From 010f7a29fdec322cc6190e36f74ae387ed18e1eb Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Thu, 15 May 2025 14:23:19 +0200
Subject: [PATCH 1/9] Add dladdr symbolication

---
 .../src/core/internal/backtrace/dwarf.d       | 160 +++---------------
 1 file changed, 25 insertions(+), 135 deletions(-)

diff --git a/runtime/druntime/src/core/internal/backtrace/dwarf.d b/runtime/druntime/src/core/internal/backtrace/dwarf.d
index 5da98948000..2ba4f3a11fd 100644
--- a/runtime/druntime/src/core/internal/backtrace/dwarf.d
+++ b/runtime/druntime/src/core/internal/backtrace/dwarf.d
@@ -244,11 +244,8 @@ int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
 {
     if (debugLineSectionData)
         resolveAddresses(debugLineSectionData, locations, baseAddress);
-    version (Darwin)
-    {
-        if (!debugLineSectionData)
-            resolveAddressesWithAtos(locations);
-    }
+    else
+        resolveAddressesWithDladdr(locations);
 
     TraceInfoBuffer buffer;
     foreach (idx, const ref loc; locations)
@@ -267,138 +264,31 @@ int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
     return 0;
 }
 
-version (Darwin) {
-    /**
-     * Resolve the addresses of `locations` using `atos` (executable that ships with XCode)
-     *
-     * Spawns a child process that calls `atos`. Communication is through stdin/stdout pipes.
-     *
-     * After this function successfully completes, `locations` will contain
-     * file / lines informations.
-     *
-     * The lifetime of the `Location` data surpases function return (strndup is used).
-     *
-     * Params:
-     * locations = The locations to resolve
-     */
-    private void resolveAddressesWithAtos(Location[] locations) @nogc nothrow
-    {
-        import core.stdc.stdio : fclose, fflush, fgets, fprintf, printf, snprintf;
-        import core.stdc.stdlib : exit;
-        import core.sys.posix.stdio : fdopen;
-        import core.sys.posix.unistd : close, dup2, execlp, fork, getpid, pipe;
-        // Create in/out pipes to communicate with the forked exec
-        int[2] dummy_pipes; // these dummy pipes are there to prevent funny issues when stdin/stdout is closed and pipe returns id 0 or 1
-        int[2] pipes_to_atos;
-        int[2] pipes_from_atos;
-        if ( pipe(dummy_pipes) < 0 || pipe(pipes_to_atos) < 0 || pipe(pipes_from_atos) < 0 ) {
-            printf("some pipe creation error!\n");
-            return;
-        }
-        close(dummy_pipes[0]);
-        close(dummy_pipes[1]);
-        auto write_to_atos = pipes_to_atos[1];
-        auto read_from_atos = pipes_from_atos[0];
-        auto atos_stdin = pipes_to_atos[0];
-        auto atos_stdout = pipes_from_atos[1];
-        auto self_pid = cast(int) getpid();
-        // Spawn a child process that calls atos, reads/writes from the pipes, and then exits.
-        auto child_id = fork();
-        if (child_id == -1)
-        {
-            printf("some fork error!\n");
-            return;
-        }
-        else if (child_id == 0)
-        {
-            // We are in the child process, spawn atos and link pipes
-            // Close unused read/write ends of pipes
-            close(write_to_atos);
-            close(read_from_atos);
-            // Link pipes to stdin/stdout
-            dup2(atos_stdin, 0);
-            close(atos_stdin);
-            dup2(atos_stdout, 1);
-            close(atos_stdout);
-            char[10] pid_str;
-            snprintf(pid_str.ptr, pid_str.sizeof, "%d", cast(int) self_pid);
-            const(char)* atos_executable = "atos";
-            const(char)* atos_p_arg = "-p";
-            const(char)* atos_fullpath_arg = "-fullPath";
-            execlp(atos_executable, atos_executable, atos_fullpath_arg, atos_p_arg, pid_str.ptr, null);
-            // If exec returns, an error occurred, need to exit the forked process here.
-            printf("some exec error!\n");
-            exit(0);
+/**
+ * Resolve the addresses of `locations` using dladdr.
+ *
+ * Params:
+ *   locations = The locations to resolve
+*/
+void resolveAddressesWithDladdr(ref Location[] locations) @nogc nothrow {
+    import core.demangle : demangle;
+    import core.sys.posix.dlfcn : dladdr, Dl_info;
+    import core.stdc.string : strlen;
+    foreach(ref Location location; locations) {
+        
+        Dl_info info;
+        dladdr(location.address, &info);
+        location.line = -1;
+        
+        // Strip off path to image.
+        if (info.dli_fname) {
+            location.file = info.dli_fname[0..strlen(info.dli_fname)];
         }
-        // Parent process just continues from here.
-        // Close unused pipes
-        close(atos_stdin);
-        close(atos_stdout);
-        auto to_atos = fdopen(write_to_atos, "w");
-        auto from_atos = fdopen(read_from_atos, "r");
-        // buffer for atos reading. Note that symbol names can be super large...
-        static char[16 * 1024] read_buffer = void;
-        char* status_ptr = null;
-        foreach (ref loc; locations)
-        {
-            fprintf(to_atos, "%p\n", loc.address);
-            fflush(to_atos);
-            read_buffer[0] = '\0';
-            status_ptr = fgets(read_buffer.ptr, read_buffer.sizeof, from_atos);
-            if (!status_ptr)
-                break;
-            Location parsed_loc = parseAtosLine(read_buffer.ptr);
-            if (parsed_loc.line != -1)
-            {
-                // Only update the file:line info, keep the procedure name as found before (preserving the standard truncation).
-                loc.file = parsed_loc.file;
-                loc.line = parsed_loc.line;
-            }
+
+        // Demangle D symbols.
+        if (info.dli_sname) {
+            location.procedure = info.dli_sname[0..strlen(info.dli_sname)];
         }
-        if (!status_ptr)
-            printf("\nDid not succeed in using 'atos' for extra debug information.\n");
-        fclose(to_atos);
-        fclose(from_atos);
-        close(write_to_atos);
-        close(read_from_atos);
-    }
-    private Location parseAtosLine(char* buffer) @nogc nothrow
-    {
-        // The line from `atos` is in one of these formats:
-        // myfunction (in library.dylib) (sourcefile.c:17)
-        // myfunction (in library.dylib) + 0x1fe
-        // myfunction (in library.dylib) + 15
-        // 0xdeadbeef (in library.dylib) + 0x1fe
-        // 0xdeadbeef (in library.dylib) + 15
-        // 0xdeadbeef (in library.dylib)
-        // 0xdeadbeef
-        import core.stdc.stdlib : atoi;
-        import core.stdc.string : strchr, strstr;
-        import core.sys.posix.string : strndup;
-        Location loc;
-        if (!buffer)
-            return loc;
-        if (buffer[0] == '0' && buffer[1] == 'x')
-            // no named symbol found
-            return loc;
-        const symbolname_end = strstr(buffer, " (in ");
-        if (!symbolname_end)
-            return loc;
-        const symbolname_size = symbolname_end - buffer;
-        loc.procedure = strndup(buffer, symbolname_size)[0..symbolname_size];
-        const filename_start = strstr(symbolname_end, ") (") + 3;
-        if (cast(size_t)filename_start < 4)
-            return loc;
-        const colon_location = strchr(filename_start, ':');
-        if (!colon_location)
-            return loc;
-        const filename_size = colon_location - filename_start;
-        loc.file = strndup(filename_start, filename_size)[0..filename_size];
-        const final_paren = strchr(colon_location+1, ')');
-        if (!final_paren)
-            return loc;
-        loc.line = atoi(colon_location+1);
-        return loc;
     }
 }
 

From da0f49b6f3b12b0445ff5a0cec29da92122ce583 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Thu, 15 May 2025 18:04:15 +0200
Subject: [PATCH 2/9] Completely remove atos

---
 .../src/core/internal/backtrace/dwarf.d       | 50 ++++++++-----------
 1 file changed, 20 insertions(+), 30 deletions(-)

diff --git a/runtime/druntime/src/core/internal/backtrace/dwarf.d b/runtime/druntime/src/core/internal/backtrace/dwarf.d
index 2ba4f3a11fd..11a839db5b0 100644
--- a/runtime/druntime/src/core/internal/backtrace/dwarf.d
+++ b/runtime/druntime/src/core/internal/backtrace/dwarf.d
@@ -69,6 +69,7 @@ else
 
 import core.internal.container.array;
 import core.stdc.string : strlen, memcpy;
+import core.attribute : weak;
 
 //debug = DwarfDebugMachine;
 debug(DwarfDebugMachine) import core.stdc.stdio : printf;
@@ -237,6 +238,24 @@ struct TraceInfoBuffer
     }
 }
 
+/**
+ * A weakly linked hook which can be implemented by external libraries
+ * to extend the symbolication capabilites when debug info is missing.
+*/
+extern(C) void rt_dwarfSymbolicate(ref Location[] locations) @weak
+{
+    import core.sys.posix.dlfcn : dladdr, Dl_info;
+    Dl_info info;
+    foreach(ref Location location; locations)
+    {
+        if (dladdr(location.address, &info) == 0)
+            continue;
+        
+        location.file = info.dli_fname[0..strlen(info.dli_fname)];
+        location.procedure = info.dli_sname[0..strlen(info.dli_sname)];
+    }
+}
+
 private:
 
 int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
@@ -244,8 +263,7 @@ int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
 {
     if (debugLineSectionData)
         resolveAddresses(debugLineSectionData, locations, baseAddress);
-    else
-        resolveAddressesWithDladdr(locations);
+    else rt_dwarfSymbolicate(locations);
 
     TraceInfoBuffer buffer;
     foreach (idx, const ref loc; locations)
@@ -264,34 +282,6 @@ int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
     return 0;
 }
 
-/**
- * Resolve the addresses of `locations` using dladdr.
- *
- * Params:
- *   locations = The locations to resolve
-*/
-void resolveAddressesWithDladdr(ref Location[] locations) @nogc nothrow {
-    import core.demangle : demangle;
-    import core.sys.posix.dlfcn : dladdr, Dl_info;
-    import core.stdc.string : strlen;
-    foreach(ref Location location; locations) {
-        
-        Dl_info info;
-        dladdr(location.address, &info);
-        location.line = -1;
-        
-        // Strip off path to image.
-        if (info.dli_fname) {
-            location.file = info.dli_fname[0..strlen(info.dli_fname)];
-        }
-
-        // Demangle D symbols.
-        if (info.dli_sname) {
-            location.procedure = info.dli_sname[0..strlen(info.dli_sname)];
-        }
-    }
-}
-
 /**
  * Resolve the addresses of `locations` using `debugLineSectionData`
  *

From 642941a213135207b8a08d2cfa02b84a1df148d4 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Fri, 16 May 2025 18:23:38 +0200
Subject: [PATCH 3/9] Added cleanup hooks

---
 .../src/core/internal/backtrace/dwarf.d       | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/runtime/druntime/src/core/internal/backtrace/dwarf.d b/runtime/druntime/src/core/internal/backtrace/dwarf.d
index 11a839db5b0..f857553c212 100644
--- a/runtime/druntime/src/core/internal/backtrace/dwarf.d
+++ b/runtime/druntime/src/core/internal/backtrace/dwarf.d
@@ -185,6 +185,8 @@ int traceHandlerOpApplyImpl(size_t numFrames,
             startIdx = idx + 1;
     }
 
+    // Symbolicate locations
+    rt_dwarfSymbolicate(locations[startIdx .. $]);
 
     if (!image.isValid())
         return locations[startIdx .. $].processCallstack(null, 0, dg);
@@ -192,6 +194,9 @@ int traceHandlerOpApplyImpl(size_t numFrames,
     // find address -> file, line mapping using dwarf debug_line
     return image.processDebugLineSectionData(
         (line) => locations[startIdx .. $].processCallstack(line, image.baseAddress, dg));
+
+    // Allow cleaning up after ourselves.
+    rt_dwarfSymbolicateCleanup(locations[startIdx .. $]);
 }
 
 struct TraceInfoBuffer
@@ -242,18 +247,15 @@ struct TraceInfoBuffer
  * A weakly linked hook which can be implemented by external libraries
  * to extend the symbolication capabilites when debug info is missing.
 */
-extern(C) void rt_dwarfSymbolicate(ref Location[] locations) @weak
+@weak
+extern(C) void rt_dwarfSymbolicate(Location[] locations)
+{
+}
+
+/// ditto
+@weak
+extern(C) void rt_dwarfSymbolicateCleanup(Location[] locations)
 {
-    import core.sys.posix.dlfcn : dladdr, Dl_info;
-    Dl_info info;
-    foreach(ref Location location; locations)
-    {
-        if (dladdr(location.address, &info) == 0)
-            continue;
-        
-        location.file = info.dli_fname[0..strlen(info.dli_fname)];
-        location.procedure = info.dli_sname[0..strlen(info.dli_sname)];
-    }
 }
 
 private:
@@ -263,7 +265,6 @@ int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
 {
     if (debugLineSectionData)
         resolveAddresses(debugLineSectionData, locations, baseAddress);
-    else rt_dwarfSymbolicate(locations);
 
     TraceInfoBuffer buffer;
     foreach (idx, const ref loc; locations)

From 0fe3c915ec718f6f9eb4f0674ab55ceca6040a29 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Fri, 16 May 2025 18:36:05 +0200
Subject: [PATCH 4/9] Add atos removal note

---
 runtime/druntime/src/core/internal/backtrace/dwarf.d | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/runtime/druntime/src/core/internal/backtrace/dwarf.d b/runtime/druntime/src/core/internal/backtrace/dwarf.d
index f857553c212..ac358516e29 100644
--- a/runtime/druntime/src/core/internal/backtrace/dwarf.d
+++ b/runtime/druntime/src/core/internal/backtrace/dwarf.d
@@ -43,7 +43,7 @@
  * Reference: http://www.dwarfstd.org/
  * Copyright: Copyright Digital Mars 2015 - 2015.
  * License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
- * Authors:   Yazan Dabain, Sean Kelly
+ * Authors:   Yazan Dabain, Sean Kelly, Luna Nielsen
  * Source: $(DRUNTIMESRC core/internal/backtrace/dwarf.d)
  */
 
@@ -246,6 +246,16 @@ struct TraceInfoBuffer
 /**
  * A weakly linked hook which can be implemented by external libraries
  * to extend the symbolication capabilites when debug info is missing.
+ * 
+ * NOTE:
+ *   There used to be an atos based symbolication implementation built in
+ *   here, but atos is not a portable solution on darwin derived OSes.
+ *   atos conflicts with things such as the hardened runtime, iOS releases,
+ *   App Store certification and the like. I've removed that implementation
+ *   to ensure that D can easily be used to publish to the App Store.
+ *   Please avoid adding other private APIs in its place directly in to
+ *   druntime. If it resides in PrivateFrameworks or is a dev tool, 
+ *   don't use it. - Luna
 */
 @weak
 extern(C) void rt_dwarfSymbolicate(Location[] locations)

From bd9cda3017e88370d3ad805b11ce69c33b00fee0 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Sun, 6 Jul 2025 16:08:48 +0200
Subject: [PATCH 5/9] Add dSYM mapper

---
 .../src/core/internal/backtrace/dwarf.d       |  31 ---
 .../src/core/internal/backtrace/macho.d       |  45 ++--
 runtime/druntime/src/core/internal/macho/dl.d | 228 ++++++++++++++++++
 runtime/druntime/src/core/internal/macho/io.d |  77 ++++++
 .../src/core/sys/darwin/mach/loader.d         |  15 ++
 runtime/druntime/src/rt/sections_elf_shared.d |   1 -
 6 files changed, 345 insertions(+), 52 deletions(-)
 create mode 100644 runtime/druntime/src/core/internal/macho/dl.d
 create mode 100644 runtime/druntime/src/core/internal/macho/io.d

diff --git a/runtime/druntime/src/core/internal/backtrace/dwarf.d b/runtime/druntime/src/core/internal/backtrace/dwarf.d
index ac358516e29..635bc635749 100644
--- a/runtime/druntime/src/core/internal/backtrace/dwarf.d
+++ b/runtime/druntime/src/core/internal/backtrace/dwarf.d
@@ -185,18 +185,12 @@ int traceHandlerOpApplyImpl(size_t numFrames,
             startIdx = idx + 1;
     }
 
-    // Symbolicate locations
-    rt_dwarfSymbolicate(locations[startIdx .. $]);
-
     if (!image.isValid())
         return locations[startIdx .. $].processCallstack(null, 0, dg);
 
     // find address -> file, line mapping using dwarf debug_line
     return image.processDebugLineSectionData(
         (line) => locations[startIdx .. $].processCallstack(line, image.baseAddress, dg));
-
-    // Allow cleaning up after ourselves.
-    rt_dwarfSymbolicateCleanup(locations[startIdx .. $]);
 }
 
 struct TraceInfoBuffer
@@ -243,31 +237,6 @@ struct TraceInfoBuffer
     }
 }
 
-/**
- * A weakly linked hook which can be implemented by external libraries
- * to extend the symbolication capabilites when debug info is missing.
- * 
- * NOTE:
- *   There used to be an atos based symbolication implementation built in
- *   here, but atos is not a portable solution on darwin derived OSes.
- *   atos conflicts with things such as the hardened runtime, iOS releases,
- *   App Store certification and the like. I've removed that implementation
- *   to ensure that D can easily be used to publish to the App Store.
- *   Please avoid adding other private APIs in its place directly in to
- *   druntime. If it resides in PrivateFrameworks or is a dev tool, 
- *   don't use it. - Luna
-*/
-@weak
-extern(C) void rt_dwarfSymbolicate(Location[] locations)
-{
-}
-
-/// ditto
-@weak
-extern(C) void rt_dwarfSymbolicateCleanup(Location[] locations)
-{
-}
-
 private:
 
 int processCallstack(Location[] locations, const(ubyte)[] debugLineSectionData,
diff --git a/runtime/druntime/src/core/internal/backtrace/macho.d b/runtime/druntime/src/core/internal/backtrace/macho.d
index ff6a31b7faa..e6e7809846e 100644
--- a/runtime/druntime/src/core/internal/backtrace/macho.d
+++ b/runtime/druntime/src/core/internal/backtrace/macho.d
@@ -20,32 +20,37 @@ else version (WatchOS)
 version (Darwin):
 
 import core.stdc.config : c_ulong;
-import core.sys.darwin.crt_externs : _NSGetMachExecuteHeader;
-import core.sys.darwin.mach.getsect : mach_header_64, getsectiondata;
-
-struct Image
-{
-    private mach_header_64* self;
+import core.stdc.stdlib : free;
+import core.internal.macho.dl;
+import core.internal.macho.io;
+
+struct Image {
+    SharedObject self;
+    SharedObject debugObj;
+
+    this(SharedObject self) {
+        this.self = self;
+        this.debugObj = self; 
+
+        if (!self.hasSection("__DWARF", "__debug_line")) {
+            auto dsymPath = getDsymDefaultPath();
+            this.debugObj = SharedObject.fromFile(dsymPath.ptr);
+        }
+    }
 
-    static Image openSelf()
-    {
-        return Image(_NSGetMachExecuteHeader());
+    T processDebugLineSectionData(T)(scope T delegate(const(ubyte)[]) processor) {
+        return processor(debugObj.getSection("__DWARF", "__debug_line"));
     }
 
-    @property bool isValid()
-    {
-        return self !is null;
+    static Image openSelf() {
+        return Image(SharedObject.thisExecutable());
     }
 
-    T processDebugLineSectionData(T)(scope T delegate(const(ubyte)[]) processor)
-    {
-        c_ulong size;
-        auto data = getsectiondata(self, "__DWARF", "__debug_line", &size);
-        return processor(data[0 .. size]);
+    @property bool isValid() {
+        return self.isValid;
     }
 
-    @property size_t baseAddress()
-    {
-        return 0;
+    @property size_t baseAddress() {
+        return cast(size_t)self.baseAddress;
     }
 }
diff --git a/runtime/druntime/src/core/internal/macho/dl.d b/runtime/druntime/src/core/internal/macho/dl.d
new file mode 100644
index 00000000000..47586e2ac61
--- /dev/null
+++ b/runtime/druntime/src/core/internal/macho/dl.d
@@ -0,0 +1,228 @@
+/**
+ * Simplifies working with shared Macho-O objects of the current process.
+ *
+ * Copyright: Copyright Kitsunebi Games 2025
+ * License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
+ * Authors:   Luna (the Foxgirl) Nielsen
+ * Source: $(DRUNTIMESRC core/internal/macho/dl.d)
+ */
+
+module core.internal.macho.dl;
+
+version (OSX)
+    version = Darwin;
+else version (iOS)
+    version = Darwin;
+else version (TVOS)
+    version = Darwin;
+else version (WatchOS)
+    version = Darwin;
+
+version (Darwin):
+
+import core.sys.darwin.mach.getsect : mach_header_64, getsectiondata, getsectbynamefromheader_64;
+import core.sys.darwin.dlfcn;
+import core.sys.darwin.fcntl;
+import core.sys.darwin.sys.mman;
+import core.sys.posix.sys.stat;
+import core.sys.darwin.mach.loader;
+import core.sys.darwin.mach.dyld : 
+    _dyld_image_count, 
+    _dyld_get_image_name, 
+    _dyld_get_image_header, 
+    _dyld_get_image_vmaddr_slide;
+
+/**
+    Enables iterating over the process' currently loaded shared objects.
+*/
+struct SharedObjects {
+@nogc nothrow:
+    ///
+    alias Callback = int delegate(SharedObject);
+
+    ///
+    static int opApply(scope Callback dg)
+    {
+        foreach(i; 0.._dyld_image_count) {
+            if (int result = dg(SharedObject.fromIndex(i)))
+                return result;
+        }
+        return 0;
+    }
+}
+
+/**
+    A loeaded mach-o binary.
+*/
+struct SharedObject {
+@nogc nothrow:
+private:
+    mach_header_64* _header;
+    ptrdiff_t vmaddr_slide;
+    const(char)* _name;
+
+public:
+
+    /**
+        Returns the shared object with the given index.
+    */
+    static SharedObject fromIndex(uint idx) {
+        return SharedObject(
+            cast(mach_header_64*)_dyld_get_image_header(idx),
+            _dyld_get_image_vmaddr_slide(idx),
+            _dyld_get_image_name(idx)
+        );
+    }
+
+    /**
+        Returns the shared object with the given dlopen handle.
+
+        Params:
+            dlhandle = Handle returned by dlopen
+        
+        Returns:
+            A SharedObject instance matching the given dlhandle,
+            or an empty handle on failure.
+    */
+    static SharedObject fromHandle(void* dlhandle) {
+        foreach(so; SharedObjects) {
+            if (auto hndl = dlopen(so.name, RTLD_NOLOAD)) {
+                dlclose(hndl);
+
+                if (hndl is dlhandle)
+                    return so;
+            }
+        }
+        return SharedObject.init;
+    }
+
+    /**
+        Returns the shared object with the given dlopen handle.
+
+        Params:
+            path = Path to the object to load.
+        
+        Returns:
+            A SharedObject instance matching the given path,
+            or an empty handle on failure.
+    */
+    static SharedObject fromFile(const(char)* path) {
+        if (auto hndl = dlopen(path, 0))
+            return SharedObject.fromHandle(hndl);
+
+        mach_header_64* base_header = cast(mach_header_64*)_dyld_get_image_header(0);
+
+        // Try opening and mapping the file.
+        int fd = open(path, O_RDONLY);
+        if (fd == -1)
+            return SharedObject.init;
+        
+        stat_t fdInfo;
+        if (fstat(fd, &fdInfo) == -1)
+            return SharedObject.init;
+        
+        void* data = mmap(null, fdInfo.st_size, PROT_READ, MAP_SHARED, fd, 0);
+        if (data == MAP_FAILED)
+            return SharedObject.init;
+
+        // Non-fat mach-o object.
+        mach_header* hdr = cast(mach_header*)data;
+        if (hdr.magic == MH_MAGIC || hdr.magic == MH_MAGIC_64) {
+            if (hdr.cputype != base_header.cputype || hdr.cpusubtype != base_header.cpusubtype) {
+                munmap(data, fdInfo.st_size);
+                return SharedObject.init;
+            }
+
+            return SharedObject(cast(mach_header_64*)data, -1, path);
+        }
+
+        // Fat binary.
+        fat_header* fat = cast(fat_header*)data;
+        if (fat.magic == [0xca, 0xfe, 0xba, 0xbe]) {
+            fat_entry* entry = cast(fat_entry*)(data+fat_header.sizeof);
+            foreach(i; 0..fat.count) {
+                if (entry.cputype == base_header.cputype && entry.cpusubtype == base_header.cpusubtype) {
+                    return SharedObject(cast(mach_header_64*)(data+entry.file_offset), -1, path);
+                }
+
+                entry++;
+            }
+        }
+
+        // Remember to unmap the file.
+        munmap(data, fdInfo.st_size);
+        return SharedObject.init;
+    }
+
+    /**
+        Returns the object of the current process' executable.
+    */
+    static SharedObject thisExecutable() {
+        return SharedObject.fromIndex(0);
+    }
+
+    /**
+        Whether the object is valid.
+    */
+    @property bool isValid() {
+        return _header !is null;
+    }
+
+    /**
+        The name of this object.
+    */
+    @property const(char)* name() {
+        return _name;
+    }
+
+    /**
+        The base address of this object.
+    */
+    @property void* baseAddress() {
+        return cast(void*)_header;
+    }
+
+    /**
+        The mach header of the image.
+    */
+    @property mach_header_64* header() {
+        return _header;
+    }
+
+    /**
+        The virtual memory slide for the image.
+    */
+    @property ptrdiff_t slide() {
+        return vmaddr_slide;
+    }
+
+    /**
+        Gets whether the given section is present.
+    */
+    bool hasSection(const(char)* segname, const(char)* sectname) {
+        return getSection(segname, sectname).length > 0;
+    }
+
+    /**
+        Gets the given section within the shared object/image.
+    */
+    ubyte[] getSection(const(char)* segname, const(char)* sectname) {
+
+        // mmapped mach-o
+        if (vmaddr_slide == -1 && _header) {
+            if (auto sect = getsectbynamefromheader_64(_header, segname, sectname)) {
+                return (cast(ubyte*)_header+sect.offset)[0..sect.size];
+            }
+            return null;
+        }
+
+        // linked mach-o
+        if (_header) {
+            size_t len;
+            if (auto data = getsectiondata(_header, segname, sectname, &len))
+                return data[0..len];
+        }
+
+        return null;
+    }
+}
diff --git a/runtime/druntime/src/core/internal/macho/io.d b/runtime/druntime/src/core/internal/macho/io.d
new file mode 100644
index 00000000000..b2afc2a9b5e
--- /dev/null
+++ b/runtime/druntime/src/core/internal/macho/io.d
@@ -0,0 +1,77 @@
+/**
+ * Provides (read-only) memory-mapped I/O for Mach-O files.
+ *
+ *
+ * Copyright: Copyright Kitsunebi Games 2025
+ * License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
+ * Authors:   Luna (the Foxgirl) Nielsen
+ * Source: $(DRUNTIMESRC core/internal/macho/io.d)
+ */
+
+module core.internal.macho.io;
+
+version (OSX)
+    version = Darwin;
+else version (iOS)
+    version = Darwin;
+else version (TVOS)
+    version = Darwin;
+else version (WatchOS)
+    version = Darwin;
+
+version (Darwin):
+
+import core.stdc.stdio : snprintf;
+import core.stdc.stdlib : free, malloc;
+import core.sys.darwin.mach.dyld : _NSGetExecutablePath;
+
+/**
+    Returns the path to the process' executable as newly allocated slice.
+*/
+char[] thisExePath() {
+    uint len;
+    if (_NSGetExecutablePath(null, &len) != -1)
+        return null;
+
+    auto buffer = cast(char*) malloc(len);
+    if (!buffer)
+        return null;
+
+    if (_NSGetExecutablePath(buffer, &len) != 0) {
+        free(buffer);
+        return null;
+    }
+
+    return buffer[0..len];
+}
+
+/**
+    Gets the base file name of the given path.
+*/
+char[] getBaseName(char[] path) {
+    size_t i;
+    foreach_reverse(j; 0..path.length) {
+        if (path[j] == '/') {
+            i = j;
+            break;
+        }
+    }
+    return path[i+1..$];
+}
+
+/**
+    Gets the default path of a dSYM file.
+*/
+char[] getDsymDefaultPath() {
+    enum DSYM_SUBPATH_FMT = "%s.dSYM/Contents/Resources/DWARF/%s";
+
+    char[] exePath = thisExePath();
+    char[] exeBase = exePath.getBaseName();
+    int len = snprintf(null, 0, DSYM_SUBPATH_FMT, exePath.ptr, exeBase.ptr);
+
+    char* fullname = cast(char*)malloc(len+1);
+    len = snprintf(fullname, len+1, DSYM_SUBPATH_FMT, exePath.ptr, exeBase.ptr);
+
+    free(exePath.ptr);
+    return fullname[0..len];
+}
\ No newline at end of file
diff --git a/runtime/druntime/src/core/sys/darwin/mach/loader.d b/runtime/druntime/src/core/sys/darwin/mach/loader.d
index 7713eea9785..a3b2e530730 100644
--- a/runtime/druntime/src/core/sys/darwin/mach/loader.d
+++ b/runtime/druntime/src/core/sys/darwin/mach/loader.d
@@ -3423,3 +3423,18 @@ struct note_command
     ulong offset;
     ulong size;
 }
+
+struct fat_header
+{
+    ubyte[4] magic;
+    uint count;
+}
+
+struct fat_entry
+{
+    uint cputype;
+    uint cpusubtype;
+    uint file_offset;
+    uint size;
+    uint alignment;
+}
diff --git a/runtime/druntime/src/rt/sections_elf_shared.d b/runtime/druntime/src/rt/sections_elf_shared.d
index 83c0f236ef2..40d7919b032 100644
--- a/runtime/druntime/src/rt/sections_elf_shared.d
+++ b/runtime/druntime/src/rt/sections_elf_shared.d
@@ -84,7 +84,6 @@ else version (Darwin)
     else
         static assert(0, "Not implemented for this architecture");
 
-    extern(C) intptr_t _dyld_get_image_slide(const mach_header*) nothrow @nogc;
 }
 else version (NetBSD)
 {

From 3c679f5bd4b9e923d70462e3e8243f6ef9d2d186 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Sun, 6 Jul 2025 16:27:53 +0200
Subject: [PATCH 6/9] Fix image slide

---
 runtime/druntime/src/core/internal/backtrace/macho.d | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/runtime/druntime/src/core/internal/backtrace/macho.d b/runtime/druntime/src/core/internal/backtrace/macho.d
index e6e7809846e..2f66f991f13 100644
--- a/runtime/druntime/src/core/internal/backtrace/macho.d
+++ b/runtime/druntime/src/core/internal/backtrace/macho.d
@@ -51,6 +51,8 @@ struct Image {
     }
 
     @property size_t baseAddress() {
-        return cast(size_t)self.baseAddress;
+        if (debugObj.slide == -1)
+            return self.slide;
+        return 0;
     }
 }

From fa92a470ccbe25b7d9e102056216bb9f805e6abc Mon Sep 17 00:00:00 2001
From: Luna <cli-luna@protonmail.com>
Date: Mon, 7 Jul 2025 10:57:10 +0200
Subject: [PATCH 7/9] Fix typo

---
 runtime/druntime/src/core/internal/macho/dl.d | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime/druntime/src/core/internal/macho/dl.d b/runtime/druntime/src/core/internal/macho/dl.d
index 47586e2ac61..66b3afeb083 100644
--- a/runtime/druntime/src/core/internal/macho/dl.d
+++ b/runtime/druntime/src/core/internal/macho/dl.d
@@ -52,7 +52,7 @@ struct SharedObjects {
 }
 
 /**
-    A loeaded mach-o binary.
+    A loaded mach-o binary.
 */
 struct SharedObject {
 @nogc nothrow:

From c3e7ec5eeeb91eb988430a33b41c6fc6e56844bf Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Mon, 7 Jul 2025 19:37:32 +0200
Subject: [PATCH 8/9] Add dSYM generation to exception druntime tests

---
 runtime/druntime/test/exceptions/Makefile | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/runtime/druntime/test/exceptions/Makefile b/runtime/druntime/test/exceptions/Makefile
index 7565e425060..b1d74b92dd8 100644
--- a/runtime/druntime/test/exceptions/Makefile
+++ b/runtime/druntime/test/exceptions/Makefile
@@ -67,6 +67,12 @@ ifeq ($(OS),windows)
 endif
 include ../common.mak
 
+# Generate dSYMs on macOS.
+$(OBJDIR)/%$(DOTEXE).dSYM: $(OBJDIR)/%$(DOTEXE)
+	@[ "$(OS)" = "osx" ] && dsymutil -o $<.dSYM $< 
+
+$(TESTS:%=$(OBJDIR)/%.done): $(OBJDIR)/%.done: $(OBJDIR)/%$(DOTEXE) $(OBJDIR)/%$(DOTEXE).dSYM
+
 $(ROOT)/line_trace.done: $(ROOT)/line_trace$(DOTEXE)
 	@echo Testing line_trace
 	$(TIMELIMIT)$(ROOT)/line_trace > $@

From 93bc61eb79b6d7c9379b3f807f591dee7d55ff09 Mon Sep 17 00:00:00 2001
From: Luna <luna@foxgirls.gay>
Date: Tue, 8 Jul 2025 10:36:49 +0200
Subject: [PATCH 9/9] Apply @the-horo's runtime unittest patch

---
 runtime/druntime/test/exceptions/Makefile | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/runtime/druntime/test/exceptions/Makefile b/runtime/druntime/test/exceptions/Makefile
index b1d74b92dd8..5ea164d01b0 100644
--- a/runtime/druntime/test/exceptions/Makefile
+++ b/runtime/druntime/test/exceptions/Makefile
@@ -69,9 +69,15 @@ include ../common.mak
 
 # Generate dSYMs on macOS.
 $(OBJDIR)/%$(DOTEXE).dSYM: $(OBJDIR)/%$(DOTEXE)
-	@[ "$(OS)" = "osx" ] && dsymutil -o $<.dSYM $< 
+	dsymutil $<
 
-$(TESTS:%=$(OBJDIR)/%.done): $(OBJDIR)/%.done: $(OBJDIR)/%$(DOTEXE) $(OBJDIR)/%$(DOTEXE).dSYM
+ifeq ($(OS),osx)
+tests_without_exe = line_trace_21656 rt_trap_exceptions_drt_gdb
+exes = $(filter-out $(tests_without_exe),$(TESTS))
+$(exes:%=$(OBJDIR)/%.done): $(OBJDIR)/%.done: $(OBJDIR)/%$(DOTEXE) $(OBJDIR)/%$(DOTEXE).dSYM
+$(OBJDIR)/line_trace_21656.done: $(OBJDIR)/line_trace$(DOTEXE).dSYM
+$(OBJDIR)/rt_trap_exceptions_drt_gdb.done: $(OBJDIR)/rt_trap_exceptions_drt$(DOTEXE).dSYM
+endif
 
 $(ROOT)/line_trace.done: $(ROOT)/line_trace$(DOTEXE)
 	@echo Testing line_trace