Fix inlinedAt debug locations

ref #922 and 35c5234

Author: ihnorton

src/codegen.cpp

@@ -4414,6 +4414,7 @@ static Function *emit_function(jl_lambda_info_t *lam)
         }
     }
     ctx.lineno = lno;
+    int toplineno = lno;
 
     DIBuilder dbuilder(*m);
     ctx.dbuilder = &dbuilder;
@@ -4994,31 +4995,32 @@ static Function *emit_function(jl_lambda_info_t *lam)
                 MDNode *funcscope = (MDNode*)dbuilder.createLexicalBlockFile(SP, topfile);
                 MDNode *scope;
                 if ((dfil == topfile || dfil == NULL) &&
-                    lno >= ctx.lineno) // if we are in the top-level file
-                                       // and the current lineno is less than
-                                       // the last, must be same-file inline
-                                       // TODO: improve this heuristic...
+                    lno >= toplineno)
                     {
-                    // set location to the current top-level line
+                    // for sequentially-defined code,
+                    // set location to line in top file.
+                    // TODO: improve handling of nested inlines
                     loc = DebugLoc::get(lno, 1, SP, NULL);
                 } else {
-                    // otherwise, we are compiling code from another file,
-                    // so create a location for the top-level line, and
-                    // set the DebugLoc "inlinedAt" parameter.
+                    // otherwise, we are compiling inlined code,
+                    // so set the DebugLoc "inlinedAt" parameter
+                    // to the current line, then use source loc.
 #ifdef LLVM37
                     scope = (MDNode*)dbuilder.createLexicalBlockFile(SP,dfil);
-                    MDNode *inlineLocMd = DebugLoc::get(ctx.lineno, 1, funcscope, NULL).getAsMDNode();
+                    MDNode *inlineLocMd = DebugLoc::get(toplineno, 1, funcscope, NULL).
+                                                    getAsMDNode();
 #else
                     scope = (MDNode*)dbuilder.createLexicalBlockFile(SP,DIFile(dfil));
-                    MDNode *inlineLocMd = DebugLoc::get(ctx.lineno, 1, funcscope, NULL).getAsMDNode(jl_LLVMContext);
+                    MDNode *inlineLocMd = DebugLoc::get(toplineno, 1, funcscope, NULL).
+                                                    getAsMDNode(jl_LLVMContext);
 #endif
                     loc = DebugLoc::get(lno, 1, scope, inlineLocMd);
                 }
                 builder.SetCurrentDebugLocation(loc);
             }
             if (do_coverage)
                 coverageVisitLine(filename, lno);
-            ctx.lineno = lno;
+            ctx.lineno = lno; // NOO TOUCHIE; NO TOUCH! See #922
         }
         if (jl_is_labelnode(stmt)) {
             if (prevlabel) continue;

test/backtrace.jl

@@ -34,6 +34,7 @@ eval(Expr(:function, Expr(:call, :test_inline_1),
 # different-file inline
 eval(Expr(:function, Expr(:call, :test_inline_2),
                      Expr(:block, LineNumberNode(symbol("backtrace.jl"), 99),
+                     LineNumberNode(symbol("foobar.jl"), 666),
                      LineNumberNode(symbol("/foo/bar/baz.jl"), 111),
                      Expr(:call, :throw, "foo"))))
 
@@ -74,6 +75,7 @@ loc = functionloc(f12977)
 @test endswith(loc[1], "backtrace.jl")
 @test loc[2] == linenum
 
+# issue #922: SimplifyCFG pass merges throws
 code_loc(p, skipC=true) = ccall(:jl_lookup_code_address, Any, (Ptr{Void},Cint), p, skipC)
 
 @noinline function test_throw_commoning(x)