Add backend dignostic printer for unsupported features

[olista01]

Summary

The related LLVM patch adds a backend diagnostic type for reporting
unsupported features, this adds a printer for them to clang.

In the case where debug location information is not available, I've
changed the printer to report the location as the first line of the
function, rather than the closing brace, as the latter does not give the
user any information. This also affects optimisation remarks.

[ast]

looks good.
could you add a testcase for DK_Unsupported ?

[olista01]

Added a test for the new diagnostic printer.

[ast]

thanks

[olista01]

This was reverted last night, I've re-committed it as r259036 with the layering violation fixed.

include/clang/Basic/DiagnosticFrontendKinds.td

def remark_fe_backend_optimization_remark_analysis_aliasing : Remark<"%0; "
     "allow reordering by specifying '#pragma clang loop vectorize(enable)' "
     "before the loop. If the arrays will always be independent specify "
     "'#pragma clang loop vectorize(assume_safety)' before the loop or provide "
     "the '__restrict__' qualifier with the independent array arguments. "
     "Erroneous results will occur if these options are incorrectly applied!">,
     BackendInfo, InGroup<BackendOptimizationRemarkAnalysis>;
 def warn_fe_backend_optimization_failure : Warning<"%0">, BackendInfo,
     InGroup<BackendOptimizationFailure>, DefaultWarn;
-def note_fe_backend_optimization_remark_invalid_loc : Note<"could "
-  "not determine the original source location for %0:%1:%2">;
+def note_fe_backend_invalid_loc : Note<"could "
+  "not determine the original source location for %0:%1:%2">, BackendInfo;
+
+def err_fe_backend_unsupported : Error<"%0">, BackendInfo;
 
 def remark_sanitize_address_insert_extra_padding_accepted : Remark<
     "-fsanitize-address-field-padding applied to %0">, ShowInSystemHeader,
     InGroup<SanitizeAddressRemarks>;
 def remark_sanitize_address_insert_extra_padding_rejected : Remark<
     "-fsanitize-address-field-padding ignored for %0 because it "
     "%select{is not C++|is packed|is a union|is trivially copyable|"
     "has trivial destructor|is standard layout|is in a blacklisted file|"

lib/CodeGen/CodeGenAction.cpp

static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
     }
 
     static void DiagnosticHandler(const llvm::DiagnosticInfo &DI,
                                   void *Context) {
       ((BackendConsumer *)Context)->DiagnosticHandlerImpl(DI);
     }
 
+    /// Get the best possible source location to represent a diagnostic that
+    /// may have associated debug info.
+    const FullSourceLoc
+    getBestLocationFromDebugLoc(const llvm::DiagnosticInfoWithDebugLocBase &D,
+                                bool &BadDebugInfo, StringRef &Filename,
+                                unsigned &Line, unsigned &Column) const;
+
     void InlineAsmDiagHandler2(const llvm::SMDiagnostic &,
                                SourceLocation LocCookie);
 
     void DiagnosticHandlerImpl(const llvm::DiagnosticInfo &DI);
     /// \brief Specialized handler for InlineAsm diagnostic.
     /// \return True if the diagnostic has been successfully reported, false
     /// otherwise.
     bool InlineAsmDiagHandler(const llvm::DiagnosticInfoInlineAsm &D);
     /// \brief Specialized handler for StackSize diagnostic.
     /// \return True if the diagnostic has been successfully reported, false
     /// otherwise.
     bool StackSizeDiagHandler(const llvm::DiagnosticInfoStackSize &D);
+    /// \brief Specialized handler for unsupported backend feature diagnostic.
+    void UnsupportedDiagHandler(const llvm::DiagnosticInfoUnsupported &D);
     /// \brief Specialized handlers for optimization remarks.
     /// Note that these handlers only accept remarks and they always handle
     /// them.
     void EmitOptimizationMessage(const llvm::DiagnosticInfoOptimizationBase &D,
                                  unsigned DiagID);
     void
     OptimizationRemarkHandler(const llvm::DiagnosticInfoOptimizationRemark &D);
     void OptimizationRemarkHandler(
Diags.Report(ND->getASTContext().getFullLoc(ND->getLocation()),
                  diag::warn_fe_frame_larger_than)
         << D.getStackSize() << Decl::castToDeclContext(ND);
     return true;
   }
 
   return false;
 }
 
-void BackendConsumer::EmitOptimizationMessage(
-    const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
-  // We only support warnings and remarks.
-  assert(D.getSeverity() == llvm::DS_Remark ||
-         D.getSeverity() == llvm::DS_Warning);
-
+const FullSourceLoc BackendConsumer::getBestLocationFromDebugLoc(
+    const llvm::DiagnosticInfoWithDebugLocBase &D, bool &BadDebugInfo, StringRef &Filename,
+                                unsigned &Line, unsigned &Column) const {
   SourceManager &SourceMgr = Context->getSourceManager();
   FileManager &FileMgr = SourceMgr.getFileManager();
-  StringRef Filename;
-  unsigned Line, Column;
   SourceLocation DILoc;
 
   if (D.isLocationAvailable()) {
     D.getLocation(&Filename, &Line, &Column);
     const FileEntry *FE = FileMgr.getFile(Filename);
     if (FE && Line > 0) {
       // If -gcolumn-info was not used, Column will be 0. This upsets the
       // source manager, so pass 1 if Column is not set.
       DILoc = SourceMgr.translateFileLineCol(FE, Line, Column ? Column : 1);
     }
+    BadDebugInfo = DILoc.isInvalid();
   }
 
   // If a location isn't available, try to approximate it using the associated
   // function definition. We use the definition's right brace to differentiate
   // from diagnostics that genuinely relate to the function itself.
   FullSourceLoc Loc(DILoc, SourceMgr);
   if (Loc.isInvalid())
     if (const Decl *FD = Gen->GetDeclForMangledName(D.getFunction().getName()))
-      Loc = FD->getASTContext().getFullLoc(FD->getBodyRBrace());
+      Loc = FD->getASTContext().getFullLoc(FD->getLocation());
+
+  if (DILoc.isInvalid() && D.isLocationAvailable())
+    // If we were not able to translate the file:line:col information
+    // back to a SourceLocation, at least emit a note stating that
+    // we could not translate this location. This can happen in the
+    // case of #line directives.
+    Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
+        << Filename << Line;
+
+  return Loc;
+}
+
+void BackendConsumer::UnsupportedDiagHandler(
+    const llvm::DiagnosticInfoUnsupported &D) {
+  // We only support errors.
+  assert(D.getSeverity() == llvm::DS_Error);
+
+  StringRef Filename;
+  unsigned Line, Column;
+  bool BadDebugInfo;
+  FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
+      Line, Column);
+
+  Diags.Report(Loc, diag::err_fe_backend_unsupported) << D.getMessage().str();
+
+  if (BadDebugInfo)
+    // If we were not able to translate the file:line:col information
+    // back to a SourceLocation, at least emit a note stating that
+    // we could not translate this location. This can happen in the
+    // case of #line directives.
+    Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
+        << Filename << Line << Column;
+}
+
+void BackendConsumer::EmitOptimizationMessage(
+    const llvm::DiagnosticInfoOptimizationBase &D, unsigned DiagID) {
+  // We only support warnings and remarks.
+  assert(D.getSeverity() == llvm::DS_Remark ||
+         D.getSeverity() == llvm::DS_Warning);
+
+  StringRef Filename;
+  unsigned Line, Column;
+  bool BadDebugInfo = false;
+  FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
+      Line, Column);
 
   Diags.Report(Loc, DiagID)
       << AddFlagValue(D.getPassName() ? D.getPassName() : "")
       << D.getMsg().str();
 
-  if (DILoc.isInvalid() && D.isLocationAvailable())
+  if (BadDebugInfo)
     // If we were not able to translate the file:line:col information
     // back to a SourceLocation, at least emit a note stating that
     // we could not translate this location. This can happen in the
     // case of #line directives.
-    Diags.Report(Loc, diag::note_fe_backend_optimization_remark_invalid_loc)
+    Diags.Report(Loc, diag::note_fe_backend_invalid_loc)
         << Filename << Line << Column;
 }
 
 void BackendConsumer::OptimizationRemarkHandler(
     const llvm::DiagnosticInfoOptimizationRemark &D) {
   // Optimization remarks are active only if the -Rpass flag has a regular
   // expression that matches the name of the pass name in \p D.
   if (CodeGenOpts.OptimizationRemarkPattern &&
case llvm::DK_OptimizationRemarkAnalysisAliasing:
     OptimizationRemarkHandler(
         cast<DiagnosticInfoOptimizationRemarkAnalysisAliasing>(DI));
     return;
   case llvm::DK_OptimizationFailure:
     // Optimization failures are always handled completely by this
     // handler.
     OptimizationFailureHandler(cast<DiagnosticInfoOptimizationFailure>(DI));
     return;
+  case llvm::DK_Unsupported:
+    UnsupportedDiagHandler(cast<DiagnosticInfoUnsupported>(DI));
+    return;
   default:
     // Plugin IDs are not bound to any value as they are set dynamically.
     ComputeDiagRemarkID(Severity, backend_plugin, DiagID);
     break;
   }
   std::string MsgStorage;
   {
     raw_string_ostream Stream(MsgStorage);

test/CodeGen/backend-unsupported-error.ll

+; RUN: not %clang_cc1 -triple r600-unknown-unknown -S -o - %s 2>&1 | FileCheck %s
+; REQUIRES: amdgpu-registered-target
+
+; This is to check that backend errors for unsupported features are formatted correctly
+
+; CHECK: error: test.c:2:20: in function bar i32 (): unsupported call to function foo.2
+
+target triple = "r600-unknown-unknown"
+
+; Function Attrs: nounwind uwtable
+define i32 @bar() #0 !dbg !4 {
+entry:
+  %call = call i32 @foo(), !dbg !12
+  ret i32 %call, !dbg !13
+}
+
+; Function Attrs: nounwind uwtable
+define i32 @foo() #0 !dbg !8 {
+entry:
+  %call = call i32 @bar(), !dbg !14
+  ret i32 %call, !dbg !15
+}
+
+attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10}
+!llvm.ident = !{!11}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "test.c", directory: "")
+!2 = !{}
+!3 = !{!4, !8}
+!4 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: false, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{!7}
+!7 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!8 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{!"clang version 3.9.0"}
+!12 = !DILocation(line: 2, column: 20, scope: !4)
+!13 = !DILocation(line: 2, column: 13, scope: !4)
+!14 = !DILocation(line: 3, column: 20, scope: !8)
+!15 = !DILocation(line: 3, column: 13, scope: !8)

test/Frontend/optimization-remark-analysis.c

 // RUN: %clang -O1 -fvectorize -target x86_64-unknown-unknown -emit-llvm -Rpass-analysis -S %s -o - 2>&1 | FileCheck %s --check-prefix=RPASS
 // RUN: %clang -O1 -fvectorize -target x86_64-unknown-unknown -emit-llvm -S %s -o - 2>&1 | FileCheck %s
 
-// RPASS: {{.*}}:21:1: remark: loop not vectorized: loop contains a switch statement
-// CHECK-NOT: {{.*}}:21:1: remark: loop not vectorized: loop contains a switch statement
+// RPASS: {{.*}}:7:8: remark: loop not vectorized: loop contains a switch statement
+// CHECK-NOT: {{.*}}:7:8: remark: loop not vectorized: loop contains a switch statement
 
 double foo(int N, int *Array) {
   double v = 0.0;
 
   #pragma clang loop vectorize(enable)
   for (int i = 0; i < N; i++) {
     switch(Array[i]) {
     case 0: v += 1.0f; break;
     case 1: v -= 0.5f; break;
     case 2: v *= 2.0f; break;
     default: v = 0.0f;
     }
   }
 
   return v;
 }

test/Misc/backend-optimization-failure-nodbg.cpp

 // RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -O3 -emit-llvm -S -verify -o /dev/null
 // REQUIRES: x86-registered-target
 
 // Test verifies optimization failures generated by the backend are handled
 // correctly by clang. LLVM tests verify all of the failure conditions.
 
-void test_switch(int *A, int *B, int Length) {
+void test_switch(int *A, int *B, int Length) { /* expected-warning {{loop not vectorized: failed explicitly specified loop vectorization}} */
 #pragma clang loop vectorize(enable) unroll(disable)
   for (int i = 0; i < Length; i++) {
     switch (A[i]) {
     case 0:
       B[i] = 1;
       break;
     case 1:
       B[i] = 2;
       break;
     default:
       B[i] = 3;
     }
   }
-/* expected-warning {{loop not vectorized: failed explicitly specified loop vectorization}} */ }
+}