Patchwork libiberty PATCH for c++/37089 (wrong demangling of reference to reference)

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Submitter Jason Merrill
Date June 20, 2011, 2:27 p.m.
Message ID <4DFF58CE.7000006@redhat.com>
Download mbox | patch
Permalink /patch/101136/
State New
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Comments

Jason Merrill - June 20, 2011, 2:27 p.m.
C++0x specifies that a reference to reference produced by template 
argument substitution collapses to a single reference.

Tested x86_64-pc-linux-gnu, applying to trunk.

Patch

commit b66f8ede160d3f3375d7cd68988f3d498d51cc41
Author: Jason Merrill <jason@redhat.com>
Date:   Sun Jun 19 10:01:02 2011 -0400

    	PR c++/37089
    	* cp-demangle.c (d_print_comp): Handle reference smashing.

diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index 3fc5266..d664e5f 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -3554,6 +3554,10 @@  static void
 d_print_comp (struct d_print_info *dpi, int options,
               const struct demangle_component *dc)
 {
+  /* Magic variable to let reference smashing skip over the next modifier
+     without needing to modify *dc.  */
+  const struct demangle_component *mod_inner = NULL;
+
   if (dc == NULL)
     {
       d_print_error (dpi);
@@ -3869,16 +3873,37 @@  d_print_comp (struct d_print_info *dpi, int options,
 	      }
 	  }
       }
+      goto modifier;
+
+    case DEMANGLE_COMPONENT_REFERENCE:
+    case DEMANGLE_COMPONENT_RVALUE_REFERENCE:
+      {
+	/* Handle reference smashing: & + && = &.  */
+	const struct demangle_component *sub = d_left (dc);
+	if (sub->type == DEMANGLE_COMPONENT_TEMPLATE_PARAM)
+	  {
+	    struct demangle_component *a = d_lookup_template_argument (dpi, sub);
+	    if (a && a->type == DEMANGLE_COMPONENT_TEMPLATE_ARGLIST)
+	      a = d_index_template_argument (a, dpi->pack_index);
+	    sub = a;
+	  }
+
+	if (sub->type == DEMANGLE_COMPONENT_REFERENCE
+	    || sub->type == dc->type)
+	  dc = sub;
+	else if (sub->type == DEMANGLE_COMPONENT_RVALUE_REFERENCE)
+	  mod_inner = d_left (sub);
+      }
       /* Fall through.  */
+
     case DEMANGLE_COMPONENT_RESTRICT_THIS:
     case DEMANGLE_COMPONENT_VOLATILE_THIS:
     case DEMANGLE_COMPONENT_CONST_THIS:
     case DEMANGLE_COMPONENT_VENDOR_TYPE_QUAL:
     case DEMANGLE_COMPONENT_POINTER:
-    case DEMANGLE_COMPONENT_REFERENCE:
-    case DEMANGLE_COMPONENT_RVALUE_REFERENCE:
     case DEMANGLE_COMPONENT_COMPLEX:
     case DEMANGLE_COMPONENT_IMAGINARY:
+    modifier:
       {
 	/* We keep a list of modifiers on the stack.  */
 	struct d_print_mod dpm;
@@ -3889,7 +3914,10 @@  d_print_comp (struct d_print_info *dpi, int options,
 	dpm.printed = 0;
 	dpm.templates = dpi->templates;
 
-	d_print_comp (dpi, options, d_left (dc));
+	if (!mod_inner)
+	  mod_inner = d_left (dc);
+
+	d_print_comp (dpi, options, mod_inner);
 
 	/* If the modifier didn't get printed by the type, print it
 	   now.  */
diff --git a/libiberty/testsuite/demangle-expected b/libiberty/testsuite/demangle-expected
index c94eb3c..bbd418c 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -3957,6 +3957,9 @@  decltype (({parm#1}.(operator-))()) h<A>(A)
 _Z1fDn
 f(decltype(nullptr))
 --format=gnu-v3
+_Z1fIRiEvOT_b
+void f<int&>(int&, bool)
+--format=gnu-v3
 _ZN5aaaaa6bbbbbb5cccccIN23ddddddddddddddddddddddd3eeeENS2_4ffff16ggggggggggggggggENS0_9hhhhhhhhhES6_S6_S6_S6_S6_S6_S6_EE
 aaaaa::bbbbbb::ccccc<ddddddddddddddddddddddd::eee, ddddddddddddddddddddddd::ffff::gggggggggggggggg, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh, aaaaa::bbbbbb::hhhhhhhhh>
 --format=gnu-v3
@@ -4118,4 +4121,4 @@  DFA
 # http://sourceware.org/bugzilla/show_bug.cgi?id=11572
 --format=auto
 _ZN3Psi7VariantIIcPKcEE5visitIIRZN11VariantTest9TestVisit11test_methodEvEUlS2_E0_RZNS6_11test_methodEvEUlcE1_RZNS6_11test_methodEvEUlNS_4NoneEE_EEENS_13VariantDetail19SelectVisitorResultIIDpT_EE4typeEDpOSG_
-Psi::VariantDetail::SelectVisitorResult<VariantTest::TestVisit::test_method()::{lambda(char const*)#2}&, VariantTest::TestVisit::test_method()::{lambda(char)#3}&, VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&>::type Psi::Variant<char, char const*>::visit<VariantTest::TestVisit::test_method()::{lambda(char const*)#2}&, VariantTest::TestVisit::test_method()::{lambda(char)#3}&, VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&>((VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&&&)...)
+Psi::VariantDetail::SelectVisitorResult<VariantTest::TestVisit::test_method()::{lambda(char const*)#2}&, VariantTest::TestVisit::test_method()::{lambda(char)#3}&, VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&>::type Psi::Variant<char, char const*>::visit<VariantTest::TestVisit::test_method()::{lambda(char const*)#2}&, VariantTest::TestVisit::test_method()::{lambda(char)#3}&, VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&>((VariantTest::TestVisit::test_method()::{lambda(Psi::None)#1}&)...)