[llvm-commits] [llvm] r119488 - in /llvm/trunk: docs/LangRef.html lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp

[Chris Lattner]

Author: lattner
Date: Wed Nov 17 02:20:42 2010
New Revision: 119488

URL: http://llvm.org/viewvc/llvm-project?rev=119488&view=rev
Log:
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.


Modified:
    llvm/trunk/docs/LangRef.html
    llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp

Modified: llvm/trunk/docs/LangRef.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.html?rev=119488&r1=119487&r2=119488&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.html (original)
+++ llvm/trunk/docs/LangRef.html Wed Nov 17 02:20:42 2010
@@ -2625,8 +2625,8 @@
 <div class="doc_text">
 
 <p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
-   attached to it that contains a constant integer.  If present, the code
-   generator will use the integer as the location cookie value when report
+   attached to it that contains a list of constant integers.  If present, the
+  code generator will use the integer as the location cookie value when report
    errors through the LLVMContext error reporting mechanisms.  This allows a
    front-end to correlate backend errors that occur with inline asm back to the
    source code that produced it.  For example:</p>
@@ -2638,7 +2638,8 @@
 </pre>
 
 <p>It is up to the front-end to make sense of the magic numbers it places in the
-   IR.</p>
+   IR.  If the MDNode contains multiple constants, the code generator will use
+   the one that corresponds to the line of the asm that the error occurs on.</p>
 
 </div>
 

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp?rev=119488&r1=119487&r2=119488&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp Wed Nov 17 02:20:42 2010
@@ -49,11 +49,19 @@
   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);
 }