIncludeMapping("private header", *it);
} else if (it->public_headers().size() == 1) {
it->set_suggested_header(it->public_headers()[0]);
desired_headers.insert(it->suggested_header());
LogIncludeMapping("only candidate", *it);
}
}
// Steps (2): Go through the needed private-includes that map to
// more than one public #include. First choice: an include in
// associated_direct_includes (those are includes that are not going
// away, since we can't change associated files). Second choice,
// includes in direct_includes that are also already in
// desired_headers. Third choice, includes in desired_headers.
// Fourth choice, includes in direct_includes. Picking in
// this order minimizes the number of #includes we add, while
// allowing us to remove #includes if need be.
for (vector<OneUse>::iterator use = uses->begin();
use != uses->end(); ++use) {
if (!use->NeedsSuggestedHeader())
continue;
const vector<string>& public_headers = use->public_headers();
// TODO(csilvers): write ElementInBoth() in iwyu_stl_util.h
for (Each<string> choice(&public_headers);
!use->has_suggested_header() && !choice.AtEnd(); ++choice) {
if (ContainsKey(associated_direct_includes, *choice)) {
use->set_suggested_header(*choice);
desired_headers.insert(use->suggested_header());
LogIncludeMapping("in associated header", *use);
}
}
for (Each<string> choice(&public_headers);
!use->has_suggested_header() && !choice.AtEnd(); ++choice) {
if (ContainsKey(direct_includes, *choice) &&
ContainsKey(desired_headers, *choice)) {
use->set_suggested_header(*choice);
desired_headers.insert(use->suggested_header());
LogIncludeMapping("#include already present and needed", *use);
}
}
for (Each<string> choice(&public_headers);
!use->has_suggested_header() && !choice.AtEnd(); ++choice) {
if (ContainsKey(desired_headers, *choice)) {
use->set_suggested_header(*choice);
desired_headers.insert(use->suggested_header());
LogIncludeMapping("#include already needed", *use);
}
}
for (Each<string> choice(&public_headers);
!use->has_suggested_header() && !choice.AtEnd(); ++choice) {
if (ContainsKey(direct_includes, *choice)) {
use->set_suggested_header(*choice);
desired_headers.insert(use->suggested_header());
LogIncludeMapping("#include already present", *use);
}
}
}
// Step (3): Now we have a set-cover problem: we need to end up with
// a set of headers, called cover, so that for every i:
// intersection(cover, public_headers[i]) != empty_set
// We do this greedily: we find the header that's listed the most
// often. Among those, we prefer the one that's listed first in
// public_headers[i] the most often (each list is in approximate
// best-fit order). Among those, we choose arbitrarily. We repeat
// until we cover all sets.
set<OneUse*> unmapped_uses;
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
if (it->NeedsSuggestedHeader())
unmapped_uses.insert(&*it);
}
while (!unmapped_uses.empty()) {
map<string, pair<int,int> > header_counts; // total appearances, 1st's
for (Each<OneUse*> use(&unmapped_uses); !use.AtEnd(); ++use) {
CHECK_(!(*use)->has_suggested_header());
const vector<string>& public_headers = (*use)->public_headers();
for (Each<string> choice(&public_headers);
!(*use)->has_suggested_header() && !choice.AtEnd(); ++choice) {
++header_counts[*choice].first; // increment total count
if (*choice == (*use)->public_headers()[0])
++header_counts[*choice].second; // increment first-in-list count
}
}
pair<string, pair<int, int> > best = *header_counts.begin();
for (Each<string, pair<int, int> > it(&header_counts); !it.AtEnd(); ++it) {
if (it->second > best.second) // uses pair<>'s operator> to order for us
best = *it;
}
const string hdr = best.first;
desired_headers.insert(hdr);
// Now go through and assign to symbols satisfied by this header.
for (set<OneUse*>::iterator it = unmapped_uses.begin();
it != unmapped_uses.end(); ) {
if ((*it)->NeedsSuggestedHeader() && (*it)->PublicHeadersContain(hdr)) {
(*it)->set_suggested_header(hdr);
LogIncludeMapping("set cover", *(*it));
// set<> has nice property that erasing doesn't invalidate iterators.
unmapped_uses.erase(it++); // because we just mapped it!
} else {
++it;
}
}
}
return desired_headers;
}
// Calculating iwyu violations is a multi-step process. The basic
// idea is we trim the existing uses to ones that might plausibly be
// iwyu violations, for both forward-declares (A) and full uses (B).
// Then we calculate the desired (end-result) set of #includes (C).
// After that we can do suggested trimming, with knowledge of all
// #includes, to reduce to full-use (D) and forward-declare uses (E)
// that are actually iwyu violations.
//
// Trimming forward-declare uses (1st pass):
// A1) If not a class or a templated class, recategorize as a full use.
// A2) If a templated class with default template params, recategorize
// as a full use (forward-declaring in that case is too error-prone).
// A3) If a symbol in std, __gnu_cxx, or another system namespace,
// recategorize as a full use. This is entirely a policy
// decision: we've decided never to forward-declare anything in
// a system namespace, because it's best not to expose the internals
// of system headers in user code, if possible.
// A4) If the file containing the use has a pragma inhibiting the forward
// declaration of the symbol, change the use to a full info use in order
// to make sure that the compiler can see some declaration of the symbol.
// A5) If a nested class, discard this use (the parent class declaration
// is sufficient).
// A6) If any of the redeclarations of this declaration is in the same
// file as the use (and before it), and is actually a definition,
// discard the forward-declare use.
// Trimming symbol uses (1st pass):
// B1) If the definition of a full use comes after the use, change the
// full use to a forward-declare use that points to a fwd-decl
// that comes before the use. (This is for cases like typedefs
// where iwyu demands a full use but the language allows a
// forward-declare.)
// B2) Discard symbol uses of a symbol defined in the same file it's used.
// If the symbol is an enum, typedef, function, or var -- every decl
// that is re-declarable except for RecordDecl -- discard if *any*
// declaration is in the same file as the use.
// B3) Discard symbol uses for builtin symbols ('__builtin_memcmp') and
// for operator new and operator delete (excluding placement new),
// which are effectively built-in even though they're in <new>.
// B4) Discard symbol uses for member functions that live in the same
// file as the class they're part of (the parent check suffices).
// B5) Sanity check: Discard 'backwards' #includes. These are
// #includes where we say a.h should #include b.h, but b.h is
// already #including a.h. This happens when iwyu attributes a
// use to the wrong file.
// B6) In --transitive_includes_only mode, discard 'new' #includes.
// These are #includes where we say a.h should #include b.h, but
// a.h does not see b.h in its transitive #includes. (Note: This
// happens before include-picker mapping, so it's still possible to
// see 'new' includes via a manual mapping.)
// B1') Discard macro uses in the same file as the definition (B2 redux).
// B2') Discard macro uses that form a 'backwards' #include (B5 redux).
// B3') Discard macro uses from a 'new' #include (B6 redux).
// Determining 'desired' #includes:
// C1) Get a list of 'effective' direct includes. For most files, it's
// the same as the actual direct includes, but for the main .cc
// file it also gets 'free' includes from its associated .h files.
// C2) For each symbol-use, calculate the set of public header files that
// 'provide' that symbol (e.g. <stddef.h> and <stdlib.h> for NULL).
// C3) Find the minimal 'set cover' over these sets: find a "add-minimal"
// collection of files that has overlap with every set from (1).
// "Add-minimal" means that the collection should have as few
// files in it as possible *that we are not already #including*.
// C4) Sanity check: remove any .cc files from desired-includes unless
// they're already in actual-includes.
//
// Calculate IWYU violations for forward-declares:
// D1) If the definition of the forward-declaration lives in a desired
// include, or any redecl lives in the current file (and earlier
// in the file), reassign decl_ to point to that redecl; if the
// decl is not in the current file, mark the filename the decl
// comes from.
// D2) If the definition is not in current includes, and no redecl is
// in the current file (and earlier in the file), mark as an iwyu
// violation.
//
// Calculate IWYU violations for full uses:
// E1) Sanity check: ignore the use if it would require adding an
// #include of a .cc file.
// E2) If the desired include-file for this symbols is not in the
// current includes, mark as an iwyu violation.
void ProcessForwardDeclare(OneUse* use,
const IwyuPreprocessorInfo* preprocessor_info) {
CHECK_(use->decl() && "Must call ProcessForwardDeclare on a decl");
CHECK_(!use->is_full_use() && "Must call ProcessForwardDeclare on fwd-decl");
if (use->ignore_use()) // we're already ignoring it
return;
// (A1) If not a class or a templated class, recategorize as a full use.
if (!DeclCanBeForwardDeclared(use->decl())) {
VERRS(6) << "Moving " << use->symbol_name()
<< " from fwd-decl use to full use: not a class"
<< " (" << use->PrintableUseLoc() << ")\n";
use->set_full_use();
return;
}
// This is useful for the subsequent tests -- let's normalize some types.
const RecordDecl* record_decl = DynCastFrom(use->decl());
const ClassTemplateDecl* tpl_decl = DynCastFrom(use->decl());
const ClassTemplateSpecializationDecl* spec_decl = DynCastFrom(use->decl());
if (spec_decl)
tpl_decl = spec_decl->getSpecializedTemplate();
if (tpl_decl)
record_decl = tpl_decl->getTemplatedDecl();
// (A2) If it has default template parameters, recategorize as a full use.
// Suppress this if there's no definition for this class (so can't full-use).
if (tpl_decl && HasDefaultTemplateParameters(tpl_decl) &&
GetDefinitionForClass(tpl_decl) != NULL) {
VERRS(6) << "Moving " << use->symbol_name()
<< " from fwd-decl use to full use: has default template param"
<< " (" << use->PrintableUseLoc() << ")\n";
use->set_full_use();
// No return here: (A4) or (A5) may cause us to ignore this decl entirely.
}
// (A3) If it is in namespace std or a system ns, recategorize as a full use.
// We can add new system namespaces here as needed.
// TODO(csilvers): if someone has specialized a class in std, the
// specialization should be treated as in user-space and
// forward-declarable. Check for that case.
if (StartsWith(use->symbol_name(), "std::") ||
StartsWith(use->symbol_name(), "__gnu_cxx::")) {
VERRS(6) << "Moving " << use->symbol_name()
<< " from fwd-decl use to full use: in a system namespace "
<< " (" << use->PrintableUseLoc() << ")\n";
use->set_full_use();
// No return here: (A4) or (A5) may cause us to ignore this decl entirely.
}
// (A4) If the file containing the use has a pragma inhibiting the forward
// declaration of the symbol, change the use to a full info use in order
// to make sure that the compiler can see some declaration of the symbol.
if (!use->is_full_use()) {
if (preprocessor_info->ForwardDeclareIsInhibited(
GetFileEntry(use->use_loc()), use->symbol_name())) {
VERRS(6) << "Changing fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc()
<< ") to a full-info use: no_forward_declare pragma\n";
use->set_full_use();
}
}
// (A5) If using a nested class, discard this use.
if (IsNestedClass(record_decl)) {
// iwyu will require the full type of the parent class when it
// recurses on the qualifier (any use of Foo::Bar requires the
// full type of Foo). So if we're forward-declared inside Foo,
// the user will get that forward-declaration for free when
// it gets the full definition of Foo. The one exception is
// when the use is itself inside the class, in which case it
// sometimes needs the forward-declaration: for instance
// class Foo { class Nested; Nested* Fn(); class Nested { ... } };
// This exception applies only when the use is in the same class
// as the decl; we'll be conservative and apply it whenever
// they're in the same file.
if (GetFileEntry(use->use_loc()) != GetFileEntry(use->decl())) {
VERRS(6) << "Ignoring fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): nested class\n";
use->set_ignore_use();
return;
}
}
// (A6) If a definition exists earlier in this file, discard this use.
// Note: for the 'earlier' checks, what matters is the *instantiation*
// location.
const set<const NamedDecl*> redecls = GetClassRedecls(record_decl);
for (Each<const NamedDecl*> it(&redecls); !it.AtEnd(); ++it) {
CHECK_(isa<RecordDecl>(*it) && "GetClassRedecls has redecls of wrong type");
const SourceLocation defined_loc = GetLocation(*it);
if (cast<RecordDecl>(*it)->isCompleteDefinition() &&
DeclIsVisibleToUseInSameFile(*it, *use)) {
VERRS(6) << "Ignoring fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): dfn is present: "
<< PrintableLoc(defined_loc) << "\n";
use->set_ignore_use();
return;
}
}
}
void ProcessFullUse(OneUse* use,
const IwyuPreprocessorInfo* preprocessor_info) {
CHECK_(use->decl() && "Must call ProcessFullUse on a decl");
CHECK_(use->is_full_use() && "Must not call ProcessFullUse on fwd-decl");
if (use->ignore_use()) // we're already ignoring it
return;
// (B1) If the definition is after the use, re-point to a prior decl.
// If iwyu followed the language precisely, this wouldn't be
// necessary: code wouldn't compile if a full-use didn't have the
// definition handy yet. But in fact, iwyu sometimes requires a full
// type when the language doesn't, notably with typedefs. For code
// like 'struct f; typedef f g; struct f {};', iwyu will say the
// typedef requires a definition of f, and as a result will say the
// forward-decl is unnecessary (who cares about forward-decls when
// we need a definition?), when in fact it's crucial.
// For now, we assume a 'later' usage must be in the same file.
if (GetFileEntry(use->use_loc()) == GetFileEntry(use->decl()) &&
!DeclIsVisibleToUseInSameFile(use->decl(), *use) &&
DeclCanBeForwardDeclared(use->decl())) {
if (preprocessor_info->ForwardDeclareIsInhibited(
GetFileEntry(use->use_loc()), use->symbol_name())) {
// There is no include we could recommend for any full use, so just
// ignore the use.
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< ": definition found later in file"
<< " and no_forward_declare pragma present("
<< use->PrintableUseLoc() << ")\n";
use->set_ignore_use();
return;
}
// Just change us to a forward-declare use. Later, we'll decide
// which forward-declare is the best one to keep.
VERRS(6) << "Moving " << use->symbol_name()
<< " from full use to fwd-decl: definition found later in file"
<< " (" << use->PrintableUseLoc() << ")\n";
use->set_forward_declare_use();
return;
}
// (B2) Discard symbol uses of a symbol defined in the same file it's used.
// If the symbol can be declared in multiple places, we count it if
// *any* declaration is in the same file, unless the symbol is a
// class. (Every other kind of redeclarable symbol, such as
// functions, have the property that a decl is the same as a
// definition from iwyu's point of view.) We don't bother with
// RedeclarableTemplate<> types (FunctionTemplateDecl), since for
// those types, iwyu *does* care about the definition vs declaration.
set<const NamedDecl*> all_redecls;
if (isa<RecordDecl>(use->decl()) || isa<ClassTemplateDecl>(use->decl()))
all_redecls.insert(use->decl()); // for classes, just consider the dfn
else
all_redecls = GetNonclassRedecls(use->decl());
for (Each<const NamedDecl*> it(&all_redecls); !it.AtEnd(); ++it) {
if (DeclIsVisibleToUseInSameFile(*it, *use)) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): definition is present: "
<< PrintableLoc(GetLocation(use->decl())) << "\n";
use->set_ignore_use();
return;
}
}
// (B3) Discard symbol uses for builtin symbols, including new/delete.
// TODO(csilvers): we could use getBuiltinID(), but it returns
// non-zero for things like malloc. Figure out how to use it.
if (const FunctionDecl* fn_decl = DynCastFrom(use->decl())) {
if (StartsWith(use->symbol_name(), "__builtin_")) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): built-in function\n";
use->set_ignore_use();
return;
}
const string dfn_file = GetFilePath(fn_decl);
if (IsDefaultNewOrDelete(fn_decl, ConvertToQuotedInclude(dfn_file))) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): built-in new/delete\n";
use->set_ignore_use();
return;
}
}
// (B4) Discard symbol uses for member functions in the same file as parent.
if (const CXXMethodDecl* method_dfn = DynCastFrom(use->decl())) {
// See if we also recorded a use of the parent.
const NamedDecl* parent_dfn
= GetDefinitionAsWritten(method_dfn->getParent());
// We want to map the definition-files to their public headers if
// they're private headers (so bits/stl_vector.h and
// bits/vector.tcc are counted as the "same" file for this test).
// To be safe, we only do the mapping if both files have at most
// one public file they map to (otherwise we don't know which
// mapping to choose, and it's important we use the one that iwyu
// will pick later). TODO(csilvers): figure out that case too.
const IncludePicker& picker = GlobalIncludePicker();
const vector<string>& method_dfn_files
= picker.GetCandidateHeadersForFilepath(GetFilePath(method_dfn));
const vector<string>& parent_dfn_files
= picker.GetCandidateHeadersForFilepath(GetFilePath(parent_dfn));
bool same_file;
if (method_dfn_files.size() == 1 && parent_dfn_files.size() == 1) {
same_file = (method_dfn_files[0] == parent_dfn_files[0]);
} else {
// Fall back on just checking the filenames: can't figure out public.
same_file = (GetFileEntry(method_dfn) == GetFileEntry(parent_dfn));
}
if (same_file) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): member of class\n";
use->set_ignore_use();
return;
}
}
// (B5) Discard uses of symbols that form a 'backwards' #include.
// This means that we say a.h is using a symbol in b.h, but b.h
// already #includes a.h (either directly or indirectly). Since the
// include graph should be acyclic, this means that iwyu messed up,
// either by incorrectly saying it was a.h that is using the symbol
// (this can happen trying to figure out who 'owns' macro code), or
// by incorrectly saying it was a use (this can happen with typedefs
// -- we say the underlying type is 'used' in a different way than
// the language requires).
// TODO(csilvers): remove this when we resolve the bugs with macros/typedefs.
if (preprocessor_info->FileTransitivelyIncludes(
GetFileEntry(use->decl()), GetFileEntry(use->use_loc()))) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): 'backwards' #include\n";
use->set_ignore_use();
return;
}
// (B6) In --transitive_includes_only mode, discard 'new' #includes.
// In practice, if we tell a.h to add an #include that is not in its
// transitive includes, it's usually (but not always) an iwyu error
// of some sort. So we allow a flag to discard such recommendations.
if (GlobalFlags().transitive_includes_only) {
if (!preprocessor_info->FileTransitivelyIncludes(
GetFileEntry(use->use_loc()), GetFileEntry(use->decl()))) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "):"
<< " non-transitive #include\n";
use->set_ignore_use();
return;
}
}
}
void ProcessSymbolUse(OneUse* use,
const IwyuPreprocessorInfo* preprocessor_info) {
if (use->ignore_use()) // we're already ignoring it
return;
const FileEntry* use_file = GetFileEntry(use->use_loc());
const string quoted_decl_file = ConvertToQuotedInclude(use->decl_filepath());
// (B1') Like (B2), discard symbol uses in the same file as their definition.
if (GetFilePath(use->use_loc()) == use->decl_filepath()) {
VERRS(6) << "Ignoring symbol use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): defined in same file\n";
use->set_ignore_use();
return;
}
// (B2') Like (B5), discard uses of symbols that create 'backwards' includes.
// Note we suppress this check if suggested_header_ is already set:
// that only happens with hard-coded uses, which we shouldn't second guess.
// TODO(csilvers): like (B5), remove this when we have 'soft' uses.
if (!use->has_suggested_header() &&
preprocessor_info->FileTransitivelyIncludes(quoted_decl_file, use_file)) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): 'backwards' #include\n";
use->set_ignore_use();
return;
}
// (B3') Like (B6), discard uses of symbols that create 'new' includes.
if (GlobalFlags().transitive_includes_only) {
if (!use->has_suggested_header() &&
!preprocessor_info->FileTransitivelyIncludes(use_file,
quoted_decl_file)) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "):"
<< " non-transitive #include\n";
use->set_ignore_use();
return;
}
}
}
void CalculateIwyuForForwardDeclareUse(
OneUse* use,
const set<string>& actual_includes,
const set<string>& desired_includes,
const set<const FileEntry*>& associated_includes) {
CHECK_(!use->ignore_use() && "Trying to calculate on an ignored use");
CHECK_(use->decl() && "CalculateIwyuForForwardDeclareUse takes a fwd-decl");
CHECK_(!use->is_full_use() && "ForwardDeclareUse are not full uses");
const NamedDecl* same_file_decl = NULL;
const RecordDecl* record_decl = DynCastFrom(use->decl());
const ClassTemplateDecl* tpl_decl = DynCastFrom(use->decl());
const ClassTemplateSpecializationDecl* spec_decl = DynCastFrom(use->decl());
if (spec_decl)
tpl_decl = spec_decl->getSpecializedTemplate();
if (tpl_decl)
record_decl = tpl_decl->getTemplatedDecl();
CHECK_(record_decl && "Non-records should have been handled already");
// If this record is defined in one of the desired_includes, mark that
// fact. Also if it's defined in one of the actual_includes.
const NamedDecl* dfn = GetDefinitionForClass(use->decl());
// If we are, ourselves, a template specialization, then the definition
// we use is not the definition of the specialization (that's us), but
// the definition of the template we're specializing.
if (spec_decl && dfn == spec_decl)
dfn = GetDefinitionForClass(spec_decl->getSpecializedTemplate());
bool dfn_is_in_desired_includes = false;
bool dfn_is_in_actual_includes = false;
if (dfn) {
vector<string> headers
= GlobalIncludePicker().GetCandidateHeadersForFilepathIncludedFrom(
GetFilePath(dfn), GetFilePath(use->use_loc()));
for (Each<string> header(&headers); !header.AtEnd(); ++header) {
if (ContainsKey(desired_includes, *header))
dfn_is_in_desired_includes = true;
if (ContainsKey(actual_includes, *header))
dfn_is_in_actual_includes = true;
}
// We ourself are always a 'desired' and 'actual' include (though
// only if the definition is visible from the use location).
if (DeclIsVisibleToUseInSameFile(dfn, *use)) {
dfn_is_in_desired_includes = true;
dfn_is_in_actual_includes = true;
}
}
// We also want to know if *any* redecl of this record is defined
// in the same file as the use (and before it).
const set<const NamedDecl*>& redecls = GetClassRedecls(record_decl);
for (Each<const NamedDecl*> it(&redecls); !it.AtEnd(); ++it) {
if (DeclIsVisibleToUseInSameFile(*it, *use)) {
same_file_decl = *it;
break;
}
}
// If there's no redecl in the .cc file, we'll accept a redecl in
// an associated .h file. Since associated .h files are always
// desired includes, we don't need to check for that.
if (!same_file_decl) {
for (Each<const NamedDecl*> it(&redecls); !it.AtEnd(); ++it) {
if (ContainsKey(associated_includes, GetFileEntry(*it))) {
same_file_decl = *it;
break;
}
}
}
// (D1) Mark that the fwd-declare is satisfied by dfn in desired include.
const NamedDecl* providing_decl = NULL;
if (dfn_is_in_desired_includes) {
providing_decl = dfn;
VERRS(6) << "Noting fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << ") is satisfied by dfn in "
<< PrintableLoc(GetLocation(providing_decl)) << "\n";
// Mark that this use is another reason we want this header.
const string file = GetFilePath(dfn);
const string quoted_hdr = ConvertToQuotedInclude(file);
use->set_suggested_header(quoted_hdr);
} else if (same_file_decl) {
providing_decl = same_file_decl;
VERRS(6) << "Noting fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << ") is declared at "
<< PrintableLoc(GetLocation(providing_decl)) << "\n";
// If same_file_decl is actually in an associated .h, mark our use
// of that. No need to map-to-public for associated .h files.
if (GetFileEntry(same_file_decl) != GetFileEntry(use->use_loc()))
use->set_suggested_header(GetFilePath(same_file_decl));
}
if (providing_decl) {
// Change decl_ to point to this "better" redecl.
use->reset_decl(providing_decl);
}
// Be sure to store as a TemplateClassDecl if we're a templated
// class.
if (const ClassTemplateSpecializationDecl* spec_decl
= DynCastFrom(use->decl())) {
use->reset_decl(spec_decl->getSpecializedTemplate());
} else if (const CXXRecordDecl* cxx_decl = DynCastFrom(use->decl())) {
if (cxx_decl->getDescribedClassTemplate())
use->reset_decl(cxx_decl->getDescribedClassTemplate());
}
// (D2) Mark iwyu violation unless defined in a current #include.
if (dfn_is_in_actual_includes) {
VERRS(6) << "Ignoring fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): have definition at "
<< PrintableLoc(GetLocation(dfn)) << "\n";
} else if (same_file_decl) {
VERRS(6) << "Ignoring fwd-decl use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): have earlier fwd-decl at "
<< PrintableLoc(GetLocation(same_file_decl)) << "\n";
} else {
use->set_is_iwyu_violation();
}
}
void CalculateIwyuForFullUse(OneUse* use,
const set<string>& actual_includes,
const set<string>& desired_includes) {
CHECK_(!use->ignore_use() && "Trying to calculate on an ignored use");
CHECK_(use->is_full_use() && "CalculateIwyuForFullUse requires a full use");
CHECK_(use->has_suggested_header() && "All full uses must have a header");
// (E1) Discard uses of a symbol declared in a .cc and used
// elsewhere. Unless that 'elsewhere' is #including the .cc file,
// then something is wrong: we're using a symbol from a file we
// can't possibly be #including. There are several ways this could
// happen:
// (1)
// foo.h: #ifdef FOO ...
// foo-inl.cc: #define FOO
// foo.cc: #include "foo-inl.cc"
// #include "foo.h" // foo.h 'uses' FOO from foo-inl.cc
// (Though this is arguably a bug in iwyu, and FOO should be treated as
// a 'soft' use here; see comments in iwyu_preprocessor.cc:ReportMacroUse.)
// (2)
// foo.h: #define DEFINE_CLASS(classname) <backslash>
// struct classname { classname() { Init(); } void Init() {} }
// foo.cc: DEFINE_CLASS(Foo);
// iwyu will say "Init() is a member function, so say we need the
// full type information of the method's class." The method's class
// is Foo, which iwyu correctly declares lives in foo.cc. But
// iwyu also correctly says that Init() lives in foo.h (Except for
// the macro arguments, macro code belongs to the macro definer,
// not to every macro caller). Put those together, though, and
// iwyu says foo.h needs to #include foo.cc.
// TODO(csilvers): it's probably more correct to check if
// suggested_header() is in the transitive closure of actual_includes.
// TODO(csilvers): this could cause breakage for code like this:
// x.cc: class X {};
// y.h: #include "x.cc"
// z.cc: #include "y.h"; X x;
// iwyu will say 'replace the #include of y.h with an #include of
// x.cc,' which the code below will then strip. The end result is
// z.cc will not #include anything, and will fail to compile.
if (!IsHeaderFile(use->suggested_header()) &&
!ContainsKey(actual_includes, use->suggested_header())) {
VERRS(6) << "Ignoring use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): #including .cc\n";
use->set_ignore_use();
return;
}
// (E2) Mark iwyu violation unless in a current #include.
if (ContainsKey(actual_includes, use->suggested_header())) {
VERRS(6) << "Ignoring full use of " << use->symbol_name()
<< " (" << use->PrintableUseLoc() << "): #including dfn from "
<< use->suggested_header() << "\n";
} else {
use->set_is_iwyu_violation();
}
}
} // namespace internal
void IwyuFileInfo::CalculateIwyuViolations(vector<OneUse>* uses) {
VERRS(6) << "--- Calculating IWYU violations for "
<< GetFilePath(file_) << " ---\n";
// We have to do the steps in order, because a forward-declare use may
// turn into a full use, and need to be processed in the full-use step
// too. Note we can't use Each<> because it returns a const-iterator.
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
if (!it->is_full_use() && it->decl())
internal::ProcessForwardDeclare(&*it, preprocessor_info_);
}
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
if (it->is_full_use() && it->decl())
internal::ProcessFullUse(&*it, preprocessor_info_);
}
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
if (it->is_full_use() && !it->decl())
internal::ProcessSymbolUse(&*it, preprocessor_info_);
}
// (C1) Compute the direct includes of 'associated' files.
set<string> associated_direct_includes;
for (Each<const IwyuFileInfo*> it(&internal_headers_); !it.AtEnd(); ++it) {
ReportIncludeFileUse((*it)->quoted_file_);
InsertAllInto((*it)->direct_includes(), &associated_direct_includes);
}
// The 'effective' direct includes are defined to be the current
// includes of associated, plus us. This is only used to decide
// when to give iwyu warnings.
const set<string> effective_direct_includes
= Union(associated_direct_includes, direct_includes());
// (C2) + (C3) Find the minimal 'set cover' for all symbol uses.
const set<string>& desired_set_cover = internal::CalculateMinimalIncludes(
direct_includes(), associated_direct_includes, uses);
// (C4) Remove .cc files from desired-includes unless they're in actual-inc.
for (Each<string> it(&desired_set_cover); !it.AtEnd(); ++it) {
if (IsHeaderFile(*it) || ContainsKey(direct_includes(), *it))
desired_includes_.insert(*it);
}
desired_includes_have_been_calculated_ = true;
// The 'effective' desired includes are defined to be the desired
// includes of associated, plus us. These are used to decide if a
// particular use will be satisfied after fixing the #includes.
// NOTE: this depends on our internal headers having had their
// iwyu analysis done before us.
set<string> effective_desired_includes = desired_includes();
for (Each<const IwyuFileInfo*> it(&internal_headers_); !it.AtEnd(); ++it)
InsertAllInto((*it)->desired_includes(), &effective_desired_includes);
// Now that we've figured out desired_includes, figure out iwyu violations.
for (vector<OneUse>::iterator it = uses->begin(); it != uses->end(); ++it) {
if (it->ignore_use()) {
// Do nothing, we're ignoring the use
} else if (!it->is_full_use()) {
internal::CalculateIwyuForForwardDeclareUse(
&*it, effective_direct_includes, effective_desired_includes,
AssociatedFileEntries());
} else {
internal::CalculateIwyuForFullUse(
&*it, effective_direct_includes, effective_desired_includes);
}
}
}
static string GetWarningMsg(const OneUse& use) {
const FullSourceLoc spelling_loc = GetSpellingLoc(use.use_loc());
const FullSourceLoc instantiation_loc = GetInstantiationLoc(use.use_loc());
string warning = PrintableLoc(spelling_loc) + ": warning: ";
if (use.is_full_use()) {
warning += (use.symbol_name() + " is defined in " + use.suggested_header()
+ ", which isn't directly #included");
} else {
warning += (use.symbol_name() + " needs a declaration"
+ ", but does not provide or directly #include one");
}
if (!use.comment().empty()) {
warning += " " + use.comment();
}
warning += ".\n";
if (instantiation_loc != spelling_loc) {
// Only set/print this if it's different from the spelling location.
warning += PrintableLoc(instantiation_loc) + ": note: used here.\n";
}
return warning;
}
int IwyuFileInfo::EmitWarningMessages(const vector<OneUse>& uses) {
set<pair<int, string> > iwyu_warnings; // line-number, warning-msg.
for (Each<OneUse> it(&uses); !it.AtEnd(); ++it) {
if (it->is_iwyu_violation())
iwyu_warnings.insert(make_pair(it->UseLinenum(), GetWarningMsg(*it)));
}
// Nice that set<> automatically sorts things for us!
for (Each<pair<int, string> > it(&iwyu_warnings); !it.AtEnd(); ++it) {
if (ShouldPrint(3)) {
errs() << it->second;
} else if (ShouldPrint(2)) {
// TODO(csilvers): print one warning per sym per file.
}
}
return iwyu_warnings.size();
}
namespace internal {
void CalculateDesiredIncludesAndForwardDeclares(
const vector<OneUse>& uses,
const set<string>& associated_desired_includes,
vector<OneIncludeOrForwardDeclareLine>* lines) {
// We'll want to be able to map from decl or fwd-declare to the
// line where we found it. We store an index into lines.
map<string, int> include_map;
map<const NamedDecl*, int> fwd_decl_map;
int index = 0;
for (Each<OneIncludeOrForwardDeclareLine> it(lines); !it.AtEnd(); ++it) {
if (it->IsIncludeLine())
include_map[it->quoted_include()] = index;
else
fwd_decl_map[it->fwd_decl()] = index;
++index;
}
for (Each<OneUse> use(&uses); !use.AtEnd(); ++use) {
if (use->ignore_use())
continue;
// Update the appropriate map depending on the type of use.
if (use->is_full_use()) {
CHECK_(use->has_suggested_header() && "Full uses should have #includes");
if (!ContainsKey(include_map, use->suggested_header())) { // must be added
lines->push_back(OneIncludeOrForwardDeclareLine(use->suggested_header(),
-1));
include_map[use->suggested_header()] = lines->size() - 1;
}
const int index = include_map[use->suggested_header()];
(*lines)[index].set_desired();
(*lines)[index].AddSymbolUse(use->short_symbol_name());
// Forward-declare uses that are already satisfied by an #include
// have that as their suggested_header. For the rest, we need to
// make sure there's a forward-declare in the current file.
} else if (!use->has_suggested_header()) {
if (!ContainsKey(fwd_decl_map, use->decl())) { // must be added
lines->push_back(OneIncludeOrForwardDeclareLine(use->decl()));
// The OneIncludeOrForwardDeclareLine ctor sets up line
// numbers, but they're for some other file! Clear them.
lines->back().clear_line_numbers();
fwd_decl_map[use->decl()] = lines->size() - 1;
}
const int index = fwd_decl_map[use->decl()];
(*lines)[index].set_desired();
}
}
// If we satisfy a forward-declare use from a file, let the file
// know (this is just for logging). We do this after the above so
// we can make sure include_map is fully populated -- we don't want
// to bother with a "(ptr only)" use if there's already a full use.
for (Each<OneUse> use(&uses); !use.AtEnd(); ++use) {
if (!use->ignore_use() && !use->is_full_use() && use->has_suggested_header()
&& ContainsKey(include_map, use->suggested_header())) {
const string symbol_name = use->short_symbol_name();
const int index = include_map[use->suggested_header()];
if (!(*lines)[index].HasSymbolUse(symbol_name))
(*lines)[index].AddSymbolUse(symbol_name + " (ptr only)");
}
}
// If we #include a .h through an associated file (foo.h) rather
// than directly (foo.cc), we don't want to say that .h is desired
// -- that will cause us to add it when it's unnecessary. We could
// choose to actually *remove* the .h here if it's present, to keep
// #includes to a minimum, but for now we just decline to add it.
for (vector<OneIncludeOrForwardDeclareLine>::iterator
it = lines->begin(); it != lines->end(); ++it) {
if (it->is_desired() && !it->is_present() && it->IsIncludeLine() &&
ContainsKey(associated_desired_includes, it->quoted_include())) {
it->clear_desired();
}
}
}
// Used by GetSymbolsSortedByFrequency().
class CountGt {
public:
bool operator()(const pair<string, int>& a,
const pair<string, int>& b) const {
if (a.second != b.second)
return a.second > b.second; // sort by decreasing count
return a.first < b.first; // within a count, sort alphabetically
}
};
// Given a map from string to count, creates a vector of the string
// keys, sorted by decreasing count (highest first), then alphabetically.
// We also can take a vector of forward-declared symbols used by this
// file. For all symbols in this vector but not in m, we add them to
// the end of the output as well, with a "(ptr only)" suffix.
vector<string> GetSymbolsSortedByFrequency(const map<string, int>& m) {
vector<pair<string, int> > count_vector(m.begin(), m.end());
sort(count_vector.begin(), count_vector.end(), CountGt());
vector<string> retval;
for (Each<pair<string, int> > i(&count_vector); !i.AtEnd(); ++i)
retval.push_back(i->first);
return retval;
}
// A helper function that returns one line of the desired-includes blobs.
string PrintableIncludeOrForwardDeclareLine(
const OneIncludeOrForwardDeclareLine& line,
const set<string>& associated_quoted_includes) {
// Print the line number where we saw this forward-declare or
// #include, as a comment, if we don't have anything better to show.
// (For instance, when we want to delete this line.)
if (line.symbol_counts().empty() && !line.is_present()) {
return line.line() + "\n"; // if not present, doesn't have a line #
}
if (line.symbol_counts().empty() || !line.is_desired()) {
CHECK_(!StartsWith(line.LineNumberString(), "-"));
return line.line() + " // lines " + line.LineNumberString() + "\n";
}
// We don't need to explain why foo.cc #includes foo.h
if (line.IsIncludeLine() &&
ContainsKey(associated_quoted_includes, line.quoted_include())) {
return line.line() + "\n";
}
string retval = line.line();
string prefix; // what we print before each symbol in the 'why' comments
// We try to get the columns to line up nicely. The 38 is arbitrary.
if (retval.length() < 38)
prefix += string(38 - retval.length(), ' ');
prefix += " // for "; // before 1st symbol, print ' // for '
int symbols_printed = 0;
vector<string> symbols(GetSymbolsSortedByFrequency(line.symbol_counts()));
for (Each<string> it(&symbols); !it.AtEnd(); ++it) {
if (it->empty()) // ignore the empty ("") symbol
continue;
// At verbose levels of 0, 1, or 2, cut off output at 80 columns.
// Actually, at 74, to leave 5 chars for ', etc' and 1 for newline.
if (ShouldPrint(3) ||
retval.length() + prefix.length() + it->length() <= 74) {
retval += prefix + *it;
++symbols_printed;
prefix = ", "; // before 2nd and subsequent symbols, print ', '
} else {
// Truncate at 80 cols.
if (symbols_printed > 0)
retval += ", etc";
break;
}
}
retval += "\n";
return retval;
}
typedef pair<int, string> LineSortKey;
// The sort key of an include/forward-declare line is an (int, string)
// pair. The string is always the line itself. The int is a category:
// 1: associated .h, 2: associated -inl.h, 3: C header, 4: c++ header,
// 5: other header, 6: forward-declare.
LineSortKey GetSortKey(const OneIncludeOrForwardDeclareLine& line,
const set<string>& associated_quoted_includes) {
if (!line.IsIncludeLine())
return LineSortKey(6, line.line());
if (ContainsKey(associated_quoted_includes, line.quoted_include())) {
if (EndsWith(line.quoted_include(), "-inl.h\""))
return LineSortKey(2, line.line());
return LineSortKey(1, line.line());
}
if (EndsWith(line.quoted_include(), ".h>"))
return LineSortKey(3, line.line());
if (EndsWith(line.quoted_include(), ">"))
return LineSortKey(4, line.line());
return LineSortKey(5, line.line());
}
// filename is "this" filename: the file being emitted.
// associated_filepaths are the quoted-include form of internal_headers_.
string PrintableDiffs(const string& filename,
const set<string>& associated_quoted_includes,
const vector<OneIncludeOrForwardDeclareLine>& lines) {
const set<string>& aqi = associated_quoted_includes; // short alias
// Sort all the output-lines: system headers before user headers
// before forward-declares, etc. The easiest way to do this is to
// just put them all in multimap whose key is a sort-order (multimap
// because some headers might be listed twice in the source file.)
multimap<LineSortKey, const OneIncludeOrForwardDeclareLine*> sorted_lines;
for (Each<OneIncludeOrForwardDeclareLine> it(&lines); !it.AtEnd(); ++it) {
sorted_lines.insert(make_pair(GetSortKey(*it, aqi), &*it));
}
// First, check if there are no adds or deletes. If so, we print a
// shorter summary line.
bool no_adds_or_deletes = true;
for (Each<LineSortKey, const OneIncludeOrForwardDeclareLine*>
it(&sorted_lines); !it.AtEnd(); ++it) {
if ((it->second->is_desired() && !it->second->is_present()) || // add
(it->second->is_present() && !it->second->is_desired())) { // delete
no_adds_or_deletes = false;
break;
}
}
if (no_adds_or_deletes) {
return "\n(" + filename + " has correct #includes/fwd-decls)\n";
}
string output;
// First, new desired includes and forward-declares.
if (ShouldPrint(1)) {
output += "\n" + filename + " should add these lines:\n";
for (Each<LineSortKey, const OneIncludeOrForwardDeclareLine*>
it(&sorted_lines); !it.AtEnd(); ++it) {
if (it->second->is_desired() && !it->second->is_present()) {
output += PrintableIncludeOrForwardDeclareLine(*it->second, aqi);
}
}
}
// Second, includes and forward-declares that should be removed.
if (ShouldPrint(1)) {
output += "\n" + filename + " should remove these lines:\n";
for (Each<LineSortKey, const OneIncludeOrForwardDeclareLine*>
it(&sorted_lines); !it.AtEnd(); ++it) {
if (it->second->is_present() && !it->second->is_desired()) {
output += "- " + PrintableIncludeOrForwardDeclareLine(*it->second, aqi);
}
}
}
// Finally, print the final, complete include-and-forward-declare list.
if (ShouldPrint(0)) {
output += "\nThe full include-list for " + filename + ":\n";
for (Each<LineSortKey, const OneIncludeOrForwardDeclareLine*>
it(&sorted_lines); !it.AtEnd(); ++it) {
if (it->second->is_desired()) {
output += PrintableIncludeOrForwardDeclareLine(*it->second, aqi);
}
}
}
// Let's print a helpful separator as well.
output += "---\n";
return output;
}
} // namespace internal
void IwyuFileInfo::EmitDiffs(
const vector<OneIncludeOrForwardDeclareLine>& lines) {
errs() << internal::PrintableDiffs(GetFilePath(file_),
AssociatedQuotedIncludes(),
lines);
}
int IwyuFileInfo::CalculateAndReportIwyuViolations() {
// This is used to calculate our own desired includes. That depends
// on what our associated files' desired includes are: if we use
// bar.h and foo.h is adding it, we don't need to add it ourself.
// On the other hand, if foo.h used to have it but is removing it,
// we *do* need to add it.
set<string> associated_desired_includes;
for (Each<const IwyuFileInfo*> it(&internal_headers_); !it.AtEnd(); ++it) {
InsertAllInto((*it)->desired_includes(), &associated_desired_includes);
}
CalculateIwyuViolations(&symbol_uses_);
const int retval = EmitWarningMessages(symbol_uses_);
internal::CalculateDesiredIncludesAndForwardDeclares(
symbol_uses_, associated_desired_includes, &lines_);
// Remove desired inclusions that have been inhibited by pragma
// "no_include".
for (vector<OneIncludeOrForwardDeclareLine>::iterator
it = lines_.begin(); it != lines_.end(); ++it) {
if (it->IsIncludeLine() &&
preprocessor_info_->IncludeIsInhibited(file_, it->quoted_include())) {
it->clear_desired();
}
}
EmitDiffs(lines_);
return retval;
}
} // namespace include_what_you_use