diff options
Diffstat (limited to 'libbuild2/bin')
| -rw-r--r-- | libbuild2/bin/def-rule.cxx | 68 |
1 files changed, 53 insertions, 15 deletions
diff --git a/libbuild2/bin/def-rule.cxx b/libbuild2/bin/def-rule.cxx index ab31fde..032d521 100644 --- a/libbuild2/bin/def-rule.cxx +++ b/libbuild2/bin/def-rule.cxx @@ -16,11 +16,18 @@ namespace build2 { namespace bin { + // In C global uninitialized data becomes a "common symbol" (an equivalent + // definition compiled as C++ results in a BSS symbol) which allows some + // archaic merging of multiple such definitions during linking (see GNU ld + // --warn-common for background). Note that this merging may happen with + // other data symbol types, not just common. + // struct symbols { set<string> d; // data set<string> r; // read-only data set<string> b; // uninitialized data (BSS) + set<string> c; // common uninitialized data set<string> t; // text (code) }; @@ -62,6 +69,8 @@ namespace build2 // B44 00000000 SECT4 notype Static | .rdata$r // AA2 00000000 SECT5 notype Static | .bss // + // Note that an UNDEF data symbol with non-zero OFFSET is a "common + // symbol", equivalent to the nm `C` type. // Map of read-only (.rdata, .xdata) and uninitialized (.bss) sections // to their types (R and B, respectively). If a section is not found in @@ -92,7 +101,7 @@ namespace build2 // n = next_word (l, b, e); - if (n == 0 || l.compare (b, n, "UNDEF") == 0) + if (n == 0) continue; string sec (l, b, n); @@ -104,14 +113,14 @@ namespace build2 if (l.compare (b, n, "notype") != 0) continue; - bool d; + bool dat; if (l[e] == ' ' && l[e + 1] == '(' && l[e + 2] == ')') { e += 3; - d = false; + dat = false; } else - d = true; + dat = true; // VISIBILITY // @@ -140,7 +149,11 @@ namespace build2 // See if this is the section type symbol. // - if (d && off == "00000000" && vis == "Static" && s[0] == '.') + if (dat && + off == "00000000" && + sec != "UNDEF" && + vis == "Static" && + s[0] == '.') { auto cmp = [&s] (const char* n, size_t l) { @@ -159,18 +172,29 @@ namespace build2 if (vis != "External") continue; - if (d) + if (dat) { - auto i (sections.find (sec)); - switch (i == sections.end () ? 'D' : i->second) + if (sec != "UNDEF") { - case 'D': syms.d.insert (move (s)); break; - case 'R': syms.r.insert (move (s)); break; - case 'B': syms.b.insert (move (s)); break; + auto i (sections.find (sec)); + switch (i == sections.end () ? 'D' : i->second) + { + case 'D': syms.d.insert (move (s)); break; + case 'R': syms.r.insert (move (s)); break; + case 'B': syms.b.insert (move (s)); break; + } + } + else + { + if (off != "00000000") + syms.c.insert (move (s)); } } else - syms.t.insert (move (s)); + { + if (sec != "UNDEF") + syms.t.insert (move (s)); + } } } @@ -209,6 +233,8 @@ namespace build2 case 'D': syms.d.insert (move (s)); break; case 'R': syms.r.insert (move (s)); break; case 'B': syms.b.insert (move (s)); break; + case 'c': + case 'C': syms.c.insert (move (s)); break; case 'T': syms.t.insert (move (s)); break; } } @@ -311,6 +337,13 @@ namespace build2 if (const char* v = filter (s)) os << " " << v << " DATA\n"; + // For common symbols, only write extern C. + // + for (const string& s: syms.c) + if (extern_c (s)) + if (const char* v = filter (s)) + os << " " << v << " DATA\n"; + // Read-only data contains an especially large number of various // special symbols. Instead of trying to filter them out case by case, // we will try to recognize C/C++ identifiers plus the special symbols @@ -386,6 +419,10 @@ namespace build2 if (const char* v = filter (s)) os << " " << v << " DATA\n"; + for (const string& s: syms.c) + if (const char* v = filter (s)) + os << " " << v << " DATA\n"; + // Read-only data contains an especially large number of various // special symbols. Instead of trying to filter them out case by case, // we will try to recognize C/C++ identifiers plus the special symbols @@ -667,12 +704,13 @@ namespace build2 fail << "unable to extract symbols from " << arg; } - /* +#if 0 for (const string& s: syms.d) text << "D " << s; for (const string& s: syms.r) text << "R " << s; for (const string& s: syms.b) text << "B " << s; + for (const string& s: syms.c) text << "C " << s; for (const string& s: syms.t) text << "T " << s; - */ +#endif if (verb >= 3) text << "cat >" << tp; @@ -712,6 +750,6 @@ namespace build2 return target_state::changed; } - const string def_rule::rule_id_ {"bin.def 1"}; + const string def_rule::rule_id_ {"bin.def 2"}; } } |