slim down parser.y

most EvalState and Expr members defined here could be elsewhere, where
they'd be easier to maintain (not being embedded in a file with arcane
syntax) and *somewhat* more faithfully placed according to the path of
the file they're defined in.
This commit is contained in:
pennae 2024-01-15 16:52:18 +01:00
parent 835a6c7bcf
commit e1aa585964
3 changed files with 166 additions and 176 deletions

View file

@ -20,6 +20,8 @@
#include "gc-small-vector.hh"
#include "url.hh"
#include "fetch-to-store.hh"
#include "tarball.hh"
#include "flake/flakeref.hh"
#include <algorithm>
#include <chrono>
@ -2636,6 +2638,168 @@ void EvalState::printStatistics()
}
SourcePath resolveExprPath(SourcePath path)
{
unsigned int followCount = 0, maxFollow = 1024;
/* If `path' is a symlink, follow it. This is so that relative
path references work. */
while (!path.path.isRoot()) {
// Basic cycle/depth limit to avoid infinite loops.
if (++followCount >= maxFollow)
throw Error("too many symbolic links encountered while traversing the path '%s'", path);
auto p = path.parent().resolveSymlinks() + path.baseName();
if (p.lstat().type != InputAccessor::tSymlink) break;
path = {path.accessor, CanonPath(p.readLink(), path.path.parent().value_or(CanonPath::root))};
}
/* If `path' refers to a directory, append `/default.nix'. */
if (path.resolveSymlinks().lstat().type == InputAccessor::tDirectory)
return path + "default.nix";
return path;
}
Expr * EvalState::parseExprFromFile(const SourcePath & path)
{
return parseExprFromFile(path, staticBaseEnv);
}
Expr * EvalState::parseExprFromFile(const SourcePath & path, std::shared_ptr<StaticEnv> & staticEnv)
{
auto buffer = path.resolveSymlinks().readFile();
// readFile hopefully have left some extra space for terminators
buffer.append("\0\0", 2);
return parse(buffer.data(), buffer.size(), Pos::Origin(path), path.parent(), staticEnv);
}
Expr * EvalState::parseExprFromString(std::string s_, const SourcePath & basePath, std::shared_ptr<StaticEnv> & staticEnv)
{
auto s = make_ref<std::string>(std::move(s_));
s->append("\0\0", 2);
return parse(s->data(), s->size(), Pos::String{.source = s}, basePath, staticEnv);
}
Expr * EvalState::parseExprFromString(std::string s, const SourcePath & basePath)
{
return parseExprFromString(std::move(s), basePath, staticBaseEnv);
}
Expr * EvalState::parseStdin()
{
//Activity act(*logger, lvlTalkative, "parsing standard input");
auto buffer = drainFD(0);
// drainFD should have left some extra space for terminators
buffer.append("\0\0", 2);
auto s = make_ref<std::string>(std::move(buffer));
return parse(s->data(), s->size(), Pos::Stdin{.source = s}, rootPath(CanonPath::fromCwd()), staticBaseEnv);
}
SourcePath EvalState::findFile(const std::string_view path)
{
return findFile(searchPath, path);
}
SourcePath EvalState::findFile(const SearchPath & searchPath, const std::string_view path, const PosIdx pos)
{
for (auto & i : searchPath.elements) {
auto suffixOpt = i.prefix.suffixIfPotentialMatch(path);
if (!suffixOpt) continue;
auto suffix = *suffixOpt;
auto rOpt = resolveSearchPathPath(i.path);
if (!rOpt) continue;
auto r = *rOpt;
Path res = suffix == "" ? r : concatStrings(r, "/", suffix);
if (pathExists(res)) return rootPath(CanonPath(canonPath(res)));
}
if (hasPrefix(path, "nix/"))
return {corepkgsFS, CanonPath(path.substr(3))};
debugThrow(ThrownError({
.msg = hintfmt(evalSettings.pureEval
? "cannot look up '<%s>' in pure evaluation mode (use '--impure' to override)"
: "file '%s' was not found in the Nix search path (add it using $NIX_PATH or -I)",
path),
.errPos = positions[pos]
}), 0, 0);
}
std::optional<std::string> EvalState::resolveSearchPathPath(const SearchPath::Path & value0, bool initAccessControl)
{
auto & value = value0.s;
auto i = searchPathResolved.find(value);
if (i != searchPathResolved.end()) return i->second;
std::optional<std::string> res;
if (EvalSettings::isPseudoUrl(value)) {
try {
auto storePath = fetchers::downloadTarball(
store, EvalSettings::resolvePseudoUrl(value), "source", false).storePath;
res = { store->toRealPath(storePath) };
} catch (FileTransferError & e) {
logWarning({
.msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", value)
});
}
}
else if (hasPrefix(value, "flake:")) {
experimentalFeatureSettings.require(Xp::Flakes);
auto flakeRef = parseFlakeRef(value.substr(6), {}, true, false);
debug("fetching flake search path element '%s''", value);
auto storePath = flakeRef.resolve(store).fetchTree(store).first;
res = { store->toRealPath(storePath) };
}
else {
auto path = absPath(value);
/* Allow access to paths in the search path. */
if (initAccessControl) {
allowPath(path);
if (store->isInStore(path)) {
try {
StorePathSet closure;
store->computeFSClosure(store->toStorePath(path).first, closure);
for (auto & p : closure)
allowPath(p);
} catch (InvalidPath &) { }
}
}
if (pathExists(path))
res = { path };
else {
logWarning({
.msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", value)
});
res = std::nullopt;
}
}
if (res)
debug("resolved search path element '%s' to '%s'", value, *res);
else
debug("failed to resolve search path element '%s'", value);
searchPathResolved.emplace(value, res);
return res;
}
std::string ExternalValueBase::coerceToString(const Pos & pos, NixStringContext & context, bool copyMore, bool copyToStore) const
{
throw TypeError({

View file

@ -9,6 +9,8 @@
namespace nix {
unsigned long Expr::nrExprs = 0;
ExprBlackHole eBlackHole;
// FIXME: remove, because *symbols* are abstract and do not have a single

View file

@ -389,25 +389,11 @@ formal
%%
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "eval.hh"
#include "filetransfer.hh"
#include "tarball.hh"
#include "store-api.hh"
#include "flake/flake.hh"
#include "fs-input-accessor.hh"
#include "memory-input-accessor.hh"
namespace nix {
unsigned long Expr::nrExprs = 0;
Expr * EvalState::parse(
char * text,
size_t length,
@ -435,166 +421,4 @@ Expr * EvalState::parse(
}
SourcePath resolveExprPath(SourcePath path)
{
unsigned int followCount = 0, maxFollow = 1024;
/* If `path' is a symlink, follow it. This is so that relative
path references work. */
while (!path.path.isRoot()) {
// Basic cycle/depth limit to avoid infinite loops.
if (++followCount >= maxFollow)
throw Error("too many symbolic links encountered while traversing the path '%s'", path);
auto p = path.parent().resolveSymlinks() + path.baseName();
if (p.lstat().type != InputAccessor::tSymlink) break;
path = {path.accessor, CanonPath(p.readLink(), path.path.parent().value_or(CanonPath::root))};
}
/* If `path' refers to a directory, append `/default.nix'. */
if (path.resolveSymlinks().lstat().type == InputAccessor::tDirectory)
return path + "default.nix";
return path;
}
Expr * EvalState::parseExprFromFile(const SourcePath & path)
{
return parseExprFromFile(path, staticBaseEnv);
}
Expr * EvalState::parseExprFromFile(const SourcePath & path, std::shared_ptr<StaticEnv> & staticEnv)
{
auto buffer = path.resolveSymlinks().readFile();
// readFile hopefully have left some extra space for terminators
buffer.append("\0\0", 2);
return parse(buffer.data(), buffer.size(), Pos::Origin(path), path.parent(), staticEnv);
}
Expr * EvalState::parseExprFromString(std::string s_, const SourcePath & basePath, std::shared_ptr<StaticEnv> & staticEnv)
{
auto s = make_ref<std::string>(std::move(s_));
s->append("\0\0", 2);
return parse(s->data(), s->size(), Pos::String{.source = s}, basePath, staticEnv);
}
Expr * EvalState::parseExprFromString(std::string s, const SourcePath & basePath)
{
return parseExprFromString(std::move(s), basePath, staticBaseEnv);
}
Expr * EvalState::parseStdin()
{
//Activity act(*logger, lvlTalkative, "parsing standard input");
auto buffer = drainFD(0);
// drainFD should have left some extra space for terminators
buffer.append("\0\0", 2);
auto s = make_ref<std::string>(std::move(buffer));
return parse(s->data(), s->size(), Pos::Stdin{.source = s}, rootPath(CanonPath::fromCwd()), staticBaseEnv);
}
SourcePath EvalState::findFile(const std::string_view path)
{
return findFile(searchPath, path);
}
SourcePath EvalState::findFile(const SearchPath & searchPath, const std::string_view path, const PosIdx pos)
{
for (auto & i : searchPath.elements) {
auto suffixOpt = i.prefix.suffixIfPotentialMatch(path);
if (!suffixOpt) continue;
auto suffix = *suffixOpt;
auto rOpt = resolveSearchPathPath(i.path);
if (!rOpt) continue;
auto r = *rOpt;
Path res = suffix == "" ? r : concatStrings(r, "/", suffix);
if (pathExists(res)) return rootPath(CanonPath(canonPath(res)));
}
if (hasPrefix(path, "nix/"))
return {corepkgsFS, CanonPath(path.substr(3))};
debugThrow(ThrownError({
.msg = hintfmt(evalSettings.pureEval
? "cannot look up '<%s>' in pure evaluation mode (use '--impure' to override)"
: "file '%s' was not found in the Nix search path (add it using $NIX_PATH or -I)",
path),
.errPos = positions[pos]
}), 0, 0);
}
std::optional<std::string> EvalState::resolveSearchPathPath(const SearchPath::Path & value0, bool initAccessControl)
{
auto & value = value0.s;
auto i = searchPathResolved.find(value);
if (i != searchPathResolved.end()) return i->second;
std::optional<std::string> res;
if (EvalSettings::isPseudoUrl(value)) {
try {
auto storePath = fetchers::downloadTarball(
store, EvalSettings::resolvePseudoUrl(value), "source", false).storePath;
res = { store->toRealPath(storePath) };
} catch (FileTransferError & e) {
logWarning({
.msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", value)
});
}
}
else if (hasPrefix(value, "flake:")) {
experimentalFeatureSettings.require(Xp::Flakes);
auto flakeRef = parseFlakeRef(value.substr(6), {}, true, false);
debug("fetching flake search path element '%s''", value);
auto storePath = flakeRef.resolve(store).fetchTree(store).first;
res = { store->toRealPath(storePath) };
}
else {
auto path = absPath(value);
/* Allow access to paths in the search path. */
if (initAccessControl) {
allowPath(path);
if (store->isInStore(path)) {
try {
StorePathSet closure;
store->computeFSClosure(store->toStorePath(path).first, closure);
for (auto & p : closure)
allowPath(p);
} catch (InvalidPath &) { }
}
}
if (pathExists(path))
res = { path };
else {
logWarning({
.msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", value)
});
res = std::nullopt;
}
}
if (res)
debug("resolved search path element '%s' to '%s'", value, *res);
else
debug("failed to resolve search path element '%s'", value);
searchPathResolved.emplace(value, res);
return res;
}
}