diff options
Diffstat (limited to 'src/cmd/compile/internal/noder/noder.go')
| -rw-r--r-- | src/cmd/compile/internal/noder/noder.go | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go index 1c38f1a934..d692bf97aa 100644 --- a/src/cmd/compile/internal/noder/noder.go +++ b/src/cmd/compile/internal/noder/noder.go @@ -1455,6 +1455,20 @@ func (p *noder) basicLit(lit *syntax.BasicLit) constant.Value { switch lit.Kind { case syntax.IntLit, syntax.FloatLit, syntax.ImagLit: checkLangCompat(lit) + // The max. mantissa precision for untyped numeric values + // is 512 bits, or 4048 bits for each of the two integer + // parts of a fraction for floating-point numbers that are + // represented accurately in the go/constant package. + // Constant literals that are longer than this many bits + // are not meaningful; and excessively long constants may + // consume a lot of space and time for a useless conversion. + // Cap constant length with a generous upper limit that also + // allows for separators between all digits. + const limit = 10000 + if len(lit.Value) > limit { + p.errorAt(lit.Pos(), "excessively long constant: %s... (%d chars)", lit.Value[:10], len(lit.Value)) + return constant.MakeUnknown() + } } v := constant.MakeFromLiteral(lit.Value, tokenForLitKind[lit.Kind], 0) |