Add -cc1 option -fno-diagnostics-use-presumed-location, a handy mode for
working with preprocessed testcases. This causes source locations in
diagnostics to point at the spelling location instead of the presumed location,
while still keeping the semantic effects of the line directives (entering and
leaving system-header mode, primarily).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticOptions.def b/include/clang/Basic/DiagnosticOptions.def
index 476ac1e..41bbff2 100644
--- a/include/clang/Basic/DiagnosticOptions.def
+++ b/include/clang/Basic/DiagnosticOptions.def
@@ -54,6 +54,7 @@
 DIAGOPT(ShowFixits, 1, 1)       /// Show fixit information.
 DIAGOPT(ShowSourceRanges, 1, 0) /// Show source ranges in numeric form.
 DIAGOPT(ShowParseableFixits, 1, 0) /// Show machine parseable fix-its.
+DIAGOPT(ShowPresumedLoc, 1, 0)  /// Show presumed location for diagnostics.
 DIAGOPT(ShowOptionNames, 1, 0)  /// Show the option name for mappable
                                 /// diagnostics.
 DIAGOPT(ShowNoteIncludeStack, 1, 0) /// Show include stacks for notes.
diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index db6bfd2..5717816 100644
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -1187,7 +1187,8 @@
   /// presumed location cannot be calculate (e.g., because \p Loc is invalid
   /// or the file containing \p Loc has changed on disk), returns an invalid
   /// presumed location.
-  PresumedLoc getPresumedLoc(SourceLocation Loc) const;
+  PresumedLoc getPresumedLoc(SourceLocation Loc,
+                             bool UseLineDirectives = true) const;
 
   /// \brief Returns true if both SourceLocations correspond to the same file.
   bool isFromSameFile(SourceLocation Loc1, SourceLocation Loc2) const {
@@ -1423,7 +1424,8 @@
 
   /// Get a presumed location suitable for displaying in a diagnostic message,
   /// taking into account macro arguments and expansions.
-  PresumedLoc getPresumedLocForDisplay(SourceLocation Loc) const {
+  PresumedLoc getPresumedLocForDisplay(SourceLocation Loc,
+                                       bool UseLineDirectives = true) const{
     // This is a condensed form of the algorithm used by emitCaretDiagnostic to
     // walk to the top of the macro call stack.
     while (Loc.isMacroID()) {
@@ -1431,7 +1433,7 @@
       Loc = getImmediateMacroCallerLoc(Loc);
     }
 
-    return getPresumedLoc(Loc);
+    return getPresumedLoc(Loc, UseLineDirectives);
   }
 
   /// Look through spelling locations for a macro argument expansion, and if
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index 61c3d49..be0653c 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -230,6 +230,8 @@
   HelpText<"Change diagnostic formatting to match IDE and command line tools">;
 def fdiagnostics_show_category : Separate<["-"], "fdiagnostics-show-category">,
   HelpText<"Print diagnostic category">;
+def fno_diagnostics_use_presumed_location : Flag<["-"], "fno-diagnostics-use-presumed-location">,
+  HelpText<"Ignore #line directives when displaying diagnostic locations">;
 def ftabstop : Separate<["-"], "ftabstop">, MetaVarName<"<N>">,
   HelpText<"Set the tab stop distance.">;
 def ferror_limit : Separate<["-"], "ferror-limit">, MetaVarName<"<N>">,
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index cd0284a..a32e41e 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -1361,7 +1361,8 @@
 ///
 /// Note that a presumed location is always given as the expansion point of an
 /// expansion location, not at the spelling location.
-PresumedLoc SourceManager::getPresumedLoc(SourceLocation Loc) const {
+PresumedLoc SourceManager::getPresumedLoc(SourceLocation Loc,
+                                          bool UseLineDirectives) const {
   if (Loc.isInvalid()) return PresumedLoc();
 
   // Presumed locations are always for expansion points.
@@ -1395,7 +1396,7 @@
 
   // If we have #line directives in this file, update and overwrite the physical
   // location info if appropriate.
-  if (FI.hasLineDirectives()) {
+  if (UseLineDirectives && FI.hasLineDirectives()) {
     assert(LineTable && "Can't have linetable entries without a LineTable!");
     // See if there is a #line directive before this.  If so, get it.
     if (const LineEntry *Entry =
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 31dcb23..1da462a 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -538,6 +538,7 @@
   
   Opts.ShowSourceRanges = Args.hasArg(OPT_fdiagnostics_print_source_range_info);
   Opts.ShowParseableFixits = Args.hasArg(OPT_fdiagnostics_parseable_fixits);
+  Opts.ShowPresumedLoc = !Args.hasArg(OPT_fno_diagnostics_use_presumed_location);
   Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
   Opts.ElideType = !Args.hasArg(OPT_fno_elide_type);
   Opts.ShowTemplateTree = Args.hasArg(OPT_fdiagnostics_show_template_tree);
diff --git a/lib/Frontend/DiagnosticRenderer.cpp b/lib/Frontend/DiagnosticRenderer.cpp
index 359b82b..2d156f7 100644
--- a/lib/Frontend/DiagnosticRenderer.cpp
+++ b/lib/Frontend/DiagnosticRenderer.cpp
@@ -128,7 +128,7 @@
   
   PresumedLoc PLoc;
   if (Loc.isValid()) {
-    PLoc = SM->getPresumedLocForDisplay(Loc);
+    PLoc = SM->getPresumedLocForDisplay(Loc, DiagOpts->ShowPresumedLoc);
   
     // First, if this diagnostic is not in the main file, print out the
     // "included from" lines.
@@ -208,7 +208,7 @@
   if (Loc.isInvalid())
     return;
   
-  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
+  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
   if (PLoc.isInvalid())
     return;
   
diff --git a/test/Misc/diag-presumed.c b/test/Misc/diag-presumed.c
new file mode 100644
index 0000000..07b7cdf
--- /dev/null
+++ b/test/Misc/diag-presumed.c
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -fsyntax-only -pedantic-errors %s 2>&1 | FileCheck %s --check-prefix=PRESUMED
+// RUN: %clang_cc1 -fsyntax-only -pedantic-errors -fno-diagnostics-use-presumed-location %s 2>&1 | FileCheck %s --check-prefix=SPELLING
+
+#line 100
+#define X(y) y
+X(int n = error);
+
+// PRESUMED: diag-presumed.c:101:11: error: use of undeclared identifier 'error'
+// PRESUMED: diag-presumed.c:100:14: note: expanded from
+// SPELLING: diag-presumed.c:6:11: error: use of undeclared identifier 'error'
+// SPELLING: diag-presumed.c:5:14: note: expanded from
+
+;
+// PRESUMED: diag-presumed.c:108:1: error: extra ';' outside of a functio
+// SPELLING: diag-presumed.c:13:1: error: extra ';' outside of a functio
+
+# 1 "thing1.cc" 1
+# 1 "thing1.h" 1
+# 1 "systemheader.h" 1 3
+;
+// No diagnostic here: we're in a system header, even if we're using spelling
+// locations for the diagnostics..
+// PRESUMED-NOT: extra ';'
+// SPELLING-NOT: extra ';'
+
+another error;
+// PRESUMED: included from {{.*}}diag-presumed.c:112:
+// PRESUMED: from thing1.cc:1:
+// PRESUMED: from thing1.h:1:
+// PRESUMED: systemheader.h:7:1: error: unknown type name 'another'
+
+// SPELLING-NOT: included from
+// SPELLING: diag-presumed.c:26:1: error: unknown type name 'another'
+
+# 1 "thing1.h" 2
+# 1 "thing1.cc" 2