953ea7667f
The crash that this diff fixes occurred when giving a command such as
"print Var^1" to mdb, where the first argument of Var is a direct arg.
runtime/mercury_ml_expand_body.h:
When deconstructing a term with a direct arg, return NULL
as the value of expand_info->chosen_arg_word_sized_ptr.
The crash occurred when we returned a non-null pointer,
which violated the expectations of trace/mercury_trace_vars.c
and its callers. (Not surprising, since those that function and
its callers were written long before the direct_arg optimization
was added to the system.)
runtime/mercury_deconstruct.h:
Document the rationale behind the above changes. (The contents of
mercury_ml_expand_body.h are #included in mercury_deconstruct.c.)
trace/mercury_trace_vars.c:
Add the debugging code I used to track down this issue, in disabled form.
Fix missing copyright year.
trace/mercury_trace_browse.c:
Delete obsolete comment.
Fix missing copyright years.
tests/debugger/direct_arg_test.{m,inp,exp}:
A test case for this bug.
tests/debugger/Mmakefile:
Enable the new test case.
compiler/hlds_out_type_table.m:
When dumping out the data constructors in the type table,
if a constructor has names for some of its fields,
put the name and the type of each field on different lines.
In the original test case for this bug, of which direct_arg_test.m
is an extreme simplification, pretty much every line overflows
without this.
Also, factor out some duplicated code, and replace bools with values
of a bespoke type.
Mercury
Mercury is a logic/functional programming language which combines the clarity and the expressiveness of declarative programming with advanced static analysis and error detection features.
More information is available on the website's about pages, in other README files in the source code repository, and in the documentation.
Small sample programs written in Mercury can be found in the samples and extras directories of the source code repository.
README files
The Mercury compiler has two different backends and works on different operating systems. Specific information is contained in individual README files in the Documentation directory:
-
Bootstrapping discusses how to get Mercury installed.
This is important, as the Mercury compiler is written in Mercury.
-
C Low-level backend
This backend works well with GCC but also works with:
-
High-level backend targets
-
Supported operating systems
-
Other platform information
Other information
See the current release notes for the latest stable release.
The news file lists any recent changes.
The files in the Documentation directory
whose names start with NEWS are relevant
if you want to find out more about the past development of Mercury.
The limitations file lists some ways
in which the Mercury implementation does not yet meet its goals.
Information for developers
If you are considering contributing to the Mercury project, the website contains some documents that may be helpful. These include a document about contributions in general and specific information about contributing such as coding styles.
Contact
See our contact page.