[CUDA][HIP] Defer overloading resolution diagnostics for host device functions

In CUDA/HIP a function may become implicit host device function by
pragma or constexpr. A host device function is checked in both
host and device compilation. However it may be emitted only
on host or device side, therefore the diagnostics should be
deferred until it is known to be emitted.

Currently clang is only able to defer certain diagnostics. This causes
false alarms and limits the usefulness of host device functions.

This patch lets clang defer all overloading resolution diagnostics for host device functions.

An option -fgpu-defer-diag is added to control this behavior. By default
it is off.

It is NFC for other languages.

Differential Revision: https://reviews.llvm.org/D84364

Author: yxsamliu

clang/include/clang/Basic/Diagnostic.td

@@ -45,6 +45,7 @@ class TextSubstitution<string Text> {
   // diagnostics
   string Component = "";
   string CategoryName = "";
+  bit Deferrable = 0;
 }
 
 // Diagnostic Categories.  These can be applied to groups or individual
@@ -83,6 +84,7 @@ class Diagnostic<string text, DiagClass DC, Severity defaultmapping> {
   bit            AccessControl = 0;
   bit            WarningNoWerror = 0;
   bit            ShowInSystemHeader = 0;
+  bit            Deferrable = 0;
   Severity       DefaultSeverity = defaultmapping;
   DiagGroup      Group;
   string         CategoryName = "";
@@ -106,6 +108,14 @@ class SuppressInSystemHeader {
   bit ShowInSystemHeader = 0;
 }
 
+class Deferrable {
+  bit Deferrable = 1;
+}
+
+class NonDeferrable {
+  bit Deferrable = 0;
+}
+
 // FIXME: ExtWarn and Extension should also be SFINAEFailure by default.
 class Error<string str>     : Diagnostic<str, CLASS_ERROR, SEV_Error>, SFINAEFailure {
   bit ShowInSystemHeader = 1;

clang/include/clang/Basic/DiagnosticAST.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define ASTSTART
 #include "clang/Basic/DiagnosticASTKinds.inc"

clang/include/clang/Basic/DiagnosticAnalysis.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define ANALYSISSTART
 #include "clang/Basic/DiagnosticAnalysisKinds.inc"

clang/include/clang/Basic/DiagnosticComment.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define COMMENTSTART
 #include "clang/Basic/DiagnosticCommentKinds.inc"

clang/include/clang/Basic/DiagnosticCrossTU.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define CROSSTUSTART
 #include "clang/Basic/DiagnosticCrossTUKinds.inc"

clang/include/clang/Basic/DiagnosticDriver.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define DRIVERSTART
 #include "clang/Basic/DiagnosticDriverKinds.inc"

clang/include/clang/Basic/DiagnosticFrontend.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define FRONTENDSTART
 #include "clang/Basic/DiagnosticFrontendKinds.inc"

clang/include/clang/Basic/DiagnosticIDs.h

@@ -64,8 +64,9 @@ namespace clang {
 
     // Get typedefs for common diagnostics.
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
-             SFINAE,CATEGORY,NOWERROR,SHOWINSYSHEADER) ENUM,
+#define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, CATEGORY,      \
+             NOWERROR, SHOWINSYSHEADER, DEFFERABLE)                            \
+  ENUM,
 #define COMMONSTART
 #include "clang/Basic/DiagnosticCommonKinds.inc"
       NUM_BUILTIN_COMMON_DIAGNOSTICS
@@ -280,6 +281,13 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
   /// are not SFINAE errors.
   static SFINAEResponse getDiagnosticSFINAEResponse(unsigned DiagID);
 
+  /// Whether the diagnostic message can be deferred.
+  ///
+  /// For single source offloading languages, a diagnostic message occurred
+  /// in a device host function may be deferred until the function is sure
+  /// to be emitted.
+  static bool isDeferrable(unsigned DiagID);
+
   /// Get the string of all diagnostic flags.
   ///
   /// \returns A list of all diagnostics flags as they would be written in a

clang/include/clang/Basic/DiagnosticLex.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define LEXSTART
 #include "clang/Basic/DiagnosticLexKinds.inc"

clang/include/clang/Basic/DiagnosticParse.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define PARSESTART
 #include "clang/Basic/DiagnosticParseKinds.inc"

clang/include/clang/Basic/DiagnosticRefactoring.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define REFACTORINGSTART
 #include "clang/Basic/DiagnosticRefactoringKinds.inc"

clang/include/clang/Basic/DiagnosticSema.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define SEMASTART
 #include "clang/Basic/DiagnosticSemaKinds.inc"

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -4060,6 +4060,8 @@ def err_ovl_static_nonstatic_member : Error<
   "static and non-static member functions with the same parameter types "
   "cannot be overloaded">;
 
+let Deferrable = 1 in {
+
 def err_ovl_no_viable_function_in_call : Error<
   "no matching function for call to %0">;
 def err_ovl_no_viable_member_function_in_call : Error<
@@ -4373,6 +4375,8 @@ def err_addr_ovl_not_func_ptrref : Error<
 def err_addr_ovl_no_qualifier : Error<
   "cannot form member pointer of type %0 without '&' and class name">;
 
+} // let Deferrable
+
 // C++11 Literal Operators
 def err_ovl_no_viable_literal_operator : Error<
   "no matching literal operator for call to %0"

clang/include/clang/Basic/DiagnosticSerialization.h

@@ -15,7 +15,7 @@ namespace clang {
 namespace diag {
 enum {
 #define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, NOWERROR,      \
-             SHOWINSYSHEADER, CATEGORY)                                        \
+             SHOWINSYSHEADER, DEFERRABLE, CATEGORY)                            \
   ENUM,
 #define SERIALIZATIONSTART
 #include "clang/Basic/DiagnosticSerializationKinds.inc"

clang/include/clang/Basic/LangOptions.def

@@ -241,6 +241,7 @@ LANGOPT(CUDADeviceApproxTranscendentals, 1, 0, "using approximate transcendental
 LANGOPT(GPURelocatableDeviceCode, 1, 0, "generate relocatable device code")
 LANGOPT(GPUAllowDeviceInit, 1, 0, "allowing device side global init functions for HIP")
 LANGOPT(GPUMaxThreadsPerBlock, 32, 256, "default max threads per block for kernel launch bounds for HIP")
+LANGOPT(GPUDeferDiag, 1, 0, "defer host/device related diagnostic messages for CUDA/HIP")
 
 LANGOPT(SYCL              , 1, 0, "SYCL")
 LANGOPT(SYCLIsDevice      , 1, 0, "Generate code for SYCL device")

clang/include/clang/Driver/Options.td

@@ -669,6 +669,9 @@ defm hip_new_launch_api : OptInFFlag<"hip-new-launch-api",
   "Use", "Don't use", " new kernel launching API for HIP">;
 defm gpu_allow_device_init : OptInFFlag<"gpu-allow-device-init",
   "Allow", "Don't allow", " device side init function in HIP">;
+defm gpu_defer_diag : OptInFFlag<"gpu-defer-diag",
+  "Defer", "Don't defer", " host/device related diagnostic messages"
+  " for CUDA/HIP">;
 def gpu_max_threads_per_block_EQ : Joined<["--"], "gpu-max-threads-per-block=">,
   Flags<[CC1Option]>,
   HelpText<"Default max threads per block for kernel launch bounds for HIP">;