diff options
| -rw-r--r-- | src/libexpr/eval.cc | 462 |
1 files changed, 274 insertions, 188 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 6e78f00f5..456bc25f3 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -8,6 +8,10 @@ #include "globals.hh" +#define LocalNoInline(f) static f __attribute__((noinline)); f +#define LocalNoInlineNoReturn(f) static f __attribute__((noinline, noreturn)); f + + namespace nix { @@ -29,6 +33,42 @@ void EvalState::addPrimOp(const string & name, } +/* Every "format" object (even temporary) takes up a few hundred bytes + of stack space, which is a real killer in the recursive + evaluator. So here are some helper functions for throwing + exceptions. */ + +LocalNoInlineNoReturn(void throwEvalError(const char * s)) +{ + throw EvalError(s); +} + +LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2)) +{ + throw EvalError(format(s) % s2); +} + +LocalNoInlineNoReturn(void throwTypeError(const char * s, const string & s2)) +{ + throw TypeError(format(s) % s2); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s)) +{ + e.addPrefix(s); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2)) +{ + e.addPrefix(format(s) % s2); +} + +LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2, const string & s3)) +{ + e.addPrefix(format(s) % s2 % s3); +} + + /* Substitute an argument set into the body of a function. */ static Expr substArgs(EvalState & state, Expr body, ATermList formals, Expr arg) @@ -111,7 +151,7 @@ static Expr substArgs(EvalState & state, to attributes substituted with selection expressions on the original set. E.g., e = `rec {x = f x y; y = x;}' becomes `{x = f (e.x) (e.y); y = e.x;}'. */ -ATerm expandRec(ATerm e, ATermList rbnds, ATermList nrbnds) +LocalNoInline(ATerm expandRec(ATerm e, ATermList rbnds, ATermList nrbnds)) { ATerm name; Expr e2; @@ -147,7 +187,7 @@ ATerm expandRec(ATerm e, ATermList rbnds, ATermList nrbnds) } -static Expr updateAttrs(Expr e1, Expr e2) +LocalNoInline(Expr updateAttrs(Expr e1, Expr e2)) { /* Note: e1 and e2 should be in normal form. */ @@ -164,7 +204,7 @@ string evalString(EvalState & state, Expr e, PathSet & context) e = evalExpr(state, e); string s; if (!matchStr(e, s, context)) - throw TypeError(format("value is %1% while a string was expected") % showType(e)); + throwTypeError("value is %1% while a string was expected", showType(e)); return s; } @@ -185,7 +225,7 @@ int evalInt(EvalState & state, Expr e) e = evalExpr(state, e); int i; if (!matchInt(e, i)) - throw TypeError(format("value is %1% while an integer was expected") % showType(e)); + throwTypeError("value is %1% while an integer was expected", showType(e)); return i; } @@ -195,7 +235,7 @@ bool evalBool(EvalState & state, Expr e) e = evalExpr(state, e); if (e == eTrue) return true; else if (e == eFalse) return false; - else throw TypeError(format("value is %1% while a boolean was expected") % showType(e)); + else throwTypeError("value is %1% while a boolean was expected", showType(e)); } @@ -204,7 +244,7 @@ ATermList evalList(EvalState & state, Expr e) e = evalExpr(state, e); ATermList list; if (!matchList(e, list)) - throw TypeError(format("value is %1% while a list was expected") % showType(e)); + throwTypeError("value is %1% while a list was expected", showType(e)); return list; } @@ -292,7 +332,7 @@ string coerceToString(EvalState & state, Expr e, PathSet & context, } } - throw TypeError(format("cannot coerce %1% to a string") % showType(e)); + throwTypeError("cannot coerce %1% to a string", showType(e)); } @@ -362,6 +402,215 @@ Expr autoCallFunction(Expr e, const ATermMap & args) } +/* Evaluation of various language constructs. These have been taken + out of evalExpr2 to reduce stack space usage. (GCC is really dumb + about stack space: it just adds up all the local variables and + temporaries of every scope into one huge stack frame. This is + really bad for deeply recursive functions.) */ + + +LocalNoInline(Expr evalVar(EvalState & state, ATerm name)) +{ + ATerm primOp = state.primOps.get(name); + if (!primOp) + throw EvalError(format("impossible: undefined variable `%1%'") % aterm2String(name)); + int arity; + ATermBlob fun; + if (!matchPrimOpDef(primOp, arity, fun)) abort(); + if (arity == 0) + /* !!! backtrace for primop call */ + return ((PrimOp) ATgetBlobData(fun)) (state, ATermVector()); + else + return makePrimOp(arity, fun, ATempty); +} + + +LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg)) +{ + ATermList formals; + ATerm pos, name; + Expr body; + + /* Evaluate the left-hand side. */ + fun = evalExpr(state, fun); + + /* Is it a primop or a function? */ + int arity; + ATermBlob funBlob; + ATermList args; + if (matchPrimOp(fun, arity, funBlob, args)) { + args = ATinsert(args, arg); + if (ATgetLength(args) == arity) { + /* Put the arguments in a vector in reverse (i.e., + actual) order. */ + ATermVector args2(arity); + for (ATermIterator i(args); i; ++i) + args2[--arity] = *i; + /* !!! backtrace for primop call */ + return ((PrimOp) ATgetBlobData(funBlob)) + (state, args2); + } else + /* Need more arguments, so propagate the primop. */ + return makePrimOp(arity, funBlob, args); + } + + else if (matchFunction(fun, formals, body, pos)) { + arg = evalExpr(state, arg); + try { + return evalExpr(state, substArgs(state, body, formals, arg)); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the function at %1%:\n", + showPos(pos)); + throw; + } + } + + else if (matchFunction1(fun, name, body, pos)) { + try { + ATermMap subs(1); + subs.set(name, arg); + return evalExpr(state, substitute(Substitution(0, &subs), body)); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the function at %1%:\n", + showPos(pos)); + throw; + } + } + + else throwTypeError( + "the left-hand side of the function call is neither a function nor a primop (built-in operation) but %1%", + showType(fun)); +} + + +LocalNoInline(Expr evalSelect(EvalState & state, Expr e, ATerm name)) +{ + ATerm pos; + string s = aterm2String(name); + Expr a = queryAttr(evalExpr(state, e), s, pos); + if (!a) throwEvalError("attribute `%1%' missing", s); + try { + return evalExpr(state, a); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the attribute `%1%' at %2%:\n", + s, showPos(pos)); + throw; + } +} + + +LocalNoInline(Expr evalAssert(EvalState & state, Expr cond, Expr body, ATerm pos)) +{ + if (!evalBool(state, cond)) + throw AssertionError(format("assertion failed at %1%") % showPos(pos)); + return evalExpr(state, body); +} + + +LocalNoInline(Expr evalWith(EvalState & state, Expr defs, Expr body, ATerm pos)) +{ + ATermMap attrs; + try { + defs = evalExpr(state, defs); + queryAllAttrs(defs, attrs); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the `with' definitions at %1%:\n", + showPos(pos)); + throw; + } + try { + body = substitute(Substitution(0, &attrs), body); + checkVarDefs(state.primOps, body); + return evalExpr(state, body); + } catch (Error & e) { + addErrorPrefix(e, "while evaluating the `with' body at %1%:\n", + showPos(pos)); + throw; + } +} + + +LocalNoInline(Expr evalHasAttr(EvalState & state, Expr e, ATerm name)) +{ + ATermMap attrs; + queryAllAttrs(evalExpr(state, e), attrs); + return makeBool(attrs.get(name) != 0); +} + + +LocalNoInline(Expr evalPlusConcat(EvalState & state, Expr e)) +{ + Expr e1, e2; + ATermList es; + + ATermVector args; + + if (matchOpPlus(e, e1, e2)) { + + /* !!! Awful compatibility hack for `drv + /path'. + According to regular concatenation, /path should be + copied to the store and its store path should be + appended to the string. However, in Nix <= 0.10, /path + was concatenated. So handle that case separately, but + do print out a warning. This code can go in Nix 0.12, + maybe. */ + e1 = evalExpr(state, e1); + e2 = evalExpr(state, e2); + + ATermList as; + ATerm p; + if (matchAttrs(e1, as) && matchPath(e2, p)) { + static bool haveWarned = false; + warnOnce(haveWarned, format( + "concatenation of a derivation and a path is deprecated; " + "you should write `drv + \"%1%\"' instead of `drv + %1%'") + % aterm2String(p)); + PathSet context; + return makeStr( + coerceToString(state, makeSelect(e1, toATerm("outPath")), context) + + aterm2String(p), context); + } + + args.push_back(e1); + args.push_back(e2); + } + + else if (matchConcatStrings(e, es)) + for (ATermIterator i(es); i; ++i) args.push_back(*i); + + try { + return concatStrings(state, args); + } catch (Error & e) { + addErrorPrefix(e, "in a string concatenation:\n"); + throw; + } +} + + +LocalNoInline(Expr evalSubPath(EvalState & state, Expr e1, Expr e2)) +{ + static bool haveWarned = false; + warnOnce(haveWarned, "the subpath operator (~) is deprecated, use string concatenation (+) instead"); + ATermVector args; + args.push_back(e1); + args.push_back(e2); + return concatStrings(state, args, "/"); +} + + +LocalNoInline(Expr evalOpConcat(EvalState & state, Expr e1, Expr e2)) +{ + try { + ATermList l1 = evalList(state, e1); + ATermList l2 = evalList(state, e2); + return makeList(ATconcat(l1, l2)); + } catch (Error & e) { + addErrorPrefix(e, "in a list concatenation:\n"); + throw; + } +} + + static char * deepestStack = (char *) -1; /* for measuring stack usage */ @@ -370,7 +619,7 @@ Expr evalExpr2(EvalState & state, Expr e) char x; if (&x < deepestStack) deepestStack = &x; - Expr e1, e2, e3, e4; + Expr e1, e2, e3; ATerm name, pos; AFun sym = ATgetAFun(e); @@ -394,91 +643,13 @@ Expr evalExpr2(EvalState & state, Expr e) /* Any encountered variables must be primops (since undefined variables are detected after parsing). */ - if (matchVar(e, name)) { - ATerm primOp = state.primOps.get(name); - if (!primOp) - throw EvalError(format("impossible: undefined variable `%1%'") % aterm2String(name)); - int arity; - ATermBlob fun; - if (!matchPrimOpDef(primOp, arity, fun)) abort(); - if (arity == 0) - /* !!! backtrace for primop call */ - return ((PrimOp) ATgetBlobData(fun)) (state, ATermVector()); - else - return makePrimOp(arity, fun, ATempty); - } + if (matchVar(e, name)) return evalVar(state, name); /* Function application. */ - if (matchCall(e, e1, e2)) { - - ATermList formals; - ATerm pos; - - /* Evaluate the left-hand side. */ - e1 = evalExpr(state, e1); - - /* Is it a primop or a function? */ - int arity; - ATermBlob fun; - ATermList args; - if (matchPrimOp(e1, arity, fun, args)) { - args = ATinsert(args, e2); - if (ATgetLength(args) == arity) { - /* Put the arguments in a vector in reverse (i.e., - actual) order. */ - ATermVector args2(arity); - for (ATermIterator i(args); i; ++i) - args2[--arity] = *i; - /* !!! backtrace for primop call */ - return ((PrimOp) ATgetBlobData((ATermBlob) fun)) - (state, args2); - } else - /* Need more arguments, so propagate the primop. */ - return makePrimOp(arity, fun, args); - } - - else if (matchFunction(e1, formals, e4, pos)) { - e2 = evalExpr(state, e2); - try { - return evalExpr(state, substArgs(state, e4, formals, e2)); - } catch (Error & e) { - e.addPrefix(format("while evaluating the function at %1%:\n") - % showPos(pos)); - throw; - } - } - - else if (matchFunction1(e1, name, e4, pos)) { - try { - ATermMap subs(1); - subs.set(name, e2); - return evalExpr(state, substitute(Substitution(0, &subs), e4)); - } catch (Error & e) { - e.addPrefix(format("while evaluating the function at %1%:\n") - % showPos(pos)); - throw; - } - } - - else throw TypeError( - format("the left-hand side of the function call is neither a function nor a primop (built-in operation) but %1%") - % showType(e1)); - } + if (matchCall(e, e1, e2)) return evalCall(state, e1, e2); /* Attribute selection. */ - if (matchSelect(e, e1, name)) { - ATerm pos; - string s1 = aterm2String(name); - Expr a = queryAttr(evalExpr(state, e1), s1, pos); - if (!a) throw EvalError(format("attribute `%1%' missing") % s1); - try { - return evalExpr(state, a); - } catch (Error & e) { - e.addPrefix(format("while evaluating the attribute `%1%' at %2%:\n") - % s1 % showPos(pos)); - throw; - } - } + if (matchSelect(e, e1, name)) return evalSelect(state, e1, name); /* Mutually recursive sets. */ ATermList rbnds, nrbnds; @@ -486,41 +657,14 @@ Expr evalExpr2(EvalState & state, Expr e) return expandRec(e, rbnds, nrbnds); /* Conditionals. */ - if (matchIf(e, e1, e2, e3)) { - if (evalBool(state, e1)) - return evalExpr(state, e2); - else - return evalExpr(state, e3); - } + if (matchIf(e, e1, e2, e3)) + return evalExpr(state, evalBool(state, e1) ? e2 : e3); /* Assertions. */ - if (matchAssert(e, e1, e2, pos)) { - if (!evalBool(state, e1)) - throw AssertionError(format("assertion failed at %1%") % showPos(pos)); - return evalExpr(state, e2); - } + if (matchAssert(e, e1, e2, pos)) return evalAssert(state, e1, e2, pos); /* Withs. */ - if (matchWith(e, e1, e2, pos)) { - ATermMap attrs; - try { - e1 = evalExpr(state, e1); - queryAllAttrs(e1, attrs); - } catch (Error & e) { - e.addPrefix(format("while evaluating the `with' definitions at %1%:\n") - % showPos(pos)); - throw; - } - try { - e2 = substitute(Substitution(0, &attrs), e2); - checkVarDefs(state.primOps, e2); - return evalExpr(state, e2); - } catch (Error & e) { - e.addPrefix(format("while evaluating the `with' body at %1%:\n") - % showPos(pos)); - throw; - } - } + if (matchWith(e, e1, e2, pos)) return evalWith(state, e1, e2, pos); /* Generic equality/inequality. Note that the behaviour on composite data (lists, attribute sets) and functions is @@ -555,88 +699,31 @@ Expr evalExpr2(EvalState & state, Expr e) return updateAttrs(evalExpr(state, e1), evalExpr(state, e2)); /* Attribute existence test (?). */ - if (matchOpHasAttr(e, e1, name)) { - ATermMap attrs; - queryAllAttrs(evalExpr(state, e1), attrs); - return makeBool(attrs.get(name) != 0); - } + if (matchOpHasAttr(e, e1, name)) return evalHasAttr(state, e1, name); /* String or path concatenation. */ - ATermList es = ATempty; - if (matchOpPlus(e, e1, e2) || matchConcatStrings(e, es)) { - ATermVector args; - if (matchOpPlus(e, e1, e2)) { - - /* !!! Awful compatibility hack for `drv + /path'. - According to regular concatenation, /path should be - copied to the store and its store path should be - appended to the string. However, in Nix <= 0.10, /path - was concatenated. So handle that case separately, but - do print out a warning. This code can go in Nix 0.12, - maybe. */ - e1 = evalExpr(state, e1); - e2 = evalExpr(state, e2); - - ATermList as; - ATerm p; - if (matchAttrs(e1, as) && matchPath(e2, p)) { - static bool haveWarned = false; - warnOnce(haveWarned, format( - "concatenation of a derivation and a path is deprecated; " - "you should write `drv + \"%1%\"' instead of `drv + %1%'") - % aterm2String(p)); - PathSet context; - return makeStr( - coerceToString(state, makeSelect(e1, toATerm("outPath")), context) - + aterm2String(p), context); - } - - args.push_back(e1); - args.push_back(e2); - } else - for (ATermIterator i(es); i; ++i) args.push_back(*i); - - try { - return concatStrings(state, args); - } catch (Error & e) { - e.addPrefix(format("in a string concatenation:\n")); - throw; - } - } + if (sym == symOpPlus || sym == symConcatStrings) + return evalPlusConcat(state, e); /* Backwards compatability: subpath operator (~). */ - if (matchSubPath(e, e1, e2)) { - static bool haveWarned = false; - warnOnce(haveWarned, "the subpath operator (~) is deprecated, use string concatenation (+) instead"); - ATermVector args; - args.push_back(e1); - args.push_back(e2); - return concatStrings(state, args, "/"); - } + if (matchSubPath(e, e1, e2)) return evalSubPath(state, e1, e2); /* List concatenation. */ - if (matchOpConcat(e, e1, e2)) { - try { - ATermList l1 = evalList(state, e1); - ATermList l2 = evalList(state, e2); - return makeList(ATconcat(l1, l2)); - } catch (Error & e) { - e.addPrefix(format("in a list concatenation:\n")); - throw; - } - } + if (matchOpConcat(e, e1, e2)) return evalOpConcat(state, e1, e2); /* Barf. */ - throw badTerm("invalid expression", e); + abort(); } Expr evalExpr(EvalState & state, Expr e) { checkInterrupt(); - + +#if 0 startNest(nest, lvlVomit, format("evaluating expression: %1%") % e); +#endif state.nrEvaluated++; @@ -645,7 +732,7 @@ Expr evalExpr(EvalState & state, Expr e) Expr nf = state.normalForms.get(e); if (nf) { if (nf == makeBlackHole()) - throw EvalError("infinite recursion encountered"); + throwEvalError("infinite recursion encountered"); state.nrCached++; return nf; } @@ -655,7 +742,6 @@ Expr evalExpr(EvalState & state, Expr e) try { nf = evalExpr2(state, e); } catch (Error & err) { - debug("removing black hole"); state.normalForms.remove(e); throw; } |