PR 72812 points out that Go can generate non-ASCII characters in
assembly code. This is a consequence of the fact that Go permits
identifiers to contain non-ASCII Unicode code points. The GNU
assembler doesn't seem to mind, but the Solaris assembler does.
This patch changes the GCC Go interface to encode non-ASCII characters
in identifier names by setting DECL_ASSEMBLER_NAME to an encoded
value. This fixes the problem with the Solaris assembler without
disturbing the debug info.
Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu. Ran reflect
package tests on Solaris and confirmed that they now pass. Committed
to mainline.
Ian
2016-08-05 Ian Lance Taylor <i...@google.com>
PR go/72812
* go-gcc.cc (char_needs_encoding): New static function.
(needs_encoding, fetch_utf8_char): New static functions.
(encode_id): New static function.
(Gcc_backend::global_variable): Set asm name if the name is not
simple ASCII.
(Gcc_backend::implicit_variable): Likewise.
(Gcc_backend::implicit_variable_reference): Likewise.
(Gcc_backend::immutable_struct): Likewise.
(Gcc_backend::immutable_struct_reference): Likewise.
(Gcc_backend::function): Likewise.
Index: gcc/go/go-gcc.cc
===================================================================
--- gcc/go/go-gcc.cc (revision 238653)
+++ gcc/go/go-gcc.cc (working copy)
@@ -541,7 +541,7 @@ private:
std::map<std::string, Bfunction*> builtin_functions_;
};
-// A helper function.
+// A helper function to create a GCC identifier from a C++ string.
static inline tree
get_identifier_from_string(const std::string& str)
@@ -549,6 +549,102 @@ get_identifier_from_string(const std::st
return get_identifier_with_length(str.data(), str.length());
}
+// Return whether the character c is OK to use in the assembler.
+
+static bool
+char_needs_encoding(char c)
+{
+ switch (c)
+ {
+ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+ case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
+ case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
+ case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
+ case 'Y': case 'Z':
+ case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
+ case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
+ case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
+ case 's': case 't': case 'u': case 'v': case 'w': case 'x':
+ case 'y': case 'z':
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ case '_': case '.': case '$': case '/':
+ return false;
+ default:
+ return true;
+ }
+}
+
+// Return whether the identifier needs to be translated because it
+// contains non-ASCII characters.
+
+static bool
+needs_encoding(const std::string& str)
+{
+ for (std::string::const_iterator p = str.begin();
+ p != str.end();
+ ++p)
+ if (char_needs_encoding(*p))
+ return true;
+ return false;
+}
+
+// Pull the next UTF-8 character out of P and store it in *PC. Return
+// the number of bytes read.
+
+static size_t
+fetch_utf8_char(const char* p, unsigned int* pc)
+{
+ unsigned char c = *p;
+ if ((c & 0x80) == 0)
+ {
+ *pc = c;
+ return 1;
+ }
+ size_t len = 0;
+ while ((c & 0x80) != 0)
+ {
+ ++len;
+ c <<= 1;
+ }
+ unsigned int rc = *p & ((1 << (7 - len)) - 1);
+ for (size_t i = 1; i < len; i++)
+ {
+ unsigned int u = p[i];
+ rc <<= 6;
+ rc |= u & 0x3f;
+ }
+ *pc = rc;
+ return len;
+}
+
+// Encode an identifier using ASCII characters.
+
+static std::string
+encode_id(const std::string id)
+{
+ std::string ret;
+ const char* p = id.c_str();
+ const char* pend = p + id.length();
+ while (p < pend)
+ {
+ unsigned int c;
+ size_t len = fetch_utf8_char(p, &c);
+ if (len == 1 && !char_needs_encoding(c))
+ ret += c;
+ else
+ {
+ ret += "$U";
+ char buf[30];
+ snprintf(buf, sizeof buf, "%x", c);
+ ret += buf;
+ ret += "$";
+ }
+ p += len;
+ }
+ return ret;
+}
+
// Define the built-in functions that are exposed to GCCGo.
Gcc_backend::Gcc_backend()
@@ -2454,8 +2550,14 @@ Gcc_backend::global_variable(const std::
std::string asm_name(pkgpath);
asm_name.push_back('.');
asm_name.append(name);
+ if (needs_encoding(asm_name))
+ asm_name = encode_id(asm_name);
SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name));
}
+ else if (needs_encoding(var_name))
+ SET_DECL_ASSEMBLER_NAME(decl,
+ get_identifier_from_string(encode_id(var_name)));
+
TREE_USED(decl) = 1;
if (in_unique_section)
@@ -2690,6 +2792,8 @@ Gcc_backend::implicit_variable(const std
SET_DECL_ALIGN(decl, alignment * BITS_PER_UNIT);
DECL_USER_ALIGN(decl) = 1;
}
+ if (needs_encoding(name))
+ SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(encode_id(name)));
go_preserve_from_gc(decl);
return new Bvariable(decl);
@@ -2742,6 +2846,8 @@ Gcc_backend::implicit_variable_reference
TREE_PUBLIC(decl) = 1;
TREE_STATIC(decl) = 1;
DECL_ARTIFICIAL(decl) = 1;
+ if (needs_encoding(name))
+ SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(encode_id(name)));
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
@@ -2766,6 +2872,8 @@ Gcc_backend::immutable_struct(const std:
DECL_ARTIFICIAL(decl) = 1;
if (!is_hidden)
TREE_PUBLIC(decl) = 1;
+ if (needs_encoding(name))
+ SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(encode_id(name)));
// When the initializer for one immutable_struct refers to another,
// it needs to know the visibility of the referenced struct so that
@@ -2840,6 +2948,8 @@ Gcc_backend::immutable_struct_reference(
DECL_ARTIFICIAL(decl) = 1;
TREE_PUBLIC(decl) = 1;
DECL_EXTERNAL(decl) = 1;
+ if (needs_encoding(name))
+ SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(encode_id(name)));
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
@@ -2931,6 +3041,8 @@ Gcc_backend::function(Btype* fntype, con
tree decl = build_decl(location.gcc_location(), FUNCTION_DECL, id, functype);
if (!asm_name.empty())
SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name));
+ else if (needs_encoding(name))
+ SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(encode_id(name)));
if (is_visible)
TREE_PUBLIC(decl) = 1;
if (is_declaration)
