Provide fallback locations for backend remarks

Instead of disembodied diagnostics when debug info is disabled it's now
possible to identify the associated function's location in order to provide
some amount of of context.

We use the definition's body right brace location to differentiate the fallback
from diagnostics that genuinely relate to the function declaration itself (a
convention also used by gcc).

llvm-svn: 210294

1 files changed, 15 insertions, 8 deletions

diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index 455299f2df7..db3ecc5672d 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -424,15 +424,22 @@ void BackendConsumer::EmitOptimizationRemark(
   StringRef Filename;
   unsigned Line, Column;
   D.getLocation(&Filename, &Line, &Column);
-  SourceLocation Loc;
+  SourceLocation DILoc;
   const FileEntry *FE = FileMgr.getFile(Filename);
   if (FE && Line > 0) {
     // If -gcolumn-info was not used, Column will be 0. This upsets the
-    // source manager, so if Column is not set, set it to 1.
-    if (Column == 0)
-      Column = 1;
-    Loc = SourceMgr.translateFileLineCol(FE, Line, Column);
+    // source manager, so pass 1 if Column is not set.
+    DILoc = SourceMgr.translateFileLineCol(FE, Line, Column ? Column : 1);
   }
+
+  // If a location isn't available, try to approximate it using the associated
+  // function definition. We use the definition's right brace to differentiate
+  // from diagnostics that genuinely relate to the function itself.
+  FullSourceLoc Loc(DILoc, SourceMgr);
+  if (Loc.isInvalid())
+    if (const Decl *FD = Gen->GetDeclForMangledName(D.getFunction().getName()))
+      Loc = FD->getASTContext().getFullLoc(FD->getBodyRBrace());
+
   Diags.Report(Loc, DiagID) << AddFlagValue(D.getPassName())
                             << D.getMsg().str();
 
@@ -443,13 +450,13 @@ void BackendConsumer::EmitOptimizationRemark(
     // FIXME: We should really be generating !srcloc annotations when
     // -Rpass is used. !srcloc annotations need to be emitted in
     // approximately the same spots as !dbg nodes.
-    Diags.Report(diag::note_fe_backend_optimization_remark_missing_loc);
-  else if (Loc.isInvalid())
+    Diags.Report(Loc, diag::note_fe_backend_optimization_remark_missing_loc);
+  else if (DILoc.isInvalid())
     // If we were not able to translate the file:line:col information
     // back to a SourceLocation, at least emit a note stating that
     // we could not translate this location. This can happen in the
     // case of #line directives.
-    Diags.Report(diag::note_fe_backend_optimization_remark_invalid_loc)
+    Diags.Report(Loc, diag::note_fe_backend_optimization_remark_invalid_loc)
         << Filename << Line << Column;
 }