[AsmParser] Expose an API to parse a string starting with a type.

Without actually parsing a type it is difficult to perdict where
the type definition ends. In other words, instead of expecting
the user of the parser API to hand over only the relevant bits
of the string being parsed, take the whole string, parse the type,
and get back the number of characters that have been read.

This will be used by the MIR testing infrastructure.

llvm-svn: 262884

1 files changed, 18 insertions, 1 deletions

diff --git a/llvm/lib/AsmParser/Parser.cpp b/llvm/lib/AsmParser/Parser.cpp
index 9b635982477..bee07ad9e0a 100644
--- a/llvm/lib/AsmParser/Parser.cpp
+++ b/llvm/lib/AsmParser/Parser.cpp
@@ -81,12 +81,29 @@ Constant *llvm::parseConstantValue(StringRef Asm, SMDiagnostic &Err,
 
 Type *llvm::parseType(StringRef Asm, SMDiagnostic &Err, const Module &M,
                       const SlotMapping *Slots) {
+  unsigned Read;
+  Type *Ty = parseTypeAtBeginning(Asm, Read, Err, M, Slots);
+  if (!Ty)
+    return nullptr;
+  if (Read != Asm.size()) {
+    SourceMgr SM;
+    std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Asm);
+    SM.AddNewSourceBuffer(std::move(Buf), SMLoc());
+    Err = SM.GetMessage(SMLoc::getFromPointer(Asm.begin() + Read),
+                        SourceMgr::DK_Error, "expected end of string");
+    return nullptr;
+  }
+  return Ty;
+}
+Type *llvm::parseTypeAtBeginning(StringRef Asm, unsigned &Read,
+                                 SMDiagnostic &Err, const Module &M,
+                                 const SlotMapping *Slots) {
   SourceMgr SM;
   std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Asm);
   SM.AddNewSourceBuffer(std::move(Buf), SMLoc());
   Type *Ty;
   if (LLParser(Asm, SM, Err, const_cast<Module *>(&M))
-          .parseStandaloneType(Ty, Slots))
+          .parseTypeAtBeginning(Ty, Read, Slots))
     return nullptr;
   return Ty;
 }