Subzero: implemented wrapper script to replace calls to calloc()

docs/ASAN.rst

Index: docs/ASAN.rst
diff --git a/docs/ASAN.rst b/docs/ASAN.rst
index d815817c042656f9f56fb4df35bb1a1629ea4872..0c556c82ab106ad93d5f3ca8dd6bbc682a37e608 100644
--- a/docs/ASAN.rst
+++ b/docs/ASAN.rst
@@ -10,14 +10,20 @@ used in production.
 
 In Subzero, AddressSanitizer depends on being able to find and instrument calls
 to various functions such as malloc() and free(), and as such the .pexe file
-being translated must not have had those symbols stripped. Subzero will not
-complain if it is told to translate a .pexe file with its symbols stripped, but
-it will not be able to find calls to malloc() and free(), so AddressSanitizer
-will not work correctly in the final executable.
+being translated must not have had those symbols stripped or inlined. Subzero
+will not complain if it is told to translate a .pexe file with its symbols
+stripped, but it will not be able to find calls to malloc(), calloc(), free(),
+etc., so AddressSanitizer will not work correctly in the final executable.
+
+Furthermore, pnacl-clang automatically inlines calls to calloc(), even with

[Karl, 2016/07/14 17:33:50]

s/calls/some calls/?

Do you know it does this to all calls?

[tlively, 2016/07/14 20:26:14]

Done.

+inlining turned off, so we provide a wrapper script, sz-clang.py, that normally
+just passes its arguments through to pnacl-clang, but adds instrumentation to
+replace calls to calloc() at the source level if it is passed
+-fsanitize-address.
 
 These are the steps to compile hello.c to an instrumented object file::
 
-    pnacl-clang -o hello.nonfinal.pexe hello.c
+    sz-clang.py -fno-inline -fsanitize-address -o hello.nonfinal.pexe hello.c
     pnacl-finalize --no-strip-syms -o hello.pexe hello.nonfinal.pexe
     pnacl-sz -fsanitize-address -filetype=obj -o hello.o hello.pexe