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-rw-r--r--src/libexpr/eval.cc7
-rw-r--r--src/libexpr/flake/flake.cc3
-rw-r--r--src/libexpr/lexer.l23
-rw-r--r--src/libexpr/nixexpr.cc33
-rw-r--r--src/libexpr/nixexpr.hh1
-rw-r--r--src/libexpr/parser-state.hh9
-rw-r--r--src/libexpr/parser.y2
-rw-r--r--src/libexpr/pos-idx.hh1
-rw-r--r--src/libexpr/pos-table.hh85
-rw-r--r--src/libexpr/primops.cc48
-rw-r--r--src/libexpr/primops.hh2
-rw-r--r--tests/functional/lang/eval-okay-unsafeGetAttrPos.exp1
-rw-r--r--tests/functional/lang/eval-okay-unsafeGetAttrPos.imported-nix4
-rw-r--r--tests/functional/lang/eval-okay-unsafeGetAttrPos.nix4
-rw-r--r--tests/unit/libexpr/value/print.cc8
15 files changed, 151 insertions, 80 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 32766950d..6db1eaffe 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -940,12 +940,11 @@ void EvalState::mkThunk_(Value & v, Expr * expr)
void EvalState::mkPos(Value & v, PosIdx p)
{
- auto pos = positions[p];
- if (auto path = std::get_if<SourcePath>(&pos.origin)) {
+ auto origin = positions.originOf(p);
+ if (auto path = std::get_if<SourcePath>(&origin)) {
auto attrs = buildBindings(3);
attrs.alloc(sFile).mkString(path->path.abs());
- attrs.alloc(sLine).mkInt(pos.line);
- attrs.alloc(sColumn).mkInt(pos.column);
+ makePositionThunks(*this, p, attrs.alloc(sLine), attrs.alloc(sColumn));
v.mkAttrs(attrs);
} else
v.mkNull();
diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index 305d84a68..72e98f6bb 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -227,11 +227,10 @@ static Flake getFlake(
.sourceInfo = std::make_shared<fetchers::Tree>(std::move(sourceInfo))
};
+ // NOTE evalFile forces vInfo to be an attrset because mustBeTrivial is true.
Value vInfo;
state.evalFile(CanonPath(flakeFile), vInfo, true); // FIXME: symlink attack
- expectType(state, nAttrs, vInfo, state.positions.add({CanonPath(flakeFile)}, 1, 1));
-
if (auto description = vInfo.attrs->get(state.sDescription)) {
expectType(state, nString, *description->value, description->pos);
flake.description = description->value->string.s;
diff --git a/src/libexpr/lexer.l b/src/libexpr/lexer.l
index adb9d9757..1780f5cb9 100644
--- a/src/libexpr/lexer.l
+++ b/src/libexpr/lexer.l
@@ -39,33 +39,16 @@ namespace nix {
static void initLoc(YYLTYPE * loc)
{
- loc->first_line = loc->last_line = 1;
- loc->first_column = loc->last_column = 1;
+ loc->first_line = loc->last_line = 0;
+ loc->first_column = loc->last_column = 0;
}
static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
{
loc->stash();
- loc->first_line = loc->last_line;
loc->first_column = loc->last_column;
-
- for (size_t i = 0; i < len; i++) {
- switch (*s++) {
- case '\r':
- if (*s == '\n') { /* cr/lf */
- i++;
- s++;
- }
- /* fall through */
- case '\n':
- ++loc->last_line;
- loc->last_column = 1;
- break;
- default:
- ++loc->last_column;
- }
- }
+ loc->last_column += len;
}
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index c591916e3..a9989b59e 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -581,6 +581,39 @@ std::string ExprLambda::showNamePos(const EvalState & state) const
+/* Position table. */
+
+Pos PosTable::operator[](PosIdx p) const
+{
+ auto origin = resolve(p);
+ if (!origin)
+ return {};
+
+ const auto offset = origin->offsetOf(p);
+
+ Pos result{0, 0, origin->origin};
+ auto lines = this->lines.lock();
+ auto linesForInput = (*lines)[origin->offset];
+
+ if (linesForInput.empty()) {
+ auto source = result.getSource().value_or("");
+ const char * begin = source.data();
+ for (Pos::LinesIterator it(source), end; it != end; it++)
+ linesForInput.push_back(it->data() - begin);
+ if (linesForInput.empty())
+ linesForInput.push_back(0);
+ }
+ // as above: the first line starts at byte 0 and is always present
+ auto lineStartOffset = std::prev(
+ std::upper_bound(linesForInput.begin(), linesForInput.end(), offset));
+
+ result.line = 1 + (lineStartOffset - linesForInput.begin());
+ result.column = 1 + (offset - *lineStartOffset);
+ return result;
+}
+
+
+
/* Symbol table. */
size_t SymbolTable::totalSize() const
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index f0265a896..e5755bb99 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -7,7 +7,6 @@
#include "value.hh"
#include "symbol-table.hh"
#include "error.hh"
-#include "chunked-vector.hh"
#include "position.hh"
#include "eval-error.hh"
#include "pos-idx.hh"
diff --git a/src/libexpr/parser-state.hh b/src/libexpr/parser-state.hh
index 4a8b59f08..3305e05b6 100644
--- a/src/libexpr/parser-state.hh
+++ b/src/libexpr/parser-state.hh
@@ -24,20 +24,15 @@ struct ParserLocation
int last_line, last_column;
// backup to recover from yyless(0)
- int stashed_first_line, stashed_first_column;
- int stashed_last_line, stashed_last_column;
+ int stashed_first_column, stashed_last_column;
void stash() {
- stashed_first_line = first_line;
stashed_first_column = first_column;
- stashed_last_line = last_line;
stashed_last_column = last_column;
}
void unstash() {
- first_line = stashed_first_line;
first_column = stashed_first_column;
- last_line = stashed_last_line;
last_column = stashed_last_column;
}
};
@@ -275,7 +270,7 @@ inline Expr * ParserState::stripIndentation(const PosIdx pos,
inline PosIdx ParserState::at(const ParserLocation & loc)
{
- return positions.add(origin, loc.first_line, loc.first_column);
+ return positions.add(origin, loc.first_column);
}
}
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 727ee94b4..5424d8741 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -435,7 +435,7 @@ Expr * parseExprFromBuf(
.symbols = symbols,
.positions = positions,
.basePath = basePath,
- .origin = {origin},
+ .origin = positions.addOrigin(origin, length),
.s = astSymbols,
};
diff --git a/src/libexpr/pos-idx.hh b/src/libexpr/pos-idx.hh
index 9949f1dc5..e94fd85c6 100644
--- a/src/libexpr/pos-idx.hh
+++ b/src/libexpr/pos-idx.hh
@@ -6,6 +6,7 @@ namespace nix {
class PosIdx
{
+ friend struct LazyPosAcessors;
friend class PosTable;
private:
diff --git a/src/libexpr/pos-table.hh b/src/libexpr/pos-table.hh
index 1decf3c85..0b60c4f6d 100644
--- a/src/libexpr/pos-table.hh
+++ b/src/libexpr/pos-table.hh
@@ -7,6 +7,7 @@
#include "chunked-vector.hh"
#include "pos-idx.hh"
#include "position.hh"
+#include "sync.hh"
namespace nix {
@@ -17,66 +18,68 @@ public:
{
friend PosTable;
private:
- // must always be invalid by default, add() replaces this with the actual value.
- // subsequent add() calls use this index as a token to quickly check whether the
- // current origins.back() can be reused or not.
- mutable uint32_t idx = std::numeric_limits<uint32_t>::max();
-
- // Used for searching in PosTable::[].
- explicit Origin(uint32_t idx)
- : idx(idx)
- , origin{std::monostate()}
- {
- }
+ uint32_t offset;
+
+ Origin(Pos::Origin origin, uint32_t offset, size_t size):
+ offset(offset), origin(origin), size(size)
+ {}
public:
const Pos::Origin origin;
+ const size_t size;
- Origin(Pos::Origin origin)
- : origin(origin)
+ uint32_t offsetOf(PosIdx p) const
{
+ return p.id - 1 - offset;
}
};
- struct Offset
+private:
+ using Lines = std::vector<uint32_t>;
+
+ std::map<uint32_t, Origin> origins;
+ mutable Sync<std::map<uint32_t, Lines>> lines;
+
+ const Origin * resolve(PosIdx p) const
{
- uint32_t line, column;
- };
+ if (p.id == 0)
+ return nullptr;
-private:
- std::vector<Origin> origins;
- ChunkedVector<Offset, 8192> offsets;
+ const auto idx = p.id - 1;
+ /* we want the last key <= idx, so we'll take prev(first key > idx).
+ this is guaranteed to never rewind origin.begin because the first
+ key is always 0. */
+ const auto pastOrigin = origins.upper_bound(idx);
+ return &std::prev(pastOrigin)->second;
+ }
public:
- PosTable()
- : offsets(1024)
+ Origin addOrigin(Pos::Origin origin, size_t size)
{
- origins.reserve(1024);
+ uint32_t offset = 0;
+ if (auto it = origins.rbegin(); it != origins.rend())
+ offset = it->first + it->second.size;
+ // +1 because all PosIdx are offset by 1 to begin with (because noPos == 0), and
+ // another +1 to ensure that all origins can point to EOF, eg on (invalid) empty inputs.
+ if (2 + offset + size < offset)
+ return Origin{origin, offset, 0};
+ return origins.emplace(offset, Origin{origin, offset, size}).first->second;
}
- PosIdx add(const Origin & origin, uint32_t line, uint32_t column)
+ PosIdx add(const Origin & origin, size_t offset)
{
- const auto idx = offsets.add({line, column}).second;
- if (origins.empty() || origins.back().idx != origin.idx) {
- origin.idx = idx;
- origins.push_back(origin);
- }
- return PosIdx(idx + 1);
+ if (offset > origin.size)
+ return PosIdx();
+ return PosIdx(1 + origin.offset + offset);
}
- Pos operator[](PosIdx p) const
+ Pos operator[](PosIdx p) const;
+
+ Pos::Origin originOf(PosIdx p) const
{
- if (p.id == 0 || p.id > offsets.size())
- return {};
- const auto idx = p.id - 1;
- /* we want the last key <= idx, so we'll take prev(first key > idx).
- this is guaranteed to never rewind origin.begin because the first
- key is always 0. */
- const auto pastOrigin = std::upper_bound(
- origins.begin(), origins.end(), Origin(idx), [](const auto & a, const auto & b) { return a.idx < b.idx; });
- const auto origin = *std::prev(pastOrigin);
- const auto offset = offsets[idx];
- return {offset.line, offset.column, origin.origin};
+ if (auto o = resolve(p))
+ return o->origin;
+ return std::monostate{};
}
};
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index a5b539202..77601e457 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -2492,6 +2492,54 @@ static RegisterPrimOp primop_unsafeGetAttrPos(PrimOp {
.fun = prim_unsafeGetAttrPos,
});
+// access to exact position information (ie, line and colum numbers) is deferred
+// due to the cost associated with calculating that information and how rarely
+// it is used in practice. this is achieved by creating thunks to otherwise
+// inaccessible primops that are not exposed as __op or under builtins to turn
+// the internal PosIdx back into a line and column number, respectively. exposing
+// these primops in any way would at best be not useful and at worst create wildly
+// indeterministic eval results depending on parse order of files.
+//
+// in a simpler world this would instead be implemented as another kind of thunk,
+// but each type of thunk has an associated runtime cost in the current evaluator.
+// as with black holes this cost is too high to justify another thunk type to check
+// for in the very hot path that is forceValue.
+static struct LazyPosAcessors {
+ PrimOp primop_lineOfPos{
+ .arity = 1,
+ .fun = [] (EvalState & state, PosIdx pos, Value * * args, Value & v) {
+ v.mkInt(state.positions[PosIdx(args[0]->integer)].line);
+ }
+ };
+ PrimOp primop_columnOfPos{
+ .arity = 1,
+ .fun = [] (EvalState & state, PosIdx pos, Value * * args, Value & v) {
+ v.mkInt(state.positions[PosIdx(args[0]->integer)].column);
+ }
+ };
+
+ Value lineOfPos, columnOfPos;
+
+ LazyPosAcessors()
+ {
+ lineOfPos.mkPrimOp(&primop_lineOfPos);
+ columnOfPos.mkPrimOp(&primop_columnOfPos);
+ }
+
+ void operator()(EvalState & state, const PosIdx pos, Value & line, Value & column)
+ {
+ Value * posV = state.allocValue();
+ posV->mkInt(pos.id);
+ line.mkApp(&lineOfPos, posV);
+ column.mkApp(&columnOfPos, posV);
+ }
+} makeLazyPosAccessors;
+
+void makePositionThunks(EvalState & state, const PosIdx pos, Value & line, Value & column)
+{
+ makeLazyPosAccessors(state, pos, line, column);
+}
+
/* Dynamic version of the `?' operator. */
static void prim_hasAttr(EvalState & state, const PosIdx pos, Value * * args, Value & v)
{
diff --git a/src/libexpr/primops.hh b/src/libexpr/primops.hh
index 45486608f..9f76975db 100644
--- a/src/libexpr/primops.hh
+++ b/src/libexpr/primops.hh
@@ -51,4 +51,6 @@ void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Valu
*/
void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v);
+void makePositionThunks(EvalState & state, const PosIdx pos, Value & line, Value & column);
+
}
diff --git a/tests/functional/lang/eval-okay-unsafeGetAttrPos.exp b/tests/functional/lang/eval-okay-unsafeGetAttrPos.exp
new file mode 100644
index 000000000..c48e03014
--- /dev/null
+++ b/tests/functional/lang/eval-okay-unsafeGetAttrPos.exp
@@ -0,0 +1 @@
+{ column = 4; file = "/pwd/lang/eval-okay-unsafeGetAttrPos.imported-nix"; line = 6; }
diff --git a/tests/functional/lang/eval-okay-unsafeGetAttrPos.imported-nix b/tests/functional/lang/eval-okay-unsafeGetAttrPos.imported-nix
new file mode 100644
index 000000000..bdc364e76
--- /dev/null
+++ b/tests/functional/lang/eval-okay-unsafeGetAttrPos.imported-nix
@@ -0,0 +1,4 @@
+(
+
+
+ { y = "x"; })
diff --git a/tests/functional/lang/eval-okay-unsafeGetAttrPos.nix b/tests/functional/lang/eval-okay-unsafeGetAttrPos.nix
new file mode 100644
index 000000000..6d2cb86a6
--- /dev/null
+++ b/tests/functional/lang/eval-okay-unsafeGetAttrPos.nix
@@ -0,0 +1,4 @@
+let
+ pos = builtins.unsafeGetAttrPos "y" (import ./eval-okay-unsafeGetAttrPos.imported-nix);
+in
+pos
diff --git a/tests/unit/libexpr/value/print.cc b/tests/unit/libexpr/value/print.cc
index aabf156c2..d2d699a64 100644
--- a/tests/unit/libexpr/value/print.cc
+++ b/tests/unit/libexpr/value/print.cc
@@ -110,8 +110,8 @@ TEST_F(ValuePrintingTests, vLambda)
.up = nullptr,
.values = { }
};
- PosTable::Origin origin((std::monostate()));
- auto posIdx = state.positions.add(origin, 1, 1);
+ PosTable::Origin origin = state.positions.addOrigin(std::monostate(), 1);
+ auto posIdx = state.positions.add(origin, 0);
auto body = ExprInt(0);
auto formals = Formals {};
@@ -558,8 +558,8 @@ TEST_F(ValuePrintingTests, ansiColorsLambda)
.up = nullptr,
.values = { }
};
- PosTable::Origin origin((std::monostate()));
- auto posIdx = state.positions.add(origin, 1, 1);
+ PosTable::Origin origin = state.positions.addOrigin(std::monostate(), 1);
+ auto posIdx = state.positions.add(origin, 0);
auto body = ExprInt(0);
auto formals = Formals {};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 13:27:17 +0000