Subzero: Deal with substitutions in the primitive remangler.

tests_lit/llvm2ice_tests/mangle.ll

 ; Tests the Subzero "name mangling" when using the "llvm2ice --prefix"
 ; option.
 
 ; RUN: %llvm2ice --verbose none %s | FileCheck %s
 ; RUN: %llvm2ice --verbose none --prefix Subzero %s | FileCheck --check-prefix=MANGLE %s
 ; RUN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
 ; RUN: %llvm2iceinsts %s | %szdiff %s | FileCheck --check-prefix=DUMP %s
 ; RUN: %llvm2iceinsts --pnacl %s | %szdiff %s \
 ; RUN:                           | FileCheck --check-prefix=DUMP %s
 
@@ skipping 83 matching lines @@
 
 ; Test for _Z<len><str> where <len> is -1.  LLVM explicitly allows the
 ; '-' character in identifiers.
 
 define internal void @_Z-1FuncCPlusPlusi(i32 %i) {
 entry:
   ret void
 }
 ; MANGLE: Subzero_Z-1FuncCPlusPlusi:
 
+
+; Test for substitution incrementing.  This single test captures:
+;   S<num>_ ==> S<num+1>_ for single-digit <num>
+;   S_ ==> S0_

[jvoung (off chromium), 2014/07/11 20:40:08]

It's like "0" is the new "1", but I guess it's also 0 once it's past single
digits.

[Jim Stichnoth, 2014/07/11 21:05:12]

Yeah, S_ is kind of like S<num>_ where num=-1.

+;   String length increase, e.g. SZZZ_ ==> S0000_
+;   At least one digit wrapping without length increase, e.g. SZ9ZZ_ ==> SZA00_
+;   Unrelated identifiers containing S[0-9A-Z]* , e.g. MyClassS1x
+;   A proper substring of S<num>_ at the end of the string
+;     (to test parser edge cases)
+
+define internal void @_Z3fooP10MyClassS1xP10MyClassS2xRS_RS1_S_S1_SZZZ_SZ9ZZ_S12345() {
+; MANGLE:   _ZN7Subzero3fooEP10MyClassS1xP10MyClassS2xRS0_RS2_S0_S2_S0000_SZA00_S12345:
+entry:
+  ret void
+}
+
+; Test that unmangled (non-C++) strings don't have substitutions updated.
+define internal void @foo_S_S0_SZ_S() {
+; MANGLE:   Subzerofoo_S_S0_SZ_S:
+entry:
+  ret void
+}
+
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ