diff options
| author | Daniel Dunbar <daniel@zuster.org> | 2009-06-29 23:43:14 +0000 |
|---|---|---|
| committer | Daniel Dunbar <daniel@zuster.org> | 2009-06-29 23:43:14 +0000 |
| commit | 63ed6295262344301390aff5733ad69aa5112178 (patch) | |
| tree | f154cc397370fd3b59e2dd20eacb0b3c8f866358 /tools/llvm-mc/AsmParser.cpp | |
| parent | 2acdff09235b71d3aeccff83fa04ea1d8de27b1b (diff) | |
| download | external_llvm-63ed6295262344301390aff5733ad69aa5112178.zip external_llvm-63ed6295262344301390aff5733ad69aa5112178.tar.gz external_llvm-63ed6295262344301390aff5733ad69aa5112178.tar.bz2 | |
llvm-mc: Diagnose misuse (mix) of defined symbols and labels.
- For example, we diagnose errors on:
--
a:
a = 10
--
- For now we reject code like:
--
.long a
a = 10
--
which "as" accepts (on Darwin).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74476 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'tools/llvm-mc/AsmParser.cpp')
| -rw-r--r-- | tools/llvm-mc/AsmParser.cpp | 46 |
1 files changed, 40 insertions, 6 deletions
diff --git a/tools/llvm-mc/AsmParser.cpp b/tools/llvm-mc/AsmParser.cpp index 9121797..4cb515b 100644 --- a/tools/llvm-mc/AsmParser.cpp +++ b/tools/llvm-mc/AsmParser.cpp @@ -17,6 +17,7 @@ #include "llvm/MC/MCContext.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCStreamer.h" +#include "llvm/MC/MCSymbol.h" #include "llvm/Support/SourceMgr.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; @@ -82,12 +83,19 @@ bool AsmParser::ParsePrimaryExpr(AsmExpr *&Res) { return true; Res = new AsmUnaryExpr(AsmUnaryExpr::LNot, Res); return false; - case asmtok::Identifier: + case asmtok::Identifier: { // This is a label, this should be parsed as part of an expression, to // handle things like LFOO+4. - Res = new AsmSymbolRefExpr(Ctx.GetOrCreateSymbol(Lexer.getCurStrVal())); + MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); + + // If this is use of an undefined symbol then mark it external. + if (!Sym->getSection() && !Ctx.GetSymbolValue(Sym)) + Sym->setExternal(true); + + Res = new AsmSymbolRefExpr(Sym); Lexer.Lex(); // Eat identifier. return false; + } case asmtok::IntVal: Res = new AsmConstantExpr(Lexer.getCurIntVal()); Lexer.Lex(); // Eat identifier. @@ -270,16 +278,28 @@ bool AsmParser::ParseStatement() { // Consume the identifier, see what is after it. switch (Lexer.Lex()) { - case asmtok::Colon: + case asmtok::Colon: { // identifier ':' -> Label. Lexer.Lex(); + + // Diagnose attempt to use a variable as a label. + // + // FIXME: Diagnostics. Note the location of the definition as a label. + // FIXME: This doesn't diagnose assignment to a symbol which has been + // implicitly marked as external. + MCSymbol *Sym = Ctx.GetOrCreateSymbol(IDVal); + if (Sym->getSection()) + return Error(IDLoc, "invalid symbol redefinition"); + if (Ctx.GetSymbolValue(Sym)) + return Error(IDLoc, "symbol already used as assembler variable"); // Since we saw a label, create a symbol and emit it. // FIXME: If the label starts with L it is an assembler temporary label. // Why does the client of this api need to know this? - Out.EmitLabel(Ctx.GetOrCreateSymbol(IDVal)); - + Out.EmitLabel(Sym); + return ParseStatement(); + } case asmtok::Equal: // identifier '=' ... -> assignment statement @@ -440,6 +460,9 @@ bool AsmParser::ParseStatement() { } bool AsmParser::ParseAssignment(const char *Name, bool IsDotSet) { + // FIXME: Use better location, we should use proper tokens. + SMLoc EqualLoc = Lexer.getLoc(); + int64_t Value; if (ParseAbsoluteExpression(Value)) return true; @@ -450,9 +473,20 @@ bool AsmParser::ParseAssignment(const char *Name, bool IsDotSet) { // Eat the end of statement marker. Lexer.Lex(); - // Get the symbol for this name. + // Diagnose assignment to a label. + // + // FIXME: Diagnostics. Note the location of the definition as a label. + // FIXME: This doesn't diagnose assignment to a symbol which has been + // implicitly marked as external. // FIXME: Handle '.'. + // FIXME: Diagnose assignment to protected identifier (e.g., register name). MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name); + if (Sym->getSection()) + return Error(EqualLoc, "invalid assignment to symbol emitted as a label"); + if (Sym->isExternal()) + return Error(EqualLoc, "invalid assignment to external symbol"); + + // Do the assignment. Out.EmitAssignment(Sym, MCValue::get(Value), IsDotSet); return false; |