From 9088dee9e265db8176b61e53ac43a916fdd34a3d Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 8 Mar 2006 14:11:19 +0000 Subject: [PATCH] * Some refactoring of the exception handling code so that we can catch Nix expression assertion failures. --- src/libexpr/eval.cc | 32 +++++++++++++++++++------------- src/libexpr/eval.hh | 4 ++++ src/libexpr/primops.cc | 10 ++++++---- src/libutil/util.cc | 7 +++++++ src/libutil/util.hh | 14 +++++++++----- 5 files changed, 45 insertions(+), 22 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 9a6d414db7..045e5f632f 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -223,8 +223,9 @@ Expr evalExpr2(EvalState & state, Expr e) try { return evalExpr(state, substArgs(e4, formals, e2)); } catch (Error & e) { - throw Error(format("while evaluating the function at %1%:\n%2%") - % showPos(pos) % e.msg()); + e.addPrefix(format("while evaluating the function at %1%:\n") + % showPos(pos)); + throw; } } @@ -234,8 +235,9 @@ Expr evalExpr2(EvalState & state, Expr e) subs.set(name, e2); return evalExpr(state, substitute(subs, e4)); } catch (Error & e) { - throw Error(format("while evaluating the function at %1%:\n%2%") - % showPos(pos) % e.msg()); + e.addPrefix(format("while evaluating the function at %1%:\n") + % showPos(pos)); + throw; } } @@ -251,8 +253,9 @@ Expr evalExpr2(EvalState & state, Expr e) try { return evalExpr(state, a); } catch (Error & e) { - throw Error(format("while evaluating the attribute `%1%' at %2%:\n%3%") - % s1 % showPos(pos) % e.msg()); + e.addPrefix(format("while evaluating the attribute `%1%' at %2%:\n") + % s1 % showPos(pos)); + throw; } } @@ -272,7 +275,7 @@ Expr evalExpr2(EvalState & state, Expr e) /* Assertions. */ if (matchAssert(e, e1, e2, pos)) { if (!evalBool(state, e1)) - throw Error(format("assertion failed at %1%") % showPos(pos)); + throw AssertionError(format("assertion failed at %1%") % showPos(pos)); return evalExpr(state, e2); } @@ -283,16 +286,18 @@ Expr evalExpr2(EvalState & state, Expr e) e1 = evalExpr(state, e1); queryAllAttrs(e1, attrs); } catch (Error & e) { - throw Error(format("while evaluating the `with' definitions at %1%:\n%2%") - % showPos(pos) % e.msg()); + e.addPrefix(format("while evaluating the `with' definitions at %1%:\n") + % showPos(pos)); + throw; } try { e2 = substitute(attrs, e2); checkVarDefs(state.primOps, e2); return evalExpr(state, e2); } catch (Error & e) { - throw Error(format("while evaluating the `with' body at %1%:\n%2%") - % showPos(pos) % e.msg()); + e.addPrefix(format("while evaluating the `with' body at %1%:\n") + % showPos(pos)); + throw; } } @@ -391,8 +396,9 @@ Expr evalFile(EvalState & state, const Path & path) try { return evalExpr(state, e); } catch (Error & e) { - throw Error(format("while evaluating the file `%1%':\n%2%") - % path % e.msg()); + e.addPrefix(format("while evaluating the file `%1%':\n") + % path); + throw; } } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index 5562066fda..11185159c1 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -37,6 +37,10 @@ struct EvalState }; +MakeError(EvalError, Error) +MakeError(AssertionError, EvalError) + + /* Evaluate an expression to normal form. */ Expr evalExpr(EvalState & state, Expr e); diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 310bca5ae9..31fff0b493 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -244,8 +244,9 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args) try { processBinding(state, value, drv, ss); } catch (Error & e) { - throw Error(format("while processing the derivation attribute `%1%' at %2%:\n%3%") - % key % showPos(pos) % e.msg()); + e.addPrefix(format("while processing the derivation attribute `%1%' at %2%:\n") + % key % showPos(pos)); + throw; } /* The `args' attribute is special: it supplies the @@ -547,8 +548,9 @@ static Expr primDependencyClosure(EvalState & state, const ATermVector & args) } } catch (Error & e) { - throw Error(format("while finding dependencies in `%1%':\n%2%") - % path % e.msg()); + e.addPrefix(format("while finding dependencies in `%1%':\n") + % path); + throw; } } diff --git a/src/libutil/util.cc b/src/libutil/util.cc index ee34cb18a5..0d970e69e3 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -25,6 +25,13 @@ Error::Error(const format & f) } +Error & Error::addPrefix(const format & f) +{ + err = f.str() + err; + return *this; +} + + SysError::SysError(const format & f) : Error(format("%1%: %2%") % f.str() % strerror(errno)) { diff --git a/src/libutil/util.hh b/src/libutil/util.hh index aac2acd173..05cf777f1e 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -26,6 +26,7 @@ public: ~Error() throw () { }; const char * what() const throw () { return err.c_str(); } const string & msg() const throw () { return err; } + Error & addPrefix(const format & f); }; class SysError : public Error @@ -34,11 +35,14 @@ public: SysError(const format & f); }; -class UsageError : public Error -{ -public: - UsageError(const format & f) : Error(f) { }; -}; +#define MakeError(newClass, superClass) \ + class newClass : public superClass \ + { \ + public: \ + newClass(const format & f) : superClass(f) { }; \ + }; + +MakeError(UsageError, Error) typedef list Strings;