MC asm parser: allow ?'s in symbol names, and handle @'s in names in MS asm

This is another (final?) stab at making us able to parse our own asm output
on Windows.

Symbols on Windows often contain @'s and ?'s in their names. Our asm parser
didn't like this. ?'s were not allowed, and @'s were intepreted as trying to
reference PLT/GOT/etc.

We can't just add quotes around the bad names, since e.g. for MinGW, we use gas
to assemble, and it doesn't like quotes in some places (notably in .def
directives).

This commit makes us allow ?'s in symbol names, and @'s in symbol names for MS
assembly.

Differential Revision: http://llvm-reviews.chandlerc.com/D1978

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193000 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h
index c9cecc17387b6456f017b3c4883b09a7ca2b6e16..bcf6fe8d58a7d38fb2149d026111f88cef978088 100644 (file)
--- a/include/llvm/MC/MCAsmInfo.h
+++ b/include/llvm/MC/MCAsmInfo.h
@@ -156,6 +156,10 @@ namespace llvm {
     /// symbol names.  This defaults to true.
     bool AllowPeriodsInName;
 
+    /// \brief This is true if the assembler allows @ characters in symbol
+    /// names. Defaults to false.
+    bool AllowAtInName;
+
     /// AllowUTF8 - This is true if the assembler accepts UTF-8 input.
     // FIXME: Make this a more general encoding setting?
     bool AllowUTF8;
@@ -485,6 +489,9 @@ namespace llvm {
     bool doesAllowPeriodsInName() const {
       return AllowPeriodsInName;
     }
+    bool doesAllowAtInName() const {
+      return AllowAtInName;
+    }
     bool doesAllowUTF8() const {
       return AllowUTF8;
     }

diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index 6112ad1fcaca372e77f3765887314d47e22114d6..0eea75ef04ef977f39187adb5659c0fcfcf75393 100644 (file)
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -53,6 +53,7 @@ MCAsmInfo::MCAsmInfo() {
   AllowQuotesInName = false;
   AllowNameToStartWithDigit = false;
   AllowPeriodsInName = true;
+  AllowAtInName = false;
   AllowUTF8 = true;
   UseDataRegionDirectives = false;
   ZeroDirective = "\t.zero\t";

diff --git a/lib/MC/MCParser/AsmLexer.cpp b/lib/MC/MCParser/AsmLexer.cpp
index 1ce0cc2a1d79d06b976bd8f23ef2774eadabccb8..b49dd010479310b55710f73f6df9e2cf1490f9a1 100644 (file)
--- a/lib/MC/MCParser/AsmLexer.cpp
+++ b/lib/MC/MCParser/AsmLexer.cpp
@@ -138,9 +138,9 @@ AsmToken AsmLexer::LexHexFloatLiteral(bool NoIntDigits) {
   return AsmToken(AsmToken::Real, StringRef(TokStart, CurPtr - TokStart));
 }
 
-/// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
+/// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@?]*
 static bool IsIdentifierChar(char c) {
-  return isalnum(c) || c == '_' || c == '$' || c == '.' || c == '@';
+  return isalnum(c) || c == '_' || c == '$' || c == '.' || c == '@' || c == '?';
 }
 AsmToken AsmLexer::LexIdentifier() {
   // Check for floating point literals.

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 9a362563a7ea93c855f9a22293756a979f642cd6..1fb8480b057130e750a5f77ff654845a9d2c214c 100644 (file)
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -769,6 +769,7 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
     Res = MCUnaryExpr::CreateLNot(Res, getContext());
     return false;
   case AsmToken::Dollar:
+  case AsmToken::At:
   case AsmToken::String:
   case AsmToken::Identifier: {
     StringRef Identifier;
@@ -792,19 +793,25 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
     EndLoc = SMLoc::getFromPointer(Identifier.end());
 
     // This is a symbol reference.
+    StringRef SymbolName = Identifier;
+    MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
     std::pair<StringRef, StringRef> Split = Identifier.split('@');
-    MCSymbol *Sym = getContext().GetOrCreateSymbol(Split.first);
 
     // Lookup the symbol variant if used.
-    MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
     if (Split.first.size() != Identifier.size()) {
       Variant = MCSymbolRefExpr::getVariantKindForName(Split.second);
-      if (Variant == MCSymbolRefExpr::VK_Invalid) {
+      if (Variant != MCSymbolRefExpr::VK_Invalid) {
+        SymbolName = Split.first;
+      } else if (MAI.doesAllowAtInName()) {
+        Variant = MCSymbolRefExpr::VK_None;
+      } else {
         Variant = MCSymbolRefExpr::VK_None;
         return TokError("invalid variant '" + Split.second + "'");
       }
     }
 
+    MCSymbol *Sym = getContext().GetOrCreateSymbol(SymbolName);
+
     // If this is an absolute variable reference, substitute it now to preserve
     // semantics in the face of reassignment.
     if (Sym->isVariable() && isa<MCConstantExpr>(Sym->getVariableValue())) {
@@ -2105,25 +2112,25 @@ bool AsmParser::parseAssignment(StringRef Name, bool allow_redef,
 ///   ::= string
 bool AsmParser::parseIdentifier(StringRef &Res) {
   // The assembler has relaxed rules for accepting identifiers, in particular we
-  // allow things like '.globl $foo', which would normally be separate
-  // tokens. At this level, we have already lexed so we cannot (currently)
+  // allow things like '.globl $foo' and '.def @feat.00', which would normally be
+  // separate tokens. At this level, we have already lexed so we cannot (currently)
   // handle this as a context dependent token, instead we detect adjacent tokens
   // and return the combined identifier.
-  if (Lexer.is(AsmToken::Dollar)) {
-    SMLoc DollarLoc = getLexer().getLoc();
+  if (Lexer.is(AsmToken::Dollar) || Lexer.is(AsmToken::At)) {
+    SMLoc PrefixLoc = getLexer().getLoc();
 
-    // Consume the dollar sign, and check for a following identifier.
+    // Consume the prefix character, and check for a following identifier.
     Lex();
     if (Lexer.isNot(AsmToken::Identifier))
       return true;
 
-    // We have a '$' followed by an identifier, make sure they are adjacent.
-    if (DollarLoc.getPointer() + 1 != getTok().getLoc().getPointer())
+    // We have a '$' or '@' followed by an identifier, make sure they are adjacent.
+    if (PrefixLoc.getPointer() + 1 != getTok().getLoc().getPointer())
       return true;
 
     // Construct the joined identifier and consume the token.
     Res =
-        StringRef(DollarLoc.getPointer(), getTok().getIdentifier().size() + 1);
+        StringRef(PrefixLoc.getPointer(), getTok().getIdentifier().size() + 1);
     Lex();
     return false;
   }

diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index d3f5258a8df1045bf37a3429ef46db1e23e88a9e..3861e1ce290a778f5dacc3a406fe874084fa6e5d 100644 (file)
--- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -135,6 +135,8 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
   AssemblerDialect = AsmWriterFlavor;
 
   TextAlignFillValue = 0x90;
+
+  AllowAtInName = true;
 }
 
 void X86MCAsmInfoGNUCOFF::anchor() { }

diff --git a/test/MC/COFF/tricky-names.ll b/test/MC/COFF/tricky-names.ll
new file mode 100644 (file)
index 0000000..6e041d3
--- /dev/null
+++ b/test/MC/COFF/tricky-names.ll
@@ -0,0 +1,38 @@
+; Check how tricky symbols are printed in the asm output.
+; RUN: llc -mtriple=i686-pc-win32 %s -o - | FileCheck %s --check-prefix=ASM
+
+; Check that we can roundtrip these names through our assembler.
+; RUN: llc -mtriple=i686-pc-win32 %s -o - | llvm-mc -triple i686-pc-win32 -filetype=obj | llvm-readobj -t | FileCheck %s --check-prefix=READOBJ
+
+
+@"\01??__E_Generic_object@?$_Error_objects@H@std@@YAXXZ" = global i32 0
+@"\01__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4" = global i32 0
+@"\01@foo.bar" = global i32 0
+
+define weak i32 @"\01??_B?$num_put@_WV?$back_insert_iterator@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@std@@@std@@51"() section ".text" {
+  %a = load i32* @"\01??__E_Generic_object@?$_Error_objects@H@std@@YAXXZ"
+  %b = load i32* @"\01__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4"
+  %c = load i32* @"\01@foo.bar"
+  %x = add i32 %a, %b
+  %y = add i32 %x, %c
+  ret i32 %y
+}
+
+; Check that these symbols are not quoted. They occur in output that gets passed to GAS.
+; ASM: .globl __ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4
+; ASM-NOT: .globl "__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4"
+; ASM: .globl @foo.bar
+; ASM-NOT: .globl "@foo.bar"
+
+; READOBJ: Symbol
+; READOBJ: Name: .text$??_B?$num_put@_WV?$back_insert_iterator@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@std@@@std@@51
+; READOBJ: Section: .text$??_B?$num_put@_WV?$back_insert_iterator@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@std@@@std@@51
+; READOBJ: Symbol
+; READOBJ: Name: ??_B?$num_put@_WV?$back_insert_iterator@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@std@@@std@@51
+; READOBJ: Section: .text$??_B?$num_put@_WV?$back_insert_iterator@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@std@@@std@@51
+; READOBJ: Symbol
+; READOBJ: Name: ??__E_Generic_object@?$_Error_objects@H@std@@YAXXZ
+; READOBJ: Symbol
+; READOBJ: Name: __ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4
+; READOBJ: Symbol
+; READOBJ: Name: @foo.bar

diff --git a/test/MC/ELF/bad-relocation.s b/test/MC/ELF/bad-relocation.s
new file mode 100644 (file)
index 0000000..1a66744
--- /dev/null
+++ b/test/MC/ELF/bad-relocation.s
@@ -0,0 +1,7 @@
+// RUN: not llvm-mc -filetype=obj -triple i386-pc-linux-gnu %s -o /dev/null 2>&1 | FileCheck  %s
+
+// CHECK: error: invalid variant 'BADRELOC'
+
+        .text
+foo:
+       leal    .Lfoo@BADRELOC(%ebx), %eax

diff --git a/test/MC/ELF/symbol-names.s b/test/MC/ELF/symbol-names.s
new file mode 100644 (file)
index 0000000..6459ac9
--- /dev/null
+++ b/test/MC/ELF/symbol-names.s
@@ -0,0 +1,12 @@
+// RUN: llvm-mc -triple i686-pc-linux -filetype=obj %s -o - | llvm-readobj -t | FileCheck %s
+
+// MC allows ?'s in symbol names as an extension.
+
+.text
+.globl foo?bar
+.type foo?bar, @function
+foo?bar:
+ret
+
+// CHECK: Symbol
+// CHECK: Name: foo?bar