[MC] Fix floating-point literal lexing.

This patch has three related fixes to improve float literal lexing:

1. Make AsmLexer::LexDigit handle floats without a decimal point more
   consistently.
2. Make AsmLexer::LexFloatLiteral print an error for floats which are
   apparently missing an "e".
3. Make APFloat::convertFromString use binutils-compatible exponent
   parsing.

Together, this fixes some cases where a float would be incorrectly
rejected, fixes some cases where the compiler would crash, and improves
diagnostics in some cases.

Patch by Brandon Jones.

Differential Revision: https://reviews.llvm.org/D57321

llvm-svn: 357214

1 files changed, 27 insertions, 30 deletions

diff --git a/llvm/unittests/ADT/APFloatTest.cpp b/llvm/unittests/ADT/APFloatTest.cpp
index fb3607772f0..c76347ed056 100644
--- a/llvm/unittests/ADT/APFloatTest.cpp
+++ b/llvm/unittests/ADT/APFloatTest.cpp
@@ -868,6 +868,33 @@ TEST(APFloatTest, fromDecimalString) {
   EXPECT_EQ(2.05e+12,  APFloat(APFloat::IEEEdouble(), "002.05000e+12").convertToDouble());
   EXPECT_EQ(2.05e-12,  APFloat(APFloat::IEEEdouble(), "002.05000e-12").convertToDouble());
 
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1e").convertToDouble());
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "+1e").convertToDouble());
+  EXPECT_EQ(-1.0,      APFloat(APFloat::IEEEdouble(), "-1e").convertToDouble());
+
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1.e").convertToDouble());
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "+1.e").convertToDouble());
+  EXPECT_EQ(-1.0,      APFloat(APFloat::IEEEdouble(), "-1.e").convertToDouble());
+
+  EXPECT_EQ(0.1,      APFloat(APFloat::IEEEdouble(), ".1e").convertToDouble());
+  EXPECT_EQ(0.1,      APFloat(APFloat::IEEEdouble(), "+.1e").convertToDouble());
+  EXPECT_EQ(-0.1,      APFloat(APFloat::IEEEdouble(), "-.1e").convertToDouble());
+
+  EXPECT_EQ(1.1,      APFloat(APFloat::IEEEdouble(), "1.1e").convertToDouble());
+  EXPECT_EQ(1.1,      APFloat(APFloat::IEEEdouble(), "+1.1e").convertToDouble());
+  EXPECT_EQ(-1.1,      APFloat(APFloat::IEEEdouble(), "-1.1e").convertToDouble());
+
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1e+").convertToDouble());
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1e-").convertToDouble());
+
+  EXPECT_EQ(0.1,      APFloat(APFloat::IEEEdouble(), ".1e").convertToDouble());
+  EXPECT_EQ(0.1,      APFloat(APFloat::IEEEdouble(), ".1e+").convertToDouble());
+  EXPECT_EQ(0.1,      APFloat(APFloat::IEEEdouble(), ".1e-").convertToDouble());
+
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1.0e").convertToDouble());
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1.0e+").convertToDouble());
+  EXPECT_EQ(1.0,      APFloat(APFloat::IEEEdouble(), "1.0e-").convertToDouble());
+
   // These are "carefully selected" to overflow the fast log-base
   // calculations in APFloat.cpp
   EXPECT_TRUE(APFloat(APFloat::IEEEdouble(), "99e99999").isInfinity());
@@ -1165,36 +1192,6 @@ TEST(APFloatTest, StringDecimalSignificandDeath) {
   EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "-.e"), "Significand has no digits");
 }
 
-TEST(APFloatTest, StringDecimalExponentDeath) {
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),   "1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "+1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "-1e"), "Exponent has no digits");
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),   "1.e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "+1.e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "-1.e"), "Exponent has no digits");
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),   ".1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "+.1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "-.1e"), "Exponent has no digits");
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),   "1.1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "+1.1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "-1.1e"), "Exponent has no digits");
-
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "1e+"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "1e-"), "Exponent has no digits");
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  ".1e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), ".1e+"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), ".1e-"), "Exponent has no digits");
-
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "1.0e"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "1.0e+"), "Exponent has no digits");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "1.0e-"), "Exponent has no digits");
-}
-
 TEST(APFloatTest, StringHexadecimalDeath) {
   EXPECT_DEATH(APFloat(APFloat::IEEEdouble(),  "0x"), "Invalid string");
   EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), "+0x"), "Invalid string");