[ThinLTO] Print module summary index to assembly

Summary:
Implements AsmWriter support for printing the module summary index to
assembly with the format discussed in the RFC "LLVM Assembly format for
ThinLTO Summary".

Implements just enough of the parsing support to recognize and ignore
the summary entries. As agreed in the RFC thread, this will be the
behavior when assembling the IR. A follow on change will implement
parsing/assembling of the summary entries for use by tools that
currently build the summary index from bitcode.

Reviewers: dexonsmith, pcc

Subscribers: inglorion, eraman, steven_wu, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D46699

llvm-svn: 333335

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/test/Assembler/thinlto-bad-summary2.ll b/llvm/test/Assembler/thinlto-bad-summary2.ll
new file mode 100644
index 00000000000..b736c101adc
--- /dev/null
+++ b/llvm/test/Assembler/thinlto-bad-summary2.ll
@@ -0,0 +1,18 @@
+; Test that we get appropriate error when parsing summary that doesn't
+; have a '(' after the summary type label.
+; RUN: not llvm-as %s 2>&1 | FileCheck %s
+
+; CHECK: error: expected '(' at start of summary entry
+
+; ModuleID = 'thinlto-function-summary-callgraph.ll'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: nounwind uwtable
+define i32 @main() #0 {
+entry:
+    ret i32 1
+}
+
+^0 = module: (path: "{{.*}}/test/Assembler/thinlto-bad-summary1.ll", hash: (0, 0, 0, 0, 0))
+^1 = gv: )(