On Mon, Feb 1, 2021 at 5:20 PM Martin Sebor <mse...@gmail.com> wrote: > > I have pushed the tree.h comments in g:6a2053773b8. I will wait > for an approval of the changes to the manual.
Sorry for not looking earlier. +/* The scope enclosing the scope NODE, or FUNCTION_DECL for the "outermost" + function scope. Inlined functions are chained by this so that given + expression E and its TREE_BLOCK(E) B, BLOCK_SUPERCONTEXT(B) is the scope + in which E has been made or into which E has been inlined. */ I can't really understand what you are trying to say with the second sentence. There's nothing really special about BLOCK_SUPERCONTEXT and inlines so I believe this sentence only adds confusion. #define BLOCK_SUPERCONTEXT(NODE) (BLOCK_CHECK (NODE)->block.supercontext) +/* Points to the next scope at the same level of nesting as scope NODE. */ #define BLOCK_CHAIN(NODE) (BLOCK_CHECK (NODE)->block.chain) +/* A BLOCK, or FUNCTION_DECL of the function from which a block has been + inlined. ... from which a block has been ultimatively copied for example by inlining. [clones also will have abstract origins] In a scope immediately enclosing an inlined leaf expression, + points to the outermost scope into which it has been inlined (thus + bypassing all intermediate BLOCK_SUPERCONTEXTs). */ ? Maybe: An inlined function is represented by a scope with BLOCK_ABSTRACT_ORIGIN being the FUNCTION_DECL of the inlined function containing the inlined functions scope tree as children. All abstract origins are ultimate, that is BLOCK_ABSTRACT_ORIGIN(NODE) == BLOCK_ABSTRACT_ORIGIN(BLOCK_ABSTRACT_ORIGIN (NODE)). #define BLOCK_ABSTRACT_ORIGIN(NODE) (BLOCK_CHECK (NODE)->block.abstract_origin) > On 1/27/21 5:54 PM, Martin Sebor wrote: > > Attached is an updated patch for both tree.h and the internals manual > > documenting the most important BLOCK_ macros and what they represent. > > > > On 1/21/21 2:52 PM, Martin Sebor wrote: > >> On 1/18/21 6:25 AM, Richard Biener wrote: > >>>> PS Here are my notes on the macros and the two related functions: > >>>> > >>>> BLOCK: Denotes a lexical scope. Contains BLOCK_VARS of variables > >>>> declared in it, BLOCK_SUBBLOCKS of scopes nested in it, and > >>>> BLOCK_CHAIN pointing to the next BLOCK. Its BLOCK_SUPERCONTEXT > >>>> point to the BLOCK of the enclosing scope. May have > >>>> a BLOCK_ABSTRACT_ORIGIN and a BLOCK_SOURCE_LOCATION. > >>>> > >>>> BLOCK_SUPERCONTEXT: The scope of the enclosing block, or FUNCTION_DECL > >>>> for the "outermost" function scope. Inlined functions are chained by > >>>> this so that given expression E and its TREE_BLOCK(E) B, > >>>> BLOCK_SUPERCONTEXT(B) is the scope (BLOCK) in which E has been made > >>>> or into which E has been inlined. In the latter case, > >>>> > >>>> BLOCK_ORIGIN(B) evaluates either to the enclosing BLOCK or to > >>>> the enclosing function DECL. It's never null. > >>>> > >>>> BLOCK_ABSTRACT_ORIGIN(B) is the FUNCTION_DECL of the function into > >>>> which it has been inlined, or null if B is not inlined. > >>> > >>> It's the BLOCK or FUNCTION it was inlined _from_, not were it was > >>> inlined to. > >>> It's the "ultimate" source, thus the abstract copy of the block or > >>> function decl > >>> (for the outermost scope, aka inlined_function_outer_scope_p). It > >>> corresponds > >>> to what you'd expect for the DWARF abstract origin. > >> > >> Thanks for the correction! It's just the "innermost" block that > >> points to the "ultimate" destination into which it's been inlined. > >> > >>> > >>> BLOCK_ABSTRACT_ORIGIN can be NULL (in case it isn't an inline instance). > >>> > >>>> BLOCK_ABSTRACT_ORIGIN: A BLOCK, or FUNCTION_DECL of the function > >>>> into which a block has been inlined. In a BLOCK immediately enclosing > >>>> an inlined leaf expression points to the outermost BLOCK into which it > >>>> has been inlined (thus bypassing all intermediate BLOCK_SUPERCONTEXTs). > >>>> > >>>> BLOCK_FRAGMENT_ORIGIN: ??? > >>>> BLOCK_FRAGMENT_CHAIN: ??? > >>> > >>> that's for scope blocks split by hot/cold partitioning and only > >>> temporarily > >>> populated. > >> > >> Thanks, I now see these documented in detail in tree.h. > >> > >>> > >>>> bool inlined_function_outer_scope_p(BLOCK) [tree.h] > >>>> Returns true if a BLOCK has a source location. > >>>> True for all but the innermost (no SUBBLOCKs?) and outermost blocks > >>>> into which an expression has been inlined. (Is this always true?) > >>>> > >>>> tree block_ultimate_origin(BLOCK) [tree.c] > >>>> Returns BLOCK_ABSTRACT_ORIGIN(BLOCK), AO, after asserting that > >>>> (DECL_P(AO) && DECL_ORIGIN(AO) == AO) || BLOCK_ORIGIN(AO) == AO). > >> > >> The attached diff adds the comments above to tree.h. > >> > >> I looked for a good place in the manual to add the same text but I'm > >> not sure. Would the Blocks @subsection in generic.texi be appropriate? > >> > >> Martin > > > > >
