LibSymbolClient+bt: Move bt logic to SymbolClient::symbolicate_thread()

Since this is useful in many places, let's have a common implementation
of walking the stack of a given thread via /proc and symbolicating each
of the frames.

3 files changed, 130 insertions, 113 deletions

diff --git a/Userland/Libraries/LibSymbolClient/Client.cpp b/Userland/Libraries/LibSymbolClient/Client.cpp
index e860493dc8..3ef06b44a4 100644
--- a/Userland/Libraries/LibSymbolClient/Client.cpp
+++ b/Userland/Libraries/LibSymbolClient/Client.cpp
@@ -24,6 +24,10 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <AK/JsonArray.h>
+#include <AK/JsonObject.h>
+#include <AK/JsonValue.h>
+#include <LibCore/File.h>
 #include <LibSymbolClient/Client.h>
 
 namespace SymbolClient {
@@ -58,4 +62,122 @@ Vector<Symbol> Client::symbolicate(const String& path, const Vector<FlatPtr>& ad
     return symbols;
 }
 
+Vector<Symbol> symbolicate_thread(pid_t pid, pid_t tid)
+{
+    struct RegionWithSymbols {
+        FlatPtr base { 0 };
+        size_t size { 0 };
+        String path;
+        bool is_relative { true };
+    };
+
+    Vector<FlatPtr> stack;
+    Vector<RegionWithSymbols> regions;
+
+    regions.append(RegionWithSymbols {
+        .base = 0xc0000000,
+        .size = 0x3fffffff,
+        .path = "/boot/Kernel",
+        .is_relative = false });
+
+    {
+
+        auto stack_path = String::formatted("/proc/{}/stacks/{}", pid, tid);
+        auto file_or_error = Core::File::open(stack_path, Core::IODevice::ReadOnly);
+        if (file_or_error.is_error()) {
+            warnln("Could not open {}: {}", stack_path, file_or_error.error());
+            return {};
+        }
+
+        auto json = JsonValue::from_string(file_or_error.value()->read_all());
+        if (!json.has_value() || !json.value().is_array()) {
+            warnln("Invalid contents in {}", stack_path);
+            return {};
+        }
+
+        stack.ensure_capacity(json.value().as_array().size());
+        for (auto& value : json.value().as_array().values()) {
+            stack.append(value.to_u32());
+        }
+    }
+
+    {
+        auto vm_path = String::formatted("/proc/{}/vm", pid);
+        auto file_or_error = Core::File::open(vm_path, Core::IODevice::ReadOnly);
+        if (file_or_error.is_error()) {
+            warnln("Could not open {}: {}", vm_path, file_or_error.error());
+            return {};
+        }
+
+        auto json = JsonValue::from_string(file_or_error.value()->read_all());
+        if (!json.has_value() || !json.value().is_array()) {
+            warnln("Invalid contents in {}", vm_path);
+            return {};
+        }
+
+        for (auto& region_value : json.value().as_array().values()) {
+            auto& region = region_value.as_object();
+            auto name = region.get("name").to_string();
+            auto address = region.get("address").to_u32();
+            auto size = region.get("size").to_u32();
+
+            String path;
+            if (name == "/usr/lib/Loader.so") {
+                path = name;
+            } else if (name.ends_with(": .text")) {
+                auto parts = name.split_view(':');
+                path = parts[0];
+                if (!path.starts_with('/'))
+                    path = String::formatted("/usr/lib/{}", path);
+            } else {
+                continue;
+            }
+
+            RegionWithSymbols r;
+            r.base = address;
+            r.size = size;
+            r.path = path;
+            regions.append(move(r));
+        }
+    }
+
+    auto client = SymbolClient::Client::construct();
+
+    Vector<Symbol> symbols;
+
+    for (auto address : stack) {
+        const RegionWithSymbols* found_region = nullptr;
+        for (auto& region : regions) {
+            if (address >= region.base && address < (region.base + region.size)) {
+                found_region = &region;
+                break;
+            }
+        }
+
+        if (!found_region) {
+            outln("{:p}  ??", address);
+            continue;
+        }
+
+        Vector<FlatPtr> addresses;
+        if (found_region->is_relative)
+            addresses.append(address - found_region->base);
+        else
+            addresses.append(address);
+
+        auto result = client->symbolicate(found_region->path, addresses);
+        if (result.is_empty()) {
+            symbols.append(Symbol {
+                .address = address,
+            });
+            continue;
+        }
+
+        symbols.append(Symbol {
+            .address = address,
+            .name = result[0].name });
+    }
+    return symbols;
+}
+
 }
diff --git a/Userland/Libraries/LibSymbolClient/Client.h b/Userland/Libraries/LibSymbolClient/Client.h
index 9faab216ca..8fa1cf75b9 100644
--- a/Userland/Libraries/LibSymbolClient/Client.h
+++ b/Userland/Libraries/LibSymbolClient/Client.h
@@ -34,12 +34,14 @@ namespace SymbolClient {
 
 struct Symbol {
     FlatPtr address { 0 };
-    String name;
+    String name {};
     u32 offset { 0 };
-    String filename;
+    String filename {};
     u32 line_number { 0 };
 };
 
+Vector<Symbol> symbolicate_thread(pid_t pid, pid_t tid);
+
 class Client
     : public IPC::ServerConnection<SymbolClientEndpoint, SymbolServerEndpoint>
     , public SymbolClientEndpoint {
diff --git a/Userland/Utilities/bt.cpp b/Userland/Utilities/bt.cpp
index 55fbbd6921..0bf569a0ad 100644
--- a/Userland/Utilities/bt.cpp
+++ b/Userland/Utilities/bt.cpp
@@ -24,9 +24,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/JsonArray.h>
-#include <AK/JsonObject.h>
-#include <AK/JsonValue.h>
 #include <AK/LogStream.h>
 #include <LibCore/ArgsParser.h>
 #include <LibCore/EventLoop.h>
@@ -63,118 +60,14 @@ int main(int argc, char** argv)
     Core::ArgsParser args_parser;
     pid_t pid = 0;
     args_parser.add_positional_argument(pid, "PID", "pid");
-
     args_parser.parse(argc, argv);
 
-    struct RegionWithSymbols {
-        FlatPtr base { 0 };
-        size_t size { 0 };
-        String path;
-        bool is_relative { true };
-    };
-
-    Vector<FlatPtr> stack;
-    Vector<RegionWithSymbols> regions;
-
-    regions.append(RegionWithSymbols {
-        .base = 0xc0000000,
-        .size = 0x3fffffff,
-        .path = "/boot/Kernel",
-        .is_relative = false });
-
-    {
-        // FIXME: Support multiple threads in the same process!
-        auto stack_path = String::formatted("/proc/{}/stacks/{}", pid, pid);
-        auto file_or_error = Core::File::open(stack_path, Core::IODevice::ReadOnly);
-        if (file_or_error.is_error()) {
-            warnln("Could not open {}: {}", stack_path, file_or_error.error());
-            return 1;
-        }
-
-        auto json = JsonValue::from_string(file_or_error.value()->read_all());
-        if (!json.has_value() || !json.value().is_array()) {
-            warnln("Invalid contents in {}", stack_path);
-            return 1;
-        }
-
-        stack.ensure_capacity(json.value().as_array().size());
-        for (auto& value : json.value().as_array().values()) {
-            stack.append(value.to_u32());
-        }
-    }
-
-    {
-        auto vm_path = String::formatted("/proc/{}/vm", pid);
-        auto file_or_error = Core::File::open(vm_path, Core::IODevice::ReadOnly);
-        if (file_or_error.is_error()) {
-            warnln("Could not open {}: {}", vm_path, file_or_error.error());
-            return 1;
-        }
-
-        auto json = JsonValue::from_string(file_or_error.value()->read_all());
-        if (!json.has_value() || !json.value().is_array()) {
-            warnln("Invalid contents in {}", vm_path);
-            return 1;
-        }
-
-        for (auto& region_value : json.value().as_array().values()) {
-            auto& region = region_value.as_object();
-            auto name = region.get("name").to_string();
-            auto address = region.get("address").to_u32();
-            auto size = region.get("size").to_u32();
-
-            String path;
-            if (name == "/usr/lib/Loader.so") {
-                path = name;
-            } else if (name.ends_with(": .text")) {
-                auto parts = name.split_view(':');
-                path = parts[0];
-                if (!path.starts_with('/'))
-                    path = String::formatted("/usr/lib/{}", path);
-            } else {
-                continue;
-            }
-
-            RegionWithSymbols r;
-            r.base = address;
-            r.size = size;
-            r.path = path;
-            regions.append(move(r));
-        }
-    }
-
     Core::EventLoop loop;
 
-    auto client = SymbolClient::Client::construct();
-
-    for (auto address : stack) {
-        const RegionWithSymbols* found_region = nullptr;
-        for (auto& region : regions) {
-            if (address >= region.base && address < (region.base + region.size)) {
-                found_region = &region;
-                break;
-            }
-        }
-
-        if (!found_region) {
-            outln("{:p}  ??", address);
-            continue;
-        }
-
-        Vector<FlatPtr> addresses;
-        if (found_region->is_relative)
-            addresses.append(address - found_region->base);
-        else
-            addresses.append(address);
-
-        auto symbols = client->symbolicate(found_region->path, addresses);
-        if (symbols.is_empty()) {
-            outln("{:p}  ??", address);
-            continue;
-        }
-
-        outln("{:p}  {}", address, symbols[0].name);
+    // FIXME: Support multiple threads in the same process!
+    auto symbols = SymbolClient::symbolicate_thread(pid, pid);
+    for (auto& symbol : symbols) {
+        outln("{:p}  {}", symbol.address, symbol.name);
     }
-
     return 0;
 }