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nix dev-shell: Improve environment handling

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Only variables that were marked as exported are exported in the dev
shell. Also, we no longer try to parse the function section of the env
file, fixing

  $ nix dev-shell
  error: shell environment '/nix/store/h7ama3kahb8lypf4nvjx34z06g9ncw4h-nixops-1.7pre20190926.4c7acbb-env' has unexpected line '/^[a-z]?"""/ {'
This commit is contained in:
Eelco Dolstra 2019-09-27 17:01:25 +02:00
parent 15b888c9a5
commit 9b9de3a5e3
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GPG key ID: 8170B4726D7198DE
1 changed files with 69 additions and 41 deletions
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110
src/nix/shell.cc
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@ -7,55 +7,76 @@
#include "affinity.hh"
#include "progress-bar.hh"
#include <regex>
using namespace nix;
struct Var
{
bool exported;
std::string value; // quoted string or array
};
struct BuildEnvironment
{
// FIXME: figure out which vars should be exported.
std::map<std::string, std::string> env;
std::map<std::string, std::string> functions;
std::map<std::string, Var> env;
std::string bashFunctions;
};
BuildEnvironment readEnvironment(const Path & path)
{
BuildEnvironment res;
auto lines = tokenizeString<Strings>(readFile(path), "\n");
std::set<std::string> exported;
auto getLine =
[&]() {
if (lines.empty())
throw Error("shell environment '%s' ends unexpectedly", path);
auto line = lines.front();
lines.pop_front();
return line;
};
auto file = readFile(path);
//auto file = readFile("/tmp/x");
while (!lines.empty()) {
auto line = getLine();
auto pos = file.cbegin();
auto eq = line.find('=');
if (eq != std::string::npos) {
std::string name(line, 0, eq);
std::string value(line, eq + 1);
// FIXME: parse arrays
res.env.insert({name, value});
static std::string varNameRegex =
R"re((?:[a-zA-Z_][a-zA-Z0-9_]*))re";
static std::regex declareRegex(
"^declare -x (" + varNameRegex + ")" +
R"re((?:="((?:[^"\\]|\\.)*)")?\n)re");
static std::string simpleStringRegex =
R"re((?:[a-zA-Z0-9_/:\.\-1\+]*))re";
static std::string quotedStringRegex =
R"re((?:\$?'[^']*'))re";
static std::string arrayRegex =
R"re((?:\(( *\[[^\]]+\]="(?:[^"\\]|\\.)*")*\)))re";
static std::regex varRegex(
"^(" + varNameRegex + ")=(" + simpleStringRegex + "|" + quotedStringRegex + "|" + arrayRegex + ")\n");
static std::regex functionRegex(
"^" + varNameRegex + " \\(\\) *\n");
while (pos != file.end()) {
std::smatch match;
if (std::regex_search(pos, file.cend(), match, declareRegex)) {
pos = match[0].second;
exported.insert(match[1]);
}
else if (hasSuffix(line, " () ")) {
std::string name(line, 0, line.size() - 4);
// FIXME: validate name
auto l = getLine();
if (l != "{ ") throw Error("shell environment '%s' has unexpected line '%s'", path, l);
std::string body;
while ((l = getLine()) != "}") {
body += l;
body += '\n';
}
res.functions.insert({name, body});
else if (std::regex_search(pos, file.cend(), match, varRegex)) {
pos = match[0].second;
res.env.insert({match[1], Var { (bool) exported.count(match[1]), match[2] }});
}
else throw Error("shell environment '%s' has unexpected line '%s'", path, line);
else if (std::regex_search(pos, file.cend(), match, functionRegex)) {
res.bashFunctions = std::string(pos, file.cend());
break;
}
else throw Error("shell environment '%s' has unexpected line '%s'",
path, file.substr(pos - file.cbegin(), 60));
}
return res;
@ -72,7 +93,16 @@ Path getDerivationEnvironment(ref<Store> store, Derivation drv)
if (builder != "bash")
throw Error("'nix shell' only works on derivations that use 'bash' as their builder");
drv.args = {"-c", "set -e; export IN_NIX_SHELL=impure; export dontAddDisableDepTrack=1; if [[ -n $stdenv ]]; then source $stdenv/setup; fi; set > $out"};
drv.args = {
"-c",
"set -e; "
"export IN_NIX_SHELL=impure; "
"export dontAddDisableDepTrack=1; "
"if [[ -n $stdenv ]]; then "
" source $stdenv/setup; "
"fi; "
"export > $out; "
"set >> $out "};
/* Remove derivation checks. */
drv.env.erase("allowedReferences");
@ -146,18 +176,16 @@ struct Common : InstallableCommand, MixProfile
out << "nix_saved_PATH=\"$PATH\"\n";
for (auto & i : buildEnvironment.env) {
// FIXME: shellEscape
// FIXME: figure out what to export
// FIXME: handle arrays
if (!ignoreVars.count(i.first) && !hasPrefix(i.first, "BASH_"))
out << fmt("export %s=%s\n", i.first, i.second);
if (!ignoreVars.count(i.first) && !hasPrefix(i.first, "BASH_")) {
out << fmt("%s=%s\n", i.first, i.second.value);
if (i.second.exported)
out << fmt("export %s\n", i.first);
}
}
out << "PATH=\"$PATH:$nix_saved_PATH\"\n";
for (auto & i : buildEnvironment.functions) {
out << fmt("%s () {\n%s\n}\n", i.first, i.second);
}
out << buildEnvironment.bashFunctions << "\n";
// FIXME: set outputs