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Rejigger output mechanism from script to just use pipes.
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@khuey
khuey committed Mar 29, 2024
1 parent f15e770 commit 1cdfd78
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Showing 2 changed files with 74 additions and 75 deletions.
58 changes: 25 additions & 33 deletions scripts/rr-gdb-script-host.py
View file
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
#!/usr/bin/env python3
""" rr-gdb-script-host.py <output> <user-gdb-script> <primary binary name>"""
""" rr-gdb-script-host.py <user-gdb-script> <primary binary name>"""
# Performs a limited emulation of the runtime environment of gdb scripts so that
# we can run them for `rr sources` to locate debug information.
from typing import Optional, List, Callable
Expand Down Expand Up @@ -157,36 +157,28 @@ def events(self) -> GdbApiEvents:
self._events = GdbApiEvents(self.gdb)
return self._events

def synchronize():
os.kill(os.getpid(), signal.SIGSTOP)

if __name__ == '__main__':
with open(sys.argv[1], 'w') as output:
with open(sys.argv[2], 'r') as user_script_file:
user_script = user_script_file.read()
host = GdbScriptHost(sys.argv[3])
try:
host.execute_script(user_script)
except NameError as e:
if getattr(e, "name", None) == "python" or e == "NameError: name 'python' is not defined":
# This might be a gdb script that wraps a python script.
start = user_script.find("python") + len("python")
end = user_script.find("end")
if end == -1:
raise(e)
user_script = user_script[start:end]
try:
host.execute_script(user_script)
except:
raise(e)

print(host.debug_file_directory, file=output, flush=True)
print(host._dir, file=output, flush=True)
synchronize()
for line in sys.stdin:
line = line.rstrip()
logging.debug("Processing %s"%line)
host.new_objfile(line)
print(host.debug_file_directory, file=output, flush=True)
print(host._dir, file=output, flush=True)
synchronize()
with open(sys.argv[1], 'r') as user_script_file:
user_script = user_script_file.read()
host = GdbScriptHost(sys.argv[2])
try:
host.execute_script(user_script)
except NameError as e:
if getattr(e, "name", None) == "python" or e == "NameError: name 'python' is not defined":
# This might be a gdb script that wraps a python script.
start = user_script.find("python") + len("python")
end = user_script.find("end")
if end == -1:
raise(e)
user_script = user_script[start:end]
try:
host.execute_script(user_script)
except:
raise(e)

print("%s\n%s" % (host.debug_file_directory, host._dir), flush=True)
for line in sys.stdin:
line = line.rstrip()
logging.debug("Processing %s"%line)
host.new_objfile(line)
print("%s\n%s" % (host.debug_file_directory, host._dir), flush=True)
91 changes: 49 additions & 42 deletions src/SourcesCommand.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -148,8 +148,8 @@ struct DebugDirs {
};

/// Manages integration with rr-gdb-script-host.py to allow a gdb script to
/// control which directories we search. If pipe_fd is open we have a
/// python child process. If pipe_fd is closed then everything here
/// control which directories we search. If input_pipe_fd is open we have a
/// python child process. If input_pipe_fd is closed then everything here
/// becomes a no-op.
class DebugDirManager {
public:
Expand All @@ -165,44 +165,42 @@ class DebugDirManager {
DebugDirManager(const DebugDirManager&) = delete;
DebugDirManager& operator=(const DebugDirManager&) = delete;

void synchronize();
DebugDirs read_result();

ScopedFd pipe_fd;
ScopedFd input_pipe_fd;
ScopedFd output_pipe_fd;
pid_t pid;
FILE* output_file;
};

DebugDirManager::~DebugDirManager() {
if (!pipe_fd.is_open()) {
if (!input_pipe_fd.is_open()) {
return;
}

pipe_fd.close();
input_pipe_fd.close();
output_pipe_fd.close();

int status;
if (waitpid(pid, &status, 0) == -1) {
FATAL() << "Failed to wait on gdb script host";
}

if (!(WIFEXITED(status) && WEXITSTATUS(status) == 0)) {
FATAL() << "gdb script host in unexpected state " << HEX(status);
}
}

DebugDirManager::DebugDirManager(const string& program, const string& gdb_script)
: pid(-1), output_file(nullptr)
: pid(-1)
{
if (gdb_script.empty()) {
return;
}

TempFile output_file = create_temporary_file("rr-gdb-script-host-output-XXXXXX");

int stdin_pipe_fds[2];
if (pipe(stdin_pipe_fds) == -1) {
FATAL();
}
int stdout_pipe_fds[2];
if (pipe(stdout_pipe_fds) == -1) {
FATAL();
}

posix_spawn_file_actions_t file_actions;
int ret = posix_spawn_file_actions_init(&file_actions);
Expand All @@ -216,15 +214,27 @@ DebugDirManager::DebugDirManager(const string& program, const string& gdb_script
FATAL() << "posix_spawn_file_actions_addclose failed with " << ret;
}

// Close unused read end in the child.
ret = posix_spawn_file_actions_addclose(&file_actions, stdout_pipe_fds[0]);
if (ret != 0) {
FATAL() << "posix_spawn_file_actions_addclose failed with " << ret;
}

// Replace child's stdin with the read end.
ret = posix_spawn_file_actions_adddup2(&file_actions, stdin_pipe_fds[0], 0);
if (ret != 0) {
FATAL() << "posix_spawn_file_actions_adddup2 failed with " << ret;
}

// Replace child's stdout with the write end.
ret = posix_spawn_file_actions_adddup2(&file_actions, stdout_pipe_fds[1], 1);
if (ret != 0) {
FATAL() << "posix_spawn_file_actions_adddup2 failed with " << ret;
}

string gdb_script_host_path = resource_path() + "bin/rr-gdb-script-host.py";
pid_t pid;
vector<string> gdb_script_host_argv_vec = { gdb_script_host_path, output_file.name, gdb_script, program };
vector<string> gdb_script_host_argv_vec = { gdb_script_host_path, gdb_script, program };
StringVectorToCharArray gdb_script_host_argv(gdb_script_host_argv_vec);
ret = posix_spawn(&pid, gdb_script_host_path.c_str(), &file_actions, nullptr,
gdb_script_host_argv.get(), environ);
Expand All @@ -236,33 +246,28 @@ DebugDirManager::DebugDirManager(const string& program, const string& gdb_script
posix_spawn_file_actions_destroy(&file_actions);

close(stdin_pipe_fds[0]);
close(stdout_pipe_fds[1]);

this->pid = pid;
this->pipe_fd = ScopedFd(stdin_pipe_fds[1]);
this->output_file = fopen(output_file.name.c_str(), "r");
if (!this->output_file) {
FATAL() << "Failed to open gdb script host result file " << output_file.name;
}

synchronize();
this->input_pipe_fd = ScopedFd(stdin_pipe_fds[1]);
this->output_pipe_fd = ScopedFd(stdout_pipe_fds[0]);
}

DebugDirs DebugDirManager::process_one_binary(const string& binary_path) {
if (!pipe_fd.is_open()) {
if (!input_pipe_fd.is_open()) {
return DebugDirs();
}

auto len = binary_path.length();
size_t written = write(pipe_fd, binary_path.c_str(), len);
size_t written = write(input_pipe_fd, binary_path.c_str(), len);
if (written != len) {
FATAL() << "Failed to write filename";
}
written = write(pipe_fd, "\n", 1);
written = write(input_pipe_fd, "\n", 1);
if (written != 1) {
FATAL() << "Failed to write trailing newline";
}

synchronize();
return read_result();
}

Expand All @@ -271,12 +276,26 @@ DebugDirs DebugDirManager::read_result() {
DebugDirs result;
size_t index;
const char delimiter[2] = ":";
int output_fd;
FILE* output = NULL;

if (!pipe_fd.is_open()) {
if (!input_pipe_fd.is_open()) {
return result;
}

if (!fgets(buf, sizeof(buf) - 1, output_file)) {
// Convert our fd to a FILE so we can use fgets instead of writing
// our own buffering code.
output_fd = dup(output_pipe_fd);
if (output_fd < 0) {
FATAL() << "Failed to dup output_pipe_fd";
}

output = fdopen(output_fd, "r");
if (!output) {
FATAL() << "Failed to fdopen(output_fd)";
}

if (!fgets(buf, sizeof(buf) - 1, output)) {
FATAL() << "Failed to read gdb script output";
}
index = strcspn(buf, "\n");
Expand All @@ -291,7 +310,7 @@ DebugDirs DebugDirManager::read_result() {
token = strtok(nullptr, delimiter);
}

if (!fgets(buf, sizeof(buf) - 1, output_file)) {
if (!fgets(buf, sizeof(buf) - 1, output)) {
FATAL() << "Failed to read gdb script output";
}
index = strcspn(buf, "\n");
Expand All @@ -311,22 +330,10 @@ DebugDirs DebugDirManager::read_result() {
token = strtok(nullptr, delimiter);
}

fclose(output);
return result;
}

void DebugDirManager::synchronize() {
int status;
if (waitpid(pid, &status, WUNTRACED) == -1) {
FATAL() << "Failed to wait on gdb script host";
}

if (!(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP)) {
FATAL() << "gdb script host in unexpected state " << HEX(status);
}

kill(pid, SIGCONT);
}

// Resolve a file name relative to a compilation directory and relative directory.
// file_name cannot be null, but the others can be.
// Takes into account the original file name as follows:
Expand Down

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