With the newly simplified SourceMgr interfaces and the generalized

SrcMgrDiagHandler, we can improve clang diagnostics for inline asm:
instead of reporting them on a source line of the original line,
we can report it on the correct line wherever the string literal came
from. For something like this:

void foo() {
  asm("push %rax\n"
      ".code32\n");
}

we used to get this: (note that the line in t.c isn't helpful)

t.c:4:7: error: warning: ignoring directive for now
  asm("push %rax\n"
      ^
<inline asm>:2:1: note: instantiated into assembly here
.code32
^

now we get:

t.c:5:8: error: warning: ignoring directive for now
      ".code32\n"
       ^
<inline asm>:2:1: note: instantiated into assembly here
.code32
^

Note that we're pointing to line 5 properly now.

llvm-svn: 119488

1 files changed, 11 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index 9e5d679aa3c..ff9ecf2dbd0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -49,11 +49,19 @@ static void SrcMgrDiagHandler(const SMDiagnostic &Diag, void *diagInfo) {
   SrcMgrDiagInfo *DiagInfo = static_cast<SrcMgrDiagInfo *>(diagInfo);
   assert(DiagInfo && "Diagnostic context not passed down?");
   
+  // If the inline asm had metadata associated with it, pull out a location
+  // cookie corresponding to which line the error occurred on.
   unsigned LocCookie = 0;
-  if (const MDNode *LocInfo = DiagInfo->LocInfo) 
-    if (LocInfo->getNumOperands() > 0)
-      if (const ConstantInt *CI = dyn_cast<ConstantInt>(LocInfo->getOperand(0)))
+  if (const MDNode *LocInfo = DiagInfo->LocInfo) {
+    unsigned ErrorLine = Diag.getLineNo()-1;
+    if (ErrorLine >= LocInfo->getNumOperands())
+      ErrorLine = 0;
+    
+    if (LocInfo->getNumOperands() != 0)
+      if (const ConstantInt *CI =
+          dyn_cast<ConstantInt>(LocInfo->getOperand(ErrorLine)))
         LocCookie = CI->getZExtValue();
+  }
   
   DiagInfo->DiagHandler(Diag, DiagInfo->DiagContext, LocCookie);
 }