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#pragma once
///@file
#include "eval.hh"
namespace nix::parser {
struct StringToken
{
std::string_view s;
bool hasIndentation;
operator std::string_view() const { return s; }
};
struct State
{
SymbolTable & symbols;
PosTable & positions;
SourcePath basePath;
PosTable::Origin origin;
const Expr::AstSymbols & s;
void dupAttr(const AttrPath & attrPath, const PosIdx pos, const PosIdx prevPos);
void dupAttr(Symbol attr, const PosIdx pos, const PosIdx prevPos);
void addAttr(ExprAttrs * attrs, AttrPath && attrPath, std::unique_ptr<Expr> e, const PosIdx pos);
std::unique_ptr<Formals> validateFormals(std::unique_ptr<Formals> formals, PosIdx pos = noPos, Symbol arg = {});
std::unique_ptr<Expr> stripIndentation(const PosIdx pos,
std::vector<std::pair<PosIdx, std::variant<std::unique_ptr<Expr>, StringToken>>> && es);
// lazy positioning means we don't get byte offsets directly, in.position() would work
// but also requires line and column (which is expensive)
PosIdx at(const auto & in)
{
return positions.add(origin, in.begin() - in.input().begin());
}
PosIdx atEnd(const auto & in)
{
return positions.add(origin, in.end() - in.input().begin());
}
};
inline void State::dupAttr(const AttrPath & attrPath, const PosIdx pos, const PosIdx prevPos)
{
throw ParseError({
.msg = HintFmt("attribute '%1%' already defined at %2%",
showAttrPath(symbols, attrPath), positions[prevPos]),
.pos = positions[pos]
});
}
inline void State::dupAttr(Symbol attr, const PosIdx pos, const PosIdx prevPos)
{
throw ParseError({
.msg = HintFmt("attribute '%1%' already defined at %2%", symbols[attr], positions[prevPos]),
.pos = positions[pos]
});
}
inline void State::addAttr(ExprAttrs * attrs, AttrPath && attrPath, std::unique_ptr<Expr> e, const PosIdx 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 (i->symbol) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol);
if (j != attrs->attrs.end()) {
if (j->second.kind != ExprAttrs::AttrDef::Kind::Inherited) {
ExprAttrs * attrs2 = dynamic_cast<ExprAttrs *>(j->second.e.get());
if (!attrs2) {
attrPath.erase(i + 1, attrPath.end());
dupAttr(attrPath, pos, j->second.pos);
}
attrs = attrs2;
} else {
attrPath.erase(i + 1, attrPath.end());
dupAttr(attrPath, pos, j->second.pos);
}
} else {
auto next = attrs->attrs.emplace(std::piecewise_construct,
std::tuple(i->symbol),
std::tuple(std::make_unique<ExprAttrs>(), pos));
attrs = static_cast<ExprAttrs *>(next.first->second.e.get());
}
} else {
auto & next = attrs->dynamicAttrs.emplace_back(std::move(i->expr), std::make_unique<ExprAttrs>(), pos);
attrs = static_cast<ExprAttrs *>(next.valueExpr.get());
}
}
// Expr insertion.
// ==========================
if (i->symbol) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol);
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.get());
auto * jAttrs = dynamic_cast<ExprAttrs *>(j->second.e.get());
if (jAttrs && ae) {
if (ae->inheritFromExprs && !jAttrs->inheritFromExprs)
jAttrs->inheritFromExprs = std::make_unique<std::vector<std::unique_ptr<Expr>>>();
for (auto & ad : ae->attrs) {
auto j2 = jAttrs->attrs.find(ad.first);
if (j2 != jAttrs->attrs.end()) // Attr already defined in iAttrs, error.
return dupAttr(ad.first, j2->second.pos, ad.second.pos);
if (ad.second.kind == ExprAttrs::AttrDef::Kind::InheritedFrom) {
auto & sel = dynamic_cast<ExprSelect &>(*ad.second.e);
auto & from = dynamic_cast<ExprInheritFrom &>(*sel.e);
from.displ += jAttrs->inheritFromExprs->size();
}
jAttrs->attrs.emplace(ad.first, std::move(ad.second));
}
std::ranges::move(ae->dynamicAttrs, std::back_inserter(jAttrs->dynamicAttrs));
if (ae->inheritFromExprs)
std::ranges::move(*ae->inheritFromExprs, std::back_inserter(*jAttrs->inheritFromExprs));
} else {
dupAttr(attrPath, pos, j->second.pos);
}
} else {
// This attr path is not defined. Let's create it.
e->setName(i->symbol);
attrs->attrs.emplace(std::piecewise_construct,
std::tuple(i->symbol),
std::tuple(std::move(e), pos));
}
} else {
attrs->dynamicAttrs.emplace_back(std::move(i->expr), std::move(e), pos);
}
}
inline std::unique_ptr<Formals> State::validateFormals(std::unique_ptr<Formals> formals, PosIdx pos, Symbol arg)
{
std::sort(formals->formals.begin(), formals->formals.end(),
[] (const auto & a, const auto & b) {
return std::tie(a.name, a.pos) < std::tie(b.name, b.pos);
});
std::optional<std::pair<Symbol, PosIdx>> duplicate;
for (size_t i = 0; i + 1 < formals->formals.size(); i++) {
if (formals->formals[i].name != formals->formals[i + 1].name)
continue;
std::pair thisDup{formals->formals[i].name, formals->formals[i + 1].pos};
duplicate = std::min(thisDup, duplicate.value_or(thisDup));
}
if (duplicate)
throw ParseError({
.msg = HintFmt("duplicate formal function argument '%1%'", symbols[duplicate->first]),
.pos = positions[duplicate->second]
});
if (arg && formals->has(arg))
throw ParseError({
.msg = HintFmt("duplicate formal function argument '%1%'", symbols[arg]),
.pos = positions[pos]
});
return formals;
}
inline std::unique_ptr<Expr> State::stripIndentation(const PosIdx pos,
std::vector<std::pair<PosIdx, std::variant<std::unique_ptr<Expr>, StringToken>>> && es)
{
if (es.empty()) return std::make_unique<ExprString>("");
/* 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_pos, i] : es) {
auto * str = std::get_if<StringToken>(&i);
if (!str || !str->hasIndentation) {
/* Anti-quotations and escaped characters end the current start-of-line whitespace. */
if (atStartOfLine) {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
continue;
}
for (size_t j = 0; j < str->s.size(); ++j) {
if (atStartOfLine) {
if (str->s[j] == ' ')
curIndent++;
else if (str->s[j] == '\n') {
/* Empty line, doesn't influence minimum
indentation. */
curIndent = 0;
} else {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
} else if (str->s[j] == '\n') {
atStartOfLine = true;
curIndent = 0;
}
}
}
/* Strip spaces from each line. */
std::vector<std::pair<PosIdx, std::unique_ptr<Expr>>> es2;
atStartOfLine = true;
size_t curDropped = 0;
size_t n = es.size();
auto i = es.begin();
const auto trimExpr = [&] (std::unique_ptr<Expr> e) {
atStartOfLine = false;
curDropped = 0;
es2.emplace_back(i->first, std::move(e));
};
const auto trimString = [&] (const StringToken t) {
std::string s2;
for (size_t j = 0; j < t.s.size(); ++j) {
if (atStartOfLine) {
if (t.s[j] == ' ') {
if (curDropped++ >= minIndent)
s2 += t.s[j];
}
else if (t.s[j] == '\n') {
curDropped = 0;
s2 += t.s[j];
} else {
atStartOfLine = false;
curDropped = 0;
s2 += t.s[j];
}
} else {
s2 += t.s[j];
if (t.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.emplace_back(i->first, std::make_unique<ExprString>(std::move(s2)));
};
for (; i != es.end(); ++i, --n) {
std::visit(overloaded { trimExpr, trimString }, std::move(i->second));
}
/* If this is a single string, then don't do a concatenation. */
if (es2.size() == 1 && dynamic_cast<ExprString *>(es2[0].second.get())) {
return std::move(es2[0].second);
}
return std::make_unique<ExprConcatStrings>(pos, true, std::move(es2));
}
}
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