[clang] Use i64 for the !srcloc metadata on asm IR nodes.

This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.

!srcloc is generated in clang codegen, and pulled back out by llvm
functions like AsmPrinter::emitInlineAsm that need to report errors in
the inline asm. From there it goes to LLVMContext::emitError, is
stored in DiagnosticInfoInlineAsm, and ends up back in clang, at
BackendConsumer::InlineAsmDiagHandler(), which reconstitutes a true
clang::SourceLocation from the integer cookie.

Throughout this code path, it's now 64-bit rather than 32, which means
that if SourceLocation is expanded to a 64-bit type, this error report
won't lose half of the data.

The compiler will tolerate both of i32 and i64 !srcloc metadata in
input IR without faulting. Test added in llvm/MC. (The semantic
accuracy of the metadata is another matter, but I don't know of any
situation where that matters: if you're reading an IR file written by
a previous run of clang, you don't have the SourceManager that can
relate those source locations back to the original source files.)

Original version of the patch by Mikhail Maltsev.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D105491

include/llvm/IR/DiagnosticInfo.h

@@ -131,7 +131,7 @@ using DiagnosticHandlerFunction = std::function<void(const DiagnosticInfo &)>;
 class DiagnosticInfoInlineAsm : public DiagnosticInfo {
 private:
   /// Optional line information. 0 if not set.
-  unsigned LocCookie = 0;
+  uint64_t LocCookie = 0;
   /// Message to be reported.
   const Twine &MsgStr;
   /// Optional origin of the problem.
@@ -149,7 +149,7 @@ public:
   /// \p MsgStr gives the message.
   /// This class does not copy \p MsgStr, therefore the reference must be valid
   /// for the whole life time of the Diagnostic.
-  DiagnosticInfoInlineAsm(unsigned LocCookie, const Twine &MsgStr,
+  DiagnosticInfoInlineAsm(uint64_t LocCookie, const Twine &MsgStr,
                           DiagnosticSeverity Severity = DS_Error)
       : DiagnosticInfo(DK_InlineAsm, Severity), LocCookie(LocCookie),
         MsgStr(MsgStr) {}
@@ -162,7 +162,7 @@ public:
   DiagnosticInfoInlineAsm(const Instruction &I, const Twine &MsgStr,
                           DiagnosticSeverity Severity = DS_Error);
 
-  unsigned getLocCookie() const { return LocCookie; }
+  uint64_t getLocCookie() const { return LocCookie; }
   const Twine &getMsgStr() const { return MsgStr; }
   const Instruction *getInstruction() const { return Instr; }
 

include/llvm/IR/LLVMContext.h

@@ -290,7 +290,7 @@ public:
   /// be prepared to drop the erroneous construct on the floor and "not crash".
   /// The generated code need not be correct.  The error message will be
   /// implicitly prefixed with "error: " and should not end with a ".".
-  void emitError(unsigned LocCookie, const Twine &ErrorStr);
+  void emitError(uint64_t LocCookie, const Twine &ErrorStr);
   void emitError(const Instruction *I, const Twine &ErrorStr);
   void emitError(const Twine &ErrorStr);
 

lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp

@@ -130,7 +130,7 @@ void AsmPrinter::emitInlineAsm(StringRef Str, const MCSubtargetInfo &STI,
 
 static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
                                MachineModuleInfo *MMI, AsmPrinter *AP,
-                               unsigned LocCookie, raw_ostream &OS) {
+                               uint64_t LocCookie, raw_ostream &OS) {
   // Switch to the inline assembly variant.
   OS << "\t.intel_syntax\n\t";
 
@@ -272,7 +272,7 @@ static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
 
 static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
                                 MachineModuleInfo *MMI, const MCAsmInfo *MAI,
-                                AsmPrinter *AP, unsigned LocCookie,
+                                AsmPrinter *AP, uint64_t LocCookie,
                                 raw_ostream &OS) {
   int CurVariant = -1;            // The number of the {.|.|.} region we are in.
   const char *LastEmitted = AsmStr; // One past the last character emitted.
@@ -483,7 +483,7 @@ void AsmPrinter::emitInlineAsm(const MachineInstr *MI) const {
 
   // Get the !srcloc metadata node if we have it, and decode the loc cookie from
   // it.
-  unsigned LocCookie = 0;
+  uint64_t LocCookie = 0;
   const MDNode *LocMD = nullptr;
   for (unsigned i = MI->getNumOperands(); i != 0; --i) {
     if (MI->getOperand(i-1).isMetadata() &&

lib/CodeGen/MachineInstr.cpp

@@ -2083,7 +2083,7 @@ MachineInstrExpressionTrait::getHashValue(const MachineInstr* const &MI) {
 
 void MachineInstr::emitError(StringRef Msg) const {
   // Find the source location cookie.
-  unsigned LocCookie = 0;
+  uint64_t LocCookie = 0;
   const MDNode *LocMD = nullptr;
   for (unsigned i = getNumOperands(); i != 0; --i) {
     if (getOperand(i-1).isMetadata() &&

lib/IR/LLVMContext.cpp

@@ -248,7 +248,7 @@ void LLVMContext::diagnose(const DiagnosticInfo &DI) {
     exit(1);
 }
 
-void LLVMContext::emitError(unsigned LocCookie, const Twine &ErrorStr) {
+void LLVMContext::emitError(uint64_t LocCookie, const Twine &ErrorStr) {
   diagnose(DiagnosticInfoInlineAsm(LocCookie, ErrorStr));
 }
 

test/MC/ARM/inline-asm-srcloc.ll

@@ -20,6 +20,8 @@ entry:
 ; CHECK: note: !srcloc = 181
   call void asm sideeffect " .word -foo", ""() #1, !srcloc !5
 ; CHECK: note: !srcloc = 257
+  call void asm sideeffect " .word -stoat", ""() #1, !srcloc !6
+; CHECK: note: !srcloc = 534
   ret void
 }
 
@@ -33,5 +35,11 @@ attributes #1 = { nounwind }
 !1 = !{i32 1, !"min_enum_size", i32 4}
 !2 = !{!"clang version 5.0.0 "}
 !3 = !{i32 107}
+
+; These !srcloc metadata nodes are intentionally not all the same type: D105491
+; changed the creation of !srcloc to generate i64 instead of the previous i32.
+; So one thing we're testing here is that both types are acceptable on input,
+; i.e. IR generated both before and after the change can be consumed.
 !4 = !{i32 181}
 !5 = !{i32 257}
+!6 = !{i64 534}