Add clangd support for VS Code (#2207)

* Add clangd support for VS Code

* Revert accidental change

.gitignore

@@ -1,13 +1,35 @@
+# IDE folders
+.idea/
+.vs/
+
+# Caches
 __pycache__
-.idea
-.vscode
-.ninja_*
 .mypy_cache
-*.exe
+.cache/
-build
+
-build.ninja
+# Original files
-objdiff.json
 orig/*/*
 !orig/*/.gitkeep
+*.dol
+*.rel
+*.elf
+*.o
+*.map
+*.MAP
+
+# Build files
+build/
+.ninja_*
+build.ninja
+
+# decompctx output
+ctx.*
+*.ctx
+
+# Generated configs
+objdiff.json
+compile_commands.json
+
+# Miscellaneous
 /*.txt
-ctx.c
+*.exe

.vscode/extensions.json

@@ -0,0 +1,12 @@
+{
+  "recommendations": [
+    "llvm-vs-code-extensions.vscode-clangd",
+    "ms-python.black-formatter",
+    "ms-python.flake8",
+  ],
+  "unwantedRecommendations": [
+    "ms-vscode.cmake-tools",
+    "ms-vscode.cpptools-extension-pack",
+    "ms-vscode.cpptools",
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,23 @@
+{
+  "[c]": {
+    "files.encoding": "utf8",
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  },
+  "[cpp]": {
+    "files.encoding": "utf8",
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  },
+  "[python]": {
+    "editor.defaultFormatter": "ms-python.black-formatter"
+  },
+  "editor.tabSize": 4,
+  "files.autoSave": "onFocusChange",
+  "files.insertFinalNewline": true,
+  "files.trimFinalNewlines": true,
+  "files.associations": {
+    "*.inc": "c",
+    ".clangd": "yaml"
+  },
+  // Disable C/C++ IntelliSense, use clangd instead
+  "C_Cpp.intelliSenseEngine": "disabled",
+}

.vscode/tasks.json

@@ -0,0 +1,16 @@
+{
+  // Use Ctrl+Shift+B to run build tasks.
+  // Or "Run Build Task" in the Command Palette.
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "ninja",
+      "type": "shell",
+      "command": "ninja",
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      }
+    },
+  ]
+}

include/JSystem/JGadget/linklist.h

@@ -249,9 +249,9 @@ struct TLinkList_factory : public TLinkList<T, I> {
     virtual T* Do_create() = 0;
     virtual void Do_destroy(T*) = 0;
     void Clear_destroy() {
-        while (!empty()) {
+        while (!this->empty()) {
-            T* item = &front();
+            T* item = &this->front();
-            pop_front();
+            this->pop_front();
             Do_destroy(item);
         }
     }
@@ -298,16 +298,16 @@ struct TEnumerator2 {
 };
 
 template <typename T, int I>
-struct TContainerEnumerator : public TEnumerator2<TLinkList<T, I>::iterator, T> {
+struct TContainerEnumerator : public TEnumerator2<typename TLinkList<T, I>::iterator, T> {
     inline TContainerEnumerator(TLinkList<T, I>* param_0)
-        : TEnumerator2<TLinkList<T, I>::iterator, T>(param_0->begin(), param_0->end()) {}
+        : TEnumerator2<typename TLinkList<T, I>::iterator, T>(param_0->begin(), param_0->end()) {}
 };
 
 
 template <typename T, int I>
-struct TContainerEnumerator_const : public TEnumerator2<TLinkList<T, I>::const_iterator, const T> {
+struct TContainerEnumerator_const : public TEnumerator2<typename TLinkList<T, I>::const_iterator, const T> {
     inline TContainerEnumerator_const(const TLinkList<T, I>* param_0)
-        : TEnumerator2<TLinkList<T, I>::const_iterator, const T>(param_0->begin(), param_0->end()) {}
+        : TEnumerator2<typename TLinkList<T, I>::const_iterator, const T>(param_0->begin(), param_0->end()) {}
 };
 
 };  // namespace JGadget

include/dol2asm.h

@@ -2,7 +2,7 @@
 #define DOL2ASM
 
 // this helps remove useless error from the linter when using vscode.
-#ifndef IN_VSCODE_EDITOR
+#ifdef __MWERKS__
 
 #ifdef __cplusplus
 #define SECTION_INIT extern "C" __declspec(section ".init")

include/dolphin/dsp.h

@@ -8,8 +8,8 @@
 extern "C" {
 #endif
 
-volatile u16 __DSPRegs[32] : 0xCC005000;
+volatile u16 __DSPRegs[32] AT_ADDRESS(0xCC005000);
-volatile u32 __AIRegs[8] : 0xCC006C00;
+volatile u32 __AIRegs[8] AT_ADDRESS(0xCC006C00);
 
 #define DSP_TASK_FLAG_CLEARALL 0x00000000
 #define DSP_TASK_FLAG_ATTACHED 0x00000001

include/dolphin/dvd/dvdlow.h

@@ -4,6 +4,6 @@
 #include "dolphin/types.h"
 
 typedef void (*DVDLowCallback)(u32 intType);
-vu32 __DIRegs[16] : 0xCC006000;
+vu32 __DIRegs[16] AT_ADDRESS(0xCC006000);
 
 #endif /* DVDLOW_H */

include/dolphin/exi/EXIBios.h

@@ -9,7 +9,7 @@ extern "C" {
 
 typedef struct OSContext OSContext;
 
-vu32 __EXIRegs[16] : 0xCC006800;
+vu32 __EXIRegs[16] AT_ADDRESS(0xCC006800);
 
 #define EXI_MEMORY_CARD_59 0x00000004
 #define EXI_MEMORY_CARD_123 0x00000008

include/dolphin/gx.h

@@ -58,7 +58,7 @@ typedef union {
 } PPCWGPipe;
 
 #define GXFIFO_ADDR 0xCC008000
-volatile PPCWGPipe GXWGFifo : GXFIFO_ADDR;
+volatile PPCWGPipe GXWGFifo AT_ADDRESS(GXFIFO_ADDR);
 
 #define GX_WRITE_U8(data) GXWGFifo.u8 = data;
 #define GX_WRITE_U32(data) GXWGFifo.u32 = data;

include/dolphin/os.h

@@ -65,19 +65,19 @@ extern "C" {
 #define OS_CONSOLE_PC_EMULATOR 0x10000001
 #define OS_CONSOLE_EMULATOR 0x10000000
 
-volatile u16 __OSDeviceCode : 0x800030E6;
+volatile u16 __OSDeviceCode AT_ADDRESS(0x800030E6);
 
-volatile u32 OS_PI_INTR_CAUSE : 0xCC003000;
+volatile u32 OS_PI_INTR_CAUSE AT_ADDRESS(0xCC003000);
-volatile u32 OS_PI_INTR_MASK : 0xCC003004;
+volatile u32 OS_PI_INTR_MASK AT_ADDRESS(0xCC003004);
 
-volatile u16 OS_MI_INTR_MASK : 0xCC00401C;
+volatile u16 OS_MI_INTR_MASK AT_ADDRESS(0xCC00401C);
 
-volatile u16 OS_DSP_DMA_ADDR_HI : 0xCC005030;
+volatile u16 OS_DSP_DMA_ADDR_HI AT_ADDRESS(0xCC005030);
-volatile u16 OS_DSP_DMA_ADDR_LO : 0xCC005032;
+volatile u16 OS_DSP_DMA_ADDR_LO AT_ADDRESS(0xCC005032);
-volatile u16 OS_DSP_INTR_MASK : 0xCC00500A;
+volatile u16 OS_DSP_INTR_MASK AT_ADDRESS(0xCC00500A);
 
-volatile u16 OS_ARAM_DMA_ADDR_HI : 0xCC005020;
+volatile u16 OS_ARAM_DMA_ADDR_HI AT_ADDRESS(0xCC005020);
-volatile u16 OS_ARAM_DMA_ADDR_LO : 0xCC005022;
+volatile u16 OS_ARAM_DMA_ADDR_LO AT_ADDRESS(0xCC005022);
 
 BOOL OSIsThreadSuspended(OSThread* thread);
 

include/dolphin/os/OSContext.h

@@ -151,8 +151,8 @@ typedef struct OSContext {
     /* 0x1C4 */ f64 ps[32];
 } OSContext;
 
-OSContext* OS_CURRENT_CONTEXT : 0x800000D4;
+OSContext* OS_CURRENT_CONTEXT AT_ADDRESS(0x800000D4);
-OSContext* OS_CURRENT_FPU_CONTEXT : 0x800000D8;
+OSContext* OS_CURRENT_FPU_CONTEXT AT_ADDRESS(0x800000D8);
 
 void __OSLoadFPUContext(void);
 void __OSSaveFPUContext(s32 unused0, s32 unused1, OSContext* context);

include/dolphin/os/OSLink.h

@@ -1,6 +1,7 @@
 #ifndef OSLINK_H
 #define OSLINK_H
 
+#include "dolphin/types.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -18,14 +19,14 @@ typedef struct OSSectionInfo OSSectionInfo;
 typedef struct OSImportInfo OSImportInfo;
 typedef struct OSRel OSRel;
 
-OSModuleQueue __OSModuleList : 0x800030C8;
-void* __OSStringTable : 0x800030D0;
-
 struct OSModuleQueue {
     OSModuleInfo* head;
     OSModuleInfo* tail;
 };
 
+OSModuleQueue __OSModuleList AT_ADDRESS(0x800030C8);
+void* __OSStringTable AT_ADDRESS(0x800030D0);
+
 struct OSModuleLink {
     OSModuleInfo* next;
     OSModuleInfo* prev;

include/dolphin/os/OSReset.h

@@ -7,7 +7,7 @@
 extern "C" {
 #endif
 
-vu32 __PIRegs[12] : 0xCC003000;
+vu32 __PIRegs[12] AT_ADDRESS(0xCC003000);
 
 #define OS_RESETCODE_RESTART 0x80000000
 #define OS_RESETCODE_SYSTEM 0x40000000

include/dolphin/os/OSThread.h

@@ -75,8 +75,8 @@ struct OSThread {
 
 typedef void (*OSSwitchThreadCallback)(OSThread* from, OSThread* to);
 
-OSThreadQueue OS_THREAD_QUEUE : 0x800000DC;
+OSThreadQueue OS_THREAD_QUEUE AT_ADDRESS(0x800000DC);
-OSThread* OS_CURRENT_THREAD : 0x800000E4;
+OSThread* OS_CURRENT_THREAD AT_ADDRESS(0x800000E4);
 
 static void DefaultSwitchThreadCallback(OSThread* from, OSThread* to);
 OSSwitchThreadCallback OSSetSwitchThreadCallback(OSSwitchThreadCallback func);

include/dolphin/os/OSTime.h

@@ -10,7 +10,7 @@ extern "C" {
 typedef s64 OSTime;
 typedef u32 OSTick;
 
-OSTime OS_SYSTEM_TIME : 0x800030D8;
+OSTime OS_SYSTEM_TIME AT_ADDRESS(0x800030D8);
 
 typedef struct OSCalendarTime {
     /* 0x00 */ s32 seconds;
@@ -32,7 +32,7 @@ OSTime __OSTimeToSystemTime(OSTime time);
 void GetDates(s32 days, OSCalendarTime* ct);
 void OSTicksToCalendarTime(OSTime ticks, OSCalendarTime* ct);
 
-extern u32 __OSBusClock : 0x800000F8;
+extern u32 __OSBusClock AT_ADDRESS(0x800000F8);
 
 #define OS_BUS_CLOCK (__OSBusClock)
 #define OS_CORE_CLOCK (*(u32*)0x800000FC)

include/dolphin/si/SIBios.h

@@ -120,7 +120,7 @@ BOOL SITransfer(s32 chan, void* output, u32 outputBytes, void* input, u32 inputB
 u32 SIGetType(s32 chan);
 u32 SIGetTypeAsync(s32 chan, SITypeAndStatusCallback callback);
 
-vu32 __SIRegs[64] : 0xCC006400;
+vu32 __SIRegs[64] AT_ADDRESS(0xCC006400);
 
 #ifdef __cplusplus
 }

include/dolphin/types.h

@@ -42,4 +42,10 @@ typedef int BOOL;
 #define FLOAT_MIN (1.175494351e-38f)
 #define FLOAT_MAX (3.40282346638528860e+38f)
 
-#endif
+#ifdef __MWERKS__
+#define AT_ADDRESS(xyz) : (xyz)
+#else
+#define AT_ADDRESS(xyz)
+#endif
+
+#endif

include/dolphin/vi.h

@@ -138,7 +138,7 @@ u32 VIGetRetraceCount();
 u32 VIGetDTVStatus();
 u32 VIGetTvFormat(void);
 
-vu16 __VIRegs[59] : 0xCC002000;
+vu16 __VIRegs[59] AT_ADDRESS(0xCC002000);
 
 #ifdef __cplusplus
 };

include/global.h

@@ -24,7 +24,7 @@
 #define _SDA_BASE_(dummy) 0
 #define _SDA2_BASE_(dummy) 0
 
-#ifndef IN_VSCODE_EDITOR
+#ifdef __MWERKS__
 #define GLUE(a, b) a##b
 #define GLUE2(a, b) GLUE(a, b)
 #define STATIC_ASSERT(cond) typedef char GLUE2(static_assertion_failed, __LINE__)[(cond) ? 1 : -1]

src/PowerPC_EABI_Support/MSL/MSL_C/MSL_Common/Include/stddef.h

@@ -23,4 +23,4 @@ typedef long ptrdiff_t;
 };
 #endif
 
-#endif
+#endif

src/PowerPC_EABI_Support/Runtime/Inc/__va_arg.h

@@ -19,7 +19,7 @@ extern "C" void* __va_arg(_va_list_struct*, int);
 void* __va_arg(_va_list_struct*, int);
 #endif
 
-#if IN_VSCODE_EDITOR
+#ifndef __MWERKS__
 #define __builtin_va_info(...)
 #define _var_arg_typeof(...)
 #endif
@@ -37,4 +37,4 @@ void* __va_arg(_va_list_struct*, int);
 
 #define __va_copy(a, b) (*(a) = *(b))
 
-#endif /* __VA_ARG_H */
+#endif /* __VA_ARG_H */

src/dolphin/card/CARDMount.c

@@ -3,7 +3,7 @@
 #include "dolphin/card/CARDPriv.h"
 #include "dolphin/os/OSRtc.h"
 
-u8 GameChoice : 0x800030E3;
+u8 GameChoice AT_ADDRESS(0x800030E3);
 
 static BOOL IsCard(u32 id);
 static s32 DoMount(s32 chan);
@@ -395,4 +395,4 @@ s32 CARDUnmount(s32 chan) {
     }
     DoUnmount(chan, CARD_RESULT_NOCARD);
     return CARD_RESULT_READY;
-}
+}

src/dolphin/os/OS.c

@@ -678,7 +678,7 @@ asm void __OSPSInit(void){
     // clang-format on
 }
 
-vu32 __DIRegs[16] : 0xCC006000;
+vu32 __DIRegs[16] AT_ADDRESS(0xCC006000);
 #define DI_CONFIG_IDX 0x9
 #define DI_CONFIG_CONFIG_MASK 0xFF
 
@@ -690,4 +690,4 @@ u32 __OSGetDIConfig(void) {
 /* 8033A874-8033A8A0 3351B4 002C+00 1/1 11/11 0/0 .text            OSRegisterVersion */
 void OSRegisterVersion(const char* version) {
     OSReport("%s\n", version);
-}
+}

src/dolphin/os/OSExec.c

@@ -104,7 +104,7 @@ static void Callback(s32, DVDCommandBlock*) {
     Prepared = TRUE;
 }
 
-OSExecParams* osExecParams : 0x800030f0;
+OSExecParams* osExecParams AT_ADDRESS(0x800030f0);
 
 static int IsStreamEnabled() {
     if (DVDGetCurrentDiskID()->is_streaming) {
@@ -148,7 +148,7 @@ static void StopStreaming() {
 }
 
 /* 8033CCFC-8033CDC0 33763C 00C4+00 1/1 0/0 0/0 .text            GetApploaderPosition */
-s32 __OSAppLoaderOffset : 0x800030f4;
+s32 __OSAppLoaderOffset AT_ADDRESS(0x800030f4);
 
 static int GetApploaderPosition(void) {
     static s32 apploaderPosition;
@@ -220,9 +220,9 @@ static BOOL IsNewApploader(AppLoaderStruct* header) {
     return strncmp(header->date, "2004/02/01", 10) > 0 ? TRUE : FALSE;
 }
 
-extern volatile u32 BOOT_REGION_START : 0x812FDFF0;
+extern volatile u32 BOOT_REGION_START AT_ADDRESS(0x812FDFF0);
-extern volatile u32 BOOT_REGION_END : 0x812FDFEC;
+extern volatile u32 BOOT_REGION_END AT_ADDRESS(0x812FDFEC);
-extern volatile u8 g_unk_800030E2 : 0x800030E2;
+extern volatile u8 g_unk_800030E2 AT_ADDRESS(0x800030E2);
 
 /* 8033CDC0-8033D244 337700 0484+00 1/1 0/0 0/0 .text            __OSBootDolSimple */
 void __OSBootDolSimple(u32 doloffset, u32 restartCode, void* regionStart, void* regionEnd, BOOL argsUseDefault, s32 argc, char** argv) {
@@ -312,4 +312,4 @@ void __OSBootDol(u32 doloffset, u32 restartCode, const char** argv) {
     }
 
     __OSBootDolSimple(-1, restartCode, saveStart, saveEnd, FALSE, argvlen, argvToPass);
-}
+}

src/dolphin/os/OSInterrupt.c

@@ -3,8 +3,8 @@
 #include "dolphin/exi/EXIBios.h"
 #include "dolphin/os.h"
 
-vu32 __PIRegs[12] : 0xCC003000;
+vu32 __PIRegs[12] AT_ADDRESS(0xCC003000);
-vu16 __MEMRegs[64] : 0xCC004000;
+vu16 __MEMRegs[64] AT_ADDRESS(0xCC004000);
 
 /* 8033D6F4-8033D700 338034 000C+00 2/2 200/200 5/5 .text            OSDisableInterrupts */
 asm BOOL OSDisableInterrupts(void) {
@@ -445,4 +445,4 @@ static asm void ExternalInterruptHandler(register __OSInterrupt type, register O
     stwu r1, -8(r1)
     b __OSDispatchInterrupt
     // clang-format on
-}
+}

src/dolphin/os/OSMemory.c

@@ -4,7 +4,7 @@
 #define TRUNC(n, a) (((u32)(n)) & ~((a)-1))
 #define ROUND(n, a) (((u32)(n) + (a)-1) & ~((a)-1))
 
-vu16 __MEMRegs[64] : 0xCC004000;
+vu16 __MEMRegs[64] AT_ADDRESS(0xCC004000);
 
 extern OSErrorHandlerEx __OSErrorTable[16];
 
@@ -216,4 +216,4 @@ void __OSInitMemoryProtection() {
 
     __OSUnmaskInterrupts(OS_INTERRUPTMASK_MEM_ADDRESS);
     OSRestoreInterrupts(enabled);
-}
+}

src/dolphin/os/OSReset.c

@@ -1,7 +1,7 @@
 #include "dolphin/os/OSReset.h"
 #include "dolphin/os.h"
 
-vu16 __VIRegs[59] : 0xCC002000;
+vu16 __VIRegs[59] AT_ADDRESS(0xCC002000);
 OSThreadQueue __OSActiveThreadQueue : (OS_BASE_CACHED | 0x00DC);
 
 extern OSExecParams __OSRebootParams;
@@ -217,4 +217,4 @@ u32 OSGetResetCode(void) {
         return 0x80000000 | __OSRebootParams.restartCode;
 
     return ((__PIRegs[9] & ~7) >> 3);
-}
+}

tools/project.py

@@ -17,7 +17,7 @@ import os
 import platform
 import sys
 from pathlib import Path
-from typing import IO, Any, Dict, List, Optional, Set, Tuple, Union, cast
+from typing import IO, Any, Dict, Iterable, List, Optional, Set, Tuple, cast
 
 from . import ninja_syntax
 from .ninja_syntax import serialize_path
@@ -155,6 +155,9 @@ class ProjectConfig:
         self.custom_build_steps: Optional[Dict[str, List[Dict[str, Any]]]] = (
             None  # Custom build steps, types are ["pre-compile", "post-compile", "post-link", "post-build"]
         )
+        self.generate_compile_commands: bool = (
+            True  # Generate compile_commands.json for clangd
+        )
 
         # Progress output, progress.json and report.json config
         self.progress = True  # Enable progress output
@@ -200,9 +203,40 @@ class ProjectConfig:
                 out[obj.name] = obj.resolve(self, lib)
         return out
 
+    # Gets the output path for build-related files.
     def out_path(self) -> Path:
         return self.build_dir / str(self.version)
 
+    # Gets the path to the compilers directory.
+    # Exits the program if neither `compilers_path` nor `compilers_tag` is provided.
+    def compilers(self) -> Path:
+        if self.compilers_path:
+            return self.compilers_path
+        elif self.compilers_tag:
+            return self.build_dir / "compilers"
+        else:
+            sys.exit("ProjectConfig.compilers_tag missing")
+
+    # Gets the wrapper to use for compiler commands, if set.
+    def compiler_wrapper(self) -> Optional[Path]:
+        wrapper = self.wrapper
+
+        if self.use_wibo():
+            wrapper = self.build_dir / "tools" / "wibo"
+        if not is_windows() and wrapper is None:
+            wrapper = Path("wine")
+
+        return wrapper
+
+    # Determines whether or not to use wibo as the compiler wrapper.
+    def use_wibo(self) -> bool:
+        return (
+            self.wibo_tag is not None
+            and sys.platform == "linux"
+            and platform.machine() in ("i386", "x86_64")
+            and self.wrapper is None
+        )
+
 
 def is_windows() -> bool:
     return os.name == "nt"
@@ -214,13 +248,26 @@ CHAIN = "cmd /c " if is_windows() else ""
 EXE = ".exe" if is_windows() else ""
 
 
-def make_flags_str(flags: Optional[Union[str, List[str]]]) -> str:
+def file_is_asm(path: Path) -> bool:
+    return path.suffix.lower() == ".s"
+
+
+def file_is_c(path: Path) -> bool:
+    return path.suffix.lower() == ".c"
+
+
+def file_is_cpp(path: Path) -> bool:
+    return path.suffix.lower() in (".cc", ".cp", ".cpp", ".cxx")
+
+
+def file_is_c_cpp(path: Path) -> bool:
+    return file_is_c(path) or file_is_cpp(path)
+
+
+def make_flags_str(flags: Optional[List[str]]) -> str:
     if flags is None:
         return ""
-    elif isinstance(flags, list):
+    return " ".join(flags)
-        return " ".join(flags)
-    else:
-        return flags
 
 
 # Load decomp-toolkit generated config.json
@@ -253,13 +300,14 @@ def load_build_config(
     return build_config
 
 
-# Generate build.ninja and objdiff.json
+# Generate build.ninja, objdiff.json and compile_commands.json
 def generate_build(config: ProjectConfig) -> None:
     config.validate()
     objects = config.objects()
     build_config = load_build_config(config, config.out_path() / "config.json")
     generate_build_ninja(config, objects, build_config)
     generate_objdiff_config(config, objects, build_config)
+    generate_compile_commands(config, objects, build_config)
 
 
 # Generate build.ninja
@@ -406,16 +454,10 @@ def generate_build_ninja(
     else:
         sys.exit("ProjectConfig.sjiswrap_tag missing")
 
+    wrapper = config.compiler_wrapper()
     # Only add an implicit dependency on wibo if we download it
-    wrapper = config.wrapper
     wrapper_implicit: Optional[Path] = None
-    if (
+    if wrapper is not None and config.use_wibo():
-        config.wibo_tag is not None
-        and sys.platform == "linux"
-        and platform.machine() in ("i386", "x86_64")
-        and config.wrapper is None
-    ):
-        wrapper = build_tools_path / "wibo"
         wrapper_implicit = wrapper
         n.build(
             outputs=wrapper,
@@ -426,15 +468,11 @@ def generate_build_ninja(
                 "tag": config.wibo_tag,
             },
         )
-    if not is_windows() and wrapper is None:
-        wrapper = Path("wine")
     wrapper_cmd = f"{wrapper} " if wrapper else ""
 
+    compilers = config.compilers()
     compilers_implicit: Optional[Path] = None
-    if config.compilers_path:
+    if config.compilers_path is None and config.compilers_tag is not None:
-        compilers = config.compilers_path
-    elif config.compilers_tag:
-        compilers = config.build_dir / "compilers"
         compilers_implicit = compilers
         n.build(
             outputs=compilers,
@@ -445,8 +483,6 @@ def generate_build_ninja(
                 "tag": config.compilers_tag,
             },
         )
-    else:
-        sys.exit("ProjectConfig.compilers_tag missing")
 
     binutils_implicit = None
     if config.binutils_path:
@@ -660,7 +696,6 @@ def generate_build_ninja(
             n.comment(f"Link {self.name}")
             if self.module_id == 0:
                 elf_path = build_path / f"{self.name}.elf"
-                dol_path = build_path / f"{self.name}.dol"
                 elf_ldflags = f"$ldflags -lcf {serialize_path(self.ldscript)}"
                 if config.generate_map:
                     elf_map = map_path(elf_path)
@@ -725,17 +760,36 @@ def generate_build_ninja(
         source_added: Set[Path] = set()
 
         def c_build(obj: Object, src_path: Path) -> Optional[Path]:
-            cflags_str = make_flags_str(obj.options["cflags"])
-            if obj.options["extra_cflags"] is not None:
-                extra_cflags_str = make_flags_str(obj.options["extra_cflags"])
-                cflags_str += " " + extra_cflags_str
-            used_compiler_versions.add(obj.options["mw_version"])
-
             # Avoid creating duplicate build rules
             if obj.src_obj_path is None or obj.src_obj_path in source_added:
                 return obj.src_obj_path
             source_added.add(obj.src_obj_path)
 
+            cflags = obj.options["cflags"]
+            extra_cflags = obj.options["extra_cflags"]
+
+            # Add appropriate language flag if it doesn't exist already
+            # Added directly to the source so it flows to other generation tasks
+            if not any(flag.startswith("-lang") for flag in cflags) and (
+                extra_cflags is None
+                or not any(flag.startswith("-lang") for flag in extra_cflags)
+            ):
+                # Ensure extra_cflags is a unique instance,
+                # and insert into there to avoid modifying shared sets of flags
+                if extra_cflags is None:
+                    extra_cflags = []
+                extra_cflags = obj.options["extra_cflags"] = list(extra_cflags)
+                if file_is_cpp(src_path):
+                    extra_cflags.insert(0, "-lang=c++")
+                else:
+                    extra_cflags.insert(0, "-lang=c")
+
+            cflags_str = make_flags_str(cflags)
+            if extra_cflags is not None:
+                extra_cflags_str = make_flags_str(extra_cflags)
+                cflags_str += " " + extra_cflags_str
+            used_compiler_versions.add(obj.options["mw_version"])
+
             # Add MWCC build rule
             lib_name = obj.options["lib"]
             n.comment(f"{obj.name}: {lib_name} (linked {obj.completed})")
@@ -767,7 +821,7 @@ def generate_build_ninja(
             if obj.options["host"] and obj.host_obj_path is not None:
                 n.build(
                     outputs=obj.host_obj_path,
-                    rule="host_cc" if src_path.suffix == ".c" else "host_cpp",
+                    rule="host_cc" if file_is_c(src_path) else "host_cpp",
                     inputs=src_path,
                     variables={
                         "basedir": os.path.dirname(obj.host_obj_path),
@@ -827,10 +881,10 @@ def generate_build_ninja(
             link_built_obj = obj.completed
             built_obj_path: Optional[Path] = None
             if obj.src_path is not None and obj.src_path.exists():
-                if obj.src_path.suffix in (".c", ".cp", ".cpp"):
+                if file_is_c_cpp(obj.src_path):
                     # Add MWCC & host build rules
                     built_obj_path = c_build(obj, obj.src_path)
-                elif obj.src_path.suffix == ".s":
+                elif file_is_asm(obj.src_path):
                     # Add assembler build rule
                     built_obj_path = asm_build(obj, obj.src_path, obj.src_obj_path)
                 else:
@@ -1274,30 +1328,20 @@ def generate_objdiff_config(
 
         cflags = obj.options["cflags"]
         reverse_fn_order = False
-        if type(cflags) is list:
+        for flag in cflags:
-            for flag in cflags:
+            if not flag.startswith("-inline "):
-                if not flag.startswith("-inline "):
+                continue
-                    continue
+            for value in flag.split(" ")[1].split(","):
-                for value in flag.split(" ")[1].split(","):
+                if value == "deferred":
-                    if value == "deferred":
+                    reverse_fn_order = True
-                        reverse_fn_order = True
+                elif value == "nodeferred":
-                    elif value == "nodeferred":
+                    reverse_fn_order = False
-                        reverse_fn_order = False
 
-            # Filter out include directories
+        # Filter out include directories
-            def keep_flag(flag):
+        def keep_flag(flag):
-                return not flag.startswith("-i ") and not flag.startswith("-I ")
+            return not flag.startswith("-i ") and not flag.startswith("-I ")
 
-            cflags = list(filter(keep_flag, cflags))
+        cflags = list(filter(keep_flag, cflags))
-
-            # Add appropriate lang flag
-            if obj.src_path is not None and not any(
-                flag.startswith("-lang") for flag in cflags
-            ):
-                if obj.src_path.suffix in (".cp", ".cpp"):
-                    cflags.insert(0, "-lang=c++")
-                else:
-                    cflags.insert(0, "-lang=c")
 
         compiler_version = COMPILER_MAP.get(obj.options["mw_version"])
         if compiler_version is None:
@@ -1388,6 +1432,199 @@ def generate_objdiff_config(
         json.dump(cleandict(objdiff_config), w, indent=2, default=unix_path)
 
 
+def generate_compile_commands(
+    config: ProjectConfig,
+    objects: Dict[str, Object],
+    build_config: Optional[Dict[str, Any]],
+) -> None:
+    if build_config is None or not config.generate_compile_commands:
+        return
+
+    # The following code attempts to convert mwcc flags to clang flags
+    # for use with clangd.
+
+    # Flags to ignore explicitly
+    CFLAG_IGNORE: Set[str] = {
+        # Search order modifier
+        # Has a different meaning to Clang, and would otherwise
+        # be picked up by the include passthrough prefix
+        "-I-",
+        "-i-",
+    }
+    CFLAG_IGNORE_PREFIX: Tuple[str, ...] = tuple()
+
+    # Flags to replace
+    CFLAG_REPLACE: Dict[str, str] = {}
+    CFLAG_REPLACE_PREFIX: Tuple[Tuple[str, str], ...] = (
+        # Includes
+        ("-i ", "-I"),
+        ("-I ", "-I"),
+        ("-I+", "-I"),
+        # Defines
+        ("-d ", "-D"),
+        ("-D ", "-D"),
+        ("-D+", "-D"),
+    )
+
+    # Flags with a finite set of options
+    CFLAG_REPLACE_OPTIONS: Tuple[Tuple[str, Dict[str, Tuple[str, ...]]], ...] = (
+        # Exceptions
+        (
+            "-Cpp_exceptions",
+            {
+                "off": ("-fno-cxx-exceptions",),
+                "on": ("-fcxx-exceptions",),
+            },
+        ),
+        # RTTI
+        (
+            "-RTTI",
+            {
+                "off": ("-fno-rtti",),
+                "on": ("-frtti",),
+            },
+        ),
+        # Language configuration
+        (
+            "-lang",
+            {
+                "c": ("--language=c", "--std=c89"),
+                "c99": ("--language=c", "--std=c99"),
+                "c++": ("--language=c++", "--std=c++98"),
+                "cplus": ("--language=c++", "--std=c++98"),
+            },
+        ),
+    )
+
+    # Flags to pass through
+    CFLAG_PASSTHROUGH: Set[str] = set()
+    CFLAG_PASSTHROUGH_PREFIX: Tuple[str, ...] = (
+        "-I",  # includes
+        "-D",  # defines
+    )
+
+    clangd_config = []
+
+    def add_unit(build_obj: Dict[str, Any]) -> None:
+        obj = objects.get(build_obj["name"])
+        if obj is None:
+            return
+
+        # Skip unresolved objects
+        if (
+            obj.src_path is None
+            or obj.src_obj_path is None
+            or not file_is_c_cpp(obj.src_path)
+        ):
+            return
+
+        # Gather cflags for source file
+        cflags: list[str] = []
+
+        def append_cflags(flags: Iterable[str]) -> None:
+            # Match a flag against either a set of concrete flags, or a set of prefixes.
+            def flag_match(
+                flag: str, concrete: Set[str], prefixes: Tuple[str, ...]
+            ) -> bool:
+                if flag in concrete:
+                    return True
+
+                for prefix in prefixes:
+                    if flag.startswith(prefix):
+                        return True
+
+                return False
+
+            # Determine whether a flag should be ignored.
+            def should_ignore(flag: str) -> bool:
+                return flag_match(flag, CFLAG_IGNORE, CFLAG_IGNORE_PREFIX)
+
+            # Determine whether a flag should be passed through.
+            def should_passthrough(flag: str) -> bool:
+                return flag_match(flag, CFLAG_PASSTHROUGH, CFLAG_PASSTHROUGH_PREFIX)
+
+            # Attempts replacement for the given flag.
+            def try_replace(flag: str) -> bool:
+                replacement = CFLAG_REPLACE.get(flag)
+                if replacement is not None:
+                    cflags.append(replacement)
+                    return True
+
+                for prefix, replacement in CFLAG_REPLACE_PREFIX:
+                    if flag.startswith(prefix):
+                        cflags.append(flag.replace(prefix, replacement, 1))
+                        return True
+
+                for prefix, options in CFLAG_REPLACE_OPTIONS:
+                    if not flag.startswith(prefix):
+                        continue
+
+                    # "-lang c99" and "-lang=c99" are both generally valid option forms
+                    option = flag.removeprefix(prefix).removeprefix("=").lstrip()
+                    replacements = options.get(option)
+                    if replacements is not None:
+                        cflags.extend(replacements)
+
+                    return True
+
+                return False
+
+            for flag in flags:
+                # Ignore flags first
+                if should_ignore(flag):
+                    continue
+
+                # Then find replacements
+                if try_replace(flag):
+                    continue
+
+                # Pass flags through last
+                if should_passthrough(flag):
+                    cflags.append(flag)
+                    continue
+
+        append_cflags(obj.options["cflags"])
+        if isinstance(obj.options["extra_cflags"], list):
+            append_cflags(obj.options["extra_cflags"])
+
+        unit_config = {
+            "directory": Path.cwd(),
+            "file": obj.src_path,
+            "output": obj.src_obj_path,
+            "arguments": [
+                "clang",
+                "-nostdinc",
+                "-fno-builtin",
+                "--target=powerpc-eabi",
+                *cflags,
+                "-c",
+                obj.src_path,
+                "-o",
+                obj.src_obj_path,
+            ],
+        }
+        clangd_config.append(unit_config)
+
+    # Add DOL units
+    for unit in build_config["units"]:
+        add_unit(unit)
+
+    # Add REL units
+    for module in build_config["modules"]:
+        for unit in module["units"]:
+            add_unit(unit)
+
+    # Write compile_commands.json
+    with open("compile_commands.json", "w", encoding="utf-8") as w:
+
+        def default_format(o):
+            if isinstance(o, Path):
+                return o.resolve().as_posix()
+            return str(o)
+
+        json.dump(clangd_config, w, indent=2, default=default_format)
+
+
 # Calculate, print and write progress to progress.json
 def calculate_progress(config: ProjectConfig) -> None:
     config.validate()