Implement a %plural modifier for complex plural forms in diagnostics. Use it in the overload diagnostics.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59871 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 164ac1b..e1183c6 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -293,6 +293,128 @@
}
+/// PluralNumber - Parse an unsigned integer and advance Start.
+static unsigned PluralNumber(const char *&Start, const char *End)
+{
+ // Programming 101: Parse a decimal number :-)
+ unsigned Val = 0;
+ while (Start != End && *Start >= '0' && *Start <= '9') {
+ Val *= 10;
+ Val += *Start - '0';
+ ++Start;
+ }
+ return Val;
+}
+
+/// TestPluralRange - Test if Val is in the parsed range. Modifies Start.
+static bool TestPluralRange(unsigned Val, const char *&Start, const char *End)
+{
+ if (*Start != '[') {
+ unsigned Ref = PluralNumber(Start, End);
+ return Ref == Val;
+ }
+
+ ++Start;
+ unsigned Low = PluralNumber(Start, End);
+ assert(*Start == ',' && "Bad plural expression syntax: expected ,");
+ ++Start;
+ unsigned High = PluralNumber(Start, End);
+ assert(*Start == ']' && "Bad plural expression syntax: expected )");
+ ++Start;
+ return Low <= Val && Val <= High;
+}
+
+/// EvalPluralExpr - Actual expression evaluator for HandlePluralModifier.
+static bool EvalPluralExpr(unsigned ValNo, const char *Start, const char *End)
+{
+ // Empty condition?
+ if (*Start == ':')
+ return true;
+
+ while (1) {
+ char C = *Start;
+ if (C == '%') {
+ // Modulo expression
+ ++Start;
+ unsigned Arg = PluralNumber(Start, End);
+ assert(*Start == '=' && "Bad plural expression syntax: expected =");
+ ++Start;
+ unsigned ValMod = ValNo % Arg;
+ if (TestPluralRange(ValMod, Start, End))
+ return true;
+ } else {
+ assert(C == '[' || (C >= '0' && C <= '9') &&
+ "Bad plural expression syntax: unexpected character");
+ // Range expression
+ if (TestPluralRange(ValNo, Start, End))
+ return true;
+ }
+
+ // Scan for next or-expr part.
+ Start = std::find(Start, End, ',');
+ if(Start == End)
+ break;
+ ++Start;
+ }
+ return false;
+}
+
+/// HandlePluralModifier - Handle the integer 'plural' modifier. This is used
+/// for complex plural forms, or in languages where all plurals are complex.
+/// The syntax is: %plural{cond1:form1|cond2:form2|:form3}, where condn are
+/// conditions that are tested in order, the form corresponding to the first
+/// that applies being emitted. The empty condition is always true, making the
+/// last form a default case.
+/// Conditions are simple boolean expressions, where n is the number argument.
+/// Here are the rules.
+/// condition := expression | empty
+/// empty := -> always true
+/// expression := numeric [',' expression] -> logical or
+/// numeric := range -> true if n in range
+/// | '%' number '=' range -> true if n % number in range
+/// range := number
+/// | '[' number ',' number ']' -> ranges are inclusive both ends
+///
+/// Here are some examples from the GNU gettext manual written in this form:
+/// English:
+/// {1:form0|:form1}
+/// Latvian:
+/// {0:form2|%100=11,%10=0,%10=[2,9]:form1|:form0}
+/// Gaeilge:
+/// {1:form0|2:form1|:form2}
+/// Romanian:
+/// {1:form0|0,%100=[1,19]:form1|:form2}
+/// Lithuanian:
+/// {%10=0,%100=[10,19]:form2|%10=1:form0|:form1}
+/// Russian (requires repeated form):
+/// {%100=[11,14]:form2|%10=1:form0|%10=[2,4]:form1|:form2}
+/// Slovak
+/// {1:form0|[2,4]:form1|:form2}
+/// Polish (requires repeated form):
+/// {1:form0|%100=[10,20]:form2|%10=[2,4]:form1|:form2}
+static void HandlePluralModifier(unsigned ValNo,
+ const char *Argument, unsigned ArgumentLen,
+ llvm::SmallVectorImpl<char> &OutStr)
+{
+ const char *ArgumentEnd = Argument + ArgumentLen;
+ while (1) {
+ assert(Argument < ArgumentEnd && "Plural expression didn't match.");
+ const char *ExprEnd = Argument;
+ while (*ExprEnd != ':') {
+ assert(ExprEnd != ArgumentEnd && "Plural missing expression end");
+ ++ExprEnd;
+ }
+ if (EvalPluralExpr(ValNo, Argument, ExprEnd)) {
+ Argument = ExprEnd + 1;
+ ExprEnd = std::find(Argument, ArgumentEnd, '|');
+ OutStr.append(Argument, ExprEnd);
+ return;
+ }
+ Argument = std::find(Argument, ArgumentEnd - 1, '|') + 1;
+ }
+}
+
+
/// FormatDiagnostic - Format this diagnostic into a string, substituting the
/// formal arguments into the %0 slots. The result is appended onto the Str
/// array.
@@ -374,6 +496,8 @@
HandleSelectModifier((unsigned)Val, Argument, ArgumentLen, OutStr);
} else if (ModifierIs(Modifier, ModifierLen, "s")) {
HandleIntegerSModifier(Val, OutStr);
+ } else if (ModifierIs(Modifier, ModifierLen, "plural")) {
+ HandlePluralModifier((unsigned)Val, Argument, ArgumentLen, OutStr);
} else {
assert(ModifierLen == 0 && "Unknown integer modifier");
// FIXME: Optimize
@@ -389,6 +513,8 @@
HandleSelectModifier(Val, Argument, ArgumentLen, OutStr);
} else if (ModifierIs(Modifier, ModifierLen, "s")) {
HandleIntegerSModifier(Val, OutStr);
+ } else if (ModifierIs(Modifier, ModifierLen, "plural")) {
+ HandlePluralModifier((unsigned)Val, Argument, ArgumentLen, OutStr);
} else {
assert(ModifierLen == 0 && "Unknown integer modifier");