#include "libexpr/parser.hh"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "libexpr/eval.hh"
#include "libstore/download.hh"
#include "libstore/store-api.hh"
namespace nix {
void addAttr(ExprAttrs* attrs, AttrPath& attrPath, Expr* e, const Pos& pos) {
AttrPath::iterator i;
// All attrpaths have at least one attr
assert(!attrPath.empty());
// Checking attrPath validity.
// ===========================
for (i = attrPath.begin(); i + 1 < attrPath.end(); i++) {
if (const auto* sym = std::get_if<Symbol>(&(*i)); sym && sym->set()) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(*sym);
if (j != attrs->attrs.end()) {
if (!j->second.inherited) {
ExprAttrs* attrs2 = dynamic_cast<ExprAttrs*>(j->second.e);
if (!attrs2) {
dupAttr(attrPath, pos, j->second.pos);
}
attrs = attrs2;
} else {
dupAttr(attrPath, pos, j->second.pos);
}
} else {
ExprAttrs* nested = new ExprAttrs;
attrs->attrs[*sym] = ExprAttrs::AttrDef(nested, pos);
attrs = nested;
}
} else {
// Yes, this code does not handle all conditions
// exhaustively. We use std::get to throw if the condition
// that isn't covered happens, which is potentially a
// behaviour change from the previous default constructed
// Symbol. It should alert us about anything untoward going
// on here.
auto* expr = std::get<Expr*>(*i);
ExprAttrs* nested = new ExprAttrs;
attrs->dynamicAttrs.push_back(
ExprAttrs::DynamicAttrDef(expr, nested, pos));
attrs = nested;
}
}
// Expr insertion.
// ==========================
if (auto* sym = std::get_if<Symbol>(&(*i)); sym && sym->set()) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(*sym);
if (j != attrs->attrs.end()) {
// This attr path is already defined. However, if both
// e and the expr pointed by the attr path are two attribute sets,
// we want to merge them.
// Otherwise, throw an error.
auto ae = dynamic_cast<ExprAttrs*>(e);
auto jAttrs = dynamic_cast<ExprAttrs*>(j->second.e);
if (jAttrs && ae) {
for (auto& ad : ae->attrs) {
auto j2 = jAttrs->attrs.find(ad.first);
if (j2 !=
jAttrs->attrs.end()) { // Attr already defined in iAttrs, error.
dupAttr(ad.first, j2->second.pos, ad.second.pos);
}
jAttrs->attrs[ad.first] = ad.second;
}
} else {
dupAttr(attrPath, pos, j->second.pos);
}
} else {
// This attr path is not defined. Let's create it.
attrs->attrs[*sym] = ExprAttrs::AttrDef(e, pos);
}
} else {
// Same caveat as the identical line above.
auto* expr = std::get<Expr*>(*i);
attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(expr, e, pos));
}
}
void addFormal(const Pos& pos, Formals* formals, const Formal& formal) {
if (formals->argNames.find(formal.name) != formals->argNames.end())
throw ParseError(format("duplicate formal function argument '%1%' at %2%") %
formal.name % pos);
formals->formals.push_front(formal);
formals->argNames.insert(formal.name);
}
Expr* stripIndentation(const Pos& pos, SymbolTable& symbols,
std::vector<Expr*>& es) {
if (es.empty()) {
return new ExprString(symbols.Create(""));
}
/* Figure out the minimum indentation. Note that by design
whitespace-only final lines are not taken into account. (So
the " " in "\n ''" is ignored, but the " " in "\n foo''" is.) */
bool atStartOfLine = true; /* = seen only whitespace in the current line */
size_t minIndent = 1000000;
size_t curIndent = 0;
for (auto& i : es) {
ExprIndStr* e = dynamic_cast<ExprIndStr*>(i);
if (!e) {
/* Anti-quotations end the current start-of-line whitespace. */
if (atStartOfLine) {
atStartOfLine = false;
if (curIndent < minIndent) {
minIndent = curIndent;
}
}
continue;
}
for (size_t j = 0; j < e->s.size(); ++j) {
if (atStartOfLine) {
if (e->s[j] == ' ')
curIndent++;
else if (e->s[j] == '\n') {
/* Empty line, doesn't influence minimum
indentation. */
curIndent = 0;
} else {
atStartOfLine = false;
if (curIndent < minIndent) {
minIndent = curIndent;
}
}
} else if (e->s[j] == '\n') {
atStartOfLine = true;
curIndent = 0;
}
}
}
/* Strip spaces from each line. */
std::vector<Expr*>* es2 = new std::vector<Expr*>;
atStartOfLine = true;
size_t curDropped = 0;
size_t n = es.size();
for (std::vector<Expr*>::iterator i = es.begin(); i != es.end(); ++i, --n) {
ExprIndStr* e = dynamic_cast<ExprIndStr*>(*i);
if (!e) {
atStartOfLine = false;
curDropped = 0;
es2->push_back(*i);
continue;
}
std::string s2;
for (size_t j = 0; j < e->s.size(); ++j) {
if (atStartOfLine) {
if (e->s[j] == ' ') {
if (curDropped++ >= minIndent) s2 += e->s[j];
} else if (e->s[j] == '\n') {
curDropped = 0;
s2 += e->s[j];
} else {
atStartOfLine = false;
curDropped = 0;
s2 += e->s[j];
}
} else {
s2 += e->s[j];
if (e->s[j] == '\n') {
atStartOfLine = true;
}
}
}
/* Remove the last line if it is empty and consists only of
spaces. */
if (n == 1) {
std::string::size_type p = s2.find_last_of('\n');
if (p != std::string::npos &&
s2.find_first_not_of(' ', p + 1) == std::string::npos) {
s2 = std::string(s2, 0, p + 1);
}
}
es2->push_back(new ExprString(symbols.Create(s2)));
}
/* If this is a single string, then don't do a concatenation. */
return es2->size() == 1 && dynamic_cast<ExprString*>((*es2)[0])
? (*es2)[0]
: new ExprConcatStrings(pos, true, es2);
}
Path resolveExprPath(Path path) {
assert(path[0] == '/');
/* If `path' is a symlink, follow it. This is so that relative
path references work. */
struct stat st;
while (true) {
if (lstat(path.c_str(), &st))
throw SysError(format("getting status of '%1%'") % path);
if (!S_ISLNK(st.st_mode)) {
break;
}
path = absPath(readLink(path), dirOf(path));
}
/* If `path' refers to a directory, append `/default.nix'. */
if (S_ISDIR(st.st_mode)) path = canonPath(path + "/default.nix");
return path;
}
// These methods are actually declared in eval.hh, and were - for some
// reason - previously implemented in parser.y.
Expr* EvalState::parseExprFromFile(const Path& path) {
return parseExprFromFile(path, staticBaseEnv);
}
Expr* EvalState::parseExprFromFile(const Path& path, StaticEnv& staticEnv) {
return parse(readFile(path).c_str(), path, dirOf(path), staticEnv);
}
Expr* EvalState::parseExprFromString(const std::string& s, const Path& basePath,
StaticEnv& staticEnv) {
return parse(s.c_str(), "(std::string)", basePath, staticEnv);
}
Expr* EvalState::parseExprFromString(const std::string& s,
const Path& basePath) {
return parseExprFromString(s, basePath, staticBaseEnv);
}
Expr* EvalState::parseStdin() {
// Activity act(*logger, lvlTalkative, format("parsing standard input"));
return parseExprFromString(drainFD(0), absPath("."));
}
void EvalState::addToSearchPath(const std::string& s) {
size_t pos = s.find('=');
std::string prefix;
Path path;
if (pos == std::string::npos) {
path = s;
} else {
prefix = std::string(s, 0, pos);
path = std::string(s, pos + 1);
}
searchPath.emplace_back(prefix, path);
}
Path EvalState::findFile(const std::string& path) {
return findFile(searchPath, path);
}
Path EvalState::findFile(SearchPath& searchPath, const std::string& path,
const Pos& pos) {
for (auto& i : searchPath) {
std::string suffix;
if (i.first.empty())
suffix = "/" + path;
else {
auto s = i.first.size();
if (path.compare(0, s, i.first) != 0 ||
(path.size() > s && path[s] != '/'))
continue;
suffix = path.size() == s ? "" : "/" + std::string(path, s);
}
auto r = resolveSearchPathElem(i);
if (!r.first) {
continue;
}
Path res = r.second + suffix;
if (pathExists(res)) {
return canonPath(res);
}
}
format f = format(
"file '%1%' was not found in the Nix search path (add it using $NIX_PATH "
"or -I)" +
std::string(pos ? ", at %2%" : ""));
f.exceptions(boost::io::all_error_bits ^ boost::io::too_many_args_bit);
throw ThrownError(f % path % pos);
}
std::pair<bool, std::string> EvalState::resolveSearchPathElem(
const SearchPathElem& elem) {
auto i = searchPathResolved.find(elem.second);
if (i != searchPathResolved.end()) {
return i->second;
}
std::pair<bool, std::string> res;
if (isUri(elem.second)) {
try {
CachedDownloadRequest request(elem.second);
request.unpack = true;
res = {true, getDownloader()->downloadCached(store, request).path};
} catch (DownloadError& e) {
LOG(WARNING) << "Nix search path entry '" << elem.second
<< "' cannot be downloaded, ignoring";
res = {false, ""};
}
} else {
auto path = absPath(elem.second);
if (pathExists(path)) {
res = {true, path};
} else {
LOG(WARNING) << "Nix search path entry '" << elem.second
<< "' does not exist, ignoring";
res = {false, ""};
}
}
DLOG(INFO) << "resolved search path element '" << elem.second << "' to '"
<< res.second << "'";
searchPathResolved[elem.second] = res;
return res;
}
} // namespace nix
