[AArch64, inline-asm] Improve diagnostic that is printed when the size of a
variable that has regiser constraint "r" is not 64-bit.
General register operands are output using 64-bit "x" register names, regardless
of the size of the variable, unless the asm operand is prefixed with the "%w"
modifier. This surprises and confuses many users who aren't familiar with
aarch64 inline assembly rules.
With this commit, a note and fixit hint are printed which tell the users that
they need modifier "%w" in order to output a "w" register instead of an "x"
register.
<rdar://problem/12764785>
llvm-svn: 216260
diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index d12642d..c80e0ef 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -357,6 +357,11 @@
return Res;
}
+char GCCAsmStmt::AsmStringPiece::getModifier() const {
+ assert(isOperand() && "Only Operands can have modifiers.");
+ return isLetter(Str[0]) ? Str[0] : '\0';
+}
+
StringRef GCCAsmStmt::getClobber(unsigned i) const {
return getClobberStringLiteral(i)->getString();
}
@@ -517,17 +522,25 @@
CurStringPiece.clear();
}
- // Handle %x4 and %x[foo] by capturing x as the modifier character.
- char Modifier = '\0';
+ // Handle operands that have asmSymbolicName (e.g., %x[foo]) and those that
+ // don't (e.g., %x4). 'x' following the '%' is the constraint modifier.
+
+ const char *Begin = CurPtr - 1; // Points to the character following '%'.
+ const char *Percent = Begin - 1; // Points to '%'.
+
if (isLetter(EscapedChar)) {
if (CurPtr == StrEnd) { // Premature end.
DiagOffs = CurPtr-StrStart-1;
return diag::err_asm_invalid_escape;
}
- Modifier = EscapedChar;
EscapedChar = *CurPtr++;
}
+ const TargetInfo &TI = C.getTargetInfo();
+ const SourceManager &SM = C.getSourceManager();
+ const LangOptions &LO = C.getLangOpts();
+
+ // Handle operands that don't have asmSymbolicName (e.g., %x4).
if (isDigit(EscapedChar)) {
// %n - Assembler operand n
unsigned N = 0;
@@ -543,11 +556,21 @@
return diag::err_asm_invalid_operand_number;
}
- Pieces.push_back(AsmStringPiece(N, Modifier));
+ // Str contains "x4" (Operand without the leading %).
+ std::string Str(Begin, CurPtr - Begin);
+
+ // (BeginLoc, EndLoc) represents the range of the operand we are currently
+ // processing. Unlike Str, the range includes the leading '%'.
+ SourceLocation BeginLoc =
+ getAsmString()->getLocationOfByte(Percent - StrStart, SM, LO, TI);
+ SourceLocation EndLoc =
+ getAsmString()->getLocationOfByte(CurPtr - StrStart, SM, LO, TI);
+
+ Pieces.push_back(AsmStringPiece(N, Str, BeginLoc, EndLoc));
continue;
}
- // Handle %[foo], a symbolic operand reference.
+ // Handle operands that have asmSymbolicName (e.g., %x[foo]).
if (EscapedChar == '[') {
DiagOffs = CurPtr-StrStart-1;
@@ -566,7 +589,18 @@
DiagOffs = CurPtr-StrStart;
return diag::err_asm_unknown_symbolic_operand_name;
}
- Pieces.push_back(AsmStringPiece(N, Modifier));
+
+ // Str contains "x[foo]" (Operand without the leading %).
+ std::string Str(Begin, NameEnd + 1 - Begin);
+
+ // (BeginLoc, EndLoc) represents the range of the operand we are currently
+ // processing. Unlike Str, the range includes the leading '%'.
+ SourceLocation BeginLoc =
+ getAsmString()->getLocationOfByte(Percent - StrStart, SM, LO, TI);
+ SourceLocation EndLoc =
+ getAsmString()->getLocationOfByte(NameEnd + 1 - StrStart, SM, LO, TI);
+
+ Pieces.push_back(AsmStringPiece(N, Str, BeginLoc, EndLoc));
CurPtr = NameEnd+1;
continue;