[DebugInfo] Add calling convention support for DWARF and CodeView

Summary:
Now DISubroutineType has a 'cc' field which should be a DW_CC_ enum.  If
it is present and non-zero, the backend will emit it as a
DW_AT_calling_convention attribute. On the CodeView side, we translate
it to the appropriate enum for the LF_PROCEDURE record.

I added a new LLVM vendor specific enum to the list of DWARF calling
conventions. DWARF does not appear to attempt to standardize these, so I
assume it's OK to do this until we coordinate with GCC on how to emit
vectorcall convention functions.

Reviewers: dexonsmith, majnemer, aaboud, amccarth

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21114

llvm-svn: 272197

3 files changed, 26 insertions, 1 deletions

diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index bf457a95cd7..1ba698ebd61 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -793,6 +793,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   DWKEYWORD(ATE, DwarfAttEncoding);
   DWKEYWORD(VIRTUALITY, DwarfVirtuality);
   DWKEYWORD(LANG, DwarfLang);
+  DWKEYWORD(CC, DwarfCC);
   DWKEYWORD(OP, DwarfOp);
   DWKEYWORD(MACINFO, DwarfMacinfo);
 #undef DWKEYWORD
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 8081ef23297..cc7b98fa56d 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -3341,6 +3341,9 @@ struct DwarfVirtualityField : public MDUnsignedField {
 struct DwarfLangField : public MDUnsignedField {
   DwarfLangField() : MDUnsignedField(0, dwarf::DW_LANG_hi_user) {}
 };
+struct DwarfCCField : public MDUnsignedField {
+  DwarfCCField() : MDUnsignedField(0, dwarf::DW_CC_hi_user) {}
+};
 struct EmissionKindField : public MDUnsignedField {
   EmissionKindField() : MDUnsignedField(0, DICompileUnit::LastEmissionKind) {}
 };
@@ -3484,6 +3487,24 @@ bool LLParser::ParseMDField(LocTy Loc, StringRef Name, DwarfLangField &Result) {
 }
 
 template <>
+bool LLParser::ParseMDField(LocTy Loc, StringRef Name, DwarfCCField &Result) {
+  if (Lex.getKind() == lltok::APSInt)
+    return ParseMDField(Loc, Name, static_cast<MDUnsignedField &>(Result));
+
+  if (Lex.getKind() != lltok::DwarfCC)
+    return TokError("expected DWARF calling convention");
+
+  unsigned CC = dwarf::getCallingConvention(Lex.getStrVal());
+  if (!CC)
+    return TokError("invalid DWARF calling convention" + Twine(" '") + Lex.getStrVal() +
+                    "'");
+  assert(CC <= Result.Max && "Expected valid DWARF calling convention");
+  Result.assign(CC);
+  Lex.Lex();
+  return false;
+}
+
+template <>
 bool LLParser::ParseMDField(LocTy Loc, StringRef Name, EmissionKindField &Result) {
   if (Lex.getKind() == lltok::APSInt)
     return ParseMDField(Loc, Name, static_cast<MDUnsignedField &>(Result));
@@ -3863,11 +3884,13 @@ bool LLParser::ParseDICompositeType(MDNode *&Result, bool IsDistinct) {
 bool LLParser::ParseDISubroutineType(MDNode *&Result, bool IsDistinct) {
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
   OPTIONAL(flags, DIFlagField, );                                              \
+  OPTIONAL(cc, DwarfCCField, );                                                \
   REQUIRED(types, MDField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
-  Result = GET_OR_DISTINCT(DISubroutineType, (Context, flags.Val, types.Val));
+  Result = GET_OR_DISTINCT(DISubroutineType,
+                           (Context, flags.Val, cc.Val, types.Val));
   return false;
 }
 
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 9713cd67598..85881d6f11b 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -344,6 +344,7 @@ enum Kind {
   DwarfAttEncoding, // DW_ATE_foo
   DwarfVirtuality,  // DW_VIRTUALITY_foo
   DwarfLang,        // DW_LANG_foo
+  DwarfCC,          // DW_CC_foo
   EmissionKind,     // lineTablesOnly
   DwarfOp,          // DW_OP_foo
   DIFlag,           // DIFlagFoo